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The proteome serves as the primary basis for identifying targets for treatment. This study conducted proteomic range two-sample Mendelian randomization (MR) analysis to pinpoint potential protein markers and treatment targets for ankylosing spondylitis (AS). A total of 4907 data points on circulating protein expression were collected from a large-scale protein quantitative trait locus investigation involving 35,559 individuals. Using data from a Finnish study on AS as the outcome, the dataset comprised 166,144 individuals of European ancestry (1462 cases and 164,682 controls), and causal relationships were determined through bidirectional Mendelian randomization of two samples. Proteins were further validated and identified through single-cell expression analysis, certain cells showing enriched expression levels were detected, and possible treatment targets were optimized. Increased HERC5 expression predicted by genes was related to increased AS risk, whereas the expression of the remaining five circulating proteins, AIF1, CREB3L4, MLN, MRPL55, and SPAG11B, was negatively correlated with AS risk. For each increase in gene-predicted protein levels, the ORs of AS were 2.11 (95% CI 1.44-3.09) for HERC5, 0.14 (95% CI 0.05-0.41) for AIF1, 0.48 (95% CI 0.34-0.68) for CREB3L4, 0.54 (95% CI 0.42-0.68) for MLN, 0.23 (95% CI 0.13-0.38) for MRPL55, and 0.26 (95% CI 0.17-0.39) for SPAG11B. The hypothesis of a reverse causal relationship between these six circulating proteins and AS is not supported. Three of the six protein-coding genes were expressed in both the AS and healthy control groups, while CREB3L4, MLN, and SPAG11B were not detected. Increased levels of HERC5 predicted by genes are related to increased AS risk, whereas the levels of the remaining five circulating proteins, AIF1, CREB3L4, MLN, MRPL55, and SPAG11B, negatively correlate with AS risk. HERC5, AIF1, and MRPL55 are potential therapeutic targets for AS. This study advanced the field by employing a novel combination of proteomic range two-sample MR analysis and single-cell expression analysis to identify potential protein markers and therapeutic targets for AS. This approach enabled a comprehensive understanding of the causal relationships between circulating proteins and AS, which has not been extensively explored in previous studies., (© 2024. The Author(s).)

Objective: This study aims to comprehensively investigate immune-cell landscapes in ankylosing spondylitis (AS) patients and explore longitudinal immunophenotyping changes induced by biological agents., Methods: We employed mass cytometry with 35 cellular markers to analyze blood samples from 34 AS patients and 13 healthy controls (HC). Eleven AS patients were re-evaluated 1 month (4 patients) and 3 months (7 patients) after treatment with biological agents. Flow Self-Organizing Maps (FlowSOM) clustering was performed to identify specific cellular metaclusters. We compared cellular abundances across distinct subgroups and validated subset differences using gating strategies in flow cytometry scatter plots, visualized with FlowJo software. The proportions of differential subsets were then used for intercellular and clinical correlation analysis, as well as for constructing diagnostic models based on the random forest algorithm., Results: In AS patients, we identified and validated nine different immune-cell subsets compared to HC. Three subsets increased: helper T-cell 17 (Th17), mucosa-associated invariant T-cell (MAIT), and classical monocytes (CM). Six subsets decreased: effector memory T-cell (TEM), naïve B cells, transitional B cells, IL10+ memory B cells, non-classical monocytes (NCM), and neutrophils. Treatments with biological agents could rectify cellular abnormalities, particularly the imbalance of CM/NCM. Furthermore, these subsets may serve as biomarkers for assessing disease activity and constructing effective diagnostic models for AS., Conclusion: These findings provide novel insights into the specific patterns of immune cell in AS, facilitating the further development of novel biomarkers and potential therapeutic targets for AS patients., (© 2024 Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Ltd.)

Aim: This study investigates changes in immune cell subsets in peripheral blood of ankylosing spondylitis (AS) patients with colitis or terminal ileitis. It aims to explore the connection between changes in lymphocyte subsets and gut inflammation, providing insights for early detection., Methods: Overall, 50 AS patients undergoing colonoscopy were enrolled. Flow cytometry was employed to analyze lymphocyte subsets, including T and B cells, in peripheral blood. Disease activity was assessed using CRP, ESR, BASDAI, ASDAS-CRP, and ASDAS-ESR., Results: Compared to AS patients without gut inflammation, those with colorectal inflammation showed a significant increase in total T cells (p < .05), an increase in exhausted CD4 + T cells (p < .05), and a decrease in Th2 cells and total Tc cells (p < .05). Notably, in AS patients with terminal ileitis, there was an increase in total B cells and classic switched B cells (p < .05), with a decrease in double-positive T cells (p < .05). However, no significant differences were observed in the distribution of Tfh-cell subpopulations (Tfh1, Tfh2, Tfh17) and Tc-cell subpopulations (Tc1, Tc2, Tc17) between AS patients with either colorectal inflammation or terminal ileitis (p > .05). We explored the relationship between disease activity scores, ESR, CRP, and lymphocyte subsets, but found no statistically significant correlation between them., Conclusion: Distinct immune patterns may exist in AS with different types of intestinal inflammation. Colitis in AS is primarily characterized by a significant increase in exhausted CD4 + T cells, along with a decrease in Th2 cells. In contrast, terminal ileum inflammation in AS is marked by an increase in total B cells and classic switched B cells. These findings offer new insights for early detection and therapeutic intervention., (© 2024 Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Ltd.)

Background: Among the Pentraxins, the long Pentraxin-3 (PTX-3) is associated with several processes, particularly in the earliest phases of the innate humoral response. Increased blood PTX-3 concentrations have been observed in a wide range of conditions, from infectious to cardiovascular disorders. Since its increase is more rapid than C-reactive protein (CRP), PTX-3 can be useful to detect and monitor early inflammation. To dissect its pathophysiological role in rheumatic diseases (RD), we conducted a systematic review and meta-analysis comparing blood PTX-3 concentrations in RD patients and healthy individuals and investigating possible associations with clinical, demographic, and study characteristics., Methods: We performed a search of published evidence until April 2024 in PubMed, Web of Science and Scopus, which led to the selection of 60 relevant manuscripts from a total of 1072 records., Results: Our synthesis revealed a statistically significant difference in PTX-3 concentrations between RD patients and controls (standard mean difference, SMD = 1.02, 95% CI 0.77-1.26, p < .001), that correlated with CRP concentrations. The effect size was associated with geographical region of study conduction, RD type, with a reduction of the observed heterogeneity in patients with low LDL-cholesterol and triglycerides concentrations., Conclusions: Our study has shown a significant increase in blood PTX-3 concentrations in RD patients, which was associated with specific patient characteristics. Nevertheless, additional studies are needed to better define the utility of measuring PTX-3 in the early phase of RD. Our study was conducted in compliance with the PRISMA 2020 statement (study protocol available at PROSPERO CRD42024516600)., (© 2024 Stichting European Society for Clinical Investigation Journal Foundation. Published by John Wiley & Sons Ltd.)

Ankylosing spondylitis (AS) is a chronic systemic inflammatory disease that significantly impairs physical function in young individuals. However, the identification of radiographic changes in AS is frequently delayed, and the diagnostic efficacy of biomarkers like HLA-B27 remains moderately effective, with unsatisfactory sensitivity and specificity. In contrast to existing literature, our current experiment utilized a larger sample size and employed both untargeted and targeted UHPLC-QTOF-MS/MS based metabolomics to identify the metabolite profile and potential biomarkers of AS. The results indicated a notable divergence between the two groups, and a total of 170 different metabolites were identified, which were associated with the 6 primary metabolic pathways exhibiting a correlation with AS. Among these, 26 metabolites exhibited high sensitivity and specificity with area under curve (AUC) values greater than 0.8. Subsequent targeted quantitative analysis discovered 3 metabolites, namely 3-amino-2-piperidone, hypoxanthine and octadecylamine, exhibiting excellent distinguishing ability based on the results of the ROC curve and the Random Forest model, thus qualifying as potential biomarkers for AS. Summarily, our untargeted and targeted metabolomics investigation offers novel and precise insights into potential biomarkers for AS, potentially enhancing diagnostic capabilities and furthering the comprehension of the condition's pathophysiology.

Background: According to reports, iron status has been associated with the risk of bone and joint-related diseases. However, the exact role of iron status in the development of these conditions remains uncertain., Method: We obtained genetic data on iron status, specifically serum iron, ferritin, transferrin saturation (TSAT), and transferrin, as well as data on five common bone and joint-related diseases (osteoarthritis, osteoporosis, rheumatoid arthritis [RA], ankylosing spondylitis [AS], and gout) from independent genome-wide association studies involving individuals of European ancestry. Our primary approach for causal estimation utilized the inverse variance weighted (IVW) method. To ensure the reliability of our findings, we applied complementary sensitivity analysis and conducted reverse causal analysis., Result: Using the IVW method, we revealed a positive causal relationship between ferritin levels and the risk of osteoarthritis (OR [95% CI], 1.0114 [1.0021-1.0207]). Besides, we identified a protective causal relationship between serum iron levels and TSAT levels in the risk of RA (OR [95% CI] values of serum iron and TSAT were 0.9987 [0.9973-0.9999] and 0.9977 [0.9966-0.9987], respectively). Furthermore, we found a positive causal relationship between serum iron levels and the risk of AS (OR [95% CI], 1.0015 [1.0005-1.0026]). Regarding gout, both serum iron and TSAT showed a positive causal relationship (OR [95% CI] values of 1.3357 [1.0915-1.6345] and 1.2316 [1.0666-1.4221] for serum iron and TSAT, respectively), while transferrin exhibited a protective causal relationship (OR [95% CI], 0.8563 [0.7802-0.9399]). Additionally, our reverse causal analysis revealed a negative correlation between RA and ferritin and TSAT levels (OR [95% CI] values of serum iron and TSAT were 0.0407 [0.0034-0.4814] and 0.0049 [0.0002-0.1454], respectively), along with a positive correlation with transferrin (OR [95% CI], 853.7592 [20.7108-35194.4325]). To ensure the validity of our findings, we replicated the results through sensitivity analysis during the validation process., Conclusion: Our study demonstrated a significant correlation between iron status and bone and joint-related diseases., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Wang, Qiu, Yang, Wu, Xie, Zhang, Li, Li, Gao and Zhang.)

Background: Ankylosing spondylitis (AS) has been known to have auto-inflammatory nature; hence, the efficacy of autoantibodies is low. However, studies on autoantibodies are ongoing, with some studies showing associations. Previous studies showed that anti-protein phosphatase magnesium-dependent 1A (PPM1A) IgG was increased in patients with AS and associated with radiographic progression. However, the diagnostic usefulness was limited due to relatively low sensitivity and specificity. This pilot study evaluated the diagnostic utility of anti-PPM1A-IgM and anti-PPM1A-IgG in patients with active AS., Methods: Serum samples were obtained from the registry cohort of a single tertiary center in Korea. Serum levels of anti-PPM1A-IgG/IgM were measured by direct ELISA. Receiver operating characteristic (ROC) analysis was used to predict the diagnostic sensitivity and specificity of serum anti-PPM1A-IgG/IgM., Results: Samples were collected from 28 patients with active AS, 16 healthy controls (HCs), and 28 patients with rheumatoid arthritis (RA). Although total serum IgM was lower in the RA and AS groups than in the HC group, anti-PPM1A-IgM was significantly lower in the AS group than in the other groups. In evaluating the diagnostic utility of anti-PPM1A-IgG/IgM for AS patients compared with HCs, the area under the curve (AUC) of anti-PPM1A-IgM was 0.998 (sensitivity 96.4%, specificity 100.0%). When ROC analysis of anti-PPM1A-IgM for AS patients compared with RA patients was conducted, sensitivity was 78.6% and specificity was 71.4%, with an AUC of 0.839., Conclusion: Decreased anti-PPM1A-IgM levels in AS patients suggests a potential role for anti-PPM1A-IgM in the diagnosis of active AS., (© 2024. The Author(s).)

Objectives: No article on serum lipids in ankylosing spondylitis (AS) and control subjects has been reported from USA. The primary aim of this study was to determine if any difference occurred in serum lipid levels in AS and control rheumatic disorders in two time periods, 1978-98 and 2000-10. The secondary aim was to investigate variables associated with lipid levels and if a difference was found between AS and control disorders., Methods: The AS patients were compared to non-inflammatory rheumatic disorders (NIRDs) in 1978-98 and 2000-10 surveys and to rheumatoid arthritis (RA) in the 2000-10 survey. Patients were matched within 5 years of age, sex, and clinic or hospital source., Results: In the 1978-98 survey, entry mean (SEM) serum cholesterol level [mg/dL] was highly (p<0.001) significantly lower in 69 AS [179.0 (4.8)] than 69 matched NIRD controls [208.0 (5.6)]. In 29 pairs of AS and NIRD subjects having manual labour occupations, mean (SEM) cholesterol level was additionally lower in AS [156.7 (5.9)] and higher in 29 NIRD controls [213.3 (8.6)] (p<0.001). In manual labour workers, mean (SEM) serum triglyceride was significantly lower (p=0.004) in 15 AS [110.3 (14.1)] than 14 NIRD controls [185.2 (19.3)]. In the 2000-10 survey, no lipid difference was found between AS vs. NIRD control patients., Conclusions: In the 1978-98 survey, AS had significantly lower mean serum cholesterol and triglyceride levels than NIRD control patients. Associated manual labour occupations may have significantly contributed to results, possibly related to increased energy expenditures from physical activity in the pre-2000 era.

Ankylosing spondylitis (AS) is a chronic autoimmune disease. The purpose of this study was to investigate the levels of serum IL-36γ in AS patients and their association with AS. The study enrolled 131 subjects, including 45 with active AS, 46 with inactive AS, and 40 healthy controls (HCs). The basic clinical information of each participant was obtained through physical examination and relevant clinical medical records. Serum IL-36γ levels were detected through an enzyme-linked immunosorbent assay. Serum IL-36γ levels in the active AS group were significantly higher than those in the HC group (94.72 vs. 65.76 pg/mL, P = 0.0087). The serum IL-36γ concentration in the inactive AS group was increased as compared to that in the HC group (100.90 vs. 65.76 pg/mL, P = 0.0138). Correlation analysis indicated that serum IL-36γ was positively correlated with glutamyl transferase in the active AS group (P = 0.0172), while serum IL-36γ was positively correlated with uric acid in the inactive AS group (P = 0.0151). The area under the curve (AUC) for IL-36γ was 0.6824 (P = 0.0009), and the AUC for IL-36γ combined with the erythrocyte sedimentation rate and C-reactive protein levels was 0.8102 (P < 0.0001), according to receiver operating characteristic curve analysis. This study found that serum IL-36γ levels were elevated in AS patients and correlated with disease activity. Our results suggest that IL-36γ may be involved in the progression of AS disease and is a potential biomarker for AS., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Ankylosing spondylitis (AS) is a chronic inflammatory disease affecting the spine and sacroiliac joints. Recent genetic studies suggest certain plasma proteins may play a causal role in AS development. This study aims to identify and characterize these proteins using Mendelian randomization (MR) and colocalization analyses., Methods: Plasma protein data were obtained from recent publications in Nature Genetics , integrating data from five previous GWAS datasets, including 738 cis-pQTLs for 734 plasma proteins. GWAS summary data for AS were sourced from IGAS and other European cohorts. MR analyses were conducted using "TwoSampleMR" to assess causal links between plasma protein levels and AS. Colocalization analysis was performed with the coloc R package to identify shared genetic variants. Sensitivity analyses and protein-protein interaction (PPI) network analyses were conducted to validate findings and explore therapeutic targets. We performed Phenome-wide association study (PheWAS) to examine the potential side effects of drug protein on AS treatment., Results: After FDR correction, eight significant proteins were identified: IL7R, TYMP, IL12B, CCL8, TNFAIP6, IL18R1, IL23R, and ERAP1. Elevated levels of IL7R, IL12B, CCL8, IL18R1, IL23R, and ERAP1 increased AS risk, whereas elevated TYMP and TNFAIP6 levels decreased AS risk. Colocalization analysis indicated that IL23R, IL7R, and TYMP likely share causal variants with AS. PPI network analysis identified IL23R and IL7R as potential new therapeutic targets., Conclusions: This study identified eight plasma proteins with significant associations with AS risk, suggesting IL23R, IL7R, and TYMP as promising therapeutic targets. Further research is needed to explore underlying mechanisms and potential for drug repurposing., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 You, Lin, Liu, Lin, Ye, Zhang and Zeng.)

Objective: Ankylosing Spondylitis Disease Activity Score based on C-reactive protein (ASDAS-CRP) is recommended over ASDAS based on erythrocyte sedimentation rate (ASDAS-ESR) to assess disease activity in axial spondyloarthritis (axSpA). Although ASDAS-CRP and ASDAS-ESR are not interchangeable, the same disease activity cut-offs are used for both. We aimed to estimate optimal ASDAS-ESR values corresponding to the established ASDAS-CRP cut-offs (1.3, 2.1, and 3.5) and investigate the potential improvement of level of agreement between ASDAS-ESR and ASDAS-CRP disease activity states when applying these estimated cut-offs., Methods: We used data from patients with axSpA from 9 European registries initiating a tumor necrosis factor inhibitor. ASDAS-ESR cut-offs were estimated using the Youden index. The level of agreement between ASDAS-ESR and ASDAS-CRP disease activity states was compared against each other., Results: In 3664 patients, mean ASDAS-CRP was higher than ASDAS-ESR at both baseline (3.6 and 3.4, respectively) and aggregated follow-up at 6, 12, or 24 months (1.9 and 1.8, respectively). The estimated ASDAS-ESR values corresponding to the established ASDAS-CRP cut-offs were 1.4, 1.9, and 3.3. By applying these cut-offs, the proportion of discordance between disease activity states according to ASDAS-ESR and ASDAS-CRP decreased from 22.93% to 19.81% in baseline data but increased from 27.17% to 28.94% in follow-up data., Conclusion: We estimated the optimal ASDAS-ESR values corresponding to the established ASDAS-CRP cut-off values. However, applying the estimated cut-offs did not increase the level of agreement between ASDAS-ESR and ASDAS-CRP disease activity states to a relevant degree. Our findings did not provide evidence to reject the established cut-off values for ASDAS-ESR., (Copyright © 2024 by the Journal of Rheumatology.)

Aim: To study the frequency of hypogonadism (HG) in men with rheumatoid arthritis (RA), ankylosing spondylitis (AS) and psoriatic arthritis (PsA) and to evaluate the impact of HG on the course of RA and and concomitant diseases., Materials and Methods: A single-stage continuous study included 170 men with RA, 57 men with AS and 85 men with PsA, who were hospitalized at the Nasonova Research Institute of Rheumatology. Patients were assessed for total testosterone (ТS) levels and subsequently divided into subgroups with normal (>12 nmol/l) and reduced levels. An intergroup comparison was carried out on the main indicators used in clinical rheumatological practice to assess the stage, activity and other medical and demographic characteristics of rheumatic disease, as well as on concomitant conditions. The second stage of the study involved a pairwise intergroup comparison among patients with HG with RA, AS and PsA., Results: The incidence of ТS deficiency among patients with RA was 24.1%, among patients with AS - 17.5%, and with PsA - 31.8%. In patients with RA, HG was associated with a significantly higher mean body mass index, higher fasting blood glucose and uric acid, higher erythrocyte sedimentation rate and anemia. Patients with AS with HG had significantly lower hemoglobin levels and more frequent anemia, as well as higher levels of C-reactive protein and erythrocyte sedimentation rate. In PsA, older age was observed in the androgen deficiency group, as well as higher body mass index and fasting glucose levels; obesity was more common. An intergroup comparison of quantitative and qualitative indicators between patients with androgen deficiency in all three rheumatic diseases (RDs) did not reveal significant differences in the average concentrations of ТS, luteinizing hormone, sex hormone binding globulin, experience of RD, laboratory markers of inflammatory activity, as well as glucose and uric acid. A similar incidence of diabetes mellitus, obesity and anemia was noted for all three nosologies., Conclusion: ТS levels and the presence of HG were not associated with the stage and activity of RD, but ТS deficiency was accompanied by higher laboratory indicators of inflammatory activity, lower hemoglobin values, and metabolic disorders. Patients with HG, regardless of nosology, had similar levels of sex hormones and indicators reflecting RD and concomitant conditions.

Objective: Alterations in gut microbiota have been implicated in the pathogenesis of ankylosing spondylitis (AS), but the underlying mechanisms remain elusive. This study aims to investigate changes in gut microbiota and metabolites in individuals with AS before and after treatment with secukinumab, to identify the biological characteristics specific to AS patients and investigate the potential biomarkers, for optimizing therapeutic strategies more effectively., Methods: Fecal microbiome data were collected from 30 AS patients before and after secukinumab therapy and compared with data from 40 healthy controls (HC). Additionally, we analyzed the metabolic profile of both groups from plasma., Results: Findings indicated that the treatment-induced changes in the composition of several crucial bacterial groups, including Megamonas, Prevotella&#95;9, Faecalibacterium, Roseburia, Bacteroides, and Agathobacter. Post-treatment, these groups exhibited a distribution more akin to that of the healthy populations compared with their pretreatment status. We identified three gut microbial taxa, namely Prevotellaceae&#95;bacterium&#95;Marseille&#95;P2831, Prevotella&#95;buccae, and Elusimicrobiota, as potential biomarkers for diagnosing individuals at a higher risk of developing AS and assessing disease outcomes. Plasma metabolomics analysis revealed 479 distinct metabolites and highlighted three disrupted metabolic pathways. Integration of microbiome and metabolomics datasets demonstrated a significant degree of correlation, underscoring the impact of the microbiome on metabolic activity., Conclusion: Secukinumab can restore the balance of the gut microbiome and metabolites in AS patients, rendering them more similar to those found in the healthy population. The analysis of microbiome and metabolomics data have unveiled some candidate biomarkers capable of evaluating treatment efficacy., (© 2024 Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Ltd.)

Objective: Choroidal thickness (CT) has been evaluated as a marker of systemic inflammation in ankylosing spondylitis (AS). This study evaluates the CT of AS patients before and after 6 months of biological treatment., Methods: This longitudinal multicenter study evaluated CT in 44 AS patients. The correlations between CT and C-reactive protein (CRP) with disease activity indices were calculated. The concordance between CT and CRP was determined. We assessed factors associated with response to treatment. Clinically important improvement was defined as a decrease in Ankylosing Spondylitis Disease Activity Score of 1.1 points or greater., Results: Forty-four eyes in patients aged 18 to 65 years were included. Mean CT values were significantly higher at baseline than after 6 months of treatment (baseline: 355.28 ± 80.46 μm; 6 months: 341.26 ± 81.06 μm; p < 0.001). There was a 95% concordance between CT and CRP at baseline and 6 months. Clinically important improvement was associated with lower baseline CT and age as independent factors (odds ratios, 0.97 [95% confidence interval, 0.91-0.93; p = 0.009] and 0.81 [95% confidence interval, 0.7-0.95; p = 0.005]), with baseline CT of less than 374 μm (sensitivity 78%, specificity 78%, area under the curve 0.70, likelihood ratio 3.6)., Conclusions: Choroidal thickness decreased significantly after 6 months of biological treatment in all treatment groups. Choroidal thickness and CRP had a 95% concordance. A high CT was associated with a risk of biological treatment failure. Choroidal thickness can be considered a useful biomarker of inflammation and a factor associated with response to treatment in AS., Competing Interests: The authors declare no conflict of interest., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Ankylosing spondylitis (AS) as a autoimmune disease involves inflammatory responses in the development of the disease, often causing changes in the neutrophil to lymphocyte ratio (NLR). In the past few decades, research on the relationship between NLR and AS has generally shown an upward trend. This study adopts the bibliometrics method to analyze the development trend, frontier, and hotspots of global research in this field in the past 2 decades. By searching for publications in the SCI-Expanded edition of the Web of Science Core Collection, the information of literature published between 2000 and 2023 is recorded. Based on the VOSviewer, CiteSpace and Excel, bibliometric analysis, and visualization analysis are conducted on the overall distribution of annual output, leading countries, active institutions, journals, authors, co-cited references, and keywords. Through retrieving and screening, a total of 1654 papers are obtained for analysis. In the past 2 decades, the number of publications related to this field has shown an increasing trend. The United States has the highest Hirsch index (H-index) and publication volume. The most productive institution is Harvard University, while the H-index of the University of Milan in Italy is far ahead. Frontiers in Immunology is the institution with the highest output. The H-index of the Annals of the Rheumatic holds the top position. This study has uncovered the main emphasis on NLR in AS research and has provided clarification regarding the value of NLR as a biomarker for immune inflammatory response in the diagnosis and prognosis of AS., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Study Design: Prospective case-control study., Objective: To explore the role of Bruton's tyrosine kinase (BTK) in ankylosing spondylitis (AS)., Summary of Background Data: AS substantially affects patients, impairing the range of motion in the whole spine and peripheral joints, as well as overall quality of life. However, surveillance for this condition is limited, and biomarkers that can predict disease activity are not well documented., Patients and Methods: The expression of the BTK gene in peripheral blood mononuclear cells (PBMCs) was measured using flow cytometry and real-time quantitative polymerase chain reaction in 36 patients with AS and 30 healthy controls. Demographic features, Ankylosing Spondylitis Disease Activity Score-C-reactive protein (CRP) based, Bath Ankylosing Spondylitis Disease Activity Index, Bath Ankylosing Spondylitis Functional Index, HLA-B27, erythrocyte sedimentation rate (ESR), and CRP were evaluated to identify factors associated with BTK expression. Analyses were performed using the Spearman rank correlation test for continuous data, the χ 2 test for categorical data, and that between continuous and dichotomous variables was measured using a point-biserial correlation test. The area under the curve of the receiver operating characteristic curve was used to assess the performance of each candidate biomarker., Results: BTK gene expression was significantly higher in patients with AS than in controls ( P = 0.026) according to quantitative polymerase chain reaction results. BTK Y223 was also high in CD19 + PBMCs from patients with AS, with CD 19+ BTK Y223+high cells being significantly positively correlated to ESR, CRP, and Ankylosing Spondylitis Disease Activity Score. A negative association was observed between BTK expression and the chest expansion distance. The area under the curve for CD 19+ BTK Y223+ was larger than that for ESR, but CRP still had the largest area., Conclusions: BTK expression was higher in PBMCs from patients with AS when compared with controls, and was associated with a higher disease activity index, inflammatory reactants, and arthritis and extra-articular manifestations. These findings suggest that BTK expression may play a crucial role in the inflammatory process in individuals with AS., Competing Interests: The authors report no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Objectives: To measure the levels of superoxide dismutase and malondialdehyde along with erythrocyte sedimentation rate and C-reactive protein in patients of rheumatoid arthritis and ankylosing spondylitis., Methods: The comparative, cross-sectional study was conducted from February 2 to December 30, 2022, at the Centre for Research in Experimental and Applied Medicine laboratory of the Department of Biochemistry and Molecular Biology, Army Medical College, Rawalpindi, Pakistan, in collaboration with the Department of Rheumatology, Pak Emirates Military Hospital, Rawalpindi. The sample comprised healthy controls in group 1, patients of rheumatoid arthritis in group 2 and patients of ankylosing spondylitis in group 3. Blood samples were assessed for levels of superoxide dismutase, malondialdehyde, erythrocyte sedimentation rate and C-reactive protein. Data was analysed using SPSS 25., Results: Of the 180 subjects, 60(33.3%) were in group 1; 32(53.3%) females and 28(46.7%) males with mean age 34.9±6.4 years. There were 60(33.3%) patients in group 2; 35(58.3%) females and 25(41.7%) males with mean age 46.0±11.1 years. There were 60(33.3%) patients in group 3, and all 60(100%) were males with mean age 35.9±6.9 years. Superoxide dismutase level was significantly low and malondialdehyde level was significantly high in groups 2 and 3 compared to group 1 (p<0.05). Erythrocyte sedimentation rate was the highest in group 2, followed by group 3 (p<0.05). C-reactive protein levels were the highest in group 2 and the lowest in group 3 (p<0.05). A significantly negative correlation (p<0.001) was found between superoxide dismutase and malondialdehyde., Conclusions: Oxidative stress played a pivotal role in chronic inflammatory rheumatic diseases, like rheumatoid arthritis and ankylosing spondylitis.

Spondyloarthritis (SpA) constitute a group of chronic inflammatory immune-mediated rheumatic diseases characterized by genetic, clinical, and radiological features. Recent efforts have concentrated on identifying biomarkers linked to axial SpA associated with inflammatory bowel disease (IBD), offering predictive insights into disease onset, activity, and progression. Genetically, the significance of the HLA-B27 antigen is notably diminished in ankylosing spondylitis (AS) associated with IBD, but is heightened in concurrent sacroiliitis. Similarly, certain polymorphisms of endoplasmic reticulum aminopeptidase (ERAP-1) appear to be involved. Carriage of variant NOD2/CARD15 polymorphisms has been demonstrated to correlate with the risk of subclinical intestinal inflammation in AS. Biomarkers indicative of pro-inflammatory activity, including C-reactive protein (CRP) along with erythrocyte sedimentation rate (ESR), are among the consistent predictive biomarkers of disease progression. Nevertheless, these markers are not without limitations and exhibit relatively low sensitivity. Other promising markers encompass IL-6, serum calprotectin (s-CLP), serum amyloid (SAA), as well as biomarkers regulating bone formation such as metalloproteinase-3 (MMP-3) and Dickkopf-related protein 1 (DKK-1). Additional candidate indicators of structural changes in SpA patients include matrix metalloproteinase-3 (MMP-3), vascular endothelial growth factor (VEGF), tenascin C (TNC), and CD74 IgG. Fecal caprotein (f-CLP) levels over long-term follow-up of AS patients have demonstrated predictive value in anticipating the development of IBD. Serologic antibodies characteristic of IBD (ASCA, ANCA) have also been compared; however, results exhibit variability. In this review, we will focus on biomarkers associated with both axial SpA and idiopathic intestinal inflammation, notably enteropathic spondyloarthritis., Competing Interests: Declaration of Competing Iinterest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Ankylosing spondylitis (AS) is an autoimmune disease that has the characteristics of difficult early diagnosis and a high disability rate., Objective: The objective of this study was to further explore the possible mechanism and potential function of lncRNA in AS., Methods: We used lncRNA microarray technology to detect the expression of lncRNA and mRNA in patients with active AS, stable patients, and healthy controls (HC). Afterward, bioinformatics analysis was conducted on differentially expressed genes. Seven differentially expressed lncRNAs were screened out for real-time fluorescent quantitative PCR (RT-qPCR), combined with various clinical indicators for correlation analysis, and the receiver operating characteristic (ROC) curve was used to analyze the potential of lncRNA as a diagnostic marker for AS., Results: The results showed that the expression levels of NR-037662 and ENST00000599316 in the AS subgroups were significantly higher than those in the HC group, while the expression levels of ENST00000577914 and ENST00000579003 were lower than those in the HC group. The expression levels of NR-003542 and ENST00000512051 in the ASA group were significantly higher than those in the ASS and HC groups, while NR-026756 was just the opposite. Spearman's correlation analysis showed that the expression level of NR-003542 was positively correlated with Bath Ankylosing Spondylitis Functional Index (BASFI), Erythrocyte Sedimentation Rate (ESR), and high sensitivity C-Reactive Protein (hsCRP). The expression level of NR-026756 was negatively correlated with the Bath Ankylosing Spine Inflammatory Disease Activity Index (BASDAI), BASFI, ESR, hsCRP, and globulin (GLOB). In addition, it was also found that the ROC curve analysis of the 4 lncRNAs between the AS group (ASA group and ASS group) and the HC group were statistically significant, and the area under the curve (AUC) of NR-037662, ENST00000599316, ENST00000577914, and ENST00000579003 was 0.804, 0.812, 0.706, and 0.698, respectively., Conclusion: It was found that these differentially expressed lncRNAs of AS may be involved in the occurrence and development of the disease. Among them, NR-037662, ENST00000599316, ENST00000577914, and ENST00000579003 might have the potential to become AS diagnostic molecular markers. Moreover, NR -003542, ENST00000512051, and NR-026756 might have the potential to be indicators of disease activity., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Background: We sought to discover serum biomarkers of ankylosing spondylitis (AS) for diagnosis and monitoring disease activity., Methods: We studied biologic-treatment-naïve AS and healthy control (HC) patients' sera. Eighty samples matched by age, gender, and race (1:1:1 ratio) for AS patients with active disease, inactive disease, and HC were analyzed with SOMAscan™, an aptamer-based discovery platform. T-tests tests were performed for high/low-disease activity AS patients versus HCs (diagnosis) and high versus low disease activity (Monitoring) in a 2:1 and 1:1 ratio, respectively, to identify differentially expressed proteins (DEPs). We used the Cytoscape Molecular Complex Detection (MCODE) plugin to find clusters in protein-protein interaction networks and Ingenuity Pathway Analysis (IPA) for upstream regulators. Lasso regression analysis was performed for diagnosis., Results: Of the 1317 proteins detected in our diagnosis and monitoring analyses, 367 and 167 (317 and 59, FDR-corrected q < .05) DEPs, respectively, were detected. MCODE identified complement, IL-10 signaling, and immune/interleukin signaling as the top 3 diagnosis PPI clusters. Complement, extracellular matrix organization/proteoglycans, and MAPK/RAS signaling were the top 3 monitoring PPI clusters. IPA showed interleukin 23/17 (interleukin 22, interleukin 23A), TNF (TNF receptor-associated factor 3), cGAS-STING (cyclic GMP-AMP synthase, Stimulator of Interferon Gene 1), and Jak/Stat (Signal transducer and activator of transcription 1), signaling in predicted upstream regulators. Lasso regression identified a Diagnostic 13-protein model predictive of AS. This model had a sensitivity of 0.75, specificity of 0.90, a kappa of 0.59, and overall accuracy of 0.80 (95% CI: 0.61-0.92). The AS vs HC ROC curve was 0.79 (95% CI: 0.61-0.96)., Conclusion: We identified multiple candidate AS diagnostic and disease activity monitoring serum biomarkers using a comprehensive proteomic screen. Enrichment analysis identified key pathways in AS diagnosis and monitoring. Lasso regression identified a multi-protein panel with modest predictive ability., (© 2023. The Author(s).)

Objective: Genetic polymorphisms of the cytokine genes could alter their protein expression, thus creating a genetic basis of dysregulated cytokine production and function, which render them as excellent candidates predisposing to autoimmune diseases. We investigated single nucleotide polymorphisms (SNPs) at TNFA - 308G/A and IL10 - 1082A/G locus to identify their involvement, separately or in combination, in determining susceptibility to ankylosing spondylitis (AS), as well as their functional connections with relevant serum cytokines and associations with disease characteristics., Methods: Eighty-one AS patients and 215 healthy controls were genotyped by polymerase chain reaction-based method; 76 patients and sex-matched controls were also subjected to analysis of serum TNF-α and IL-10 levels by enzyme-linked immunosorbent assay., Results: We identified the homozygous genotype GG of the TNFA-308 significantly more common in patients than controls; whereas the - 308 minor A-allele predicts a threefold decreased risk against developing AS and shows associations with milder radiographic spinal impairments and functional limitations. This protective effect was multiplied by fivefold in synergistic interaction with the homozygous - 1082AA genotype of the IL10 which acts as a modifying factor, since IL10 - 1082A/G SNPs by itself did not have a significant impact on AS genetic susceptibility. In comparison with controls, AS patients had significantly elevated mean serum TNF-α levels and decreased mean IL-10 concentrations not restricted to any particular genotype., Conclusion: TNFA - 308 A-allele is essential for reducing susceptibility to AS, with a considerable synergistic protective effect of the combined TNF-α - 308 (GA/AA)/IL-10 - 1082AA genotypes. In addition, the presence of this variant allele is associated with more benign clinical phenotype of the disease. No conclusive statements on the functional relevance of both gene variants on cytokines production should be made., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The study was aimed to determine the association of the platelet-lymphocyte ratio (PLR) with the disease activity of ankylosing spondylitis (AS). A total of 275 patients, including 180 AS patients and 95 non-AS patients, participated in the study. We assessed a full blood count for each participant. Platelet to monocyte ratio (PMR), monocytes to lymphocyte ratio (MLR), monocyte to neutrophil ratio (MNR), platelet to lymphocyte ratio (PLR), neutrophil to lymphocyte ratio (NLR), and platelet to neutrophil ratio (PNR) were calculated. LASSO and logistic regression analyses were performed to establish the nomogram. Receiver operating characteristic (ROC) analysis was performed to evaluate the clinical value of the nomogram. We constructed a novel nomogram, which incorporated easily accessible clinical characteristics like sex, PLR, WBC, EOS, and ESR for AS diagnosis. The AUC value of this nomogram was 0.806; also, the calibration curves indicated a satisfactory agreement between nomogram prediction and actual probabilities. Furthermore, PLR was positively correlated with the severity of AS. PLR was identified as an independent factor for the diagnosis of AS and was associated with the severity of AS., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Liang, Chen, Xu, Zhang, Xue, Zeng, Jiang, Chen, Qin, Li, Ye, Nie, Zhan and Liu.)

Background: Cardiovascular (CV) morbidity, mortality, and metabolic syndrome are associated with rheumatoid arthritis (RA) and ankylosing spondylitis (AS). Here, lipids and other metabolic markers in relation to vascular function and clinical markers were evaluated in RA and AS patients undergoing one-year anti-TNF therapy., Patients and Methods: Fifty-three patients including 36 RA patients treated with either etanercept (ETN) or certolizumab pegol (CZP) and 17 AS patients treated with ETN were included in a 12-month follow-up study. Various lipids, paraoxonase (PON) and arylesterase (ARE) activities, myeloperoxidase (MPO) and adipokine levels were determined overtime. Ultrasonography was performed to determine flow-mediated vasodilation (FMD), common carotid intima-media thickness (ccIMT), and arterial pulse-wave velocity (PWV) in all patients. All assessments were performed at baseline and 6 and 12 months after treatment initiation., Results: Anti-TNF therapy decreased ARE activity, MPO, adiponectin, and chemerin levels after 12 months ( p < 0.05). Lipids, PON activity, and leptin remained unchanged. Regression analyses suggested variable associations of IMT, PWV, and FMD with ARE, MPO, leptin, and lipids ( p < 0.05). On the other hand, these metabolic parameters were significantly associated with disease duration, CV history, CRP, obesity, PWV, and IMT ( p < 0.05). One-year anti-TNF treatment together with baseline leptin ( p = 0.039) or CRP ( p = 0.016) levels determined 12 months of lipid changes overtime. TNF inhibition together with baseline disease activity determined ARE activity changes ( p = 0.046). Anti-TNF therapy and baseline chemerin levels determined IMT changes overtime ( p = 0.003)., Conclusions: Assessment of various metabolic parameters together with disease activity, CRP, and ultrasound-based techniques may exert additional value in determining CV burden and in monitoring the effects of biologics on preclinical vascular pathophysiology.

Tumor necrosis factor- α (TNF- α ) inhibitors are the main types of biological conventional synthetic disease-modifying antirheumatic drugs and have efficacy in treating ankylosing spondylitis (AS) which is not sensitive for nonsteroidal anti-inflammatory drug. However, the impact of TNF- α inhibitors on immune cells in patients with AS is still clearly undefined, and the impact of immune cells on treatment response is also largely elusive. This study is aimed at evaluating the longitudinal changes of circulating immune cells after anti-TNF- α therapy and their associations with treatment response in AS patients. Thirty-five AS patients receiving the treatment of anti-TNF- α therapy were included into this prospective observational study. The frequencies of immune cells including Th1, Th2, Th17, regulatory T cell (Treg), T follicular helper cell (Tfh), and regulatory B cell (Breg) in the peripheral blood were measured by flow cytometry at baseline and 4 time points after therapy. The difference in the circulating immune cells between responders and nonresponders was compared. This study suggested that anti-TNF- α therapy could significantly reduce circulating proinflammatory immune cells such as Th17 and Tfh, but significantly increased the percentages of circulating Treg and Breg. Moreover, circulating Breg may be a promising predictor of response to anti-TNF- α therapy in AS patients., Competing Interests: All authors declare that they have no conflict of interest in this paper., (Copyright © 2021 Rongjuan Chen et al.)

Background: Various studies reported that increased proinflammatory cytokines in patients with ankylosing spondylitis (AS). Proinflammatory cytokines can affect the expression of various kynurenine pathway enzymes and therefore lead to metabolic changes that can affect the inflammatory response and immunity. Our aim was to measure serum levels of kynurenine pathway metabolites in patients with AS., Methods: The study included 85 patients with AS and 50 healthy volunteers. Serum tryptophan, kynurenine, kynurenic acid, 3-hydroxyanthranilic acid, 3-hydroxykynurenine, quinolinic acid concentrations were measured with tandem mass spectrometry. In addition, participants were divided into four groups according to the treatment regimen: TNF-α inhibitor group, conventional therapy group, control group and newly diagnosed AS group. These groups were compared in terms of kynurenine pathways metabolites, interleukin 6 (IL-6), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels., Results: Serum tryptophan, kynurenic acid, 3-hydroxykynurenine levels were significantly decreased (p < 0.05) in both AS groups compared to the control group, while the levels of kynurenine, quinolinic acid, CRP, ESR, and IL-6 were higher (p < 0.05). The Kynurenine/Tryptophan ratio and CRP levels of the conventional therapy and anti-TNF therapy group were significantly lower than the newly diagnosed AS patients (p < 0.05)., Conclusion: As a result of our study, we found that altered kynurenine pathway metabolism in patients with AS. Conventional therapy and anti-TNF-α therapy are effective in reducing the Kynurenine/Tryptophan ratio and CRP levels, although the effect of both treatments on other metabolites appears to be limited., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Our aim in this study was to measure serum levels of methylarginines and related metabolites in patients with ankylosing spondylitis (AS), moreover, to investigate the relationship between these parameters and various clinical and laboratory parameters of patients with AS. The study included 60 patients with AS and 60 healthy volunteers. Serum asymmetric dimethylarginine (ADMA), L-N monomethylarginine (L-NMMA), symmetric dimethylarginine (SDMA), arginine (Arg), homoarginine (hArg), ornithine, and citrulline concentrations were measured with tandem mass spectrometry. In addition, participants were divided into three groups according to the treatment regimen: TNF-α inhibitor group (n = 25), conventional therapy group (n = 35), and control group (n = 60). These groups were compared in terms of serum levels of methylarginine pathway metabolites and various biochemical parameters. It was found that total methylated arginine load significantly increased in patients with AS (p < 0.001), and the Arg/ADMA ratio was positively correlated with HDL levels and negatively correlated with glucose, ESR, total cholesterol, triglyceride, and LDL levels. In addition, serum ADMA, SDMA, total methylated arginine load, and CRP levels were lower (p < 0.05) in the TNF-α group compared to the conventional treatment group. To the best of our knowledge, this is the first study to comprehensively investigate serum methylarginine levels in patients with AS. Elevated total methylated arginine load and decreased global arginine bioavailability ratio (GABR) indicate that NO metabolism is impaired in patients with AS. Therefore, the increased cardiovascular risk in patients with AS may be related to the decreased NO production or bioavailability due to the elevated total methylarginine load., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Background/aim: Atherosclerotic heart diseases can occur at an early age in patients with ankylosing spondylitis (AS). Flow-mediated dilation (FMD) and carotid intima-media thickness (cIMT) values are reliable markers for early detection of subclinical atherosclerosis in patients with AS. We aimed to investigate the relationship between visfatin levels and indirect markers of subclinical atherosclerosis and endothelial dysfunction in patients with AS., Materials and Methods: Forty-two patients diagnosed with AS and 42 age, sex, and body mass index (BMI)-matched controls were included in the study. Visfatin levels, FMD, and cIMT were measured using appropriate methods., Results: Visfatin levels of the patients were significantly higher than controls (p < 0.001). FMD values in patients with AS were significantly lower (p = 0.007) whereas cIMT were significantly higher than the controls (p = 0.003). There was a negative relationship between FMD with visfatin levels (p = 0.004), BASDAI (p = 0.010), and BASFI (p = 0.007). There was a positive relationship between cIMT with visfatin (p = 0.005), BASDAI (p < 0.001), and BASFI (p < 0.001). There was a positive relationship between visfatin with BASDAI (p < 0.001), and BASFI (p < 0.001)., Conclusion: Visfatin levels are increased and associated with impaired FMD and increased cIMT in patients with AS. Increased visfatin levels may be associated with subclinical atherosclerosis in AS., (This work is licensed under a Creative Commons Attribution 4.0 International License.)

Abstract: To investigate the association of sleep disturbance with calcium regulatory hormones, disease severity and health index among the patients with ankylosing spondylitis (AS).There were 104 AS patients enrolled in the cross-sectional study, and their sleep quality was recorded. Serum levels of calcium, parathyroid hormone, vitamin D3 and calcitonin were measured. We evaluated patient's disease activity, functional ability, patient's global assessment, physical mobility, radiographic damage and health index. Blood ESR and CRP levels were tested.Sleep quality was positively correlated with serum calcitonin levels (r = 0.260, P = .008). Bad sleep and advanced radiographic damage were found among the AS patients with detectable serum calcitonin levels (P < .05). Sleep quality was significantly correlated with disease duration, CRP, BASDAI, ASDAS-ESR, ASDAS-CRP, BASFI, BAS-G, BASMI and ASAS-HI among the AS patients (all P < .05). Female gender, longer disease duration, higher ASDAS-CRP and serum calcitonin levels (OR [95% CI] = 3.210 [1.012-10.181], P = .048) were independent factors associated with bad sleep. Inflammation, disease activity, functional ability, patient's global assessment and cervical rotation were useful in predicting bad sleep among the AS patients, and ASDAS-CRP was the best predictor (AUC = 0.772, P < .001).Serum calcitonin levels was elevated in the AS patients with bad sleep, and may participate in the pathophysiology of sleep disturbance. Bad sleep was associated with female gender, longer disease duration, higher inflammation, disease activity, functional impairment, mobility restriction, poor patient's global assessment and health index in AS. ASDAS-CRP was best in predicting bad sleep., Competing Interests: The authors have declared no conflicts of interest., (Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.)

Objective: Ankylosing spondylitis (AS) is a chronic inflammatory arthritis primarily affecting the spine and sacroiliac joints. TNF inhibitor (TNFi) drugs are recommended for patients not responding to NSAIDs; however, there is a significant need for biomarkers of response. IFN-regulated genes (IRGs) and other cytokines/chemokines are linked to autoimmune diseases and have been associated with treatment response. Our objective was to explore whether IRGs and cytokines/chemokines can be associated with response to TNFiagents in AS., Methods: Peripheral blood mononuclear cells were obtained from 26 AS patients who were to receive a TNFi (I, n = 15) or placebo (P, n = 11) at week 0 and week 22. Response (R)/non-response (NR) was defined as reduction in ASDAS ≥ 1.2 points or reduction in sacroiliac/vertebral MRI lesions. The expression of 96 genes was quantified using TaqMan assays. Finally, ELISA was used to measure IL-6 in serum samples from another 38 AS patients., Results: Analysis of gene expression in 26 baseline samples segregated patients into four groups defined by a signature of 15 genes (mainly IRGs). ASDAS response was associated with one group independently of treatment received. We then analysed response to the TNFi (n = 15) and identified a 12-gene signature associated with MRI response. A third IRG signature was also associated with a reduction in IRGs expression post-TNFi samples (n = 10 pairs). Finally, decreased circulating IL-6 was associated with BASDAI-R., Conclusion: This pilot study suggests an association between IRG expression and response to TNFi in AS. These findings require validation in a larger cohort in order to construct predictive algorithms for patient stratification., (© The Author(s) 2021. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Rheumatoid arthritis (RA), ankylosing spondylitis (AS), and psoriatic arthritis (PsA) are comprehensive immunological disorders. The treatment of these disorders is limited to ameliorating the symptoms and improving the quality of life of patients. In this study, serum samples from RA, AS, and PsA patients were analyzed with metabolomic tools employing the 1H NMR method in combination with univariate and multivariate analyses. The results obtained in this study showed that the changes in metabolites were the highest for AS > RA > PsA. The study demonstrated that the time until remission or until low disease activity is achieved is shortest (approximately three months) for AS, longer for RA and longest for PsA. The statistically common metabolite that was found to be negatively correlated with the healing processes of these disorders is ethanol, which may indicate the involvement of the gut microflora and/or the breakdown of malondialdehyde as a cell membrane lipid peroxide product.

Ankylosing spondylitis (AS) is a chronic autoimmune inflammatory disease that mainly affects the axial and sacroiliac joints. Single-nucleotide polymorphisms (SNPs) in genes encoding cytokines have been associated with AS, which can interfere with the production of these cytokines and contribute to the development of AS. In order to contribute to a better understanding of the pathology of AS, our objective was to investigate a possible association of the IL10 -1082 A>G SNP (rs1800896) with AS and to evaluate the serum levels of TNF-α, IL-10, IL-17A, and IL-17F in AS patients and controls comparing them with their respective genotypes ( TNF rs1800629, IL10 rs1800896, IL17A rs2275913, and IL17F rs763780). Patients and controls were selected from the Maringá University Hospital and the Maringá Rheumatism Clinic, in Paraná State, Southern Brazil, and they were diagnosed by the ASAS Criteria. In total, 149 patients and 169 controls were genotyped for the IL10 -1082 A>G polymorphism using a polymerase chain reaction with sequence specific primers (PCR-SSP); the measurement of TNF-α serum levels was performed through the immunofluorimetric test and IL-10, IL-17A, and IL-17F using an ELISA test. There was a high frequency of the IL10 -1082 G allele in AS patients compared with controls with an odds ratio of 1.83 and 95% confidence interval of 1.32 to 2.54, and a significant difference in the genotype frequencies of the IL10 -1082 A/G+G/G between patients and healthy controls, with an odds ratio of 3.01 and 95% confidence interval of 1.75 to 5.17. In addition, increased serum levels of IL-10 were observed in AS patients: 2.38 (IQR, 0.91) pg/ml compared with controls 1.72 (IQR 0.93) pg/ml (P = 0.01). Our results also showed an association between IL17F rs763780 C/T+T/T genotypes and increased serum levels of IL-17F in patients with AS and also in controls. We can conclude that patients with the A/G and G/G genotypes for -1082 A>G (rs1800896) in the IL10 gene are three times more likely to develop AS, that the serum level of IL-10 was higher in AS patients and that the IL17F rs763780 polymorphism can affect the levels of IL-17F in the serum of patients and controls in the same way., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Braga, Lara-Armi, Neves, Rocha-Loures, Terron-Monich, Bahls-Pinto, de Lima Neto, Zacarias, Sell and Visentainer.)

Objective: To study erectile function in male patients with Ankylosing Spondylitis (AS) trying to correlate it with sexual hormonal profile and disease activity., Methods: We included 35 AS patients and 104 controls. Patients and controls answered the IIEF (International Index of Erectile Dysfunction) and had dosing of total testosterone, free testosterone (FT), bioavailable testosterone (BT), SHBG (serum hormone binding globulin), albumin and LH (luteinizing hormone). AS patients had epidemiological, clinical and treatment data obtained from the charts. AS disease activity was measured simultaneously with blood collection through Bath AS Disease Activity Index, ASDAS (AS Disease Activity Score) -ESR (using erythrocyte sedimentation rate) and ASDAS-CRP (using C reactive protein)., Results: The IIEF results were worse in AS patients than controls (P = .02). Total testosterone and SHBG were higher in AS (with P = .01 and P <.0001 respectively). Between the 2 groups, no differences in LH, FT, BT levels (all with P = ns) were found. In AS patients, the IIEF results did not correlate with total testosterone, SHBG, LH, FT, and BT but a negative association was found with Bath AS Disease Activity Index (P = .001) and ASDAS-CRP (P = .02)., Conclusion: AS patients had worst sexual performance than controls that was linked to disease activity but not to male sexual hormonal profile., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Ankylosing spondylitis (AS) is a chronic autoimmune disease in which let-7i has been studied to involved. But, whether let-7i-3p could regulate osteoblast differentiation in AS remains unclear. This research targeted to decipher the impact of let-7i-3p on AS progression by modulating pyruvate dehydrogenase kinase 1 (PDK1). The bone mineral density of femur and lumbar vertebra and the maximum loading and bending elastic modulus of tibia, tumor necrosis factor-α (TNF-α), matrix metalloproteinase (MMP)-3, osteoprotegerin (OPG) and receptor activator of nuclear factor-κB ligand (RANKL) in serum of AS mice, the pathological condition of synovial tissue were determined via let-7i-3p inhibitor and OE-PDK1 in animal experiment. Also, the cell viability and ALP activity were measured by let-7i-3p inhibitor and OE-PDK1 in cell experiments. let-7i-3p and PDK1 expression were detected. Let-7i-3p raised and PDK1 declined in AS mice. Depleted let-7i-3p and restored PDK1 increased bone mineral density and maximum loading and bending elastic modulus of tibia, reduced TNF-α, MMP-3 and RANKL contents, attenuated the pathological condition of synovial tissue and raised OPG content in AS mice. In cell experiments, up-regulating PDK1 and down-regulating let-7i-3p enhanced cell viability and ALP activity in AS mice. Low expression of let-7i-3p could enhance osteoblast differentiation in AS by up-regulating PDK1. Abbreviations: AS: Ankylosing spondylitis; PDK1: pyruvate dehydrogenase kinase 1; TNF-α: tumor necrosis factor-α MMP: matrix metalloproteinase; OPG: osteoprotegerin; RANKL: receptor activator of nuclear factor-κB ligand; miRNAs: MicroRNAs; BMD: bone mineral density; PFA: paraformaldehyde; NC: negative control; OE: overexpression; HE: Hematoxylin-eosin; PBS: phosphate-buffered saline; EDTA: ethylene diamine tetraacetic acid; DMEM: Dulbecco's Modified Eagle Medium; RT-qPCR: Reverse transcription quantitative polymerase chain reaction; GAPDH: glyceraldehyde phosphate dehydrogenase; UTR: untranslated region; WT: wild type; MUT: mutant type.

Ankylosing spondylitis (AS) is a chronic auto-immune disease, affecting the spine, sacroiliac, and sometimes peripheral joints. It is also involved with cardio-vascular risk factors due to accelerated atherosclerosis. Oxidative burst, systemic inflammation coupled with endothelial dysfunction (ED), resulting in reduced bioavailability of the vasodilator nitric oxide (NO) and an increased number of circulating endothelial cells (CECs) may correlate with disease activity and its sustenance. Hence, the study was aimed to detect and quantify CECs and assess the oxidative stress and inflammatory status in AS patients vis-à-vis healthy controls, as well as relate these parameters with AS disease activity and atherosclerotic markers in patients. Our study showed an increased frequency of endothelial cells in peripheral blood of AS patients in pro-inflammatory conditions. In AS patient population, they showed significant reduction of flow-mediated dilatation (%FMD) ( p  < 0.05), and increased soluble adhesion molecules such as sICAM-1 ( p  < 0.01) and sVCAM-1 ( p  < 0.05) compared to healthy controls. A marked increase in pro-inflammatory markers such as TNF-α ( p  < 0.01) and IL-1β ( p  < 0.001) and reactive free radicals ( p  < 0.05) along with reduced serum nitrite in AS, provided a strong pro-inflammatory milieu which positively correlated with Bath ankylosing spondylitis disease activity and functional indices (BASDAI and BASFI). The observed significant upregulation in CECs (CD45 - /CD31 + /CD105 + /CD144 + ) in patients compared to healthy controls positively correlated with disease activity and duration as well as with markers of oxidative stress. Thus, chronic inflammation and oxidative burst induce loss of NO bioavailability, leading to ED. This may cause the derangement of CECs that may be considered as a prognostic biomarker for ED.

Background: This study was to investigate the value of 10 serum inflammatory cytokines for predicting clinical response to celecoxib in ankylosing spondylitis (AS) patients., Methods: Totally, 103 active AS patients who underwent celecoxib treatment for 12 weeks were enrolled. Then, pre-treatment serum TNF-α, IL-1β, IL-6, IL-8, IL-17A, IL-21, IL-23, IL-32, ICAM-1, and VEGF were detected by enzyme-linked immunosorbent assay. Besides, the ASAS 20 response was assessed at week 2 (W2), week 6 (W6), and week 12 (W12). Based on the ASAS 20 response at W12, patients were divided into responders and non-responders., Results: After celecoxib treatment, 53 (51.3%), 58 (56.3%), and 60 (58.3%) patients achieved ASAS 20 response at W2, W6, and W12, respectively. Furthermore, IL-1β (P = 0.019), IL-6 (P = 0.004), and IL-17A (P = 0.007) levels were higher, while TNF-α (P = 0.086), IL-8 (P = 0.143), IL-21 (P = 0.687), IL-23 (P = 0.329), IL-32 (P = 0.216), ICAM-1 (P = 0.119), and VEGF (P = 0.732) levels were similar in responders compared with non-responders. Subsequent multivariate logistic regression analysis revealed that among these inflammatory cytokines, only IL-6 (P = 0.019) independently predicted higher ASAS 20 response to celecoxib at W12, and it had a fair value for predicting ASAS 20 response to celecoxib at W12 (area under the curve: 0.666, 95% confidence interval: 0.561-0.771) by receiver-operating characteristic curve analysis., Conclusion: Serum IL-1β, IL-6, and IL-17A serve as indicators for predicting clinical response to celecoxib in AS patients, which may assist with the optimization of personalized treatment.

Circulating miRNAs appear promising therapeutic and prognostic biomarkers. We aimed to investigate the predictive value of circulating miRNAs on the disease outcome following anti-TNF therapy in patients with ankylosing spondylitis (AS). Our study included 19 AS patients assessed at baseline (M0), after three (M3) and twelve months (M12) of therapy. Total RNA was isolated from plasma. A comprehensive analysis of 380 miRNAs using TaqMan Low Density Array (TLDA) was followed by a single assay validation of selected miRNAs. All AS patients had high baseline disease activity and an excellent response to anti-TNF therapy at M3 and M12. TLDA analysis revealed the dysregulation of 17 circulating miRNAs, including miR-145. Single assay validation confirmed that miR-145 is significantly downregulated at M3 compared to baseline. The decrease in the levels of miR-145 from M0 to M3 negatively correlated with the change in BASDAI from M0 to M3; and positively correlated with disease activity improvement from M3 to M12 as per BASDAI and ASDAS. The predictive value of the early change in miR-145 and levels of miR-145 at M3 were further validated by Receiver operating curves analysis. We show thatthe early change in circulating miR-145 may be a predictor for the future outcome ofAS patients treated with TNF inhibitors. Patients with a more significant decrease in miR-145 levels may show further significant improvement of disease activity after 12 months. Monitoring the expression of miR-145 in plasma in AS patients may, therefore, influence our therapeutic decision-making.

Background: Hyperhomocysteinemia is associated with autoimmune diseases such as ankylosing spondylitis (AS), systemic lupus erythematosus (SLE), and rheumatoid arthritis (RA). Current findings regarding plasma/serum homocysteine (HCY) levels in AS patients are inconsistent. This study aims to systematically evaluate the association between circulating HCY levels and AS., Methods: Online electronic databases (PubMed, Web of Science, Embase, ScienceDirect, China National Knowledge Infrastructure (CNKI), and Wanfang data) were used to retrieve all relevant articles published up to May 7, 2020. The pooled standardized mean difference (SMD) with 95% confidence interval (CI) was calculated using the random-effect model, Stata16 software., Results: Nine articles containing 778 AS patients and 522 controls were included in this meta-analysis. No significant differences in HCY levels were found between AS and control groups (pooled SMD = 0.46, 95% CI = - 0.30 to 1.23, P = 0.23). However, subgroup analysis suggested that HCY levels were significantly higher (P < 0.05) in the AS group treated with methotrexate (MTX) compared with the control group. In contrast, HCY levels were significantly (P < 0.05) lower in the AS group receiving anti-TNF-α treatment compared with the control group. No significant differences were detected between HCY levels and disease activity scores (Bath AS disease activity index, BASDAI), and methylenetetrahydrofolate reductase (MTHFR) C677T genotype., Conclusion: This meta-analysis indicates that HCY levels are similar between AS and controls, and do not correlate with disease activity. However, different medical treatments cause fluctuations of circulating HCY levels in AS patients. Further and larger-scale studies are needed to confirm these findings., Trial Registration: This study was registered at international prospective register of systematic reviews (PROSPERO), registration number: CRD42020184426 .

Objective: To develop an alternative Ankylosing Spondylitis Disease Activity Score (ASDAS) to be used in research settings in axial SpA (axSpA) when Patient Global Assessment (PGA) is unavailable in databases., Methods: Longitudinal data from four axSpA cohorts and two randomized controlled trials were combined. Observations were randomly split in a development (N = 1026) and a validation cohort (N = 1059). Substitutes of PGA by BASDAI total score, single or combined individual BASDAI questions, and a constant value, were established in the development cohort. Conversion factors for each substitute were defined by Generalized Estimating Equations, obtaining seven 'alternative' formulae. Validation was performed in the validation cohort according to the OMERACT filter, taking into consideration: (i) truth (agreement with original-ASDAS in the continuous score, by intraclass correlation coefficient and in disease activity states, by weighted kappa); (ii) discrimination [standardized mean difference of ASDAS scores between high/low disease activity states defined by external anchors, e.g. Patient Acceptable Symptom State; agreement (kappa) in the percentage of patients reaching ASDAS improvement criteria according to alternative vs original formulae]; and (iii) feasibility., Results: Comparing various options, alternative-ASDAS using BASDAI total as PGA replacement proved to be: truthful (intraclass correlation coefficient = 0.98, kappa = 0.90), discriminative [ASDAS scores between Patient Acceptable Symptom State no/yes: standardized mean difference = 1.37 (original-ASDAS standardized mean difference = 1.43); agreement with original-ASDAS in major improvement/clinically important improvement criteria: kappa = 0.93/0.88] and feasible (BASDAI total often available, as questions required for the ASDAS; conversion coefficient ≈ 1)., Conclusion: Alternative-ASDAS using BASDAI total score as PGA replacement is the most truthful, discriminative and feasible instrument., (© The Author(s) 2020. Published by Oxford University Press on behalf of the British Society for Rheumatology.)

Spondyloarthritis (SpA) is characterized by inflammation and new bone formation. The exact pathophysiology underlying these processes remains elusive. We propose that the extensive neoangiogenesis in SpA could play a role both in sustaining/enhancing inflammation and in new bone formation. While ample data is available on effects of anti-TNF on angiogenesis, effects of IL-17A blockade on serum markers are largely unknown. We aimed to assess the impact of secukinumab (anti-IL-17A) on synovial neoangiogenesis in peripheral SpA, and how this related to changes in inflammatory and tissue remodeling biomarkers. Serum samples from 20 active peripheral SpA patients included in a 12 week open-label trial with secukinumab were analyzed for several markers of angiogenesis and tissue remodeling. Synovial biopsies taken before and after treatment were stained for vascular markers. Serum levels of MMP-3, osteopontin, IL-6 (all P < 0.001), IL-31, S100A8, S100A9, Vascular Endothelial Growth Factor A (VEGF-A), IL-33, TNF-α (all P < 0.05) decreased significantly upon anti-IL17A treatment. Secukinumab treatment resulted in a decrease in the number of synovial high endothelial venules and lymphoid aggregate score. These results indicate that anti-IL-17A not only diminishes inflammation, but also impacts angiogenesis and tissue remodeling/new bone formation. This may have important implications for disease progression and/or structural damage.

The purpose of this work was to identify the features of the gut microbiome in cases of ankylosing spondylitis (AS) testing positive for human leukocyte antigen- (HLA-) B27 and healthy controls (HCs) as well as to determine how bacterial populations were correlated with C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). Fecal DNA extracted from fecal samples from 10 AS cases and 12 HCs was subjected to 16S rRNA gene sequencing. The two research groups did not differ significantly regarding alpha diversity. By comparison to HCs, AS cases displayed a lower relative level of Bacteroidetes ( P < 0.05), but a higher level of Firmicutes and Verrucomicrobia ( P < 0.05). Furthermore, the correlation between the specific gut bacteria and ESR or CRP was investigated. At the phylum level, Firmicutes and Verrucomicrobia had a positive association with ESR and CRP, while Bacteroidetes exhibited an inverse correlation with ESR and CRP. Meanwhile, in terms of genus, Bacteroides had a positive association with ESR and CRP, whereas Ruminococcus and Parasutterella had an inverse correlation with ESR and CRP, and Helicobacter also displayed an inverse correlation with CRP. Such findings indicated dissimilarities between AS cases and HCs regarding the gut microbiome, as well as the existence of correlations between bacterial populations and both ESR and CRP., Competing Interests: The authors declare no competing interests., (Copyright © 2020 Gang Liu et al.)

There is an ongoing quest for robust disease activity measures in Ankylosing spondylitis (AS). Thus, we prospectively validated two new disease activity indices, Simplified AS Disease Activity Score (SASDAS) and modified Juvenile Spondyloarthritis Disease Activity Score (JSpADA). Patients with AS were assessed for BASDAI, ASDAS and other outcome measures at baseline and 3 months. Comparisons were drawn between those with juvenile onset, early disease and peripheral involvement, with the rest. Fisher's r to Z transformation was used to compare correlations. Receiver-operating characteristic (ROC) curves were used to calculate cutoffs for inactive, low, high and very high disease activity. Of the 107 patients (mean age-29 years) of 6-years long disease, 38.3% had a juvenile onset. SASDAS and modified JSpADA exhibited excellent correlation with BASDAI and ASDAS (all p < 0.001) and were higher in active vs. inactive disease. Treatment responders had a greater fall in SASDAS and modified JSpADA as compared to non-responders. The novel scores were higher in those with peripheral disease. Only SASDAS could discriminate early from late disease. Based on the previously proposed cutoffs, optimal scores for inactive, moderate, high and very high disease activity were deduced. SASDAS-CRP showed better internal consistency than SASDAS-ESR and correlated better with ASDAS-CRP in late disease (Z = 3.04; p = 002) and those with adult onset disease (Z = 2.18; p = 0.03). SASDAS and Modified JSpADA perform as well as standard complex scores and have potential for simpler daily use. From our analyses, SASDAS with CRP performs better than SASDAS-ESR, pending further validation.

Ankylosing spondylitis (AS) is a chronic inflammatory disease possessing a morbid serum microenvironment with enhanced oxidative stress. Long-term exposure to an oxidative environment usually results in cellular senescence alone with cellular dysfunction. Mesenchymal stem cells (MSCs) are a kind of stem cell possessing strong capabilities for immunoregulation, and senescent MSCs may increase inflammation and participate in AS pathogenesis. The objective of this study was to explore whether and how the oxidative serum environment of AS induces MSC senescence. Here, we found that AS serum facilitated senescence of MSCs in vitro, and articular tissues from AS patients exhibited higher expression levels of the cell cycle arrest-related proteins p53, p21 and p16. Importantly, the levels of advanced oxidative protein products (AOPPs), markers of oxidative stress, were increased in AS serum and positively correlated with the extent of MSC senescence induced by AS serum. Furthermore, MSCs cultured with AS serum showed decreased mitochondrial membrane potential and ATP production together with a reduced oxygen consumption rate. Finally, we discovered that AS serum-induced mitochondrial dysfunction resulted in elevated reactive oxygen species (ROS) in MSCs, and ROS inhibition successfully rescued MSCs from senescence. In conclusion, our data demonstrated that the oxidative serum environment of AS facilitated MSC senescence through inducing mitochondrial dysfunction and excessive ROS production. These results may help elucidate the pathogenesis of AS and provide potential targets for AS treatment.

Objectives: Semaphorin 4D (Sema4D) is constitutively expressed on T cells and osteoclasts, and regulates T cell proliferation and bone remodeling. In addition, several studies have shown that Sema4D is involved in the pathogenesis of autoimmunity. We undertook this study to investigate the mechanism by which Sema4D affects the pathogenic progress of ankylosing spondylitis (AS)., Methods: Soluble Sema4D (sSema4D) levels in serum were analyzed by enzyme-linked immunosorbent assay. The cell surface levels and transcripts of Sema4D were evaluated in CD4 + and CD19 + cells from the AS patients and healthy individuals. The mRNA expression levels were assessed by quantitative polymerase chain reaction (qPCR). The proportions of Treg cells and IL-17-producing T-cells (Th17 cells) differentiated from CD4 + T cells were analyzed by flow cytometric analysis. The aryl hydrocarbon receptor (AhR) agonistic effect of Sema4D was detected by analyzing the activation of downstream signaling pathways and target genes using Luciferase and EROD assay., Results: Levels of sSema4D were elevated in both serum from AS patients, and clinical features markers were correlated with serum sSema4D levels. Sema4D facilitated CD4 + T cells proliferation and Th17 cells differentiation and inhibited Treg cells differentiation by enhancing RORγt expression and reducing Foxp3 expression, with increasing expression and secretion of IL-17 and IL-22. It induced the expression and activity of AhR target gene CYP1A1 and XRE reporter activity via interaction with CD72., Conclusion: These findings indicate that Sema4D as a potent activator of T cells in the immune response contributes to the inflammation of AS by inducing imbalance in Th17 and Treg cell populations in an AhR-dependent manner, suggesting it is a crucial participant in AS pathogenesis., (Copyright © 2020 Xie, Wang and Wang.)

Objectives: To evaluate the relationship between red cell distribution width (RDW), platelet-to-lymphocyte ratio (PLR), and mean platelet volume (MPV) and ankylosing spondylitis (AS) and establish a correlation between these haematological indices and AS inflammation. Methods: We searched the Medline, Embase, and Cochrane databases, performed a meta-analysis comparing RDW, PLR, and MPV in patients with AS to controls, and examined correlation coefficients between RDW, PLR, and MPV and C-reactive protein (CRP). Results: Eleven studies were included in this meta-analysis, which revealed that RDW was significantly higher in the AS group than in the control group (standardized mean difference (SMD) = 0.687, 95% confidence interval (CI) = 0.110-1.265, p  = .020). However, PLR was not significantly higher in the AS group than in the control group (SMD = 0.197, 95% CI = -0.045-0.439, p  = .111). No evidence of elevated MPV in the AS group was found (SMD = -0.005, 95% CI = -0.411-0.400, p  = .979). Meta-analysis of correlation coefficients revealed that RDW was positively associated with CRP (correlation coefficient = 0.327, 95% CI = 0.214-0.431, p  < .001). PLR was positively associated with CRP (correlation coefficient = 0.444, 95% CI = 0.283-0.581, p  < .001). In addition, the meta-analysis showed a correlation between MPV and CRP (correlation coefficient = 0.217, 95% CI = 0.080-0.346, p  = .002). Conclusion: This meta-analysis demonstrated that RDW is higher in patients with AS, and a significant positive correlation exists between RDW, PLR, and MPV and CRP.

Background: Ankylosing spondylitis (AS) is a common chronic inflammatory arthritis, causing lasting back pain with progressive loss of spinal mobility. However, the exact pathogenesis of AS remains unclear. We aim to use the metabolomics analysis to characterize the metabolic profile of AS, in order to better understand the pathogenesis of AS and monitor disease activity and progression., Methods: The ultra-high performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-TQ-MS) was used for investigating the serum amino acid metabolomic profiling of 30 AS patients, in comparison with 32 rheumatoid arthritis (RA) patients and 30 healthy controls, combined with multivariate statistical analysis. Metabolite association analysis with disease activity was performed using generalized linear regression. The metabolic pathway analysis for the important metabolites was performed using MetPA and the metabolic network was constructed., Results: A total of 29 amino acids and biogenic amines were detected in all participants by UPLC-TQ-MS. It showed significant amino acid differences between the AS/RA patients and control subjects. Additionally, 4-hydroxy-L-proline, alanine, γ-aminobutyric acid, glutamine, and taurine were identified as candidate markers shared by AS/RA groups. Specifically, lysine, proline, serine, and alanine were found correlated with disease activity of AS. Furthermore, the most significant metabolic pathway identified were alanine, aspartate, and glutamate metabolism, arginine and proline metabolism, aminoacyl tRNA biosynthesis and glycine, serine, and threonine metabolism., Conclusions: These preliminary results demonstrate that UPLC-TQ-MS analysis method is a powerful tool to identify metabolite profiles of AS. Research in identified disease activity-associated metabolites and biological pathways may provide assistance for clinical diagnosis and pathological mechanism of AS. Key Points • There are perturbations of serum amino acid metabolism in AS, compared with RA and healthy controls, determined by UPLC-TQ-MS. • Metabolomics pathway is used to analysis for the differential metabolites of AS. • The altered serum amino acid could monitor disease activity of AS.

Background: Ankylosing spondylitis (AS) is a common progressive autoimmune inflammatory disease. Du moxibustion can effectively treat AS with few adverse reactions. The aim of this protocol is to systematically investigate the effectiveness and safety for management of AS with Du moxibustion., Methods: Seven relevant databases, namely, PubMed, Cochrane Library, Embase, Chinese Biomedical Literatures Database (CBM), China National Knowledge Infrastructure (CNKI), WangFang Database (WF), Chinese Scientific Journal Database (VIP) will be searched from their inception until May 1st, 2020. All clinical randomized controlled trials containing eligible interventions(s) and outcome(s) will be included, regardless of blinding or publication types. Two reviewers will independently retrieval databases, extract data, and then assess the quality of studies. Data synthesis will be conducted by RevMan 5.3 software. We regard the effective rate, Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Visual Analogue Scale (VAS) as the primary outcomes, and the secondary outcomes contain C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), finger-to-floor distance (FFD), occiput to wall distance (OWD), and side effects. The result about the curative effect and safety of Du moxibustion for AS will be presented as risk ratio for dichotomous data and mean differences with a 95% confidence interval for continuous data., Results: The finding will be presented in a journal or related conferences., Conclusions: This study expects to provide high-quality, evidence-based recommendations on further treatment for clinical guidance., Prospero Registration Number: CRD42020158727.

Background: In view of the current difficulty of clinically diagnosing osteoarticular tuberculosis, our aim was to use mass spectrometry to establish diagnostic models and to screen and identify serum proteins which could serve as potential diagnostic biomarkers for early detection of osteoarticular tuberculosis., Methods: Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was used to select an osteoarticular tuberculosis-specific serum peptide profile and establish diagnostic models. Further, liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to identify potential serum biomarkers that could be used for auxiliary diagnosis of osteoarticular tuberculosis, and then clinical serum samples were used to verify these biomarkers by enzyme-linked immunosorbent assay (ELISA)., Results: We established four diagnostic models that can distinguish osteoarticular tuberculosis from rheumatoid arthritis, ankylosing spondylitis, osteoarticular infections, and healthy adults. The models were osteoarticular tuberculosis-rheumatoid arthritis, osteoarticular tuberculosis-ankylosing spondylitis, osteoarticular tuberculosis-osteoarticular infections, and osteoarticular tuberculosis-healthy adult, and their accuracy was 76.78%, 79.02%, 83.77%, and 88.16%, respectively. Next, we selected and identified 18 proteins, including complement factor H-related protein 1 (CFHR1) and complement factor H-related protein 2 (CFHR2), which were upregulated in the tuberculosis group only., Conclusions: We successfully established four diagnostic models involving osteoarticular tuberculosis, rheumatoid arthritis, ankylosing spondylitis, osteoarticular infections, and healthy adults. Furthermore, we found that CFHR1 and CFHR2 may be two valuable auxiliary diagnostic indicators for osteoarticular tuberculosis. These results provide reference values for rapid and accurate diagnosis of osteoarticular tuberculosis., (© 2020 The Authors. Journal of Clinical Laboratory Analysis published by Wiley Periodicals, Inc.)

Objectives: The aim of the present study was to investigate the differences in clinic-pathological features of secondary IgA nephropathy (SIgAN) between patients with ankylosing spondylitis (AS) and rheumatoid arthritis (RA). Methods: Forty-six patients with SIgAN related to AS (SIgAN-AS) and 26 patients with SIgAN related to RA (SIgAN-RA) were enrolled in this retrospective study. The two groups were compared for their clinic-pathological characteristics. Results: The 10-year prevalence of SIgAN-AS and SIgAN-RA were 167 per 1000 and 51.3 per 1000, respectively. Compared with SIgAN-RA patients, SIgAN-AS patients had lower incidences of edema and nephrotic syndrome, but higher levels of eGFR, serum C3, and CD3- and CD8-positive T-cell counts, but less incidences of acute tubulointerstitial lesions and interlobular arterial lesions. IgM was the most familiar co-depositing immune complex on tissue with significantly different frequencies. In SIgAN-AS patients, those with positive HLA-B27 presented with lower levels of proteinuria, higher levels of serum IgG and C3, and less incidence of renal insufficiency, crescents >14.5%, glomerular sclerosis >32.6% and segmental sclerosis >5.2%. Conclusion: SIgAN was more prevalent in AS than in RA. SIgAN-AS patients differed from SIgAN-RA patients in certain clinic-pathological characteristics. HLA-B27 likely protected SIgAN-AS patients from renal insufficiency.

Background: This study aimed to assess the role of fibrinogen (Fib) to albumin (ALB) ratio (FAR) in ankylosing spondylitis (AS) and its association with disease activity., Methods: 135 AS patients and 76 age - and gender - matched healthy controls were collected in this retrospective study. Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score was used to divide the AS patients into remission group (BASDAI < 4) and active group (BASDAI ≥ 4). The association between FAR and BASDAI was evaluated by Spearman correlation. Receiver operating characteristic (ROC) curve was made to determine the area under curve (AUC) value. The prognostic value of FAR in the AS disease activity was tested by multivariate logistical regression analyses., Results: AS patients showed higher FAR levels than the controls (P < 0.001). FAR was also increased in active group of AS patients than those in inactive group (P < 0.001). Spearman analyses showed that FAR was positively related with BASDAI (r = 0.594, P < 0.001) in AS patients. ROC curve analyses revealed that the AUC of FAR was higher than ALB and Fib. In addition, the optimal cutoff value of FAR for AS diagnosis was 78.84, with a specificity of 88.2% and sensitivity of 77.0%. Logistical regression analyses showed that FAR (odds ratio = 13.091, 95% confidence interval: 4.686-36.571, P < 0.001) was a predictor for AS disease activity., Conclusions: FAR was increased in AS and may act as a novel inflammatory parameter for mirroring disease activity in AS., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)

In this study, we aimed to examine the effect of vitamin D deficiency on all-cause mortality in ankylosing spondylitis (AS) patients and in the general population. This is a retrospective-cohort study based on the electronic database of the largest health-maintenance organization in Israel. AS patients who were first diagnosed between 2002-2007 were included. Controls were matched by age, gender and enrollment-time. Follow-up continued until death or end of study follow-up on 1 July 2019. Laboratory measures of serum 25-hydroxyvitamin-D levels during the entire follow-up period were obtained. A total of 919 AS patients and 4519 controls with a mean time of follow-up of 14.3 years were included. The mean age at the time of enrollment was 52 years, and 22% of them were females. AS was associated with a higher proportion of vitamin D deficiency (odds ratio 1.27 [95% confidence-interval (CI) 1.03-1.58]). In AS patients, insufficient levels of vitamin D (< 30 ng/mL) were significantly associated with increased incidence of all-cause mortality (hazard ratio (HR) 1.59 [95% CI 1.02-2.50]). This association was more prominent with the decrease in vitamin D levels (< 20 ng/mL, HR 1.63 [95% CI 1.03-2.60]; <10 ng/mL, HR 1.79 [95% CI 1.01-3.20]) and among male patients (< 30 ng/mL, HR 2.11 [95% CI 1.20-3.72]; <20 ng/mL, HR 2.12 [95% CI 1.19-3.80]; <10 ng/mL, HR 2.23 [95% CI 1.12-4.43]). However, inadequate levels of vitamin D among controls were not associated with an increased all-cause mortality. Our study has shown that vitamin D deficiency is more common in AS patients than controls and is linked to an increased risk for all-cause mortality. These results emphasize the need for randomized-controlled trials to evaluate the benefits of vitamin D supplementation as a secondary prevention of mortality in patients with chronic inflammatory rheumatic disease., Competing Interests: The authors declare no conflict of interest.