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This study aimed to investigate whether the influenza annual outbreak in Korea is related to hospitalisation-related flares in systemic lupus erythematosus (SLE) patients.The weekly frequency of hospitalisation-related SLE flares (2012-2015) was collected from the Korean National Health Insurance claim database. The weekly laboratory-confirmed detection rate of influenza infection was obtained from the Korea Centers for Disease Control and Prevention database. A generalised linear model was used to examine the relative risks (RRs) of hospitalisation-related SLE flares associated with influenza infection, after adjusting for time trends and meteorological data.A total of 2,223 hospitalisation-related SLE flares were analysed. An interquartile range (24.5%) increase in influenza infection was associated with a 14.0% increase in hospitalisation-related SLE flares (RR, 1.14; 95% confidence interval [CI]: 1.04-1.25; p=0.006). In addition, influenza infections at lag 0-1 (over 2 weeks including concurrent and 1 previous week) and lag 0-2 (over 3 weeks including concurrent and 2 previous weeks) were associated with increase in hospitalisation-related SLE flares (RR, 1.14; 95% confidence interval [CI]: 1.03-1.26; p=0.014 and RR, 1.13; 95% CI: 1.02-1.26; p=0.023). Significant associations were especially observed in women (RR, 1.15; 95% CI: 1.15-1.16; p=0.006) and immunosuppressant (RR, 1.26; 95% CI: 1.26-1.27; p0.001) or glucocorticoid recipients (RR, 1.17, 95% CI: 1.16-1.17; p=0.004).This study shows a significant association between seasonal influenza infection and flares in SLE patients, which suggests influenza can be a novel environmental risk factor for SLE flares.

Pyoderma gangrenosum (PG) is a rare inflammatory skin disease that is difficult to diagnose. PG may be an extra-intestinal manifestation of ulcerative colitis (UC). In recent times, coronavirus disease (COVID-19) vaccines have caused various adverse cutaneous reactions. However, to the best our knowledge, combinations thereof have not been reported. We encountered a case of PG triggered by COVID-19 vaccination in a patient with UC. A 40-year-old woman developed severe pain and an abscess in the dorsum of the left foot after receiving the first dose of the messenger RNA (mRNA)-based Pfizer/BioNTech BNT162b2 COVID-19 vaccine. Severe painful ulcers with purulent necrosis and gaseous gangrene progressed rapidly along the extensor tendons and muscles to the toes and ankle. Although surgical debridement can worsen PG by triggering pathergy, we nonetheless performed wide debridement including partial extensor tenotomy with abscess drainage to prevent progression to pyogenic ankle arthritis and to rescue the toes. Antibiotics, corticosteroids, and anticoagulants were prescribed during surgical wound management via negative pressure therapy. After the lesion improved, the skin and soft tissue defect were covered using a superficial circumflex iliac artery perforator free flap and a split-thickness skin graft. The patient was satisfied with the foot salvage, and could walk unaided (without a brace or cane) from 8 weeks after the final surgery. PG may be rare even in UC patients, but mRNA-based COVID-19 vaccines may find an immunosuppressive niche. A high level of caution and suspicion of skin manifestations after vaccination is essential.

Objective: Disturbances of diastolic function precede systolic heart failure and, although clinically silent, represent the earliest sign of cardiac involvement. Diastolic dysfunction (DD) is associated with age, gender (female), and hypertension. However, little is known about the age-specific incidence rates and risk factors for DD in patients with rheumatoid arthritis (RA).Methods: We used standard two-dimensional/Doppler echocardiography to screen for the presence of diastolic dysfunction in 61 patients with RA and 107 healthy subjects. All participants were premenopausal women with no history of hypertension. DD includes an impaired relaxation with or without increased left ventricular (LV) filling pressures, pseudonormal filling and restrictive filling based on parameters measured using echocardiography.Results: The two groups were similar with respect to age (P=0.269). Patients with RA had significantly higher LV mass index, LV filling pressure, and lower E/A velocity than controls. All patients had preserved ejection fraction (EF ≥50%). DD was more common in patients with RA at 47% compared to 26% in the controls (P=0.004). Women with RA in the 30- to 49- year age range were over 3.5 times more likely to have DD than those of similar age in the control group (OR=3.54; 95% CI 1.27 to 9.85). Among patients with RA, high CRP levels were independently associated with DD even after adjustment for cardiovascular risk factors (P=0.009).Conclusions: In premenopausal women with RA, DD is much more common and the age of onset is reduced. Early screening of myocardial function may provide an opportunity for preventing future cardiovascular disease.

Background Disturbances of diastolic function precede systolic heart failure and, although clinically silent, represent the earliest sign of cardiac involvement. Diastolic dysfunction (DD) is associated with age, gender (female), and hypertension. However, little is known about the age-specific incidence rates and risk factors for DD in patients with rheumatoid arthritis (RA). Methods We used standard two-dimensional/Doppler echocardiography to screen for the presence of diastolic dysfunction in 61 patients with RA and 107 healthy subjects. All participants were premenopausal women with no history of hypertension. DD includes an impaired relaxation with or without increased left ventricular (LV) filling pressures, pseudonormal filling, and restrictive filling based on parameters measured using echocardiography. Results The two groups were similar with respect to age (P=0.269). Patients with RA had significantly higher LV mass index, LV filling pressure, and lower E/A velocity than controls. All patients had preserved ejection fraction (EF ≥50%). DD was more common in patients with RA at 47% compared to 26% in the controls (P=0.004). Women with RA in the 30- to 49-year age range were over 3.5 times more likely to have DD than those of similar age in the control group (OR=3.54; 95% CI 1.27 to 9.85). Among patients with RA, high CRP levels were independently associated with DD even after adjustment for cardiovascular risk factors (P=0.009). Conclusions In premenopausal women with RA, DD is much more common and the age of onset is reduced. Early screening of myocardial function may provide an opportunity for preventing future cardiovascular disease.

Machine learning is applied to characterize the risk and predict outcomes in multi-dimensional data. The prediction of radiographic progression in axial spondyloarthritis (axSpA) remains limited. Hence, we tested the feasibility of supervised machine learning algorithms to predict radiographic progression in axSpA.This is a retrospective and hospital-based study. Clinical and laboratory data obtained from two independent axSpA groups were used as training and testing datasets. Radiographic progression over 2 years was assessed using the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) and mSASSS worsening by ≥ two units was defined as progression. Seven machine learning models with different algorithms were fitted, and their performance for the testing dataset was assessed using receiver-operating characteristic (ROC) and precision-recall (PR) curve.The training and testing groups had equivalent characteristics, and radiographic progression was identified in 25.3% and 23.7%, respectively. The generalized linear model (GLM) and support vector machine (SVM) were the top two best-performing models with an average area-under-curve (AUC) of ROC of over 0.78. SVM had the higher AUC of PR compared with GLM (0.56 versus 0.51). Balanced accuracy was over 65% in all models. mSASSS was the most informative variable, followed by the presence of syndesmophyte(s) at the baseline and sacroiliac joint grades.Clinical and radiographic data-driven predictive models showed reasonable performance in the prediction of radiographic progression in axSpA. Further modelling with larger and more detailed data could provide an excellent opportunity for the clinical translation of the predictive models to the management of high-risk patients.Key Points• Clinical and radiographic data-driven predictive models showed reasonable performance in the prediction of radiographic progression in axSpA.• Further modelling with larger and more detailed data could provide an excellent opportunity for the clinical translation of the predictive models to the management of high-risk patients.

In patients with systemic lupus erythematosus (SLE), there are concerns that infections may increase the risk of flares. We evaluated the association between influenza infection and SLE flares resulting in hospitalization. SLE flares resulting in hospitalization and influenza cases were ascertained from the Korean national healthcare insurance database (2014–2018). We used a self-controlled case series design. We defined the risk interval as the first 7 days after the influenza index date and the control interval was defined as all other times during the observation period of each year. We estimated the incidence rates of SLE flares resulting in hospitalization during the risk interval and control interval and compared them using a Poisson regression model. We identified 1624 influenza infections among the 1455 patients with SLE. Among those, there were 98 flares in 79 patients with SLE. The incidence ratio (IR) for flares during the risk interval as compared with the control interval was 25.75 (95% confidence interval 17.63–37.59). This significantly increased the IRs for flares during the risk interval in both women (IR 27.65) and men (IR 15.30), all age groups (IR 17.00–37.84), with and without immunosuppressive agent (IR 24.29 and 28.45, respectively), and with and without prior respiratory diseases (IR 21.86 and 26.82, respectively). We found significant association between influenza infection and SLE flares resulting in hospitalization. Influenza infection has to be considered as a risk factor for flares in all SLE patients regardless of age, sex, medications, and comorbidities.

Rheumatoid arthritis (RA) patients may benefit from exercise for several reasons. However, whole-limb strengthening exercises for such patients remain poorly studied. We hypothesized that systemic strength training that includes the upper and lower extremities would improve strength per se and enhance the quality of life. Here, we investigated the effects of 12 weeks of upper- and lower-limb strengthening exercise on the strength and quality of life of RA patients using the International Classification of Functioning, Disability, and Health model. This was a prospective, interventional controlled trial. Forty female RA patients were recruited and assigned to two groups not based on willingness to exercise, with 20 patients in the exercise group and 20 in the control group. All patients in the exercise group received once-weekly training sessions of 60 min over 12 weeks. All participants were assessed before and after the 12-week intervention period. We measured the hand grip strength and isometric quadriceps contraction, the cross-sectional area of the rectus femoris (CSA-RF) (via ultrasonography), and performed the 30 s sit-to-stand test and the 6 min walk test (6MWT). We derived the Borg scale score after the 6MWT and assessed the extent of social participation and quality of life using a Korean version of the 36-Item Short Form Health Survey (SF-36). A total of 35 subjects completed the experiment (18 in the exercise group, 17 in the control group). After the 12-week intervention period, the lower-limb strength and the CSA-RF were significantly increased in the exercise group. The activity level did not change significantly in either group. The exercise group exhibited significant improvements in the SF-36 mental health domain scores. Thus, strengthening exercise is useful for patients with RA.

ObjectivesTo summarise radiographic data in randomised controlled trials (RCTs) as part of the radiographic inhibition claim of disease-modifying antirheumatic drugs (DMARDs) approved for patients with rheumatoid arthritis (RA).MethodsA systemic literature review was performed using the Medline database from 1994 to February 2020. The results were grouped based on the scoring methods (Sharp, Genant modification, van der Heijde modification) and RA patient populations.ResultsOne hundred sixty-eight publications were selected. After detailed assessment, 52 RCTs (7 methotrexate (MTX)-naive, 23 MTX inadequate response (IR), 9 DMARDs IR and 3 tumour necrosis factor-alpha inhibitors (TNFi) IR studies) were finally included. Information on patient population, scoring method used, reader reliability, statistical analyses and detailed radiographic data on baseline and change scores over multiple follow-up periods are presented.ConclusionThe data gathered in this review serve as a repository for the design of future trials with radiographic damage as an outcome.

Despite recent advances in understanding chronic inflammation remission, global analyses have not been explored to systematically discover genes or pathways underlying the resolution dynamics of chronic inflammatory diseases. Here, we performed time-course gene expression profiling of mouse synovial tissues along progression and resolution of collagen-induced arthritis (CIA) and identified genes associated with inflammation resolution. Through network analysis of these genes, we predicted 3 key secretory factors responsible for the resolution of CIA: Itgb1, Rps3, and Ywhaz. These factors were predominantly expressed by Tregs and antiinflammatory M2 macrophages, suppressing production of proinflammatory cytokines. In particular, Ywhaz was elevated in the sera of mice with arthritis resolution and in the urine of rheumatoid arthritis (RA) patients with good therapeutic responses. Moreover, adenovirus-mediated transfer of the Ywhaz gene to the affected joints substantially inhibited arthritis progression in mice with CIA and suppressed expression of proinflammatory cytokines in joint tissues, lymph nodes, and spleens, suggesting Ywhaz is an excellent target for RA therapy. Therefore, our comprehensive analysis of dynamic synovial transcriptomes provides previously unidentified antiarthritic genes, Itgb1, Rps3, and Ywhaz, which can serve as molecular markers to predict disease remission, as well as therapeutic targets for chronic inflammatory arthritis.

The pregnancy rate in systemic lupus erythematosus (SLE) is not fully understood and comparisons of adverse pregnancy outcomes (APOs) with SLE versus the general population are limited. This study aimed to estimate the pregnancy rate and APOs in Korean SLE compared to those without SLE.Pregnant women were identified using the ICD-10 codes for delivery and abortion in the Korean national health claims database (2013-2015). APOs were classified as fetal loss, intrauterine growth retardation (IUGR), pre-eclampsia/eclampsia, and gestational diabetes. Annual incidence rates (IRs) of pregnancy and APOs were calculated in women with SLE and the general population without SLE and the two groups were compared using age-adjusted incidence rate ratios (IRRs). Age-stratified IRRs were further analyzed.The annual IRs of pregnancy in SLE were 29.54-30.70 per 1000 persons. The IRRs were lower in women with SLE than in the general population: 0.68 (0.61-0.76), 0.66 (0.60-0.74), and 0.74 (0.66-0.82) in each respective year. The IRRs of fetal loss, IUGR, and pre-eclampsia/eclampsia were 1.30 (1.14-1.49), 4.65 (3.55-6.09), and 3.43 (2.70-4.36), respectively. However, the IRR of gestational diabetes in SLE did not significantly differ from that of women without SLE. Among the APOs, fetal loss, IUGR, and pre-eclampsia/eclampsia showed decreasing tendencies as age increased.Pregnancy rates in SLE were approximately 30% lower than those in the general population. Except for gestational diabetes, fetal loss, IUGR, and pre-eclampsia/eclampsia were higher in SLE and showed a decreasing tendency with age. Key Points • This population-based cohort study showed that pregnancy rates in SLE were approximately 30% lower than those in the general population. • SLE had a 1.3-fold higher rate of fetal loss, more than 4-fold higher IUGR rate, and more than 3-fold pre-eclampsia or eclampsia rate compared with the general population. • Adverse pregnancy outcomes in SLE showed a decreasing tendency with age.

Nuclear factor of activated T cells 5 (NFAT5) has been implicated in the pathogenesis of various human diseases, including cancer and arthritis. However, therapeutic agents inhibiting NFAT5 activity are currently unavailable. To discover NFAT5 inhibitors, a library of > 40,000 chemicals was screened for the suppression of nitric oxide, a direct target regulated by NFAT5 activity, through high-throughput screening. We validated the anti-NFAT5 activity of 198 primary hit compounds using an NFAT5-dependent reporter assay and identified the novel NFAT5 suppressor KRN2, 13-(2-fluoro)-benzylberberine, and its derivative KRN5. KRN2 inhibited NFAT5 upregulation in macrophages stimulated with lipopolysaccharide and repressed the formation of NF-κB p65-DNA complexes in the NFAT5 promoter region. Interestingly, KRN2 selectively suppressed the expression of pro-inflammatory genes, including Nos2 and Il6, without hampering high-salt-induced NFAT5 and its target gene expressions. Moreover, KRN2 and KRN5, the latter of which exhibits high oral bioavailability and metabolic stability, ameliorated experimentally induced arthritis in mice without serious adverse effects, decreasing pro-inflammatory cytokine production. Particularly, orally administered KRN5 was stronger in suppressing arthritis than methotrexate, a commonly used anti-rheumatic drug, displaying better potency and safety than its original compound, berberine. Therefore, KRN2 and KRN5 can be potential therapeutic agents in the treatment of chronic arthritis., Highlights • We identify a novel NFAT5 suppressor KRN2, 13-(2-fluoro)-benzylberberine, and its derivative KRN5 to inhibit NFAT5 activity. • KRN2 inhibits the transcriptional activation of NFAT5 and the pro-inflammatory responses. • KRN2 and KRN5 suppress experimentally induced arthritis in mice. NFAT5 has been implicated in the pathogenesis of arthritis. However, therapeutic agents specifically inhibiting NFAT5 activity are currently unavailable. To discover NFAT5 inhibitors, a library of > 40,000 chemicals was screened, leading to the discovery of novel berberine-based NFAT5 suppressors, KRN2 and its oral derivative KRN5. KRN2 inhibited the transcriptional activation of NFAT5 by blocking NF-κB binding to the NFAT5 promoter region, thereby reducing the expression of pro-inflammatory genes. Moreover, KRN2 and KRN5 ameliorated experimentally induced arthritis in mice without serious adverse effects. Therefore, we propose that KRN2 and KRN5 may be potential therapeutic agents in the treatment of chronic arthritis.

Defective apoptotic death of activated macrophages has been implicated in the pathogenesis of rheumatoid arthritis (RA). However, the molecular signatures defining apoptotic resistance of RA macrophages are not fully understood. Here, global transcriptome profiling of RA macrophages revealed that the osmoprotective transcription factor nuclear factor of activated T cells 5 (NFAT5) critically regulates diverse pathologic processes in synovial macrophages including the cell cycle, apoptosis, and proliferation. Transcriptomic analysis of NFAT5-deficient macrophages revealed the molecular networks defining cell survival and proliferation. Proinflammatory M1-polarizing stimuli and hypoxic conditions were responsible for enhanced NFAT5 expression in RA macrophages. An in vitro functional study demonstrated that NFAT5-deficient macrophages were more susceptible to apoptotic death. Specifically, CCL2 secretion in an NFAT5-dependent fashion bestowed apoptotic resistance to RA macrophages in vitro. Injection of recombinant CCL2 into one of the affected joints of Nfat5+/– mice increased joint destruction and macrophage infiltration, demonstrating the essential role of the NFAT5/CCL2 axis in arthritis progression in vivo. Moreover, after intra-articular injection, NFAT5-deficient macrophages were more susceptible to apoptosis and less efficient at promoting joint destruction than were NFAT5-sufficient macrophages. Thus, NFAT5 regulates macrophage survival by inducing CCL2 secretion. Our results provide evidence that NFAT5 expression in macrophages enhances chronic arthritis by conferring apoptotic resistance to activated macrophages.

Background We aimed to investigate the effects of ambient respiratory viral infections in the general population on rheumatoid arthritis (RA) development. Methods Data of weekly incident RA (2012–2013) were obtained from the Korean National Health Insurance claims database, and those of weekly observations on eight respiratory viral infections were obtained from the Korea Centers for Disease Control and Prevention database. We estimated the percentage change in incident RA associated with ambient mean respiratory viral infections using a generalized linear model, after adjusting for time trend, air pollution, and meteorological data. Results A total of 24,117 cases of incident RA (mean age 54.7 years, 18,688 [77.5%] women) were analyzed. Ambient respiratory viral infections in the population were associated with a higher number of incident RA over time, and its effect peaked 6 or 7 weeks after exposure. Among the 8 viruses, parainfluenza virus (4.8% for 1% respiratory viral infection increase, 95% CI 1.6 to 8.1, P = .003), coronavirus (9.2%, 3.9 to 14.8, P

Background Antibody against cyclic citrullinated proteins (ACPA) is counted as one of the most important biomarkers in diagnosis, classification, and prognosis of rheumatoid arthritis (RA). The clinical implications of change in ACPA level over time remain undetermined. Objectives We examined the evolution of ACPA during disease course and assess predictive value of time-weighted cumulative ACPA titer on radiographic progression in patients with RA. Methods A group of 734 patients with RA was followed longitudinally over 2 years, with annual measurements of IgM rheumatoid factor (RF) and ACPA. Radiographs of the hands were scored with the modified Sharp score (SHS). Cumulative ACPA antibody titers were calculated using the trapezoidal rule. Results The patients with radiographic progression had a higher SHS at baseline; and smoking status, diabetes, RF positivity, and use of biologic DMARDs were independently associated with radiographic progression (all P Conclusion High cumulative ACPA titer was an independent predictor for accelerated radiographic progression, especially with initiation of joint damage. Serial measurement of ACPA titer can provide information about its dynamics over the clinical course and can facilitate an additional assessment of radiographic progression. Acknowledgement Nothing specified. Disclosure of Interests None declared

Background: Systemic lupus erythematosus (SLE) can affect people of all ages, but it occurs most often during childbearing ages. It has been documented that the fertility rates in women with SLE is similar to those without SLE. On the other hand, the pregnancy adverse outcomes are common in pregnant women with SLE. However, the pregnancy rates in women with SLE was not fully understood. In addition, comparison of the pregnancy adverse outcomes with general population is limited. Objectives: We estimated the pregnancy rates and adverse pregnancy outcomes in Korean women with SLE and compared them with women without SLE. Methods: Among all women aged 15-49 years in the Korean National Health Insurance claim database from January 2013 to December 2015, pregnant women were identified by using ICD-10 code for delivery and abortion. Pregnant women were categorized into women with SLE and control group. Adverse pregnancy outcomes classified into five categories as follows: fetal loss, intrauterine growth retardation (IUGR), preterm delivery, pre-eclampsia or eclampsia, and gestational diabetes mellitus. Crude incidence rates (IRs) of pregnancy and adverse pregnancy outcomes were calculated. Incidence rate ratios (IRRs) of those were estimated and adjusted for age. Results: In SLE, 994 pregnancy cases were observed during the study period. The crude estimated IRs of pregnancy were lower in SLE patients than general population (Table 1). Age-adjusted IRR was also lower in SLE patients (Table1). The adjusted-IRR of live birth in SLE pregnant women was 0.92 (95% CI 0.85 - 0.99) compared with control group. The adjusted-IRR of fatal loss, IUGR, and preterm delivery was 1.27 (95% CI 1.11 - 1.45), 4.52 (95% CI 3.45 - 5.91), and 3.25 (95% CI 1.62 - 6.52), respectively. The IRR of pre-eclampsia or eclampsia was 3.21 (95% CI 2.52 - 4.08), but those of gestational diabetes mellitus was not significant (IRR 0.89, 95% CI 0.80 - 1.00). Conclusion: Pregnancy rates in SLE women were lower about 30% compared with general population. Pregnancy adverse outcomes were higher in SLE pregnant women with more than 4-fold IUGR and pre-eclampsia/eclampsia, 3.2-fold preterm delivery. References: [1] EULAR recommendations for women’s health and the management of family planning, assisted reproduction, pregnancy and menopause in patients with systemic lupus erythematosus and/or antiphospholipid syndrome. Ann Rheum Dis. 2017 Mar;76(3):476-485. Disclosure of Interests: None declared

Table S1. Payer type and institutions of patients newly diagnosed with rheumatoid arthritis in 2012 or 2013. Table S2. Monthly and weekly number of Incident RA. Figure S1. Incident rheumatoid arthritis trends according to sex in 2012 and 2013. Figure S2. The weekly detection rate of eight respiratory virus in 2012 and 2013. Figure S3. Risks of incident RA associated with infection with eight respiratory viruses over 8 lag weeks. (DOCX 1539 kb)

Antibody against cyclic citrullinated protein (ACPA) is counted as one of the most important biomarkers in diagnosis, classification, and prognosis of rheumatoid arthritis (RA). We examined the evolution of ACPA during disease course and assess predictive value of time-weighted cumulative ACPA titer on radiographic progression in RA patients. A group of 734 patients with RA was followed longitudinally over 2 years, with annual measurements of ACPA. The cumulative titers of ACPA were calculated using the trapezoidal rule and were divided into three categories: negative, low-to-moderate, and high. Radiographs of the hands were scored with the modified Sharp score (SHS). Multivariable logistic regression models were performed to identify independent predictors over follow-up for individual patients with different combinations of risk factors. The effect size was computed by Cohen’s d method. The patients with radiographic progression had a higher SHS at baseline; and smoking status, diabetes, RF positivity, and use of biologic DMARDs were independently associated with radiographic progression (all P

Recent studies have shown that a combination treatment of mycophenolate mofetil (MMF) and tacrolimus (TAC) may be an option for lupus nephritis (LN) patients that do not adequately respond to initial treatment. We evaluated the efficacy and safety of the combination treatment of MMF and TAC in LN patients with suboptimal response to prior MMF or TAC treatments.In this multicentre study, we retrospectively enrolled 62 patients with class III, IV, or V LN who inadequately responded to MMF or TAC treatment. Those patients were then treated with a combination of MMF and TAC for 6 months. The primary outcome was complete remission (CR) at 6 months, and secondary outcomes included overall response and adverse events.After 6 months of treatment with the drug combination, CR was achieved in 14 of 62 patients (22.6%), and 35 (56.5%) patients responded. A significant reduction in proteinuria and lupus disease activity score was observable after 3 months. After 1 year, the CR rate increased to 36.4% (20 of 55 patients), and the overall response rate (n=38, 69.1%) also increased from 6 months. Twenty-one patients reported 29 adverse events, including severe infection requiring hospitalisation (n=3, 10.3%), infection not requiring hospitalisation (n=2, 6.9%), and herpes zoster (n=4, 13.8%).Our findings suggest that a combined MMF and TAC treatment, with a favourable adverse-event profile, may be a beneficial option for LN patients with inadequate response to either MMF or TAC treatments.

Although rheumatoid arthritis (RA) is the most common chronic inflammatory autoimmune disease, diagnosis of RA is currently based on clinical manifestations, and there is no simple, practical assessment tool in the clinical field to assess disease activity and severity. Recently, there has been increasing interest in the discovery of new diagnostic RA biomarkers that can assist in evaluating disease activity, severity, and treatment response. Proteomics, the large-scale study of the proteome, has emerged as a powerful technique for protein identification and characterization. For the past 10 years, proteomic techniques have been applied to different biological samples (synovial tissue/fluid, blood, and urine) from RA patients and experimental animal models. In this review, we summarize the current state of the application of proteomics in RA and its importance in identifying biomarkers and treatment targets.

Current serum biomarkers for rheumatoid arthritis (RA) are not highly sensitive or specific to changes of disease activities. Thus, other complementary biomarkers have been needed to improve assessment of RA activities. In many diseases, urine has been studied as a window to provide complementary information to serum measures. Here, we conducted quantitative urinary proteome profiling using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and identified 134 differentially expressed proteins (DEPs) between RA and osteoarthritis (OA) urine samples. By integrating the DEPs with gene expression profiles in joints and mononuclear cells, we initially selected 12 biomarker candidates related to joint pathology and then tested their altered expression in independent RA and OA samples using enzyme-linked immunosorbent assay. Of the initial candidates, we selected four DEPs as final candidates that were abundant in RA patients and consistent with those observed in LC-MS/MS analysis. Among them, we further focused on urinary soluble CD14 (sCD14) and examined its diagnostic value and association with disease activity. Urinary sCD14 had a diagnostic value comparable to conventional serum measures and an even higher predictive power for disease activity when combined with serum C-reactive protein. Thus, our urinary proteome provides a diagnostic window complementary to current serum parameters for the disease activity of RA.

Objective To identify factors influencing endothelial progenitor cell (EPC) counts in patients with rheumatoid arthritis (RA). Methods The number of circulating CD34+/vascular endothelial growth factor receptor 2–positive EPCs was measured in 126 RA patients and 46 non-RA control patients. Endothelial function was assessed by brachial flow-mediated dilation (FMD). Serum CXCL12 concentrations were determined using an enzyme-linked immunosorbent assay. EPCs and FMD were measured at baseline and after 24 weeks of anti–tumor necrosis factor α (TNFα) therapy in 29 patients with active RA. Results The numbers of circulating EPCs were significantly lower in the RA patients than in the non-RA controls. In multivariate analysis, older age, reduced levels of high-density lipoprotein cholesterol, and higher bone erosion scores were independent risk factors for reduced EPC counts in RA patients. Serum CXCL12 levels correlated negatively with EPC counts, but positively with bone erosion scores. FMD was impaired in RA patients, and a decreased FMD in RA was closely associated with a higher bone erosion score and a reduced EPC count. In addition, EPC counts were restored by anti-TNFα therapy, and this increase was paralleled by improvement in FMD. Interestingly, restoration of EPC counts was attenuated in patients with higher bone erosion scores than in those with lower scores, despite similar levels of improvement in disease activity. Conclusion The numbers of circulating EPCs in RA patients are reduced and are inversely correlated with serum levels of CXCL12. Reduced EPC counts are closely associated not only with bone erosion, but also with endothelial dysfunction.

The purpose of this study is to investigate the frequency of the subclinical synovitis in hand or wrist joints of the SLE patients using ultrasonography (US) and to correlate them with clinical parameters. Forty-eight systemic lupus erythematosus (SLE) patients without musculoskeletal (MS) involvement were enrolled and underwent clinical and laboratory examinations. Gray-scale and power Doppler (PD) US was performed for imaging the wrist, second and third metacarpophalangeal (MCP) joints, and flexor tendons on non-dominant sides of the individuals. US synovitis index (USSI) and PD index were calculated as sum of the synovitis and PD semiquantitative scores, respectively, obtained from each joint. Subclinical synovitis was found by US in 28 (58.3 %) out of 48 patients. US revealed synovitis of the wrist in 16 (33.3 %) patients, of the second MCP joint in 14 (29.2 %) and of the third MCP joint in 15 (31.3 %). PD signals in three (6.3 %) patients and tenosynovitis in two (4.2 %) were also detected. USSI scores showed significant positive correlation with erythrocyte sedimentation rate (ESR) levels (r = 0.30, p < 0.05) or anti-dsDNA Ab titers (r = 0.34, p < 0.05). Within 6 months after US examination, new MS symptoms were developed in 11 (22.9 %) patients. Older age at diagnosis (OR 1.283, 95 % CI 1.029–1.601, p = 0.027) or higher USSI scores (OR 12.93, 95 % CI 1.023–163.503, p = 0.048) were independently associated with development of new MS symptoms. Subclinical synovitis is common in SLE patients who do not suffer from MS symptoms. US is useful to detect joint abnormalities before symptoms appear in SLE patients.

Aim To estimate the point prevalence of pulmonary hypertension (PH) and determine the associated factors for PH in patients with systemic lupus erythematosus (SLE). Methods A prospective cross-sectional study of 114 patients with SLE was conducted in a single tertiary center. Transthoracic echocardiography was performed to estimate the pulmonary arterial pressures. PH was defined as resting systolic pulmonary artery pressure (sPAP) ≥ 40 mmHg, in the absence of left heart disease. Results PH was identified in nine patients (7.9%) who had few cardiopulmonary symptoms. SLE patients with PH had higher SLE disease activity index score. In particular, serum uric acid (UA) was significantly higher in patients with PH than in those without PH. In multivariate analysis, UA remained significant for the presence of PH. Moreover, serum UA level correlated significantly with plasma NT-pro-B-type natriuretic peptide level as well as sPAP. At the cutoff level of 6.5 mg/dL, serum UA had reasonable accuracy for predicting the presence of PH in SLE patients (sensitivity 66.7% and specificity 96.2%). Conclusion A significant number of SLE patients in rheumatology practice have undiagnosed PH with few discernible symptoms. Serum UA level may be useful as a surrogate marker for screening of PH in patients with SLE.

Objective. We undertook this study to investigate the discriminant metabolites in urine from patients with established rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and from healthy individuals. Methods. Urine samples were collected from 148 RA patients, 41 SLE patients and 104 healthy participants. The urinary metabolomic profiles were assessed using 1H nuclear magnetic resonance spectroscopy. The relationships between discriminant metabolites and clinical variables were assessed. Collagen-induced arthritis was induced in mice to determine if a choline-rich diet reduces arthritis progression. Results. The urinary metabolic fingerprint of patients with established RA differs from that of healthy controls and SLE patients. Markers of altered gut microbiota (trimethylamine-N-oxide, TMAO), and oxidative stress (dimethylamine) were upregulated in patients with RA. In contrast, markers of mitochondrial dysfunction (citrate and succinate) and metabolic waste products (p-cresol sulfate, p-CS) were downregulated in patients with RA. TMAO and dimethylamine were negatively associated with serum inflammatory markers in RA patients. In particular, patients with lower p-CS levels exhibited a more rapid radiographic progression over two years than did those with higher p-CS levels. The in vivo functional study demonstrated that mice fed with 1% choline, a source of TMAO experienced a less severe form of collagen-induced arthritis than did those fed a control diet. Conclusion. Patients with RA showed a distinct urinary metabolomics pattern. Urinary metabolites can reflect a pattern indicative of inflammation and accelerated radiographic progression of RA. A choline-rich diet reduces experimentally-induced arthritis. This finding suggests that the interaction between diet and the intestinal microbiota contributes to the RA phenotype. (J Rheum Dis 2019;26:46-56)

Objective Elevated serum osteoprotegerin (OPG) levels represent an independent risk factor for atherosclerotic disease, although the underlying mechanism is not clear. The aim of this study was to investigate the association of serum OPG levels and circulating endothelial progenitor cell (EPC) numbers, and to explore the effect of OPG on EPC apoptosis and its underlying mechanisms. Methods Flow cytometry was used to enumerate EPCs in the peripheral blood of 91 patients with systemic lupus erythematosus (SLE). Cultured EPCs, isolated from peripheral blood, were challenged with OPG, and apoptosis was evaluated by TUNEL staining. Expression of apoptosis-related proteins was measured by real-time quantitative polymerase chain reaction (qPCR) and Western blotting. Reactive oxygen species (ROS) were detected by flow cytometry, and the expression of NADPH oxidase (NOX) and MAP kinases (MAPK) was measured by qPCR and Western blotting. Results The serum OPG level was independently associated with reduced numbers of EPCs in patients with SLE. In vitro treatment with OPG significantly induced apoptosis of EPCs; this effect was mediated by syndecan 4. OPG-induced apoptosis was abolished by the ROS scavenger N-acetylcysteine and the NOX inhibitor diphenyleniodonium. OPG increased ROS production through activation of NOX-2 and NOX-4 and triggered phosphorylation of ERK-1/2 and p38 MAPK. Quenching of ROS by knockdown of NOX-2 or NOX-4 transcripts inhibited phosphorylation of ERK-1/2 and p38 MAPK. Moreover, inhibitors of ERK-1/2 and p38 MAPK decreased ROS production and subsequent EPC apoptosis, indicating a feed-forward loop between NOX and MAPK to amplify ROS production related to apoptosis. Conclusion Elevated OPG levels increase apoptosis of EPCs by induction of oxidative stress.

Objective.Dyslipidemia, a risk factor for cardiovascular diseases, is more prevalent in patients with rheumatoid arthritis (RA) than in the general population. We investigated whether single-nucleotide polymorphisms (SNP) modulating low-density lipoprotein (LDL) cholesterol affect susceptibility, severity, and progression of RA.Methods.We enrolled 302 patients with RA and 1636 healthy controls, and investigated the SNP modulating LDL cholesterol. Clinical characteristics of RA, serum adipocytokine concentrations, and radiographic severity were analyzed according to genotype score based on the number of unfavorable alleles. The influence of genotype score on radiographic progression was also investigated using multivariable logistic models.Results.We identified 3 SNP (rs688, rs693, and rs4420638) modulating LDL cholesterol in Koreans, which correlated well with LDL cholesterol levels in both patients with RA and controls. Among them, 2 SNP, rs688 and rs4420638, were more prevalent in patients with RA than in controls. In patients with RA carrying more unfavorable alleles (genotype score ≥ 3), disease activity measures, serum adipocytokine levels, and radiographic severity were all increased. The genotype score was an independent risk factor for radiographic progression of RA over 2 years, and its effect was greater than the influence of conventional risk factors.Conclusion.SNP modulating LDL cholesterol influence the risk, activity, and severity of RA. These results provide the first evidence that genetic mechanisms linked to dyslipidemia may directly contribute to the susceptibility and prognosis of RA, a representative of chronic inflammatory diseases, explaining the high incidence of dyslipidemia in RA.

Previously, we demonstrated that the urine proteome signature of patients with rheumatoid arthritis (RA) reflects inflammation-related cellular processes. Here, we measured interleukin (IL)-6, IL-8, and chemokine ligand 2 (CCL2) concentrations in the urine of RA patients and prospectively investigated their role in predicting RA activity and prognosis. One hundred seventy-three RA patients and 62 non-RA controls were recruited. Urinary IL-6, CCL2, and IL-8 levels were elevated in RA patients and correlated well with disease activity. Urinary IL-6 level at presentation was an independent risk factor of radiographic progression at 1 and 3 years. High urinary IL-6 level increased the risk ratio of radiographic progression by 2.9-fold, which was comparable to high serum CRP. Moreover, combination of urinary IL-6 and serum CRP measures synergistically increased the predictability of radiographic progression. In a subgroup with normal ESR, patients with the highest tertile of urinary IL-6 were at 6.4-fold greater risk of radiographic progression. Conclusively, high urinary IL-6 level at presentation is an independent risk factor for radiographic progression of RA, reflecting disease activity. Urinary IL-6 in combination with serum CRP may be a useful parameter for estimating RA prognosis.