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ObjectiveThe human major histocompatibility complex class I chain-related gene A (MICA) controls the immune process by balancing activities of  natural killer cells, γδ T cells and αβ CD8 T cells, and immunosuppressive CD4 T cells. MICA is located near HLA-B on chromosome 6. Recent genomewide association studies indicate that genes most strongly linked to ankylosing spondylitis (AS) susceptibility come from the region containing HLA-B and MICA. While HLA-B27 is a well-known risk genetic marker for AS, the potential effect of linkage disequilibrium (LD) shields any associations of genes around HLA-B with AS. The aim of this study was to investigate a novel independent genetic association of MICA to AS.MethodsWe examined 1543 AS patients and 1539 controls from two ethnic populations by sequencing MICA and genotyping HLA-B alleles. Initially, 1070 AS patients and 1003 controls of European ancestry were used as a discovery cohort, followed by a confirmation cohort of 473 Han Chinese AS patients and 536 controls. We performed a stratified analysis based on HLA-B27 carrier status. We also conducted logistic regression with a formal interaction term.ResultsSequencing of MICA identified that MICA*007:01 is a significant risk allele for AS in both Caucasian and Han Chinese populations, and that MICA*019 is a major risk allele in Chinese AS patients. Conditional analysis of MICA alleles on HLA-B27 that unshielded LD effect confirmed associations of the MICA alleles with AS.ConclusionsParallel with HLA-B27, MICA confers strong susceptibility to AS in US white and Han Chinese populations.

Objective To explore whether the variants in non MHC proteasome gene are associated with AS and explain the role of the variant in the disease. Material and methods Case-control analysis to identify AS predisposition genes; dual-luciferase reporter assay, immunoblot analysis and osteoclastogenesis assays to detect the function of the positive variant. Affected individuals were diagnosed according to the modified New York Criteria by at least two experienced rheumatologists, and rechecked by another rheumatologist. Results The study included 1037 AS patients and 1014 no rheumatic and arthritis disease controls. The main age of AS onset is between 16 and 35 years old. HLA-B27-positive subjects comprised 90.0% of patients. A nonsynonymous SNP rs12717 in proteasome gene PSMB1 significantly associated with AS. Individuals with CC genotype had a higher onset risk compared with those with GG/GC genotypes (OR = 1.89, P  = 0.0047). We also discovered that PSMB1 regulates the receptor activator of nuclear factor-κB (RANK)/RANK ligand (RANKL) signalling pathway and the disease-associated variant PSMB1-Pro11 significantly inhibits RANKL-induced NF-κB pathway in osteoclast differentiation via the degradation of IKK-β compared with PSMB1-Ala11. RANKL induced osteoclast differentiation was significantly lower in primary monocyte osteoclast precursor from individuals with genotype PSMB1 31C/31C compared with individuals with genotype PSMB1 31G/31G . Conclusions These results reveal a novel understanding of the bone formation and reabsorbing imbalance in AS. The new bone formation phenotype can be attributed to the inhibition of osteoclast differentiation by a more functional PSMB1 gene. [ABSTRACT FROM AUTHOR]

Taken together, the percentages of MS2 cells were decreased in AS patients and might be recovered by TNF- blockers treatment in the good responders but not the poor responders, suggesting that MS2 cell proportion could be a potential indicator to the response to TNF- blocker treatment and MS2 cells might be beneficial for AS treatment. Data of NS5 are shown in Supporting Information figures gl In conclusion, we profiled the transcriptional landscape of monocytes and NK cells, which are two pivotal cell types of innate immunity in AS at single-cell resolution. Monocytes and NK cells were isolated from peripheral blood mononuclear cells using magnetic beads with high specificity (Supporting Information). Notably, the proportion of NS2 cells (FCER1G SP - sp FCGR3A SP + sp NK cells, similar to memory-like NK cells) differed significantly between AS patients and healthy controls and might serve as a potential indicator for AS (Figure 3C). [Extracted from the article]

Objectives: MRI is an important tool for evaluating inflammation levels and assessing treatment response in patients with ankylosing spondylitis (AS). However, it is expensive and requires experienced physicians. The goal of this study was to identify a biomarker correlated with the MRI score. Methods: A total of 558 spondyloarthritis (SpA) patients including 527 AS patients, 10 psoriasis (PsA) patients, and 21 non-radiographic SpA (nr-SpA) patients and 725 controls were enrolled for the studies. Plasma IgG galactosylation (IgG-Gal) level was measured by mass spectrometry. Clinical indexes such as Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and C-reactive protein (CRP) were measured in all AS patients. MRIs and X-rays were obtained from 65 AS patients who were followed up for 6 months. Results: The IgG-Gal ratio was twice as high in the AS patients compared with the controls. It correlated with inflammation indices which is evaluated by MRI according to SPARCC. (Pearson coefficient/p value was 0.6/7E10−6). In addition, AS patients with a higher IgG-Gal ratio at baseline tended to show greater improvement in inflammation scores by MRI both in 3-month follow-up and 6-month follow-up. Conclusion: The IgG-Gal ratio was significantly increased in AS patients. In clinical care, it may be used as a potential biomarker for diagnosis in the future. Key Points • IgG galactosylation level was abnormal in SpA patients. • IgG galactosylation level was associated with MRI indices. [ABSTRACT FROM AUTHOR]

The article discusses a study on a rare but high-risk pathogenic variants within several ankylosing spondylitis (AS) families by whole-exome sequencing and whether the rare variants exist in a larger sample population. Topics include clinical characteristics and relationships of six patients in the study from different families, finding on the number of osteoclasts present in the sample treated with interferon (IFN)ß stimulation, and mutant that plays a pathogenic role in AS.

Common polymorphisms of microRNA gene MIR146A were reported as associated with different autoimmune diseases, include systemic lupus erythematosus, psoriatic arthritis, asthma and ankylosing spondylitis. In this study we investigated MIR146A SNPs in Chinese people with ankylosing spondylitis. Three common SNPs: rs2910164, rs2431697 and rs57095329 were selected and genotyped in 611 patients and 617 controls. We found no association between these SNPs and ankylosing spondylitis in our samples. [ABSTRACT FROM AUTHOR]

Background: Tumor necrosis factor (TNF) blockers have a high efficacy in treating Ankylosing Spondylitis (AS), yet up to 40% of AS patients show poor or even no response to this treatment. In this paper, we aim to build an approach to predict the response prior to clinical treatment. Methods: AS patients during the active progression were included and treated with TNF blocker for 3 months. Patients who do not fulfill ASASAS40 were considered as poor responders. The Immunoglobulin G galactosylation (IgG-Gal) ratio representing the quantity of IgG galactosylation was calculated and candidate single nucleotide polymorphisms (SNPs) in patients treated with etanercept was obtained. Machine-learning models and cross-validation were conducted to predict responsiveness. Results: Both IgG-Gal ratio at each time point and differential IgG-Gal ratios between week 0 and weeks 2, 4, 8, 12 showed significant difference between responders and poor-responders. Area under curve (AUC) of the IgG-Gal ratio prediction model was 0.8 after cross-validation, significantly higher than current clinical indexes (C-reactive protein (CRP) = 0.65, erythrocyte sedimentation rate (ESR) = 0.59). The SNP MYOM2-rs2294066 was found to be significantly associated with responsiveness of etanercept treatment. A three-stage approach consisting of baseline IgG-Gal ratio, differential IgG-Gal ratio in 2 weeks, and rs2294066 genotype demonstrated the ability to precisely predict the response of anti-TNF therapy (100% for poor-responders, 98% for responders). Conclusions: Combination of different omics can more precisely to predict the response of TNF blocker and it is potential to be applied clinically in the future. [ABSTRACT FROM AUTHOR]