Alternative expression pattern of MALT1-A20-NF-κB in patients with rheumatoid arthritis

A20 Promoter rs5029924 Concomitant with rs2230926 and rs5029937 May Be a Prognostic Predictor for Joint Deformity or Refractory Rheumatoid Arthritis

Background

There have been several studies regarding the susceptibility of A20 gene SNPs (rs2230926 and rs5029937) in rheumatoid arthritis (RA). However, little is known about the association between polymorphisms in the A20 promoter and RA. The aim of this study was to investigate the characteristics of A20 promoter polymorphisms and the association between these polymorphisms and clinical significance in Chinese RA patients.

Methods

PCR and sequencing were used to identify A20 gene polymorphisms in peripheral blood mononuclear cells (PBMCs) from 123 RA cases and 31 healthy individuals.

Results

Only one SNP (rs5029924) in the A20 gene promoter was identified in RA patients and healthy individuals. 6 patients who carried heterozygous rs5029924 (3918C>T) together with heterozygous rs5029937 (11,571 G>T) and rs2230926 (12,486 T>G, Phe127Cys) suffered from joints deformity or refractory RA.

Conclusion

We reported the A20 promoter polymorphism rs5029924 in RA patients for the first time. rs5029924 concomitant with rs2230926 and rs5029937 may be a prognostic predictor for joint deformity or refractory RA.

MALT1 regulates Th2 and Th17 differentiation via NF-κB and JNK pathways, as well as correlates with disease activity and treatment outcome in rheumatoid arthritis

Objective

MALT1 regulates immunity and inflammation in multiple ways, while its role in rheumatoid arthritis (RA) is obscure. This study aimed to investigate the relationship of MALT1 with disease features, treatment outcome, as well as its effect on Th1/2/17 cell differentiation and underlying molecule mechanism in RA.

Methods

Totally 147 RA patients were enrolled. Then their blood Th1, Th2, and Th17 cells were detected by flow cytometry. Besides, PBMC MALT1 expression was detected before treatment (baseline), at week (W) 6, W12, and W24. PBMC MALT1 in 30 osteoarthritis patients and 30 health controls were also detected. Then, blood CD4⁺ T cells were isolated from RA patients, followed by MALT1 overexpression or knockdown lentivirus transfection and Th1/2/17 polarization assay. In addition, IMD 0354 (NF-κB antagonist) and SP600125 (JNK antagonist) were also added to treat CD4⁺ T cells.

Results

MALT1 was increased in RA patients compared to osteoarthritis patients and healthy controls. Meanwhile, MALT1 positively related to CRP, ESR, DAS28 score, Th17 cells, negatively linked with Th2 cells, but did not link with other features or Th1 cells in RA patients. Notably, MALT1 decreased longitudinally during treatment, whose decrement correlated with RA treatment outcome (treatment response, low disease activity, or disease remission). In addition, MALT1 overexpression promoted Th17 differentiation, inhibited Th2 differentiation, less affected Th1 differentiation, activated NF-κB and JNK pathways in RA CD4⁺ T cells; while MALT1 knockdown exhibited the opposite effect. Besides, IMD 0354 and SP600125 addition attenuated MALT1’s effect on Th2 and Th17 differentiation.

Conclusion

MALT1 regulates Th2 and Th17 differentiation via NF-κB and JNK pathways, as well as correlates with disease activity and treatment outcome in RA.

Application and pharmacological mechanism of methotrexate in rheumatoid arthritis

Methotrexate (MTX) has been used for the treatment of rheumatoid arthritis (RA) for about forty years and to date MTX remains the part of global standard of treatment for RA. The efficacy of MTX in RA is the result of multiple mechanisms of action. In order to summarize the possible pharmacological mechanisms of MTX in the treatment of RA, this review will elaborate on folate antagonism, promotion of adenosine accumulation, regulation of inflammatory signaling pathways, bone protection and maintenance of immune system function.

Mucosa-associated lymphoid tissue lymphoma translocation protein 1 in rheumatoid arthritis: Longitudinal change after treatment and correlation with treatment efficacy of tumor necrosis factor inhibitors

Background

Mucosa‐associated lymphoid tissue lymphoma translocation protein 1 (MALT1) correlates with treatment outcomes in inflammatory bowel disease and rheumatoid arthritis (RA). This study aimed to further evaluate the MALT1 longitudinal change and its relationship with tumor necrosis factor inhibitors (TNFi) response in RA patients.

Methods

Seventy‐one RA patients receiving TNFi [etanercept (n = 42) or adalimumab (n = 29)] were enrolled. MALT1 was detected by RT‐qPCR in peripheral blood samples of RA patients before treatment (W0), at week (W)4, W12, and W24 after treatment. RA patients were divided into response/non‐response, remission/non‐remission patients according to their treatment outcome at W24. Meanwhile, MALT1 was also detected by RT‐qPCR in 30 osteoarthritis patients and 30 healthy controls (HCs).

Results

Mucosa‐associated lymphoid tissue lymphoma translocation protein 1 was elevated in RA patients compared with HCs (Z=−6.392, p < 0.001) and osteoarthritis patients (Z = −5.020, p < 0.001). In RA patients, MALT1 was positively correlated with C‐reactive protein (r_s = 0.347, p = 0.003), but not other clinical characteristics, treatment history, or current TNFi category. Meanwhile, MALT1 decreased from W0 to W12 in total RA patients (x² = 86.455, p < 0.001), etanercept subgroup (x² = 46.636, p < 0.001), and adalimumab subgroup (x² = 41.291, p < 0.001). Moreover, MALT1 at W24 (p = 0.012) was decreased in response patients compared with non‐response patients; MALT1 at W12 (p = 0.027) and W24 (p = 0.010) were reduced in remission patients than non‐remission patients. In etanercept subgroup, MALT1 at W24 (p = 0.013) was decreased in response patients compared with non‐response patients. In adalimumab subgroup, MALT1 at W24 (p = 0.015) was lower in remission patients than non‐remission patients.

Conclusion

Mucosa‐associated lymphoid tissue lymphoma translocation protein 1 reduction after treatment is associated with response and remission to TNFi in RA patients.

Potential role of MALT1 as a candidate biomarker of disease surveillance and treatment response prediction in inflammatory bowel disease patients

BACKGROUND

Mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1) regulates adaptive and innate immune responses in several inflammatory disease. However, clinical involvement of MALT1 in inflammatory bowel disease (IBD) patients remains unclear. Hence, this study was intended to investigate the correlation of blood MALT1 with disease activity, inflammation indexes as well as treatment response of IBD patients.

METHODS

Blood MALT1 expression in 100 IBD patients [including 25 active (A)-Crohn's disease (CD) patients, 25 remission (R)-CD patients, 25 A-ulcerative colitis (UC) patients, and 25 R-UC patients] and 25 health controls (HCs) was detected by reverse transcription-quantitative polymerase chain reaction; besides, serum tumor necrosis factor-alpha (TNF-α) and interleukin-17A (IL-17A) in IBD patients were detected by enzyme-linked immunosorbent assay.

RESULTS

MALT1 was increased in A-UC patients than in R-UC patients (p = 0.038) and in HCs (p < 0.001), and also elevated in A-CD patients than in R-CD patients (p = 0.048) and in HCs (p < 0.001). MALT1 was positively related to C-reactive protein (CRP, p = 0.011), TNF-α (p = 0.036), IL-17A (p = 0.023), and Mayo score (p = 0.005) in A-UC patients, CRP (p = 0.017), erythrocyte sedimentation rate (p = 0.033), TNF-α (p = 0.004), and Crohn's disease activity index score (p = 0.028) in A-CD patients. But MALT1 was not correlated with either inflammation indexes or disease activity score in R-UC and R-CD patients. MALT1 gradually declined from baseline to W12 in A-UC and A-CD patients (both p < 0.001). Moreover, MALT1 at W4 (p = 0.031) and W12 (p = 0.003) in A-UC patients as well as MALT1 at W12 (p = 0.008) in A-CD patients associated with clinical response.

CONCLUSION

MALT1 serves as a potential biomarker for disease surveillance and treatment response prediction of IBD patients.

Blood MALT1, Th1, and Th17 cells are dysregulated, inter-correlated, and correlated with disease activity in rheumatoid arthritis patients; meanwhile, MALT1 decline during therapy relates to treatment outcome

Objective

Mucosa‐associated lymphoid tissue lymphoma translocation protein 1 (MALT1) participates in inflammatory and autoimmune diseases via activating various signaling pathways and promoting the differentiation of T‐helper (Th) 1 and Th17 cells; however, it is rarely reported in rheumatoid arthritis (RA). This study aimed to assess the correlation of MALT1 with Th1 and Th17 cells and evaluate its potential as a biomarker for evaluating disease activity and treatment outcomes in RA patients.

Methods

This study enrolled 139 RA patients and 45 health controls (HCs); then, blood MALT1, Th1, and Th17 cells were determined. For RA patients only, blood MALT1 at week (W) 6 and W12 after treatment was also detected. Additionally, clinical response and remission of RA patients were assessed at W12.

Results

MALT1 (p < 0.001), Th1 (p = 0.011), and Th17 (p < 0.001) cells were all increased in RA patients than HCs; meanwhile, increased MALT1 was associated with elevated Th1 (p = 0.003) and Th17 (p < 0.001) cells in RA patients. Besides, MALT1, Th1, and Th17 cells were positively correlated with parts of disease activity indexes in RA patients (all p < 0.050). In addition, MALT1 was gradually declined from W0 to W12 (p < 0.001) in RA patients. Specifically, MALT1 at W6 and W12 was lower in response patients than no response patients (both p < 0.010), also in remission patients than no remission patients (both p < 0.050).

Conclusion

MALT1, Th1, and Th17 cells are dysregulated, inter‐correlated, and correlated with disease activity in RA patients; meanwhile, the decline of MALT1 expression can partly reflect RA treatment response and remission.

The Functional Impact of Alternative Splicing and Single Nucleotide Polymorphisms in Rheumatoid Arthritis

Advances in genomics and proteomics aid the identification of genes associated with various diseases. Genome-Wide Association Studies (GWAS) have identified multiple loci as risk alleles for susceptibility to Rheumatoid Arthritis (RA). A bisection of RA risk can be attributed to genetic factors. Over 100 associated genetic loci that encompass immune regulatory factors have been found to be linked with RA. Aberrant Single Nucleotide Polymorphisms (SNPs) and alternative splicing mechanisms in such loci induce RA. These aberrations are viewed as potential therapeutic targets due to their association with a multitude of diseases. This review presents a few imperious genes whose alterations can cause severe bone deformities culminating in RA.

3β-Hydroxycholest-5-en-7-one from seahorse alleviates lipopolysaccharide-induced inflammatory responses by downregulating miR-98-5p

AIMS

We investigated the anti-inflammatory activity of 3β-hydroxycholest-5-en-7-one from Hippocampus trimaculatus leach and provided a theoretical basis for identifying its therapeutic targets.

MAIN METHODS

Small-RNA libraries were constructed for untreated control RAW 264.7 cells and cells treated with lipopolysaccharide (LPS; 1.0 μg/mL) or 10 μM 3β-hydroxycholest-5-en-7-one +1.0 μg/mL LPS. We constructed and tested a miR-98-5p-interfering lentivirus to evaluate the role of miR-98-5p in the 3β-hydroxycholest-5-en-7-one-dependent regulation of inflammatory responses in LPS-induced macrophage and murine inflammation models. The small-RNA libraries were analyzed using high-throughput sequencing.

KEY FINDINGS

Among the differentially expressed microRNAs, miR-98-5p showed the most significant difference. Bioinformatics tools were used to identify the potential regulatory targets of miR-98-5p, which were tested using dual-luciferase reporter assays. Our results demonstrated that 3β-hydroxycholest-5-en-7-one exerted an anti-inflammatory effect via miR-98-5p, which negatively regulated the expression of its target gene TNFAIP3. The results indicate that miR-98-5p interference and 3β-hydroxycholest-5-en-7-one treatment significantly upregulated the low TNFAIP3 expression induced by LPS stimulation, thereby inhibiting TRAF6, RIP, NF-κB, IL-1β, and TNF-α secretion.

SIGNIFICANCE

3β-Hydroxycholest-5-en-7-one alleviates inflammation by downregulating miR-98-5p and upregulating TNFAIP3, thereby blocking NF-κB pathway activation. These results reveal the specific anti-inflammatory mechanism of 3β-hydroxycholest-5-en-7-one, providing a foundation for developing new drugs and identifying drug targets.

The Role of Deubiquitinating Enzymes in Hematopoiesis and Hematological Malignancies

Hematopoietic stem cells (HSCs) are responsible for the production of blood cells throughout the human lifespan. Single HSCs can give rise to at least eight distinct blood-cell lineages. Together, hematopoiesis, erythropoiesis, and angiogenesis coordinate several biological processes, i.e., cellular interactions during development and proliferation, guided migration, lineage programming, and reprogramming by transcription factors. Any dysregulation of these processes can result in hematological disorders and/or malignancies. Several studies of the molecular mechanisms governing HSC maintenance have demonstrated that protein regulation by the ubiquitin proteasomal pathway is crucial for normal HSC function. Recent studies have shown that reversal of ubiquitination by deubiquitinating enzymes (DUBs) plays an equally important role in hematopoiesis; however, information regarding the biological function of DUBs is limited. In this review, we focus on recent discoveries about the physiological roles of DUBs in hematopoiesis, erythropoiesis, and angiogenesis and discuss the DUBs associated with common hematological disorders and malignancies, which are potential therapeutic drug targets.

Identification of functional missense single-nucleotide polymorphisms in TNFAIP3 in a predominantly Hispanic population

Background:

Tumor necrosis factor alpha-induced protein 3 (TNFAIP3) is a multifunctional ubiquitin binding and editing enzyme that regulates inflammation. Genetic studies have implicated polymorphisms within the TNFAIP3 locus to the development of numerous immune-related diseases. This study evaluated the frequencies of single-nucleotide polymorphism (SNPs) within the exonic regions of the TNFAIP3 gene and an associated point mutation from the Illumina array among a predominantly Hispanic cohort.

Methods:

Genomic DNA was obtained from 721 participants and sequencing of all TNFAIP3 exons and an intergenic point mutation (rs6920220) was performed. In-vitro functional assessment was performed by transfecting mutated TNFAIP3 constructs into TNFAIP3 knockout cells containing the NF-kB luciferase reporter and stimulating with TNFα. Comparative statistics were performed with Student’s t-test for continuous variables and chi-squared test for categorical variables.

Results:

Sequencing revealed two missense SNPs, rs146534657:A>G and rs2230926:T>G, both within exon 3 of TNFAIP3, which encodes the protein’s deubiquitinating enzymatic domain. Frequencies of all three point mutations differed significantly across racial groups (χ²-test, P = 0.014 to P < 0.001). Compared to Caucasians, rs146534657:A>G was overrepresented among Hispanics (odds ratio (OR) [95% CI] 4.05 [1.24−13.18]), and rs2230926:T>G was more prevalent among African-Americans (OR [95% CI] 3.65 [1.58−8.43]). In-vitro assays confirm rs146534657:A>G and rs2230926:T>G decrease the ability of TNFAIP3 to abrogate NF-κB activation by 2-fold (P < 0.01) and 1.7-fold (P < 0.01), respectively.

Conclusions:

This study reports the frequency of rs146534657:A>G among Hispanics and is the first to evaluate its potential physiologic impact, establishing a basis for future research as a potential biomarker among this population.

Decreased MiR-128-3p alleviates the progression of rheumatoid arthritis by up-regulating the expression of TNFAIP3

Background: Rheumatoid arthritis (RA) is a inflammatory disease that characterized with the destruction of synovial joint, which could induce disability. Inflammatory response mediated the RA. It has been reported that MiR-128-3p is significantly increased in RA, while the potential role was still unclear.

Methods: T cells in peripheral blood mononuclear cell (PBMC) were isolated from the peripheral blood from people of RA and normal person were used. Real-time PCR was performed to detect the expression of MiR-128-3p, while the protein expression of tumor necrosis factor-α-induced protein 3 (TNFAIP3) was determined using Western blot. The levels of IL-6 and IL-17 were measured using enzyme-linked immunosorbent assay (ELISA). The expression of CD69 and CD25 was detected using flow cytometry. The RA mouse model was constructed for verification of the role of MiR-128-3p.

Results: The expression of MiR-128-3p was significantly increased, while TNFAIP3 was decreased, the levels of IL-6 and IL-17 were also increased in the T cells of RA patients. Down-regulated MiR-128-3p significantly suppressed the expression of p-IkBα and CD69, and CD25in T cells. MiR-128-3p targets TNFAIP3 to regulate its expression. MiR-128-3p knockdown significantly suppressed the activity of nuclear factor κB (NF-κB) and T cells by up-regulating TNFAIP3, while cells co-transfected with si-TNFAIP3 abolished the effects of MiR-128-3p knockdown. The in vivo experiments verified the potential role of MiR-128-3p on RA.

Conclusion: Down-regulated MiR-128-3p significantly suppressed the inflammation response of RA through suppressing the activity of NF-κB pathway, which was mediated by TNFAIP3.

The identification of up-regulated ebv-miR-BHRF1-2-5p targeting MALT1 and ebv-miR-BHRF1-3 in the circulation of patients with multiple sclerosis

Epstein-Barr virus (EBV) is a well-documented aetiological factor for multiple sclerosis (MS). EBV encodes at least 44 microRNAs (miRNAs) that are readily detectable in the circulation of human. Previous studies have demonstrated that EBV-encoded miRNAs regulate host immune response and may serve as biomarkers for EBV-associated diseases. However, the roles of EBV miRNAs in MS are still unknown. To fill the gap, we conducted a comprehensive profiling of 44 mature EBV miRNAs in 30 relapsing-remitting MS (RRMS) patients at relapse and 30 matched healthy controls. Expression levels of ebv-miR-BHRF1-2-5p and ebv-miR-BHRF1-3 were elevated significantly in the circulation and correlated positively with the expanded disability status scale (EDSS) scores of MS patients. Receiver operating characteristic (ROC) analyses confirmed that the expression of these two miRNAs distinguished MS patients clearly from healthy controls. Luciferase assays revealed that ebv-miR-BHRF1-2-5p may directly target MALT1 (mucosa-associated lymphoid tissue lymphoma transport protein 1), a key regulator of immune homeostasis. In conclusion, we described the expression of EBV miRNAs in MS and preliminarily validated the potential target genes of significantly altered EBV miRNAs. The findings may pave the way for prospective study about the pathogenesis of MS.

Low Protein A20 in Minor Salivary Glands is Associated with Lymphoma in Primary Sjögren's Syndrome

Patients with primary Sjögren's syndrome (pSS) have an increased risk of developing lymphomas, particularly the subtype mucosa-associated lymphoid tissue (MALT) lymphoma. Chronic antigen stimulation and increased activation of nuclear factor-κB (NF-κB) are important factors for the pathogenesis of MALT lymphomas. Protein A20 is an inhibitor of NF-κB. A recent study of pSS-associated MALT lymphomas identified potential functional abnormalities in the TNFAIP3 gene, which encodes protein A20. The present study aimed to assess protein A20 by immunohistochemistry (IHC) in minor salivary glands (MSGs) and lymphoma tissue sections of patients with pSS and investigate a potential association with lymphoma development. Protein A20 staining in lymphocytes was scored in four categories (0 = negative, 1 = weak, 2 = moderate and 3 = strong). For statistical purposes, these scores were simplified into negative (scores 0-1) and positive (scores 2-3). We investigated associations between protein A20-staining, focus scores, germinal centre (GC)-like structures and monoclonal B-cell infiltration in MSGs. MSG protein A20 staining was weaker in pSS patients with lymphomas than in those without lymphomas (P = 0.01). Weak protein A20 staining was also highly associated with a lack of GC formation (P < 0.01). Finally, weaker A20 staining was observed in the majority of pSS-associated MALT lymphoma tissues. In conclusion, we found absent or weak protein A20 immunoreactivity in MSGs of patients with pSS with lymphomas. This finding indicates that protein A20 downregulation in lymphocytes might be a mechanism underlying lymphoma genesis in patients with pSS.

A20 SNP rs77191406 may be related to secondary cancer for rheumatoid arthritis and systemic lupus erythematosus patients

AIM

An increased risk for malignancy for rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) patients may be related to factors that play a critical role in the regulation of T-cell activation. A20 is an important negative immunoregulatory factor that was found to be associated with lymphoma and the development of numerous solid tumors. Previous studies have implicated the A20 locus in RA susceptibility. In this study, we investigated polymorphisms in the A20 3' UTR and explored whether there was an association between these polymorphisms and malignancy risk in autoimmune diseases.

METHODS

PCR and sequencing were used to identify A20 gene polymorphisms in peripheral blood mononuclear cells (PBMCs) from 99 RA cases, 37 SLE cases and 99 healthy individuals. Pearson's Chi square test was used for statistical analysis.

RESULTS

Only one SNP (rs77191406) and one new mutation (20132 A>G) in A20 gene were identified in RA and SLE patients and healthy individuals. Heterozygous rs77191406 was identified in just 1 of 99 RA patients and 2 of 37 SLE patients. More importantly, a RA patient who was heterozygous for rs77191406 developed colon cancer 10 years after the RA diagnosis. Similarly, two SLE patients carrying rs77191406 (heterozygous) had severe disease or developed bladder cancer 5 years after SLE diagnosis.

CONCLUSIONS

These findings suggest that rs77191406 may be a prognostic marker for a high risk for rapid malignancy progression, poor survival and refractory disease and a new molecular marker associated with autoimmune diseases transforming into a secondary cancer.

Specific overexpression of tumour necrosis factor-α-induced protein (TNFAIP)9 in CD14(+) CD16(-) monocytes in patients with rheumatoid arthritis: comparative analysis with TNFAIP3

The tumour necrosis factor (TNF)-α-induced proteins (TNFAIP)9 and TNFAIP3 play an important pathogenic role in murine arthritis. To clarify their pathophysiological roles in patients with rheumatoid arthritis (RA), we examined their expression and localization in peripheral blood mononuclear cells (PBMC). TNFAIP9 and TNFAIP3 mRNA expression was determined in PBMC of RA patients and healthy subjects (control). Flow cytometry was used to analyse the main TNFAIP9- and TNFAIP3-expressing cell populations. TNFAIP9 and TNFAIP3 mRNA expression levels were examined in vitro on CD14(+) cells stimulated with TNF-α and lipopolysaccharide (LPS). The expression levels of TNFAIP9 and TNFAIP3 mRNA were also measured before and 12 weeks after treatment with tocilizumab and abatacept. TNFAIP9 expression was significantly higher, while TNFAIP3 expression was lower in PBMC of RA (n=36) than the control (n=24) (each P < 0.05). TNFAIP9 was expressed on CD14(+) cells, especially in human leucocyte antigen D-related (HLA-DR)(+) CD14(bright) CD16(-) cells, while TNFAIP3 was expressed mainly on CD3(+) T cells. TNF-α and LPS induced TNFAIP9 and TNFAIP3 in human CD14(+) monocytes in vitro. Treatment with tocilizumab (n=13), but not abatacept (n=11), significantly reduced TNFAIP9 mRNA expression in PBMC, which was associated with reduction in the number of circulating CD14(bright) monocytes. The expression of TNFAIP9 in CD14(+) cells was specifically elevated in patients with RA, regulated by TNF-α and LPS, and suppressed by tocilizumab, while TNFAIP3 in PBMC showed different localization and induction patterns.

Characteristics of A20 gene polymorphisms and clinical significance in patients with rheumatoid arthritis

Background

There are a number of studies regarding to the susceptibility of A20 SNPs in rheumatoid arthritis (RA); however, a few of these studies have shown an association between polymorphisms in the A20 gene and RA risk in the Chinese population. The aim of this study was to investigate the characteristics of A20 gene polymorphisms, the association between polymorphisms and clinical significance in Chinese RA patients.

Methods

PCR and sequencing were used to identify A20 gene polymorphisms in peripheral blood mononuclear cells (PBMCs) (50 cases), synovial fluid (11 cases) from RA patients and PBMCs from 30 healthy individuals. Quantitative Real-time PCR (qRT-PCR) was used to analyze the A20 mRNA expression in 38 RA patients and 40 healthy individuals. Pearson’s Chi square test and two independent-samples Wilcoxon tests were used for statistical analysis.

Results

Eight single nucleotide polymorphisms (SNPs) (rs5029937, rs3799491, rs598493, rs2307859, rs146534657, rs2230926, rs661561, and rs582757) were identified in PBMCs of RA patients. One new mutation (14284 T > A) was identified in synovial fluid mononuclear cells from one RA case. rs146534657 was identified for the first time in two RA cases. Patients with rs146534657 (12411 A > G, Asn102Ser) AG genotype or rs2230926 (12486 T > G, Phe127Cys) TG genotype had poor outcome. Significantly lower A20 mRNA expression was found in PBMCs from RA patients compared with healthy individuals (p < 0.001). There was a higher A20 mRNA expression in RA patients with rs2230926 TG genotype and rs146534657 AG genotype (11.56 ± 7.39) than patients with rs2230926 TT genotype and rs146534657 AA genotype (5.63 ± 4.37) (p = 0.031).

Conclusion

Significantly lower A20 expression was found in RA patients. The polymorphisms of A20 were characterized in RA patients. We detected rs146534657 for the first time and identified a new A20 mutation (14284 T > A). A20 rs2230926 TG genotype and rs146534657 AG genotype may be related to poor outcome in RA patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-015-0566-1) contains supplementary material, which is available to authorized users.