Type I interferon gene expression signature as a marker to predict response to cyclophosphamide based treatment in proliferative lupus nephritis.

OBJECTIVES: To assess the longitudinal effect of cyclophosphamide (CYC) treatment on type-I interferon (IFN) signature in proliferative lupus nephritis (LN) and its role in predicting treatment response. METHODS: Fifty-four biopsy proven proliferative LN patients scheduled to receive high-dose (HD) or low-dose (LD) CYC were recruited and followed up for six months. At six months, patients were classified as clinical responders (CR) or non-responders (NR) to treatment, using the EULAR/EDTA criteria. An IFN-gene based score (IGS) was developed from the mean log-transformed gene expression of MX1, OAS1, IFIT1, OASL, IFIT4, LY6E, IRF7 at baseline, three and six months. Longitudinal changes of IGS within and between groups were assessed and ΔIGS, which is the difference in IGS between baseline and three months was calculated. Independent predictors of non-response were identified and an ROC analysis was performed to evaluate their utility to predict NR. RESULTS: There was a dynamic change in IGS within the HD, LD, CR, and NR groups. Compared to baseline, there was a significant decrease in IGS at three months in HD and LD groups (HD group: 2.01 to 1.14, p = .001; LD group = 2.01 to 0.81, p < .001), followed by a significant increase from three to six months in LD group (LD: 0.81 to 1.51, p = .03; HD: 1.14 to 1.54, p = .300). A decrease in IGS from baseline to three months was seen in both CR (2.13 to 0.79, p < .001) and NR groups (1.83 to 1.27, p = .046), and a significant increase from three to six months was observed only in the CR group (CR: 0.79 to 1.57, p = .006; NR: 1.27 to 1.46, p = 1). ΔIGS (baseline to three months) was higher in CR compared to NR group (-1.339 vs -0.563, p = .017). ROC analysis showed that the model comprising of 0.81 fold decrease in IGS from baseline to three months, endocapillary hypercellularity and interstitial inflammation on renal histopathology predicted non-response with a sensitivity of 83.3% and specificity of 71.4%. CONCLUSION: In proliferative LN, treated with HD or LD-CYC, combined model comprising of decrease in IGS score by 0.81 fold from baseline to three months, along with important histopathological features such as endocapillary hypercellularity and interstitial inflammation had better predictive capability for non-response.

Low C4A copy numbers and higher HERV gene insertion contributes to increased risk of SLE, with absence of association with disease phenotype and disease activity.

Low copy numbers (CNs) of C4 genes are associated with systemic autoimmune disorders and affects autoantibody diversity and disease subgroups. The primary objective of this study was to characterize diversity of complement (C4) and C4-Human Endogenous Retrovirus (HERV) gene copy numbers in SLE. We also sought to assess the association of C4 and C4-HERV CNs with serum complement levels, autoantibodies, disease phenotypes and activity. Finally, we checked the association of C4 and HERV CNs with specific HLA alleles. Genomic DNA from 70 SLE and 90 healthy controls of south Indian Tamil origin were included. Demographic, clinical and serological data was collected in a predetermined proforma. CNs of C4A and C4B genes and the frequency of insertion of 6.4kb HERV within C4 gene (C4AL, C4BL) was determined using droplet digital polymerase chain reaction (ddPCR). A four digit high resolution HLA genotyping was done using next generation sequencing. In our cohort, the total C4 gene copies ranged from 2 to 6. Compared to controls, presence of two or less copies of C4A gene was associated with SLE risk (p = 0.005; OR = 2.79; 95% CI = 1.29-6.22). Higher frequency of HERV insertion in C4A than in C4B increases such risk (p = 0.000; OR = 12.67; 95% CI = 2.80-115.3). AL-AL-AL-BS genotype was significantly higher in controls than SLE (9%vs1%, p = 0.04; OR = 0.15, 95% CI = 0.00-0.16). Distribution of HLA alleles was not different in SLE compared to controls as well as in SLE subjects with ≤ 2 copies and > 2 copies of C4A, but HLA allele distribution was diverse in subjects with C4B ≤ 2 copies and > 2 copies. Finally, there was no correlation between the C4 and the C4-HERV diversity and complement levels, autoantibodies, disease phenotypes and activity. In conclusion, our data show that, low C4A copy number and higher insertion of HERV-K in C4A increases the risk for SLE. C4 and C4-HERV CNs did not correlate with serum complements, autoantibodies, disease phenotypes and activity in SLE. Further validation in a larger homogenous SLE cohort is needed.

Rheumatoid arthritis autologous synovial fluid affects the plasticity and function of peripheral and induced T regulatory cells in vitro.

The synovial fluid (SF) microenvironment in rheumatoid arthritis (RA) may alter the stability and function of Tregs. In the present study, we assessed cytokine levels and percentage of Tregs, Tregs expressing CXCR3 (Th1-like Treg), CCR6 (Th17-like Treg) in RA peripheral blood (PB) and RA-SF using fluorescence cytometry. Effect of autologous SF on plasticity and function of RA-PB Tregs (pTregs; CD4+CD25hiCD127Lo/-) and induced vimentin-pulsed Tregs (iTregsVIM) was assessed in vitro. Cytokines and percentage of Th1-like and Th17-like Tregs were higher in RA-PB than OA-PB; higher in RA-SF than osteoarthritis (OA)-SF. Compared to OA-SF exposed OA-pTregs, RA-SF exposed RA-pTregs showed higher percentage of Th1-like (11% vs 20%) and Th17-like (16% vs 36%) Tregs; higher T-bet (p = 0.0001), RORγ (p = 0.0001) and lower FOXP3 (p = 0.0001) gene expression; and diminished percentage suppression of autologous T effector cells (36% vs 74%). RA-SF exposed iTregsVIM showed increased percentage of Th1-like and Th17-like Tregs compared to iTregsVIM exposed to AB serum (8% vs 0.1%; 21% vs 0.1%). IL-2, Tocilizumab and 5-azacytidine reduced the conversion of iTregsVIM (8% vs 2.4%; 21% vs 6.9%), when used in combination. To conclude, microenvironment in the RA synovial fluid is possibly responsible for conversion of pTregs into Th-like Tregs and their functional loss. A blockade of cytokine receptors and methyl transferases could inhibit Tregs conversion, providing clinical relevance for future Tregs targeting therapies.

Conventional Tregs in treatment-naïve rheumatoid arthritis are deficient in suppressive function with an increase in percentage of CXCR3 and CCR6 expressing Tregs.

In rheumatoid arthritis (RA), immune homeostasis is maintained by T regulatory cells (Tregs) that in an inflammatory milieu can change towards T-helper-like phenotypes (Th-like Tregs). Our aim was to examine the phenotypic and functional characteristics of CD4+CD25+CD127lo/- Tregs, Th-like Tregs and T effector (Teff) cells in the peripheral blood (PB) and synovial fluid (SF) of treatment-naïve early RA, as compared to osteoarthritis (OA) and healthy control (HC) peripheral blood. Frequencies of Tregs, CXCR3, CCR6 expressing Tregs (Th-like Tregs), and Teff cells were analyzed using flow cytometry in RA (n = 80), OA (n = 20), and HC (n = 40). Cytokine concentrations of the respective T cell subsets in plasma and SF were measured using flow cytometric bead array. Tregs sorted from RA and HC PB using magnetic beads were analyzed for functional capacities by CFSE proliferation assay and FOXP3 gene expression using real-time PCR. We observed that the frequencies of Th17 cells in PB and SF were significantly higher in RA when compared to HC, whereas Tregs were lower in PB and high in SF compared to HC and OA respectively. Th1- and Th17-related pro-inflammatory cytokines IL12p70, INF-γ, TNF-α, and IL-6, and IL-17A were significantly higher in the plasma and SF of RA. Tregs expressing CXCR3 (Th1-like Tregs) and CCR6 (Th17-like Treg) were significantly higher in PB and SF of RA compared to controls and was positively associated with seropositivity and disease activity. Treg cells isolated from peripheral blood of RA showed decreased function and reduced FOXP3 gene expression compared to HC. In our study, we have demonstrated higher frequencies of Th1 and Th17 cells and increased circulatory and SF pro-inflammatory cytokines (IL12P70, INF-γ, IL-6, IL-17A, and TNF-α) in RA. This inflammatory milieu might alter total Tregs frequencies and influence conversion of Tregs into Th-like Tregs.

Kidney histopathology in predicting flares following drug withdrawal in proliferative lupus nephritis in clinical remission.

Residual renal histopathological activity at clinical remission in Proliferative Lupus Nephritis (PLN) can predict renal flare upon immunosuppression withdrawal. Data on the role of histological renal remission in predicting extra-renal flares is lacking. We assessed renal histopathology prior to drug withdrawal and the occurrence of renal and extra-renal flares over 52 weeks after drug withdrawal in PLN patients in long-term clinical remission. This is a subgroup analysis of a non-inferiority, open-label randomized (1:1) controlled trial. Patients with biopsy-proven Class III/IV LN in the past (biopsy 1), on immunosuppressants (IS) ≥ 3 years, in clinical remission for ≥ 1 year, on stable prednisolone dose (≤ 7.5 mg/day) plus a maintenance IS and hydroxychloroquine (HCQ) were subjected to a repeat renal biopsy (biopsy 2). Individuals with biopsy 2 having activity index (AI) < 4/24 were randomised to either prednisolone or IS withdrawal. Primary end-point was the proportion experiencing a flare [SELENA-SLEDAI flare index (SFI)] at week 52. Twenty-eight eligible patients underwent biopsy 2 and randomized to prednisolone (n = 15) and IS (n = 13) withdrawal. At biopsy 1, 12 (43%) had class III, 15 (53.5%) had class IV, and 1 (3.5%) had class III + V. At biopsy 2, PLN persisted in 4 (14.2%) while 18 (64.2%) were in histological remission (AI = 0) with 6 (21.4%) in class II. Following drug withdrawal, 9/28 (32%) had flares especially musculoskeletal (55.5%), mucocutaneous (44.4%), and renal (33.3%). Among the four persistent PLN patients, one of the two (50%) with AI = 1 had extra-renal flare while both the two with AI = 2 (100%) had renal and extra-renal flares. In those with histological remission (biopsy 2), 6/18 (66.6%) experienced extra-renal flare of whom one also had renal flare. Upon drug withdrawal, renal histopathology findings with any activity index can predict renal flare while histological remission is not enough to predict extra-renal flare, thus making it an unsuitable marker for deep SLE remission.

Synovial-fluid-derived microparticles express vimentin and GRP78 in their surface and exhibit an in vitro stimulatory effect on fibroblast-like synoviocytes in rheumatoid arthritis.

OBJECTIVES: To investigate the hypothesis that microparticles (MP) may be a source of autoantigens and drive disease progression in rheumatoid arthritis (RA) synovium. METHODS: Synovial fluid (SF) was collected from the knee joints of 41 disease-modifying anti-rheumatic drug-naive RA patients and 30 osteoarthritis (OA) patients. Samples were stained with either anti-vimentin-AlexaFluor-488 or anti-glucose-regulated protein-78-Dylight-488 (GRP78) and Annexin-V-allophycocyanin for flow cytometry analysis. RA and OA fibroblast-like synoviocytes (FLS) were co-cultured with respective SF-derived MP in vitro for 24 h. Supernatant and cell-free SF was assayed for pro-inflammatory analytes by multiplex assays. RESULTS: Elevated percentages of AnnexinV+ Vimentin+ MP (median 0.8, interquartile range [IQR] 1.30) and AnnexinV+ GRP78+ MP (median 0.3, IQR 0.28) were present in RA compared with OA patients. We observed that CXCL6 and CCL8 were secreted in excess by RA-FLS stimulated with RA-SF-MP but not by stimulation with MP-free RA-SF. CONCLUSIONS: Microparticles express vimentin and GRP78 on their surface and stimulate synoviocytes to produce inflammatory molecules, thus sustaining local inflammation in the synovium in RA.

Performance of Clinical and Biochemical Parameters in Identifying Renal Histopathology and Predictors of One-Year Renal Outcome in Lupus Nephritis-A Single Centre Study from India.

Objectives: To assess the performance of clinical and biochemical parameters in identifying renal histopathology. To assess the performance of a combination of demographic, clinical, serological and histopathological parameters in determining renal response at one year. Methods: Data of biopsy-proven (ISN/RPS­2003 criteria) Lupus Nephritis (LN) were extracted from the institute database. Demographic, clinical and biochemical parameters at the time of biopsy were noted, and their associations with histopathological class, activity and chronicity scores were evaluated. Follow-up data at one year were collected. Complete, partial or no response (CR, PR, NR) for renal outcomes at one year and the predictors of NR were assessed. Results: Out of the 333 renal biopsies, 240 (71.8%) were Class III/IV. More patients with Class III/IV LN had hypertension (52.1%) and low eGFR (p < 0.001). Among Class III/IV, AS correlated weakly with UPCR (r = 0.31, p < 0.01), eGFR (r = −0.172; p < 0.01) and CS with eGFR (r = −0.212; p < 0.01). The presence of either hypertension, UPCR > 0.5 g/day, active urinary sediments or serum creatinine >1.3 g/dL had a sensitivity of >96% and specificity of <9% in detecting proliferative LN, crescents, interstitial inflammation and chronicity. NR was higher in males (aOR:3.9, 95% CI:1.4−11.0, p < 0.001), those with abnormal baseline creatinine (aOR: 1.9, 95% CI: 1.1−3.2, p < 0.001), higher renal SLEDAI (p < 0.05), higher AS, CS (p < 0.001) and interstitial inflammation (p < 0.005). In the binary logistic regression, the combination of male sex, baseline creatinine, UPCR and CS performed best in predicting NR (AUC: 0.762; 95% CI: 0.684−0.840, p < 0.001). Conclusions: Clinical and biochemical parameters alone have a poor specificity in identifying renal histopathology. A combination of demographic, clinical and histopathology parameters can better predict renal outcomes at one year.

Association of HLA-G, HLA-E and HLA-B*27 with susceptibility and clinical phenotype of enthesitis related arthritis (ERA).

We studied the association of Enthesitis related arthritis (ERA) the most common variant of juvenile idiopathic arthritis (JIA) in Asians, with HLA-G and -E polymorphisms. HLA-G (14 bp Ins/Del rs371194629, +3142 rs1063320, +3187 rs9380142) and HLA-E (rs1264457, and rs2844724) polymorphisms were analyzed in 127 patients with ERA and 381 ethnically matched healthy controls with TaqMan 5'-nuclease assay using allele-specific fluorogenic oligonucleotide probes. HLA-G and -E polymorphisms were not found to be associated with susceptibility to ERA. HLA-G +3187 (rs9380142) G allele was associated with hip arthritis (Pc = 0.04, OR = 2.22, 95%CI = 1.07-4.63) and hip deformity (Pc = 0.02, OR = 2.51, 95%CI = 1.16-5.43). HLA-B*27 was positive in 91. HLA-E rs1264457 G and rs2844724 T alleles may be associated with B*27 positivity in ERA. Among HLA-G, -E haplotypes, frequency of -InsGAAC was significantly higher in patients than healthy controls (Pc = 0.003). In conclusion, HLA-G and HLA-E haplotype -InsGAAC may be associated with susceptibility to ERA and HLA-G +3187 rs9380142 A>G polymorphism may be a poor prognostic marker for progression to hip arthritis and deformity in ERA-JIA.

HLA Polymorphism in Regressive and Non-Regressive Autism: A Preliminary Study.

Autism spectrum disorders (ASD) comprises heterogeneous neurodevelopmental conditions with symptom onset usually during infancy. However, about 10%-30% of affected cases experience a loss of language and social skills around 18-30 months, so-called regressive autism. In this subset with regression, immune dysfunctions including inflammation and autoimmunity have been proposed to be at risk factors. Given the implication of the human histocompatibility antigens (HLA) system in various aspects of immune responses, including autoimmunity, and in ASD, we investigate here the distribution of the HLA Class I and Class II haplotypes in 131 children with ASD meeting DSM-IV TR criteria, with and without regression. We found that 62 of the 98 non-regressive ASD patients carry the HLA-DPA1*01-DPB1*04 sub-haplotype as compared to 14 of the 33 patients with regression (63% vs. 43% respectively, Pc = 0.02), suggesting that this HLA haplotype may exert a protective effect against regression. Similarly, the HLA-DPA1*01-DPB1*04 has also been found to be more represented in healthy controls as compared to patients affected with common nonpsychiatric autoimmune disorders. Overall our findings suggest a possible involvement of HLA polymorphism in the context of regressive ASD. Autism Res 2020, 13: 182-186. © 2019 The Authors. Autism Research published by International Society for Autism Research published by Wiley Periodicals, Inc. LAY SUMMARY: Immune dysfunctions including inflammatory and autoimmune processes have been reported in autism, particularly in regressive forms. In this study, we analyzed the distribution of HLA haplotypes among children with autism spectrum disorder (ASD), with and without regression from Sweden and observed that HLA-DPA1*01-DPB1*04 sub-haplotype was less represented in patients with regressive autism as compared with those without regression. Such possible protective effect, also observed in other common autoimmune disorders, may constitute a link between HLA-mediated immune processes and regressive ASD.

Folyl polyglutamate synthethase (FPGS) gene polymorphisms may influence methotrexate adverse events in South Indian Tamil Rheumatoid Arthritis patients.

The aim of the study was to look for the association of FPGS 2752 G > A (rs1544105), FPGS 1994 A > G (rs10106), and GGH 452 C > T (rs 11545078), GGH -401C > T (rs 3758149) gene polymorphisms with methotrexate (MTX) treatment response and MTX-induced adverse events in South Indian Tamil patients with rheumatoid arthritis (RA). Further the influence of these gene polymorphisms on MTX polyglutamate levels was analyzed. A total of 330 patients with RA were investigated. FPGS gene polymorphisms were analyzed by TaqMan 5'nuclease assay and GGH gene polymorphisms were analyzed by PCR-RFLP. Methotrexate polyglutamates (nmol/L of packed erythrocytes) were measured by liquid chromatography mass spectrometry (LCMS/MS) method. We found that the heterozygous genotype of FPGS rs1544105 [p = 0.02, OR 1.93, 95% CI (1.15-3.35)] and FPGS rs10106 AG genotype [p = 0.01, OR 2.11, 95% CI (1.20-3.71)] were associated with MTX adverse events. FPGS rs1544105 and GGH -401C > T SNPs influenced the polyglutamate levels. None of the investigated SNPs seems to be associated with MTX treatment outcome.

The HLA-G Genetic Contribution to Bipolar Disorder: A Trans-Ethnic Replication.

Bipolar disorder (BD) is frequently associated with immune dysfunctions. Studying the genetic diversity of the immuno-modulatory human leukocyte antigen (HLA)-G locus in a French BD cohort, we previously reported an association between a functionally relevant 14 bp Ins/Del polymorphism and BD risk. The present study investigated the genetic and expression diversities of HLA-G in a geographically distinct South Indian population-group BD patients, as well as the influence of exposure to the neurotropic Toxoplasma gondii pathogen. Three functionally relevant HLA-G polymorphisms, i.e. HLA-G 14 bp Ins/Del (rs66554220), +3142G>C (rs1063320) and +3187A>G (rs9380142) were genotyped by polymerase chain reaction (PCR) and real-time PCR. Sub-samples of BD patients and healthy controls (HC) were investigated for plasma levels of soluble HLA-G (sHLA-G) isoforms, as well as circulating stigma of T. gondii infection. Findings indicate: (i) the frequency of the HLA-G 14 bp Del/Del genotype was higher in BD cases, as compared to HC; (ii) the HLA-G + 3142 C allele and CC genotype were more prevalent in BD patients than in HC; (iii) sHLA-G levels were significantly higher in BD cases, especially in females and in the early onset sub-group; and (iv) the InsGA haplotype was more prevalent in HC. Our findings further support the genetic contribution of HLA-G to BD risk, as well as indicate relevant expression profiles. Such data may also indicate a potential developmental role in BD etiology, given that HLA-G is an important immune regulator from the intrauterine period and across development.

Reduced folate carrier-1 80G > A gene polymorphism is not associated with methotrexate treatment response in South Indian Tamils with rheumatoid arthritis.

Methotrexate (MTX) is the most commonly used disease-modifying drug to treat rheumatoid arthritis (RA). Although there are no reliable molecular markers to predict the treatment response and adverse effects to MTX therapy, the polymorphisms in genes coding for MTX metabolizing enzymes and transporters may play a crucial role. The reduced folate carrier-1 (RFC-1) is a bidirectional anion exchanger which transports MTX and folinic acid. It is reported to influence MTX treatment response and adverse effects in some ethnic populations but not in others. It is also associated with susceptibility to various diseases including systemic lupus erythematosus (SLE). The present study was aimed at investigating the role of RFC-1 80G > A gene polymorphism in association with disease susceptibility, MTX treatment response and the MTX-induced adverse events in the South Indian Tamil patients with rheumatoid arthritis. The RFC-1 80G > A gene polymorphism was investigated in 327 patients with RA and in 322 healthy controls by PCR-RFLP method. It was found that the heterozygous RFC-1 80 GA genotype was associated with protection against RA [p = 0.02, odds ratio (OR) 0.69, 95 % confidence interval (CI) 0.50-0.95]. However, it was not found to be associated with MTX treatment response. The RFC-1 G allele frequency was higher in patients with adverse effects, but the difference was not statistically significant (p = 0.08, OR 1.44, 95 % CI 0.97-2.13). RFC-1 80G > A gene polymorphism confers protection for RA. However, it is not associated with MTX treatment response and MTX-induced adverse effects in South Indian Tamil patients with RA.

Multidrug resistance 1 (MDR1) 3435C>T gene polymorphism influences the clinical phenotype and methotrexate-induced adverse events in South Indian Tamil rheumatoid arthritis.

PURPOSE: Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease primarily targeting the synovial joints causing joint damage and significant functional impairment. Methotrexate (MTX) remains the mainstay for the treatment of RA, and approximately 10-30% of the patients fail to attain remission because of inefficacy of the drug or due to development of adverse events. Multidrug resistance 1 (MDR1) gene encodes for permeable glycoprotein (P-gp) which is an integral membrane protein for the transport of chemotherapeutic agents, immunosuppressive drugs etc. MDR1 3435C>T results in a wobble mutation in exon 26 but is associated with altered P-gp expression and reduced P-gp function. The present study was carried out to find the role of MDR1 3435C>T gene polymorphism with clinical phenotype, treatment response, and MTX adverse events in 336 RA and 329 healthy controls of South Indian Tamil ethnicity. METHODS: MDR1 3435C>T gene polymorphism was analyzed by TaqMan 5' nuclease assay. RESULTS: We found MDR1 3435T allele as a risk allele for contributing to high EULAR disease activity [p = 0.02, OR 1.50, 95% CI (1.06-2.13)]. Also, MDR1 3435CT genotype was associated with deforming disease [p = 0.02, OR 1.79, 95% CI (1.11-2.88)]. However, this SNP did not influence the MTX treatment response in these patients. MDR1 3435CT genotype was associated with MTX-induced adverse events [p = 0.01, OR 2.01, 95% CI (1.15-3.52)], and the 3435 TT genotype remained protective for the development of adverse events [p = 0.009, OR 0.40, 95% CI (0.21-0.78)]. Also, the heterozygous 3435 CT genotype was associated with gastrointestinal events [p = 0.02, OR 3.62, 95% CI (1.25-10.47)], and CT genotype remained protective in patients developing infection [p = 0.002, OR 0.05, 95% CI (0.006-0.460)]. CONCLUSION: MDR1 3435C>T gene polymorphism influences the clinical phenotype and adverse events to MTX in the South Indian cohort of patients with RA.

Cytokine expression and cytokine-based T cell profiling in South Indian rheumatoid arthritis.

Rheumatoid arthritis (RA), a chronic inflammatory disease affects up to 1% of the general population. Early diagnosis and treatment are limited by the absence of specific and reliable diagnostic/prognostic biomarkers. This study was carried out in 48 Tamil South Indian RA patients and 49 healthy controls (HC) to identify any cytokine signature(s) that could potentially serve as biomarkers. Expression profiles of Th1, Th2, Th17 and Tregs cell type-specifying cytokines and transcription factors were analyzed using real time quantitative PCR (qPCR) assay. To explore if such expression profiles mirror their steady state plasma levels, a bead-based multiplex fluorescent assay was carried out. We found that the expression of transcription factors T-bet (for Th1), GATA-3 (for Th2) and FoxP3 (for Tregs) were significantly lower in patients than in healthy controls (P<0.0001) similar to lowering of IFNγ (P=0.004) and IL-10 (P=0.04). The transcript levels of IL-12p40 and TNF-α were higher among patients as compared to HC (P<0.0001 and P=0.02, respectively). Circulating levels of assessed cytokines were in general higher in RA patients as compared to controls. These alterations in the expression of transcription factors and cytokines highlight the underlying dysregulation of T cell subsets in RA that reflects a predominantly inflammatory phenotype. Despite dissecting these cellular and molecular processes, no specific signature that could be of diagnostic and/or prognostic value was identified. Additional longitudinal follow-up studies, especially on newly diagnosed treatment-naïve patients are warranted to uncover clinically useful biomarkers of RA.