Methotrexate Response In Rheumatoid Arthritis Research Articles

P122 Changes in Serum Levels of Cytokines with Methotrexate Monotherapy in Active Rheumatoid Arthritis: Results from a Multicentre, Randomized Controlled Trial on Methotrexate Escalation In Rheumatoid Arthritis

Abstract Background/Aims Identification of novel biomarkers of disease activity and prediction of treatment response in rheumatoid arthritis (RA) is an area of active research. Reliable biomarkers of methotrexate (MTX) response in RA are yet to be identified. We sought to study the change in serum levels of IL-6, MMP-3, and TNF-α with MTX monotherapy in patients with active RA. Methods Patients with active RA (SJC≥2 and TJC≥4) not on DMARDs (except HCQ and low-dose prednisolone) who had been enrolled in the multicentre, parallel-group RCT comparing two different MTX escalation strategies in RA (MEIRA) were included. All these patients received MTX monotherapy started at 15 mg/week and escalated to 25 mg/week by 4-8 weeks. Serum levels of IL-6, MMP-3, and TNF-α were measured by ELISA before starting MTX and after 16 weeks of MTX therapy. Responders were defined as patients who achieved a EULAR good or moderate response (based on DAS28ESR-3v) at 16 weeks. Analyses were intention-to-treat. Results 16 weeks of MTX therapy led to a decline in serum levels of both MMP-3 (p = 0.03, n = 129) and IL-6 (p = 0.048, n = 151). The decline in IL-6 levels was seen only in MTX responders (p = 0.003), but not in non-responders, while the decline in MMP-3 levels was seen in both MTX non-responders (p = 0.015) and responders (p = 0.44) (Table 1). Baseline (pre-treatment) serum levels of both IL-6 and MMP-3 were similar between MTX responders and non-responders. Correlations of serum levels of IL-6 (but not MMP-3) with measures of disease activity (DAS28, tender joint count) were weak but significant at 16 weeks. Serum TNF-α levels (n = 137) were undetectable in a majority of patients (93%). Serum IL-6 was not detectable in 67 (44%) patients at baseline. Conclusion Although serum levels of both MMP-3 and IL-6 reduced significantly with MTX therapy, the decline of IL-6 was seen only in MTX responders but not in non-responders. Pre-treatment serum levels did not predict future MTX response or non-response. IL-6 levels also correlated weakly but significantly with disease activity. Serial measurement of serum IL-6 merits further exploration in larger studies as a potential biomarker of MTX response in RA. Disclosure S. Jain: None. V. Dhir: None. A. Aggarwal: None. R. Gupta: None. S. Maurya: None. B. Leishangthem: None. A. Khullar: None. S. Naidu: None. S.K. Sharma: None. A. Sharma: None. S. Jain: None.

Machine learning using genetic and clinical data identifies a signature that robustly predicts methotrexate response in rheumatoid arthritis.

To develop a hypothesis-free model that best predicts response to MTX drug in RA patients utilizing biologically meaningful genetic feature selection of potentially functional single nucleotide polymorphisms (pfSNPs) through robust machine learning (ML) feature selection methods. MTX-treated RA patients with known response were divided in a 4:1 ratio into training and test sets. From the patients' exomes, potential features for classifier prediction were identified from pfSNPs and non-genetic factors through ML using recursive feature elimination with cross-validation incorporating the random forest classifier. Feature selection was repeated on random subsets of the training cohort, and consensus features were assembled into the final feature set. This feature set was evaluated for predictive potential using six ML classifiers, first by cross-validation within the training set, and finally by analysing its performance with the unseen test set. The final feature set contains 56 pfSNPs and five non-genetic factors. The majority of these pfSNPs are located in pathways related to RA pathogenesis or MTX action and are predicted to modulate gene expression. When used for training in six ML classifiers, performance was good in both the training set (area under the curve: 0.855-0.916; sensitivity: 0.715-0.892; and specificity: 0.733-0.862) and the unseen test set (area under the curve: 0.751-0.826; sensitivity: 0.581-0.839; and specificity: 0.641-0.923). Sensitive and specific predictors of MTX response in RA patients were identified in this study through a novel strategy combining biologically meaningful and machine learning feature selection and training. These predictors may facilitate better treatment decision-making in RA management.

The Macrophage Reprogramming Ability of Antifolates Reveals Soluble CD14 as a Potential Biomarker for Methotrexate Response in Rheumatoid Arthritis

The identification of “trained immunity/tolerance” in myeloid cells has changed our perception of the performance of monocytes and macrophages during inflammatory and immune responses. Pemetrexed (PMX) and methotrexate (MTX) are blockers of the one-carbon metabolism (OCM) and commonly used therapeutic agents in cancer and rheumatoid arthritis (RA). We have previously showed that MTX promotes trained immunity in human macrophages. In the present manuscript, we have assessed the anti-inflammatory effects of PMX and MTX and found that OCM blockers alter the functional and gene expression profile of human macrophages and that OCM blockade reprograms macrophages towards a state of lipopolysaccharide (LPS) tolerance at the signaling and functional levels. Moreover, OCM blockade reduced macrophage LPS responsiveness by impairing the expression of membrane-bound and soluble CD14 (sCD14). The therapeutic relevance of these results was later confirmed in early RA patients, as MTX-responder RA patients exhibit lower sCD14 serum levels, with baseline sCD14 levels predicting MTX response. As a whole, our results demonstrate that OCM is a metabolic circuit that critically mediates the acquisition of innate immune tolerance and positions sCD14 as a valuable tool to predict MTX response in RA patients.

Association Between MTHFR C677T Polymorphism and Methotrexate Treatment Outcome in Rheumatoid Arthritis Patients: A Systematic Review and Meta-Analysis.

Methotrexate (MTX) is one of the most widely used disease-modifying antirheumatic drugs for the treatment of rheumatoid arthritis (RA). However, its efficacy in RA patients is variable and unpredictable. Methylene tetrahydrofolate reductase (MTHFR) is an important enzyme in the MTX pathway and is involved in folate metabolism and DNA synthesis. Several studies have examined the association between the MTHFR C677T polymorphism and MTX toxicity and efficacy in RA, but their conclusions remain controversial. We conducted a comprehensive literature search of the PubMed, Embase, and Cochrane Library databases to identify studies reporting an association between the MTHFR C677T single nucleotide polymorphism and MTX response in RA patients. We identified 16 studies reporting MTX efficacy in 2373 RA cases, and 25 studies reporting MTX toxicity in 4063 RA cases. The pooled data analysis indicated that the MTHFR C677T polymorphism was associated with increased toxicity, but not efficacy, of MTX in RA patients. Further stratification based on ethnicity revealed an association between the MTHFR 677TT genotype and overall MTX toxicity in East Asian and Caucasian patient populations. In addition, RA patients with the MTHFR C677T polymorphism who were supplemented with folic acid displayed significantly elevated risk for MTX toxicity. Our study indicated that the MTHFR C677T polymorphism could be used as a predictor of MTX toxicity in RA patients. However, large randomized prospective studies will be required to effectively replicate and validate these findings.

Methotrexate Pharmacogenetics in Rheumatoid Arthritis: a Status Report

Methotrexate (MTX), an antifolate drug, is the first-line disease-modifying agent for the treatment of rheumatoid arthritis (RA) worldwide. MTX has excellent long-term efficacy, tolerability and safety. Early initiation of MTX in patients with RA controls joint destruction and slows progression of disease. However, the clinical response to MTX and frequency of adverse effects from the drug exhibit marked interpatient variability. Over the past decade, there has been a quest to identify genetic markers that reliably predict MTX efficacy and toxicity and help optimize MTX therapy in RA; that is, the field of MTX pharmacogenetics. This review will summarize key pharmacogenetic studies examining SNPs in the genes encoding enzymes in the MTX cellular pathway and their association with MTX response in RA. As evident from this review, MTX pharmacogenetics in RA remains a muddled field, mostly due to inconsistent results from several small underpowered studies.

Genetic polymorphisms in key methotrexate pathway genes are associated with response to treatment in rheumatoid arthritis patients

We investigated the effect of Single Nucleotide Polymorphisms (SNPs) spanning 10 methotrexate (MTX) pathway genes, namely AMPD1, ATIC, DHFR, FPGS, GGH, ITPA, MTHFD1, SHMT1, SLC19A1 (RFC) and TYMS on the outcome of MTX treatment in a UK rheumatoid arthritis (RA) patient cohort. Tagging SNPs were selected and genotyping performed in 309 patients with predefined outcomes to MTX treatment. Of the 129 SNPs tested, 11 associations were detected with efficacy (p-trend ≤ 0.05) including four SNPs in the ATIC gene (rs12995526, rs3821353, rs7563206 and rs16853834), 6 SNPs in the SLC19A1 gene region (rs11702425, rs2838956, rs7499, rs2274808, rs9977268, rs7279445) and a single SNP within the GGH gene (rs12681874). Five SNPs were significantly associated with adverse events; three in the DHFR gene (rs12517451, rs10072026, and rs1643657) and two of borderline significance in the FPGS gene. The results suggest that genetic variations in several key MTX pathway genes may influence response to MTX in RA patients. Further studies will be required to validate these findings and if confirmed these results could contribute towards a better understanding of and ability to predict MTX response in RA.

Lack of association between HLA-G 14 bp insertion/deletion polymorphism and response to long-term therapy with methotrexate response in rheumatoid arthritis

Pharmacogenetic studies examining methotrexate (MTX) response/toxicity have focused on enzymes involved in MTX transport and folate metabolism.1 However, recently it has been reported that patients with rheumatoid arthritis (RA) with...

Interaction of genes from influx-metabolism-efflux pathway and their influence on methotrexate efficacy in rheumatoid arthritis patients among Indians

Methotrexate (MTX) is the drug of choice for rheumatoid arthritis (RA) but is effective only in around 60% of treated patients. Bioavailability of MTX may be a major determinant of response status and this may be governed by variations in MTX receptor and transporter genes and genes responsible for polyglutamation and deconjugation. We investigated the contribution of single nucleotide polymorphisms (SNPs) in RFC, FOLR1, FPGS, GGH and MDR1 genes to MTX response in RA patients from North India. RA patients recruited using American College of Rheumatology criteria, were categorized into good and poor responders to MTX, based on disease activity score. A total of 17 SNPs from the above mentioned genes were genotyped and tested for association with MTX response using [chi]2 test; logistic regression along with clinical variables; and gene-gene interaction using multifactor dimensionality reduction (MDR). One novel synonymous SNP Ala324Ala (972 G > A) was identified in RFC gene. The CT genotype of C3435T in MDR1 gene conferred almost twice the risk of poor response [[chi]2 = 5.85, P = 0.01, odds ratio (95% confidence interval) = 1.97 (1.13-3.42)] and was retained in binary logistic regression [B = 0.66, P = 0.025, adjusted odds ratio (95% confidence interval) = 1.93(1.09-3.42)]. Significant interaction between SNPs in GGH and MDR1 genes seems promising. Interactions between genes coding for deconjugation and transporter seem to be important determinants of MTX response in RA but replication and functional studies would be confirmatory.