Target Gene Polymorphisms and Clinical Response to Methotrexate in Chinese Rheumatoid Arthritis Patients.

Area of Science:

• Pharmacogenomics
• Rheumatology
• Genetics

Background:

• Rheumatoid arthritis (RA) is a chronic autoimmune disease affecting joints.
• Methotrexate (MTX) is a common disease-modifying antirheumatic drug (DMARD) used for RA treatment.
• Individual response to MTX varies, necessitating research into predictive biomarkers.

Purpose of the Study:

• To investigate the association between genetic polymorphisms in key metabolic genes and MTX treatment outcomes in Chinese RA patients.
• To identify genetic markers that predict clinical response to MTX therapy.

Main Methods:

• A cohort of 115 Chinese RA patients receiving MTX was analyzed.
• Clinical response was assessed using European League Against Rheumatism (EULAR) criteria and Disease Activity Score 28-joint count (DAS28-ESR) for low disease activity (LDA).
• Genotyping was performed for 30 single nucleotide polymorphisms (SNPs) in DHFR, TYMS, ATIC, ADA, and AMPD1 genes.

Main Results:

• Specific polymorphisms in ATIC (rs2372536, rs4673991, rs4673993) and ADA (rs2057638, rs6017375) were associated with EULAR response.
• The ADA rs371927 polymorphism showed association with EULAR response under a recessive model.
• ADA polymorphisms rs1799880 and rs6031697 were significantly linked to achieving LDA based on DAS28-ESR.

Conclusions:

• Genetic variations in the ATIC and ADA genes are significantly associated with MTX clinical response in Chinese RA patients.
• These findings highlight the potential of pharmacogenetic approaches for optimizing MTX therapy in RA.
• Further validation in larger cohorts is warranted to confirm these associations.