Pharmacogenetics of Antifolate Disease Modifying Anti-Rheumatic Drugs in Rheumatoid Arthritis in Taiwan

Polymorphisms occur in several genes encoding key enzymes in the folate pathway may affect drug metabolism in patients with rheumatoid arthritis. Whether these genetic variations contribute to differential responses to antifolate drug in patients with rheumatoid arthritis (RA) remains to be investigated in the Taiwanese population.

Objective. The goal of the present study is to investigate the interactions between genetic variations in folate genes and the efficacy/side effects of anti-folate disease-modifying antirheumatic drug in Taiwan.

DESIGN. A cross-sectional study involving 100 patients with RA were enrolled from TCVGH. Genotypes in methylenetetrahydrofolate reductase (MTHFR677C>T), tandem repeat polymorphism in thymidylate synthase enhancer region (TSER) and folylpoly-gamma-glutamate synthetase (FPGS1901T>C) were determined by RFLP or pyrosequencing.

Inclusion Criteria:

• Male/female age >18
• Clinical diagnosis of Rheumatoid Arthritis

Exclusion Criteria:

• Must not be pregnant/breastfeeding
• Other conditions may lead to exclusion from the trial (e.g. Diabetes mellitis, malignant melanoma, cardiac conduction disorders, hepatic/renal insufficiency.