[Pharmacogenomics of methrotexate: a strategy for a customized therapeutic scheme for patients with rheumatoid arthritis]

Abstract

Rheumatoid arthritis (RA) is a common rheumatic disease in Mexico. Methotrexate (MTX) is a drug frequently used in the treatment of this disease. However, treatment discontinuation due to side effects is also common. Inter-individual differences in effectiveness and occurrence of side effects in RA patients treated with MTX (RA-MTX) have been reported. Several studies analyzed the presence of MTHFR C677T and A1298C polymorphisms in RA-MTX patients associated with effectiveness, side effects and toxicity. Given the high frequency of the MTHFR C677T polymorphism in Mexico, it is of utmost interest to determine the allelic and genotypic frequency of these polymorphisms in patients with RA-MTX. The use of molecular techniques, feasible in our country, such as PCR/RFLP (Polymerase Chain Reaction-Restriction Fragment Length Polymorphism) can allow us to identify these MTHFR genotypes among RA-MTX patients in order to target patients at risk of developing drug toxicity, side effects or better MTX efficacy. The ultimate goal is to develop individualized treatment, as promised by the field of pharmacogenomics.