Effects of methotrexate on the expression of the translational isoforms of glucocorticoid receptors α and β: Correlation with methotrexate efficacy in rheumatoid arthritis patients

Abstract

Objectives: To test the effect of MTX on the expression of glucocorticoid receptor (GR) α and β isoforms AB, C and D in peripheral blood mononuclear cells (PBMCs) in culture, from newly diagnosed RA patients and to evaluate whether the test results correlate with patients' subsequent response to MTX treatment. Methods: Twenty patients with early active RA were enrolled. Patients who had previously received any DMARD or cytotoxic agent, or who had received CSs in the 6 months before enrolment were excluded. PBMCs from all patients were obtained and cultured in the presence and absence of MTX (10-4, 10-6 and 10-8 M). The expression of GR isoforms was evaluated by western blot. After blood samples were taken, patients entered a 24-week study receiving MTX, diclofenac and prednisone (10 mg/day). At Week 24, the ACR core set of disease activity measures was calculated and a correlation between the MTX effect on patients' PBMC GR expression in vitro and the ACR response was evaluated. Result