Effect of treatment with methotrexate, hydroxychloroquine, and prednisone on lymphocyte polyamine levels in rheumatoid arthritis: correlation with the clinical response and rheumatoid factor synthesis.

Abstract

OBJECTIVE: Polyamines are increased in activated lymphocytes, including peripheral blood lymphocytes (PBL) from patients with rheumatoid arthritis (RA), and are important in modulating immune-mediated cellular responses. In vitro studies have suggested that methotrexate (MTX) interferes with polyamine synthesis. This study evaluated the in vivo polyamine response to MTX compared to other anti-arthritic agents, and correlated it with the clinical and immunological response. METHODS: The polyamine content of PBL was determined in 14 RA patients at initiation of treatment with MTX (n = 8), hydroxychloroquine (HCQ) (n = 3), or prednisone (n = 3), and then monthly for four months. IgM rheumatoid factor (RF) synthesis by PBL in vitro was assessed and tender joints were counted monthly. RESULTS: Polyamines (spermine and spermidine) decreased by 55% at three months in the MTX group compared to 4% and 9% in the HCQ and prednisone groups, respectively (p < 0.01). However, group differences in the clinical and immunological response were not significant. In the MTX group there was a positive correlation between polyamine levels and the joint count. Such a correlation was not observed in the other groups. CONCLUSION: These data suggest that MTX interference with the polyamine pathway is not shared by prednisone and HCQ, and is associated with its beneficial effect in RA.