Measures of immunologic and inflammatory responses in vitro in rheumatoid patients treated with methotrexate

: We examined the effects of low dose parenteral methotrexate (MTX) on immunologic and inflammatory responses of potential importance in the pathogenesis of rheumatoid arthritis. Only 2 significant changes were noted: the number of esterase positive cells in the peripheral blood decreased, and the uptake of tritiated thymidine by incubated peripheral blood mononuclear cells fell markedly. These changes were present 48 h after an injection of MTX, before decreased disease activity became clinically apparent. We therefore conclude that they were direct effects of the drug itself.