Methotrexate therapy of oral corticosteroid-dependent asthmatics reduces serum immunoglobulins: correlation with clinical response to therapy

Summary Background Concomitant methotrexate (MTX) therapy of oral corticosteroid (CS)–dependent asthmatics has been shown to spare CS therapy, but the mechanism is unknown. In a previous report, we showed that MTX increases T cell inhibition by CS. In this report we focus on effects of MTX on immunoglobulin concentrations and their possible clinical relevance. Objective To monitor changes in circulating leucocytes and Ig in a group of these patients during MTX therapy, and to relate these changes to clinical ‘response’ as defined by oral CS reduction. Methods Sixteen severe asthmatics dependent on oral prednisolone 15 (7.5–25) mg/day in addition to high dose inhaled CS were treated with MTX 15 mg intramuscularly, weekly for 28 weeks. Prednisolone dosages were maintained constant for 12 weeks then reduced systematically over the next 16 weeks provided that asthma control did not deteriorate. Patients were classified a priori as ‘responders’ or ‘non‐responders’ to MTX (reduction of initial oral prednisolone requirement by 50% or