METHOTREXATE AS STEROID SPARING AGENT IN MYASTHENIA GRAVIS: A RETROSPECTIVE STUDY IN A SMALL COHORT OF PATIENTS

Introduction Myasthenia gravis (MG) is an autoimmune disorder of neuromuscular junction. Therapy for MG is still debated and controversial: corticosteroids alone or in combination with immunosuppressive agents are the most used drugs. Azathioprine (AZA) has been shown to be effective for MG in randomized placebo-controlled studies with a significant steroid-sparing activity after 15 months administration although several side effects1. Recently, some studies on Methotrexate (MTX) activity in MG have evidenced controversial results on efficacy, tolerability and steroid-sparing activity. Patients and Methods We have retrospectively evaluated in our MG cohort of (over 850 pts), a number of patients treated with MTX and its efficacy as a steroid-sparing agent. 15 patients, previously treated with AZA and prednisone with uncomfortable side effects (AZA related), were then cured with a combination of MTX (median dose: 17.5 mg per week) and prednisone (PDN: median dose 37 mg/die). Mean clinical follow up was about 8 years (from 5 to 10 years). Each patient was evaluated 2/4 times per year by MG-Activity of daily living (MG-ADL) and Quantitative Myasthenia Gravis scores (QMG). Results We found that patients treated with MTX had a significant improvement on the MG-ADL and QMG scores. We were able to taper successfully PDN dose starting from 37 mg to a dose of 12.5 mg per day; in eleven patients out of fifteen the dose tapering of PDN was = > 20 mg and two patients stopped PDN therapy during the period of evaluation. None of patients complained of side effects. Conclusions Some recent MTX trials ended with controversial results as steroid-sparing agent compared to AZA. Our data, although observed in a limited number of MG subjects, suggests that MTX is effective and well tolerated and can be considered as an alternative steroid-sparing agent.