Efficacy and safety of tacrolimus in Osserman grade III and Osserman grade IV Myasthenia Gravis

Abstract Objective A retrospective observational cohort study was conducted to evaluate the efficacy and safety of tacrolimus in Osserman grade III and Osserman grade IV myasthenia gravis (MG) patients. Patients and methods MG patients admitted to the First Affiliated Hospital of Guangzhou University of Chinese Medicine between June 2011 and January 2017 with grade III and grade IV according to the modified Osserman scale were recruited and received a telephone follow-up in September 2017. Patients treated with tacrolimus plus prednisone were compared with those treated without tacrolimus. The efficacy of tacrolimus was assessed using MG-activities of daily living (MG-ADL) score, Osserman classification, Myasthenia Gravis Foundation of America (MGFA) post intervention status (PIS), the number of hospitalizations, the number of myasthenic crises and deaths. The adverse drug effects of tacrolimus were monitored. Results A total of 124 patients were included. The tacrolimus group had a significantly lower MG-ADL score than the control group at follow-up (1.90 ± 2.27 vs 2.97 ± 2.78, p = 0.029). The difference of MG-ADL score between baseline and after follow-up was significantly greater in the tacrolimus group than the control group (-7.20 ± 2.95 vs -5.52 ± 2.91, p  =  0.003). Fewer patients were hospitalized in the tacrolimus group ( p  =  0.011). The Osserman classification, MGFA PIS, the number of myasthenic crises and deaths did not differ significantly between the two groups. Nineteen patients in the tacrolimus group had adverse drug reactions, but no severe adverse effects appeared. Conclusion Our study suggested that tacrolimus could be an effective and safe treatment for Osserman grade III and Osserman grade IV MG patients.