Management Issues in Myasthenia Gravis Patients Living With HIV: A Case Series and Literature Review

South Africa has >7 million HIV-infected people and a high prevalence of tuberculosis. HIV-infected individuals may develop myasthenia gravis (MG) which raises questions regarding their management. An MG database, with 24-years of observational data, was audited for HIV-infected persons. Case reports of MG in HIV-infected persons were reviewed. We identified 17 persons with MG and HIV-infection. All had generalised MG with a mean age at MG onset of 37.8 years. Eleven had acetylcholine receptor-antibody positive MG; one had antibodies against muscle-specific kinase. Six developed MG prior to HIV-infection (mean CD4+ 361 cells/mm3); four worsened within 6-months of starting antiretrovirals. Eleven developed MG whilst HIV-infected (mean CD4+ 423 cells/mm3); five presented with mild MG and three in MG crisis requiring rescue therapies (intravenous immune globulin or plasma exchange and/or intravenous cyclophosphamide). Two were diagnosed with HIV-infection and MG at same time. Fifteen of 17 required maintenance steroid-sparing immune-therapies, predominantly azathioprine or methotrexate. Plasma HIV-viral loads remained below detectable levels on antiretrovirals during immunosuppressant treatment. Overall, 10 achieved minimal MG manifestation status and the remainder improved to mild symptoms after an average of 6-years follow-up. Three cases had tuberculosis before MG, but none developed tuberculosis-reactivation on immunosuppressive therapy; one used isoniazid-prophylaxis. Herpes zoster reactivation during treatment occurred in one. Conclusions include: MG in HIV-infected patients should be managed similarly to HIV-uninfected individuals; half develop moderately-severe MG; MG symptoms may worsen within six months of antiretroviral initiation; safety monitoring must include HIV-viral load estimation. Isoniazid prophylaxis may not be indicated in all cases.