[Treatment and clinical course of autoimmune myasthenia in Burkina Faso].

Introduction: In sub-Saharan Africa, autoimmune myasthenia gravis (AMG) is still poorly known and underdiagnosed (delayed diagnosis, poor availability and accessibility of proven effective diagnostic and therapeutic tools), resulting in a poor functional prognosis and high mortality. The aim of the present study was to evaluate the therapeutic and clinical course of AMG in Burkina Faso.

Patients and methods: This was a longitudinal, multicenter study conducted from March 2015 to April 2023. It included patients with clinical signs suggestive of myasthenia associated with the presence of serum anti-acetylcholine receptor (anti-RACh) antibodies and/or anti-muscle specific kinase (anti-MuSK) antibodies, and/or with the presence of a decrease >10% on electroneuromyography, and/or with a positive therapeutic test to oral anticholinesterase drugs. Data on treatment modalities and clinical evolution were analyzed using Epi InfoTM 7.2.5.0 software. Bivariate analysis with p-value calculation (<0.05) was used to identify factors associated with adverse clinical outcome.

Results: A total of 40 patients with AMG were included, with a female predominance (60%). The median age of onset was 25 years (IQ=7). The median time to neurological consultation and diagnosis was 21 months (IQ=12) and 22 months (IQ=12), respectively. The disease affected young adults in 85% of cases and was generalized in 35 cases. Anti-RACh and anti-MuSK antibodies were present in 22 and 4 of 33 patients, respectively. Thymic hyperplasia and thymoma were found on chest CT in 22 and 6 of 38 patients, respectively. All patients received symptomatic treatment with oral anticholinesterase agents and 36 patients received background treatment with corticosteroids and/or immunosuppressants (azathioprine). Four of 9 patients received a course of intravenous immunoglobulin (IVIG) or plasma exchange (PE) for myasthenic crises. Thymectomy was performed in 16 of the 40 patients. At the end of a median outpatient follow-up of 53 months (IQ=16), of the 40 patients included in the study, 6 (15%) had died, 14 (35%) were in stable clinical remission, and 17 (43%) had partial clinical improvement.

Conclusion: AMG suffers from delayed diagnosis in Burkina Faso. Almost all patients treated for AMG receive anticholinesterase and corticosteroid therapy alone or in combination with azathioprine. Access to IVIG, PE and thymectomy remains limited. Mortality occurs in nearly one in six patients, and stable clinical remission affects only about one third of patients. To improve the prognosis, we need to make available and accessible diagnostic tools and treatments of proven efficacy, such as thymectomy, immunosuppressants, IVIG and PE.