Early use of rituximab in myasthenia gravis in a resource-limited setting: A retrospective cohort study from a tertiary center in Pakistan

Abstract

Background: Myasthenia gravis (MG) is an autoimmune disorder of the neuromuscular junction, most commonly mediated by acetylcholine receptor antibodies. Standard treatments include corticosteroids, acetylcholinesterase inhibitors, and conventional immunosuppressants, while intravenous immunoglobulin (IVIg) or plasma exchange is reserved for refractory disease or myasthenic crises. Rituximab, a CD20-targeting monoclonal antibody, has demonstrated efficacy in treatment-resistant MG, particularly in MuSK-positive cases. However, its use early in the disease course, particularly soon after diagnosis or after failure of only one immunosuppressant remains underexplored, especially in resource-limited settings where access to IVIg and recurrent hospitalizations is often constrained. In our cohort, rituximab was initiated at a median disease duration of one year, although seven patients had experienced a prior myasthenic crisis. This study evaluates the efficacy and safety of early rituximab use in such settings.

Methods: In this retrospective cohort study (Dec 2021–June 2024), 12 patients with generalized MG were treated with rituximab and followed for 18 months. Clinical outcomes, including MGFA-Post Intervention Status, corticosteroid dose reduction, and adverse effects, were assessed.

Results: Seven patients had a history of myasthenic crisis before rituximab; only one had a recurrence after treatment. Overall, 91.7% of patients showed significant clinical improvement and/or reduced need for symptomatic and immunosuppressive therapy. At 18 months, Myasthenia Gravis Foundation of America (MGFA) post- intervention status indicated complete stable remission in 11%, pharmacologic remission in 11% while the rest had minimal manifestations only. Mean corticosteroid doses dropped by 22.5 mg after the first rituximab cycle, 26.4 mg after the second and 29.8 mg after the third. Seventy-five percent experienced no major treatment-related complications.

Conclusion: Early rituximab use in generalized MG appears effective and steroid-sparing, with potential to lessen disease burden and healthcare costs in resource-constrained settings.