Glomerulonephritis after Alemtuzumab Treatment for Multiple Sclerosis: A Report of Two Cases.

Introduction: Alemtuzumab, a humanized monoclonal antibody indicated for the treatment of adult patients with active relapsing-remitting multiple sclerosis (MS), has been associated with increased risk of autoimmune adverse events, including thyroid disorders, immune thrombocytopenia, and renal diseases. Renal immune-mediated adverse events, which have been reported in 0.3% of patients treated with alemtuzumab in MS clinical trials, typically occur within 39 months after the last drug administration. However, no consensus has been reached regarding the management of patients who develop glomerulonephritis after treatment with alemtuzumab. Case Presentation: We report the cases of two young adults with MS who developed biopsy-proven severe glomerulonephritis after alemtuzumab treatment. Both patients, including a 32-year-old female patient who developed membranous nephropathy and a 31-year-old male who developed drug-induced podocytopathy, were treated successfully with the calcineurin inhibitor tacrolimus followed by the anti-CD20 antibody rituximab. Conclusion: Regular renal function monitoring is required in patients who may rarely develop glomerulonephritis following treatment with alemtuzumab. There is no clear consensus on case management. In both cases, immunosuppressive therapy, which was necessary due to disease severity, resulted in successful remission, highlighting the potential utility of this approach.