Disseminated Ureaplasma urealyticum infection presenting as systemic inflammatory syndrome in ocrelizumab-treated patients with multiple sclerosis: a case series

Ocrelizumab, an anti-CD20 monoclonal antibody, is widely used to treat multiple sclerosis (MS), inducing profound B-cell depletion and disease remission. However, it may rarely lead to opportunistic infections. We report two patients with MS on ocrelizumab who developed unique complications of anti-CD20 antibody therapy. One patient developed fulminant endophthalmitis, a novel complication that has not been previously reported. A 38-year-old female of South Asian descent and a 46-year-old White female, both with MS on ocrelizumab, developed disseminated Ureaplasma urealyticum infection which was initially misdiagnosed as reactive arthritis in both cases. Both patients deteriorated following immunosuppression, with one developing fulminant endophthalmitis. Diagnosis was established via broad-range PCR from synovial and ocular samples. Prolonged antimicrobial and glucocorticoid therapy led to resolution in both cases. Novel B-cell targeting agents can be effective treatments for MS; however, their use may be associated with potentially life-threatening complications. These two cases highlight the diagnostic and therapeutic challenges associated with opportunistic infections in the context of anti-CD20 monoclonal antibody therapy.