Severe coxsackie virus B5 encephalitis mimics autoimmune limbic encephalitis in a young woman under long-term B-cell depletion with ocrelizumab: A case report.

Background: B-cell-depleting therapies are increasingly being used to treat autoimmune diseases. Although thousands of patients are and have been treated with these agents, the data are not yet strong enough to identify rare side effects with certainty.

Methods: We report the case of a patient undergoing ocrelizumab therapy for relapsing multiple sclerosis who developed a severe limbic syndrome.

Results: Autoimmune pathogenesis was initially suspected, with worsening on immunosuppressive therapy. Later, after diagnosis of an enterovirus infection, treatment with ribavirin and favipiravir in combination with intravenous immunoglobulins was initiated. After 4 weeks of therapy, the patient's clinical condition had stabilized with residual cognitive deficits.

Conclusion: Diagnosis and treatment of enterovirus infections remain challenging, especially in patients receiving immunosuppressive therapy.