Enteroviral Meningoencephalitis as a Complication of Rituximab Therapy for Rheumatoid Arthritis.

Enteroviral meningoencephalitis is a rare complication of rituximab therapy that has been described in the treatment of hematologic malignancies. We report the first case of enteroviral meningoencephalitis in a patient receiving rituximab for the treatment of rheumatoid arthritis. A 37-year-old female treated with rituximab for severe rheumatoid arthritis presented with fever, headache, confusion, and tremor. Magnetic resonance imaging (MRI) of the brain was unrevealing. Cerebrospinal fluid showed a lymphocytic pleocytosis and multiplex polymerase chain reaction (PCR) was positive for enterovirus. She was treated with intravenous immunoglobulin (IVIG) for five days and had significant improvement in symptoms. Rituximab is an anti-CD20 monoclonal antibody that induces B-cell depletion and possible hypogammaglobulinemia, putting patients at increased risk for viral infections. We present this case to highlight that patients on rituximab, regardless of the indication for use, are susceptible to severe complications of otherwise typically self-limited viral infections. Furthermore, we describe the potential use of IVIG in treating these patients.