West Nile virus neuroinvasive disease associated with rituximab therapy

Abstract

West Nile virus neuroinvasive disease (WNVND) manifests with meningitis, encephalitis, and/or acute flaccid paralysis. It represents less than 1% of the clinical syndromes associated with West Nile virus (WNV) infection in immunocompetent patients. Immunosuppressive therapy is associated with increased risk of WNVND and worse prognosis. We present a patient with WNVND during therapy with rituximab, and a review of the literature for previous similar cases with the goal to describe the clinical spectrum of WNVND in patients treated specifically with rituximab. Our review indicates that the most common initial complaints are fever and altered mental status, brain magnetic resonance imaging often shows bilateral thalamic hyperintensities, and cerebrospinal analysis consistently reveals mild lymphocytic pleocytosis with elevated protein, positive WNV polymerase chain reaction, and negative WNV antibodies. Treatment is usually supportive care, with intravenous immunoglobulins (IVIG) plus corticosteroids and WNV-specific IVIG also used. The disease is usually fatal despite intervention. Our patient's presentation was very similar to prior reports, however demonstrated spontaneous improvement with supportive management only. WNVND is a rare and serious infection with poor prognosis when associated with rituximab therapy. Diagnosis is complicated by absent or delayed development of antibodies. The presence of bilateral thalamic involvement is a diagnostic clue for WNVND. There is insufficient evidence to recommend the use of corticosteroids or IVIG.

Keywords: Immunosuppression; Rituximab; Thalamic hyperintensities; West Nile virus; West Nile virus neuroinvasive disease.