Acanthamoeba encephalitis in a patient with systemic lupus treated with rituximab.

Acanthamoeba species are free-living protozoa that can infect humans and animals. Acanthamoeba can cause serious central nervous system infections in immunocompromised hosts. Here we report a case of Acanthamoeba encephalitis in a patient with lupus nephritis, 1 month after completing a course of rituximab, an anti-CD20 chimeric antibody.