HIV-associated diseases: acute and regressive encephalopathy in a seropositive man.

We observed the development of acute encephalopathy in a healthy human-immunodeficiency-virus(HIV)-seropositive man. HIV was isolated from cerebrospinal fluid but not from peripheral blood. Signs and symptoms resolved quickly without treatment. This viral isolate could be propagated only in umbilical cord lymphocytes, but not in peripheral blood T lymphocytes or in continuous lymphoblastoid cell lines such as CEM. The absence of the virus in the patient's T lymphocytes or infectivity of the virus for T lymphocytes may explain the unusual presentation of HIV-associated encephalopathy without immunodeficiency in an asymptomatic carrier. Moreover, it raises the possibility that acute expression of HIV can be controlled by natural host defence mechanisms and that clinical manifestations may be reversible despite the fact that the patient remains seropositive.