Human immunodeficiency virus (HIV)-specific antibodies, neutralizing activity and antibody-dependent cellular cytotoxicity (ADCC) in the cerebrospinal fluid of HIV-infected patients.

We assessed the capacity of cerebrospinal fluids (CSF) and sera from human immunodeficiency virus (HIV)-seropositive patients to neutralize HIV and to mediate specific antibody-dependent lysis of HIV-infected target cells. A local HIV-specific intrathecal antibody synthesis was found in all stages of HIV infection regardless of neurological manifestations. Virus-neutralizing antibodies could not be detected in the CSF of patients with primary encephalitis or polyneuropathy. Cytotoxic antibodies mediating HIV-specific antibody-dependent cellular cytotoxicity (ADCC) were demonstrable in the CSF of most patients without evidence of central nervous system (CNS) involvement, but only in 43% of cases with HIV encephalitis. In some cases, the exclusive detection of ADCC activity in either the CSF or serum compartment suggested the presence of non-identical target antigens in the CSF and serum of the same patient. Further studies are needed to clarify the significance of these findings for the manifestation of CNS involvement in HIV infection.