HTLV-III in symptom-free seronegative persons.

Of 96 patients with acquired immunodeficiency syndrome (AIDS) or AIDS-related complex and healthy individuals at risk for AIDS, 4 had no detectable antibodies to viral proteins, though human T-cell leukaemia (lymphotropic) virus type III was isolated from their lymphocytes. 3 of these subjects were symptom-free and 1 had lymphadenopathy. All 4 were sexual partners of patients with AIDS or AIDS-related complex. The occurrence of seronegative but virus-positive persons without clinical symptoms suggests that assays other than those detecting antibody to virus, perhaps based on detection of viral antigens or immune complexes, may be required to identify all infected individuals.