Isolation of infectious human T-cell leukemia/lymphotropic virus type III (HTLV-III) from patients with acquired immunodeficiency syndrome (AIDS) or AIDS-related complex (ARC) and from healthy carriers: a study of risk groups and tissue sources.

Acquired immunodeficiency syndrome (AIDS) and AIDS-related complex (ARC) are thought to be caused by human T-cell leukemia/lymphotropic virus type III (HTLV-III). Since the fall of 1982, independent isolates of HTLV-III have been obtained in this laboratory, in collaboration with several clinical groups, from 101 AIDS and ARC patients and healthy donors at risk for AIDS. Most isolates were from peripheral blood T lymphocytes established in cell culture, but some were obtained from bone marrow, lymph node, brain tissue, and cell-free plasma and from cells associated with saliva, cerebrospinal fluid, and semen. Virus was isolated from approximately 50% of AIDS patients, 85% of ARC patients, and 30% of healthy individuals at risk for AIDS. The risk groups included homosexuals, promiscuous heterosexuals, i.v. drug users, recipients of blood or blood products, and spouses and offspring of AIDS patients and others at risk for AIDS. A high correlation was seen between persistent levels of serum antibody and the ability to isolate virus from patient or donor leukocytes. Immunologic and nucleic acid analysis demonstrated that the virus isolates were highly related, although substantial diversity was observed in the restriction enzyme cleavage patterns of those studied in detail. Biological analysis of cells from infected patients and donors as well as from normal peripheral blood mononuclear cells exposed to virus in vitro demonstrated that OKT4/Leu3a+ (helper/inducer) lymphocytes were preferentially infected and were subjected to a characteristic cytopathic effect. The availability of multiple isolates of virus from a number of different patients and donors will greatly facilitate the characterization of HTLV-III and the study of possible biological and/or biochemical variants of the virus responsible for the development of AIDS, ARC, and related diseases.