AIDS has occured in 14 patients with hemophilia A who use Factor VIII (AHF) concentrates. Many other hemophiliacs treated with AHF concentrates also had subclinical immune disorders, leasing to speculation that AIDS virus(es) may be transmitted from plasma donors with prodromal or unrecognized AIDS to hemophiliacs via AHF concentrate. Several findings suggest that even if "high risk" lots of AHF can be identified, the likelihood of detecting AIDS viruses in any given vial will be small. However if the single-virus hypothesis for AIDS is correct, viruses transmissible through AHF would be strong candidates for the putative AIDS agent. We will use two new approaches to directly test the hypothesis that infectious viruses suspected of causing AIDS could be concentrated in AHF preparations. (1). We will prepare AHF concentrates from plasma of homosexual men with prodromal signs or with AIDS; this will maximize the ability to detect viruses since they will not be diluted several thousandfold with normal plasma. The AIDS AHF concentrates will be compared with AHF made from normal controls, patients with chronic infections with cytomegalovirus (CMV) or Epstein-Barr virus (EBV) without AIDS and patients with the autoimmune disease systemic lupus. We will test for the presence of viruses previously isolated from patients with AIDS (CMV, EBV, HTLV, and adenoviruses) as well as for parvoviruses, which can infect the immune system. AIDS and control AHF concentrates will be tested for infectious viruses by inoculating cell cultures at 37C and 32C, and looking for evidence of virus growth (viral CPE, interferon, reverse transcriptase in the medium or the cells, viral inclusions in H & E stained cells, and viral antigens in immunofluorescence tests). We will also test for viral antigens in AIDS and control AHF concentrates by using a sensitive solid phase radioimmunoassay developed to detect viral antigens in immune complexes. Encapsidated viral nucleic acids in AHF concentrates will be extracted and identified in endogenous and exogenous polymerase assays. These experiments may identify defective, non-autonomous or "new" viruses which could be cloned for further study. (2). We will perform reconstruction experiments with normal plasma containing viruses from several different taxonomic groups, virus-infected cells or mononuclear cells from AIDS patients to determine which types of viruses could retain infectivity during preparation of commercial AHF concentrates.