HTLV-III/LAV antibodies and virus in hemophilia patients in Nebraska: survey and initiation of a prospective study.

Thirty-nine patients from the Nebraska Regional Hemophilia Center were studied for the prevalence and titers of antibodies to HTLV-III/LAV, and for clinical symptoms of possible progression toward the acquired immunodeficiency syndrome (AIDS). Fourteen of 26 (54%) patients with hemophilia A were positive for HTLV-III/LAV antibodies as determined by immunofluorescence and Western blotting. Retrovirus was detected in cultured lymphocytes of two out of three seropositive individuals by reverse transcriptase assay and molecular hybridization with cloned HTLV-III/LAV probe. Of the twelve factor VIII-deficient patients who were seronegative, one had received only heat-treated factor VIII concentrates, six only cryoprecipitate or fresh frozen plasma, two prothrombin complex concentrates, one had not been transfused since 1983, and two had never been transfused. None of the patients treated only with factor IX concentrates, volunteer donor plasma, or cryoprecipitate had HTLV-III/LAV antibodies. In 12 of 14 seropositive hemophiliacs, titers of serum antibodies to HTLV-III/LAV ranged from 1:1,280 to 1:10,240, indicating a strong immune response against HTLV-III/LAV antigens and/or persistent infection with the virus. In spite of the possible exposure to HTLV-III/LAV during the past four years, none of the patients in this group had AIDS. Whether or not this group of patients has developed immunity to the AIDS retrovirus remains to be determined.