HTLV-1 seroprevalence in AIDS patients and in HIV-1 seropositive and seronegative subjects at risk for AIDS in northern Italy.

Sera of 1023 subjects belonging to categories at risk for AIDS, positive for HIV-1, were tested for antibodies to human T-cell leukemia virus (HTLV-1) by ELISA, Western blotting, and radioimmunoprecipitation (RIP) assay. Sera of these subjects were positive for antibodies to HTLV-1 in a percentage of 18.54%. Nine out of 18 sera from patients with AIDS had antibodies to HTLV-1 (50%). Sera of 207 intravenous drug abusers and 64 homosexual males, seronegative for HIV-1, were tested for antibodies to HTLV-1 and 6.7% of intravenous drug abusers and 7.8% of homosexual males were found to be HTLV-1 antibody positive, showing that HTLV-1 infection occurred independently of HIV-1 and HIV-2 infections. In fact the same HIV-1 seronegative patients were also tested for the presence of antibodies to HIV-2 and none of them was found to be positive.