Serologic Evidence of an Association

We studied patients with transfusion-associated acquired immunodefi- ciency syndrome (AIDS) and their blood donors for serologic evidence of infection with human T-cell lymphotropic virus type III/lymphadenopathy- associated virus with two enzyme-linked immunosorbent assays and a Western blot assay. All 19 patients with AIDS were seropositive by at least one test. In all 28 donor sets containing "high-risk" donors, at least one donor was seropositive by one or more tests. Of 255 donors not considered high risk, two (0.8%) were seropositive by all three tests. When 30 seropositive high-risk donors were evaluated a median of 29 months after donation, four (13%) had developed AIDS and eight (27%) had lymphadenop- athy. Our findings support the hypothesis that human T-cell lymphotropic virus type III/lymphadenopathy-associated virus causes AIDS and indicate that seropositive high-risk donors may be at relatively high risk for developing AIDS or related conditions themselves. (JAMA 1985;254:770-773)