The prevalence of retroviral infection in renal transplantation remains poorly defined. We tested retrospectively sera from 224 of 331 patients undergoing renal transplantation between 1979 and 1985. Viral antigen based EIA was used for screening IgG antibodies to human immunodeficiency virus (HIV-I) and human T-cell leukemia virus type I (HTLV-I). Positive EIAs were confirmed by Western blot. Six patients (2.7%) were found to have retroviral infection, four with HIV-1 and two with HTLV-I. The four patients with HIV-1 infection were negative before and became EIA and Western blot positive following transplantation. All patients had transient HIV-1 antigenemia documented before antibody was detected. One patient died of Kaposi's sarcoma 2 years posttransplantion with a functioning graft. One is alive and asymptomatic 4 years posttransplant, and two rejected their grafts and are asymptomatic on maintenance hemodialysis. Six patients tested positive for HTLV-I by EIA. Only two patients, however, were also positive for HTLV-I by Western blot, RIPA, and p24 antigen RIA, one prior to and one after transplantation. Both had HTLV-I-positive lymphocyte cultures and remain asymptomatic of retroviral infection 3 years after renal transplantation. A third patient, positive for HTLV-I by EIA, had indeterminate Western blot and negative RIPA, RIA, and lymphocyte culture. Intravenous drug use was not a risk factor for retroviral infection in this patient population. It is likely that patients became infected peritransplantation from blood transfusions. Contamination by donor kidneys, however, cannot be excluded
