The Chicago Pediatric AIDS Clinical Trials Unit (C-PACTU) plans to participate in the multicenter AIDS clinical trials proposed by the Coordinating and Operations Center (CORC), Stephen A, Spector, M.D., Group Leader, Our goal is to participate in pathogenesis-oriented trials designed to 1) maximize the interruption of maternal- fetal/newborn transmission of HIV; 2) evaluate the effect Of new antiretroviral agents or combination of agents on viral load, immunologic markers and/or clinical outcome; 3) increase our understanding of the role of immune-based therapy; and, 4) manage opportunistic infections and/or evaluate the usefulness Of prophylactic regimens. We have special interest in phase 1/11 studies and plan to continue our participation in these (more difficult) protocols. In addition, we plan to increase participation of adolescents and women who have completed perinatal protocols in ACTG studies. We also plan to enroll patients in supportive-care and long-term follow-up studies. The proposed three units of the C-ACTU are located in different parts of the city of Chicago. The wide-range catchment area of the C-PACTU and the linkages it has developed with many community-based agencies will allow us to reach effectively many Of the families known to be affected by the HIV epidemic in Chicago and the surrounding area. We are applying for funds to support our efforts to 1) enroll 32 new patients per year; 2) enroll another 28 patients who had previously participated in PACTG studies to new protocols; and, 3) to continue follow-up on 106 patients who are already participating in PACTG protocols.