An examination of signs of disease progression in survivors of the Sydney Blood Bank Cohort (SBBC)

Background: The Sydney Blood Bank Cohort (SBBC) was infected between 1981 and 1984 with a nef/LTR defective strain of HIV-1. Different responses to HIV-1 infection have emerged between cohort members in the last 5 years. Three recipients (C135, C64 and C49) remain asymptomatic, have normal CD4 T cell counts, below detection (BD) viral loads (VL), remain therapy naive and are termed long-term non-progressors (LTNP). The donor (D36) and the two recipients (C98 and C54) have significantly declining CD4 T cell counts, detectable VL and are now long-term survivors (LTS). In contrast, in the SA cohort, comparison study group for the SBBC, five of 24 remain therapy naı̈ve after 15 years infection with HIV-1 and all have detectable VL. Objectives: This paper examines different outcomes to long-term infection with HIV-1 in the SBBC and provides a brief overview of the therapy naı̈ve in a comparison study group, the SA cohort. Study design: Retrospective epidemiological follow-up of the SBBC and the SA cohort has been conducted for >15 years. Analysis of CD4 T cell counts, VL and intermittent monitoring of HIV-specific proliferative responses are reviewed. Viral sequence changes in the SBBC will be considered. Results: Prior to therapy D36 had a CD4 T cell count of 160/mm 3 and plasma VL of 9900 copies/ml while C98 had a CD4 T cell count of 387/mm 3 and plasma VL of 11 491 copies/ml. After 1 month of therapy, plasma VL was BD (