Optimising Cohorts for HIV Cure Interventions: the Role of Very High CD4 T Cell Counts: HI-ART Study

In a recent international substudy of START (Study of Initiation of ART in Early HIV Infection), we found that people with HIV (PHIV) who initiate ART with CD4+ T cells \> 800 cells/μL achieve a substantially smaller HIV reservoir on ART, as measured by the frequency of CD4+ T cells containing HIV DNA, compared to individuals who commence ART with CD4 counts between 500-599 and 600-799 cells/µL. We have termed these individuals 'HI-ARTs' (very High CD4 prior to ART). Smaller reservoirs have also been noted in PHIV who achieve a CD4 count greater than 1000 cells/µL within 48 months of initiation of ART who are referred to as 'Hypers'. This study will establish a prospective cohort of HI-ARTs and Hypers at Alfred Health and our clinical partners. It will characterise the HIV reservoir and HIV-specific immune responses in these individuals and compare these to age-matched HIV positive controls from the Alfred HIV clinic, who have CD4+ T cells between 500-800 cells/uL, or who do not reconstitute their CD4+ T cells to greater than 1000 cells/uL within 48 months. Participants will be asked to donate a blood sample at baseline, and pending initial analyses, again at month 12 and 24.