13th Annual Conference of the British HIV Association 29 March–1 April 2007, Brighton, UK

EFFECTS OF EARLY HAART IN ACUTE HIV-1 INFECTION ON IMMUNE RESPONSES AND HIV-1 PROVIRAL DNA

HIV Med 2007; 8(Suppl. 1):6 (abstract no. O21)

Catherine Burton¹, Christopher Mela¹, Antonio Pires¹, Mark Nelson², Brian Gazzard², Frances Gotch¹ and Nesrina Imami^1
1Imperial College, London, UK, ²Chelsea and Westminster Hospital, London, UK

BACKGROUND: It is hypothesized that the HIV-1-specific T-cell responses observed immediately after infection may be preserved by initiating ART during acute disease. In a longitudinal study of nine patients, HIV-1 plasma RNA, lymphocyte subsets and HIV-1-specific T-cell responses were monitored. Proviral DNA was quantitated and compared to levels observed in chronic and non-progressor HIV-1+ patients.

METHODS: Responses to pools of peptides of HIV-1 Gag, Nef and Tat were assessed by proliferative responses (LPR) and intracellular cytokine staining. Statistical significance was calculated using Wilcoxon’s signed-ranks test, or Mann–Whitney U test, presented as P-values, with a cut-off for significance of P<0.05.

RESULTS: At baseline patients had a median CD4 and CD8 T-cell count of 706 and 776 cells/µl respectively and a median HIV-1 plasma load of 3107 copies/mL. There were more CD4+/IFN-γ responses for Tat than Gag (P<0.021) or Nef (P<0.02) at baseline. Similarly, there were more Tat than Gag (P<0.02) and Nef (P<0.021) specific CD8+/IFN-γ + cells at baseline. By week 38, Gag responses became predominant. LPR to Tat and Gag peaked at week 28, but were detectable throughout. The LPR to Nef improved over the study. Levels of HIV-1-proviral DNA post-ART were higher (P<0.002) in the chronic compared to the acute and non-progressor groups.

CONCLUSION: Anti-Tat CD8 responses waned during the study most likely due to early viral escape, whilst anti-Nef and anti-Gag responses became dominant, suggesting that even early ART might not be enough to prevent viral escape from immune control. The low levels of HIV-1 proviral DNA in the acute treated group demonstrates an association between early ART and decay of the cellular HIV-1 reservoirs.

2007-03-29
O21

Copyright © 2007 - British HIV Association (BHIVA) Reproduction of this abstract (other than one copy for personal reference) must be cleared through the BHIVA Organising Secretariat 1 Mountview Court, 310 Friern Barnet Lane, London N20 0LD