The aim is to investigate the hypothesis that IL7-receptor polymorphisms contribute to the differential immune recovery of CD4 + T cells following HAART

AIM: To examine the association between the four haplotypes of IL-7Rα gene and a cohort of HIV infected patients who have commenced HAART with varying CD4+ T lymphocyte responses.

METHODS: IL-7Rα gene SNPs and haplotypes will be measured by constructing DNA pools, and PCR amplification and DNA sequencing. IL-7Rα expression will be examined using constitutive expression of IL-7Rα, IL-7Rα gene expression, and inducible expression of IL7Rα.

Inclusion Criteria:

• Men or women at least 18 years of age
• First antiretroviral regimen composed of HAART as defined by at least three antiretrovirals
• Controlled viremia for a period of at least 12 months following commencement of HAART. Controlled viremia is defined as HIV viral load of ≤ 500 copies/mL on bDNA testing (versions 2 and 3) and <400 copies/ml measured by RT-PCR assay by 6 months treatment.
• CD4 cell count <500 at commencement of HAART
• Measurement of CD4+ cell count on at least 3 time points, in the 12 months post commencement of HAART.

Exclusion Criteria:

• Exclude patients treated for HIV seroconversion illness
• Exclude patients on immunomodulatory therapy such as IL-2, hydroxyurea or prednisolone or who have received an HIV therapeutic vaccine

HIV infected patients on HAART