Reduced NK Cell subsets in perinatally acquired long term non progressors HIV infected children.

BACKGROUND: Lymphocyte subsets of long term non progressor HIV infected children is a less studied aspect of HIV infection.

MATERIALS AND METHODS: Evaluation of different lymphocyte subsets was done in HIV infected children ≥ 8 years of age. Subjects were divided in two groups (Group 1 (LTNP), treatment naive with CD4 ≥ 500 cells/µl (n=20), Group 2, (nLTNP) receiving antiretroviral therapy (ART) with CD4 count ≤ 500 on at least one occasion (n=21). Group 3 comprised of age, sex matched healthy controls (n=20). Lymphocyte subsets were acquired on a flow cytometer (Navios, Beckman coulter) and data was analyzed using Kaluza flow analysis software.

RESULTS: The mean ages were 12.1 (±2.4), 12.5 (±2.7) years with mean duration of follow up of 6.8 (±3.4 SD) and 5.6 (±1.95 SD) years in LTNP and nLTNP subjects respectively. The mean duration of ART was 5.17 years in Group 2. Absolute count and percentage of CD4+ T cells was lower in nLTNP than in LTNPs. Cytotoxic T cells were high in both HIV infected groups as compared to healthy controls. NK cells were found to be significantly lower in LTNP and nLTNP group as compared to healthy controls (p≤0.000003 & p≤0.00003 respectively). Naïve B cells were more in HIV infected individuals than in healthy controls.

CONCLUSION: NK cells were significantly lower in LTNP and nLTNP group. Immune reconstitution was comparable in children initiated with ART early versus long term HIV infected children receiving no ART.