Differential immunophenotype and proviral composition in young adults with perinatally acquired HIV.

Objective: To characterize the immune functionality and phenotype and the proviral composition of a cohort of young adults with perinatally acquired HIV (p-YA) from Argentina.

Design: Cross-sectional study of 18 p-YA, 15 young adults with nonperinatally acquired HIV matched by age with p-YA and 14 adults with nonperinatally acquired HIV, matched by time from HIV diagnosis with p-YA, all from Argentina.

Methods: Immune memory/effector phenotype, exhaustion, activation, PTK-7 and Ki-67 expression were evaluated by flow cytometry on natural killer (NK) and T cells. Total, intact and defective proviral (TP, IP and DP) HIV-DNA were measured in CD4 + T cells by IPDA. Soluble markers were determined by ELISA.

Results: p-YA displayed lower expression of PD-1, higher levels of CD38 + CD4 + T cells and increased levels of naive T cells than control groups. Also, a trend of lower levels of IP HIV-DNA normalized to CD4 + T-cell counts and to the proportion of naive T cells was found in p-YA.

Conclusion: The higher frequency of naive CD4 + T cells in p-YA cannot be explained by elevated thymic activity nor by a higher T-cell proliferation rate. This imbalance could have been generated early in life and persisted during adulthood. Naive CD4 + T cells may not serve as a major viral reservoir in p-YA. Also, the lower PD-1 + CD4 + T-cell count suggests that p-YA did not present higher levels of exhaustion. These findings suggest that acquiring HIV perinatally may imply different challenges for proviral eradication.