Serum leptin and CD4+ T lymphocytes in HIV+ children during highly active antiretroviral therapy.

Because leptin, the adipocyte-derived hormone, affects thymocyte survival, proliferation of naive T lymphocytes and the production of proinflammatory cytokines, we aimed to investigate the role of this molecule in immunoreconstitution during highly active antiretroviral therapy (HAART). Prospective longitudinal cohort study. A series of 20 HIV+ children were studied. The subjects were grouped by their increase in serum leptin levels after HAART.All participants were weight-stable, free of endocrine disorders and opportunistic infections and equally distributed for sex (males, n=10; females, n=10). Body mass index (BMI), serum lipids, leptin, CD4+ T cells and HIV-1 RNA were measured before initiation of HAART and after a 2-year follow-up. Serum leptin concentration positively correlated with CD4+ lymphocyte number before treatment. HAART significantly reduced viraemia and increased serum levels of lipids in all patients, whereas a significant increase in CD4+ cells and serum leptin was observed in the majority of patients. Notably, in children where HAART was not effective in increasing CD4+ lymphocyte counts, serum leptin did not increase. To our knowledge, these findings reveal for the first time a novel link among CD4+ T lymphocytes, serum leptin and highly active anteretroviral theraphy.