A randomized case-control study of dynamic changes in peripheral blood Th17/Treg cell balance and interleukin-17 levels in highly active antiretroviral-treated HIV type 1/AIDS patients.

Our objective was to dynamically observe changes in peripheral blood Th17, Treg cells, and interleukin (IL)-17 levels in HIV-1/AIDS patients before and after highly active antiretroviral therapy (HAART). The study design consisted of a randomized case-controlled study. A total of 33 HIV-1/AIDS patients were chosen to receive a HAART regimen and 30 healthy volunteers were assigned as controls. Peripheral blood Th17 and Treg cells were measured by flow cytometry before or 6 and 12 months after HAART therapy. The plasma IL-17 level was determined by ELISA. The percentage of Th17 cells to total CD4(+) cells was 1.2 ± 0.37% in HIV/AIDS patients before treatment, which was significantly lower than that in uninfected controls (4.7 ± 1.43%). After HAART therapy for 6 or 12 months, the Th17 percentage increased to 2.5 ± 1.03% and 3.7±1.56%, respectively. The percentage of Treg cells to CD4(+) cells is 9.16 ± 3.33% in HIV/AIDS patients, which was significantly elevated compared to controls (4.43 ± 0.97%). HAART therapy for 6 and 12 months significantly decreased Treg cell percentage (7.19 ± 2.91% and 5.53 ± 1.88%, respectively). Interestingly, the ratio of Th17/Treg cells was significantly decreased in HIV/AIDS patients before treatment, while HAART treatment partially normalized the Th17/Treg ratio. IL-17 levels were 5.3 ± 2.5 and 17.7 ± 6.60 pg/ml in HIV/AIDS patients and controls, respectively; the HAART regimen increased the IL-17 level to 7.7 ± 2.4 and 10.4 ± 3.1 pg/ml at 6 and 12 months, respectively. The percentage of Th17 cells correlated with IL-17 level, but both negatively correlated with viral load before treatment, whereas the percentage of Treg cells positively correlated with viral load before HAART therapy. The imbalance of peripheral blood Th17 and Treg cells may play a crucial role in the pathogenesis of AIDS. HAART can restore the balance of Th17 and Treg cells as well as the IL-17 level, which may gradually rebuild the immune equilibrium in HIV/AIDS patients.