CD56(dim) NK Cell is an Important Factor in T Cell Depletion of cART-Treated AIDS Patients

PURPOSE: To investigate factors involved in T-cell depletion in combination antiretroviral therapy (cART)-treated human immunodeficiency virus 1 (HIV-1)-positive patients. PATIENTS AND METHODS: 29 HIV-1-positive patients were enrolled. The CD4+, CD8+ T cell subsets and CD56(dim) NK cells were detected by flow cytometry. The concentrations of cytokines were measured by enzyme-linked immunosorbent assay. Extraction, amplification, and viral load quantification of specimens were performed using the Roche Cobas Ampliprep/Cobas TaqMan HIV-1 test. RESULTS: Compared with IR group, the total number of red blood cells (RBCs) and lymphocytes (LCs) in INR group was significantly reduced, and there was a significant positive correlation between the number of RBCs and that of LCs. The overall production rates of T cells-related cytokines were lower in INR group. However, the cell-surface expression of programmed death-1 (PD-1) on CD4+ T and CD8+ T cells were markedly elevated in INR group. Moreover, it was found that the proportion and the killing ability of CD56(dim) NK cells significantly increased in INR patients, and significantly correlated with apoptosis of T lymphocytes. CONCLUSION: A poor immune reconstitution in HIV-positive patients might result from multiple factors, including bone marrow suppression, high PD-1 expression on the surface of CD4+ T cells, and over-activation of T and NK cells. Besides, the activity of NK cells and RBCs count might be important auxiliary indicators for immune reconstitution and provided a reliable guidance for developing strategies to improve immune reconstitution.