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.
Keywords: AIDS, T-cells, CD56^dim NK cells, antiretroviral therapy, immune reconstitution