RESUMEN
Objective To investigate the expression and significance of programmed death-1 (PD-1) in cellular immune response of patients with tuberculosis (TB) infection .Methods Twenty drug-sensitive (DS) and fifteen drug-resistant (DR ) subjects with TB infection who were hospitalized in Jiangmen Central Hospital affiliated Sun Yat-Sen University and Jiangmen tuberculosis dispensary from July 2011 to July 2012 were included in this study . Twenty-six healthy subjects were included as control . The expressions of PD-1 on CD4 + and CD8 + T lymphocytes were measured using flow cytometry and plasma interferon-γ (IFN-γ) ,levels were analyzed before and after TB treatment for 3 months .Kruskal-Wallis H test was used for analysis of multiple independent samples and Wilcoxon signed-rank test was used for analysis of paired samples . Pearson test was used for correlation analysis . Results After anti-TB chemotherapy ,the expressions of PD-1 on CD4 + and CD8 + T cells in both TB groups were significantly decreased (DS group :15 .99% vs 21 .59% and 11 .86% vs 18 .52% ;DR group :26 .64% vs 35 .47% and 29 .64% vs 34 .56% ) (both P 0 .05) .In DS group ,the expression of PD-1 on CD4 + T lymphocytes was negative correlated with plasma IFN-γ level both before and after anti-TB chemotherapy (pre-treatment : r = - 0 .510 , P < 0 .05 ; post-treatment : r = - 0 .520 , P< 0 .05 ) . Conclusions PD-1 modulates T cell function of immune response against TB infection in DS-TB subjects and plays a key regulatory role in CD4 + T lymphocyte mediated immunity during TB infection . However , the immunomodulatory mechanism of cell immunity in DR-TB subjects may be more complex .