Study of CD4+T and CD8+T cells expressing interferon γ changes in active pulmonary tuberculosis patients

Objective Percentages of CD4+ and CD8+ T cells expressing interferon gamma (IFN-γ) in patients with active tuberculosis were compared before and after 2 months standard treatment. Methods Fourty cases of newly diagnosed active tuberculosis patients admitted to the hospital from March 2015 to June 2016 were selected.The whole blood was collected before and after 2 months treatment in all 40 patients.The percentage of CD4+T, CD8+T, CD4+T and CD8+ T cells expressing IFN-γ were detected by flow cytometry.The enzyme-linked immunosorbent assay (ELISA) was used to measure the serum IFN-γ expression. Results The percentages of CD4+T and CD8+ T cells in patients with active tuberculosis before and after treatment had no statistical difference (P>0.05). The percentage of CD4+ T cells expressing IFN-γ after treatment (4.30±2.01)% was significantly lower than those before treatment (2.06±1.03)%(t=4.162, P=0.000 5). There showed no significant difference in the percentages of CD8+ T cells expressing IFN-γ between patients before and after treatment (P>0.05). Serum IFN-γ expression (53.82±8.84) ng/L before treatment was significantly higher than that after treatment (47.73±9.17) ng/L(t=2.709, P=0.013 9). Conclusions The percentage of CD4+ T cells expressing IFN-γ in newly active pulmonary tuberculosis was higher than that after 2 months treatment, suggesting that CD4+ T cells expressing IFN-γ may play a role in the prevention and treatment of tuberculosis infection. Key words: Tuberculosis, pulmonary; T-lymphocytes; Interferon γ