Changes and significance of peripheral blood T cell subsets, soluble interleukin-2 receptor and interferon-gamma in patients with retreatment pulmonary tuberculosis and initial treatment tuberculosis

Abstract

The aim of this study was to compare the expression of peripheral blood T cell subsets, soluble interleukin-2 receptor (sIL-2R) and interferon-gamma (IFN-γ) in patients with retreatment pulmonary tuberculosis, initial treatment pulmonary and extra-pulmonary tuberculosis, and therefore to explore the cellular immune changes and the significance among different types and severity of tuberculosis. A total of 170 patients with tuberculosis in Pulmonary Hospital of Shanghai from December 2009 to January 2011, including 98 males and 72 females, aged from 16 to 70 years (average 40 years), were included in this study. The patients were divided into retreatment pulmonary tuberculosis group (47 cases), initial treatment pulmonary tuberculosis group (62 cases) and initial treatment extra-pulmonary tuberculosis group (61 cases). Furthermore, the 109 patients with pulmonary tuberculosis were divided into different subgroups according to cavity formation and the lung fields involved: patients without lung cavity (52 cases) vs those with lung cavity (57 cases), patients with involvement of 1 - 2 lung fields (48 cases), vs 3 - 4 lung fields (26 cases) and 5 - 6 lung fields (35 cases). Peripheral blood T cell subsets (by flow cytometry doubled-labeled antibody), sIL-2R and IFN-γ (by ELISA) were determined in 170 patients. Differences between means of 2 groups were tested by t test, differences among multiple groups were tested by analysis of variance (ANOVA), and multiple comparisons among multiple groups were tested by LSD-t test or χ² test. Linear regression equation was used to analyze the correlations. The levels of peripheral blood CD₄/CD₈ in patients with retreatment pulmonary tuberculosis and initial treatment extra-pulmonary tuberculosis patients were significantly lower than that in initial treatment pulmonary tuberculosis patients, [(1.7 ± 0.7), (1.6 ± 0.7) and (2.0 ± 0.7) respectively (F = 4.380, P < 0.05)]. The levels of serum sIL-2R in patients with retreatment pulmonary tuberculosis and initial treatment extra-pulmonary tuberculosis were significantly higher than that in initial treatment pulmonary tuberculosis patients [(224 ± 89) pmol/L, (209 ± 98) pmol/L, (167 ± 73) pmol/L, (F = 6.402, P < 0.01)]. The levels of serum IFN-γ in patients with retreatment pulmonary tuberculosis and initial treatment extra-pulmonary tuberculosis were significantly higher than that in initial treatment pulmonary tuberculosis patients [(37 ± 23) ng/L, (37 ± 24) ng/L, (29 ± 16) ng/L, (F = 2.799, P < 0.05)]. The levels of peripheral blood CD₄/CD₈ in initial treatment and retreatment cavity pulmonary tuberculosis patients were lower than that in pulmonary tuberculosis patients without cavity, but the results of sIL-2R and IFN-γ were the opposite [(1.7 ± 0.6) vs (2.0 ± 0.8), (214 ± 93) pmol/L vs (167 ± 68) pmol/L and (38 ± 22) ng/L vs (27 ± 14) ng/L, t = -2.813 to 3.076, P < 0.05 or P < 0.01]. The level of serum sIL-2R was negatively correlated with peripheral blood CD₄/CD₈ level in all the patients (r = -0.380, P < 0.01). Patients with retreatment pulmonary tuberculosis and initial treatment extra-pulmonary tuberculosis had lower cellular immune function as compared to those with initial treatment pulmonary tuberculosis, and the cellular immune function was significantly correlated with the extent and cavity formation of pulmonary lesions.