Changes of natural killer T cells in pulmonary tuberculosis patients complicated by diabetes mellitus

Abstract

To investigate the changes of NKT cells in pulmonary tuberculosis patients (PTB) complicated by diabetes mellitus (DM). From January 2008 to June 2010, 40 cases of PTB patients without DM hospitalized in Shanghai Pulmonary Hospital were selected. There were 26 males and 14 females, aged from 19 - 65 (mean, 42 ± 11) years, with an average BMI (20.6 ± 4.7) kg/m(2). Forty cases of PTB complicated with DM were included as patient controls which consisted of 25 males and 15 females, aged from 34 - 68 (mean, 47 ± 10)years, with an average BMI (21.3 ± 1.9) kg/m(2). Thirty-seven healthy controls and 38 cases of non-TB DM in the outpatient department for physical examination were enrolled at the same period. There were 25 male and 12 female healthy controls, aged from 21 - 60 (mean, 42 ± 12) years, with an average BMI (21.9 ± 5.4) kg/m(2). There were 23 males and 15 females in the non-TB DM volunteers, aged from 36 - 65 (mean, 44 ± 8) years, with an average BMI (20.5 ± 3.2) kg/m(2). The percentages of NKT cells with the phenotype of TCRVα24(+)Vβ11(+) in peripheral blood and bronchial alveolar lavage fluid (BALF) were tested by flow cytometry for all the patients. Continuous data were analyzed by t test. Multiple comparisons were performed by SNK and LSD test. The percentages of NKT cells in peripheral blood from non-diabetic PTB [1.1% (0.8% - 1.3%)] and diabetic PTB patients [0.8% (0.5% - 1.0%)] were all significantly higher as compared with healthy controls [0.4% (0.3% - 0.7%)] and DM patients without TB [0.3%(0.2% - 0.5%)] (q = 3.258 - 7.074, respectively, all P < 0.01). The percentages of NKT cells in peripheral blood from non-diabetic PTB patients were also significantly higher as compared with diabetic PTB patients (q = 2.827, P < 0.01). The percentages of NKT cells in BALF from non-diabetic PTB patients [0.7%(0.3% - 1.0%)] were significantly higher as compared with diabetic PTB patients [0.3% (0.2% - 0.6%)] (t = 2.394, P < 0.05). The percentages of NKT cells from BALF in mild, moderate and severe PTB patients were [0.9% (0.3% - 1.3%)], [0.4% (0.3% - 0.9%)] and [0.3% (0.3% - 0.5%)], respectively, which were significantly different (F = 4.535, P < 0.05). The percentages of NKT cells from peripheral blood in mild, moderate and severe PTB patients were [1.0% (0.8% - 1.3%)], [1.0% (0.8% - 1.3%)] and [0.7% (0.5% - 1.1%)], respectively, which were also significantly different (F = 3.763, P < 0.05). The percentages of NKT cells from peripheral blood had a positive correlation with those from BALF (r = 0.709, P < 0.01). NKT cells play an important role in TB infection. The complicated milieus in PTB patients with DM have adverse effects on NKT cells, resulting in their dysfunction.