[A study on the Th1/Th2 cytokines in the pathogenesis of human tuberculous pleuritis].
OBJECTIVE
To evaluate the distribution characteristics of Th1-type cytokines (IFN-gamma and IL-2) and Th2-type cytokines (IL-4 and IL-10) in the serum and the pleural effusion in patients with pleural tuberculosis, therefore to gain insight into the possible role of the local and the systemic Th1/Th2 cell-mediated immune response in the pathogenesis of human pleural tuberculosis.


METHODS
The concentrations of IFN-gamma, IL-2, IL-4, and IL-10 in the serum and the pleural effusion of patients with pleural tuberculosis (Group pleuritis) were measured with enzyme linked immuno-sorbent assay (ELISA). The serum levels of the four cytokines were compared with those of patients with pulmonary tuberculosis (Group tuberculosis) and of healthy controls with positive reaction to PPD skin test (Group healthy).


RESULTS
(1) The median concentrations of IFN-gamma, IL-2, IL-4, and IL-10 in serum were 118.60 ng/L, 0.00 ng/L, 1.49 ng/L, and 0.00 ng/L respectively in Group pleuritis, 265.75 ng/L, 18.03 ng/L, 16.00 ng/L, and 0.00 ng/L respectively in Group tuberculosis; and 221.70 ng/L, 18.52 ng/L, 16.00 ng/L, and 0.00 ng/L respectively in Group healthy. (2) For IFN-gamma and IL-2, there existed no statistical differences among the three groups (K-W chi(2) value was 1.15 and 4.68, P > 0.05); For IL-4 and IL-10, there existed no statistical differences between Group tuberculosis and Group healthy (Mann-Whitney Z value was -0.27 and -1.93, P > 0.05), but the level of IL-4 in Group pleuritis was lower than that in Group tuberculosis (Mann-Whitney Z value was -2.84, P < 0.01). (3) The ratio of the median of IFN-gamma to IL-4 in serum was 27.93 in Group pleuritis, 21.72 in Group tuberculosis, and 10.82 in Group healthy respectively. There existed no statistical difference among the three groups (K-W chi(2) value was 4.18, P > 0.05). (4) The median concentrations of IFN-gamma, IL-2, IL-4, and IL-10 in pleural effusion of Group pleuritis were 823.37 ng/L, 43.76 ng/L, 26 ng/L and 38.69 ng/L respectively, each being statistically higher than that in the serum (Wilcoxon Signed Rank test Z value was -4.34, -2.82, -3.29 and -5.15, P < 0.05).


CONCLUSIONS
Immunocompetent persons including patients with pleural tuberculosis, with pulmonary tuberculosis or the healthy with positive results to PPD test, showed similar systemic Th1 response to Mycobacterium bacilli. Due to the relatively lower level of systemic Th2 response, patients with pleural tuberculosis had higher systemic Th1/Th2 level and the enhancement of local Th1 and Th2 responses in the pleural cavity was a pathophysiologic characteristic of human pleural tuberculosis. Both Th1 and Th2 responses might play an important role in the pathogenesis of human pleural tuberculosis.
Li
Yan-hong
YH
Department of Internal Medicine, Guangzhou Chest Hospital, Guangzhou 510095, China.
Xie
Can-mao
CM
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016207:Cytokines / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000097:blood; D007376:Interleukin-2 / Q000097:blood; D008297:Male; D008875:Middle Aged; D018417:Th1 Cells / Q000378:metabolism; D018418:Th2 Cells / Q000378:metabolism; D014396:Tuberculosis, Pleural / Q000097:blood / Q000209:etiology*
D016207:Cytokines; D007376:Interleukin-2; D007371:Interferon-gamma