Expression levels of surfactant-associated proteins and inflammation cytokines in serum and bronchoalveolar lavage fluid among coal miners: a case-control study.

OBJECTIVE: To investigate whether the Th1/Th2 balance and expressions of surfactant-associated proteins and cytokines in serum and bronchoalveolar lavage fluid (BALF) are associated with the development of coal workers' pneumoconiosis (CWP).

METHODS: A case-control study was conducted among 72 CWP cases and 68 controls. Th1 and Th2 populations were measured by flow cytometry. Expressions of surfactant-associated proteins A and D (SPA and SPD) and cytokines in serum and BALF were detected by enzyme-linked-immunosorbent serologic assay. Data were analyzed by t test and logistic regression.

RESULTS: Higher Th2 and lower Th1/Th2 were observed in CWP (P < 0.05). Increased CWP risk was associated with elevated BALF-interleukin-10 (odds ratio [OR]: 25.97; 95% confidence interval [CI]: 2.17 to 49.77), serum-SPA/BALF-SPA (OR: 12.87; 95% CI: 1.11 to 148.72), and serum-SPD/BALF-SPD (OR: 77.91; 95% CI: 5.64 to 161.46), decreased BALF-SPA (OR: 0.06; 95% CI: 0.01 to 0.31) and BALF-SPD (OR: 0.07; 95% CI: 0.02 to 0.36).

CONCLUSIONS: The development of CWP might be associated with Th1/Th2 imbalance and increased BALF-interleukin-10, serum-SPA/BALF-SPA, and serum-SPD/BALF-SPD.