OBJECTIVETo analyze the correlation between the pneumoconiosis severity and the cytokines levels in serum and bronchoalveolar lavage fluid (BALF) or blood T cell subsets.

METHODSThe subjects were divided into five groups: control group (6 cases), group exposed to dusts (6 cases) and 3 pneumoconiosis groups (36 in stage I, 12 in stage II and 10 in stage III). ELISA was used to detect IL-6, sIL-2R and TNF-α levels in serum and BALF. The subsets of blood T cells were classified by flow cytometer.

RESULTSAs compared with control group and group exposed to dusts, the levels of serum IL-6 and sIL-2R in patients with II or III stages significantly increased, which were positively correlated with pneumoconiosis stages (r(1) = 0.74, r(2) = 0.81, P < 0.05). The level of serum TNF-α significantly decreased in patients with III stages, as compared with control group and group exposed to dusts. There was a negative correlation between serum TNF-α level and pneumoconiosis severity (r = -0.58, P < 0.05). There was a positive correlation between the levels of IL-6, sIL-2R and TNF-α in BALF and the levels of IL-6, sIL-2R and TNF-α in serum (r(1) = 0.77, r(2) = 0.96 and r(3) = 0.88, P < 0.05). The proportion of CD(4)(+)T cells and the ratio of CD(4)(+)/CD(8)(+) decreased dramatically in patients with II and III stages. But there was no correlation between these values and disease severity.

CONCLUSIONThe immune function in Th cell was inhibited. The levels of IL-6, sIL-2R and TNF-α in serum and BALF were associated with the severity of pneumoconiosis.