[The study on the change of extracellular histones in human plasma during the pathogenesis of silicosis].

OBJECTIVE

To investigate the plasma level of extracellular histones in patients with silicosis, and to explore the role of extracellular histones in the pathogenesis of pulmonary fibrosis in silicosis.

METHODS

Sixty-two patients with silicosis were enrolled as the silicosis group, consisting of 23 patients with stage I silicosis, 25 with stage II silicosis, and 14 with stage III silicosis; sixty workers who had a history of occupational exposure to silica dust for more than 2 years and had not been diagnosed with silicosis were enrolled as the silica dust exposure group; sixty-five healthy workers without a history of occupational exposure to dust were enrolled as healthy controls. Enzyme-linked immunosorbent assay was applied to measure the plasma levels of plasma extracellular histone (H4) and transforming growth factor-β(TGF-β).

RESULTS

Compared with healthy controls [(0.82±0.67) μg/ml], the silica dust exposure group[(4.14±2.85) μg/ml] and silicosis group[(9.50±5.04) μg/ml] had significant increases in plasma level of H4 (P<0.01). The plasma level of H4 was significantly correlated with the stage of silicosis(r=0.8955, P=0.0388). The silicosis group had a significantly higher plasma level of TGF-β than the silica dust exposure group and healthy controls(P <0.05). In the patients with silicosis, the plasma level of H4 was significantly correlated with that of TGF-β(r=0.5375, P<0.01).

CONCLUSION

The plasma level of extracellular histones increases significantly in the pathogenesis of silicosis, and extracellular histones may play an important role in the progression of fibrosis in silicosis.