Clinical significance of CC16 and IL-12 in bronchoalveolar lavage fluid of various stages of silicosis.

Abstract

Identification of novel biomarkers for silicosis could be helpful for disease diagnosis and pathophysiological mechanism exploration. Our study aims to investigate the Clara cell secretory 16-kd protein (CC16) and interleukin-12 (IL-12) levels in bronchoalveolar lavage fluid (BALF) in patients with silicosis at various stages. The enzyme-linked immunosorbent assay (ELISA) double antibody sandwich method was used to determine the CC16 and IL-12 in BALF levels from 79 patients with silicosis of various stages. Correlation analyses were performed between CC16 and IL-12 levels, and lung function and cytological counts in patients with silicosis at various stages. There were no significant differences in the BALF recovery volume, the number of cells, percentages of macrophages and lymphocytes in the alveolar lavage fluid of patients with silicosis in different stages (P>0.05); the percentage of neutrophils in stage I and stage II were higher than the control group (P<0.05) with statistically significant differences. The CC16 in BALF levels in stage I and II silicosis groups lower than the control group and stage III silicosis group with statistically significant differences (P<0.05), whereas CC16 levels in stage II silicosis group are higher than the stage I group (P<0.01). The IL-12 levels were higher than the control group (P<0.01), and the IL-12 levels in stage II and III silicosis group was higher than the stage I silicosis group (P<0.01). With the increase of the length of dust service, the CC16 and IL-12 levels decreased and showed a positive correlation between these indexes (correlation coefficient r=0.559, P<0.01). In addition, CC16 silicosis patient levels were positively correlated with FEV1/FVC and VCmax (r=0.242, 0.257; both P<0.05); IL-12 levels were negatively correlated with FEV1 and VC max (r=-0.250, -0.483; both P<0.05). The CC16 and IL-12 levels may have a specific reference value for the early diagnosis of silicosis and the assessment of lung function.