Roles of serum clara cell protein 16 and surfactant protein-D in the early diagnosis and progression of silicosis.

OBJECTIVE: To study roles of Clara cell protein 16 (CC16) and surfactant protein-D (SP-D) as serum biomarkers in the early diagnosis and the pathogenesis of silicosis. METHODS: Thirty healthy volunteers, 30 silica-exposed workers, and 30 workers with suspected silicosis and phase I silicosis were included. Serum CC16 and SP-D concentrations were determined using enzyme-linked immunosorbent assay. RESULTS: Serum CC16 concentrations decreased in silica-exposed workers when compared with in controls, but serum SP-D levels increased, and this trend was obvious in phase 0 and I groups. Discriminant analysis showed that the accuracies of classifying group membership into control, phase 0, phase 0, and phase I were 86.7%, 46.7%, 66.7%, and 70%, respectively, and the total classification accuracy rate was 67.5%. CONCLUSION: Serum CC16 and SP-D may be useful biomarkers for early diagnosis, and serum SP-D concentration may associate with the pathogenesis of silicosis.

Screening of serum biomarkers and establishment of a decision tree in silica-exposed populations by surface-enhanced laser desorption ionization time-of-fly mass spectrometry.

OBJECTIVE: To screen for serum biomarkers of silicosis and to study their roles using surface-enhanced laser desorption ionization time-of-fly mass spectrometry (SELDI-TOF-MS) techniques. METHODS: The serum protein/peptide profile on the CM10 proteinchip was acquired using SELDI-TOF-MS from workers classified by the Chinese national diagnostic standard for pneumoconiosis. Discriminant analysis was performed to establish a decision tree using protein/peptide peaks. RESULTS: Protein/peptide peaks changed much more in silica-exposed populations than they did in the control. Discriminant analysis using Wilks' lambda method could give high sensitivity and specificity in distinguishing the silica-exposed population from the control; the decision tree could give 100% sensitivity and 95% specificity in distinguishing the silicosis phase among the control group. CONCLUSIONS: Special proteins/peptides may change in silica-exposed workers and these changes may be used to distinguish silica-exposed populations from the control with the proper discriminant analytical method.

[Changes of Clara cell protein and surfactant protein-D in serum of patients with silicosis].

OBJECTIVE: To explore changes of Clara cell protein (CC16) and surfactant protein-D (SP-D) in the serum of patients with silicosis. METHOD: The concentrations of CC16 and SP-D were measured in the serum by sandwich enzyme-linked immunosorbent assays. The subjects consisted of 30 healthy volunteers and 90 silica-exposed workers including silica-exposed group, the silicosis of suspects group (0(+)) and the silicosis phase I group, 30 subjects each groups. RESULTS: The concentrations of CC16 in the serum was significantly decreased in silica-exposed workers compared to controls (P < 0.01); The concentrations of CC16 in the serum were higher in lifelong nonsmokers than the current smokers in control subjects (P < 0.05), but they were no differences between lifelong nonsmokers and current smokers of 90 silica-exposed workers. Compared with control subjects, the levels of SP-D in the serum of silicosis suspects (0(+)) and silicosis phase I groups were significantly elevated (P < 0.01, respectively), which were also higher than silica-exposed group (P < 0.05 and P < 0.01, respectively), Discriminant equations set by CC16 and SP-D were used in diagnosis of silicosis, and the rate of accuracy in healthy volunteers, the silica-exposed group and the silicosis phase I group were 86.7%, 86.7% and 76.7%, respectively, The total rate of correct classification hit 84.2%. CONCLUSION: The serum CC16 of long-term silica-exposed workers is decreased, and SP-D is increased gradually.