[Characteristics of lung function in patients with asbestosis of different stages]

Objective: To investigate the characteristics of lung function in the patients with asbestosis of different stages, and analyze the correlations between the pulmonary function values and imaging score of chest X-ray. Methods: A cohort of newly diagnosed 249 asbestosis patients over a period of eight years in a single center were evaluated. Clinical data were collected from clinical charts. Radiographs were reviewed by the experts blinded to clinical data. The asbestosis patients were classified into I to III stages by chest X-ray according to the guideline. The correlations between the pulmonary function values and imaging score of chest X-ray were analyzed. Results: The prevalence of stage I to III in this asbestosis cohort was 73.5%, 19.3% and 7.2% respectively. With the stages increasing, the patients' forced vital capacity (FVC) , total lung capacity (TLC) , total carbon monoxide diffusion capacity (DLCO) predicted values were all reduced showing the restrictive ventilation impairment and/or gas exchange barrier. The obstruction of the small respiratory tracts was detected in the asbestosis of all the different stages. According to the small shadow density of each lung area, chest small shadow density score had a significant negative correlation with FVC, TLC or DLCO predicted values respectively (all P<0.01). Conclusion: The patients with asbestosis of different stages had varying degrees of gas exchange impairment, small airway dysfunction with or without ventilation dysfunction. The decreasing of DLCO was earlier than lung volume change. Chest X-ray image score paralleled the decline of lung function values, reflecting the severity of the disease.