Abstract: Objective  To explore the predictive value of serum biomarkers associated with alveolar epithelial cell dysfunction in the prognosis of fibrosing interstitial lung diseases(FILD). 
Methods  The patients were prospectively enrolled and clinical data were collected. Biomarkers were detected and they were followed up for 1 year to evaluate the condition. Survival analysis of competitive risk model and Fine-Gray regression model were used to extract the risk factors of progressive fibrotic phenotype and death. 
Results  Of the 58 patients, 35 cases were diagnosed as idiopathic pulmonary fibrosis, 14 as interstitial lung disease associated with connective tissue diseases, 9 as pulmonary fibrosis caused by other causes. Of them, 12(20.69%) developed into progressive fibrotic phenotype, and 8(13.79%) died. Univariate analysis showed that the risk factor for the development of progressive fibrotic phenotype was the baseline elevation of carbohydrate antigen 125(CA-125), and the risk factor for death was the baseline elevation of carbohydrate antigen 19-9(CA19-9). Multivariate analysis showed that the baseline elevation of CA19-9 was the risk factor for death(regression coefficient 0.007，hazard ratio 1.007, 95% confidence interval: 1.001-1.061， P=0.044). 
Conclusion  Patients with elevated CA-125 baseline have a higher risk of developing progressive fibrotic phenotype, while patients with elevated CA19-9 baseline have a higher risk of death.

Key words: lung diseases, interstitial, prognosis, biomarkers