Increased serum levels of sCD40L were associated with rapidly progressive interstitial lung disease in idiopathic inflammatory myopathies

ObjectiveWhether coagulopathy exists in development of idiopathic inflammatory myopathies associated rapidly progressive interstitial lung disease (IIMs-RPILD) is unclear.In this study, we aimed to investigate soluble CD40 ligand and D-dimer levels in RPILD patients. Methods Patients with IIMs-ILD were enrolled and classified as RPILD and stable-ILD group. Clinical data, laboratory examinations including coagulation-associated parameters and the myositis antibodies status, chest high-resolutioncomputed tomography (HRCT) findings and treatment regimens were collected and serum levels of sCD40L were detected by ELISA.Univariable and adjusted multivariable cox regression were performed to identify risk factors for 6-month mortality, and further to select predictors for establishing predictive model for RPILD. ResultsEighty patients with IIMs-ILD were enrolled and 34 of them were diagnosed as RPILD while 46 as stable-ILD.Multivariable cox regression showed that albumin<32.4 g/L and sCD40L<1658.55pg/ml were independent risk factors of short-term mortality in RPILD.A SMAD model consisting of serum sCD40L>1054 pg/ml, anti-MDA5 positivity, albumin<32.4 g/L and D-dimer>0.865mg/L were generated.The odds for RPILD with SMAD score of 0, 1, 2, 3 and 4 were 0, 26.9%, 66.7%, 91.7% and 100%.The 6-month survival stratified by mild (SMAD score 0), moderate (SMAD score 1 and 2) and severe group (SMAD score 3 and 4) were 100%, 79.5% and 20%, respectively. Conclusion We established a predictive model for IIMs-RPILD, which provided a clue that coagulopathy might exist inIIMs-RPILD and could help to better treat patients with RPILD.This model awaits further validations.