HRCT score and serum ferritin level are factors associated to the 1-year mortality of acute interstitial lung disease in clinically amyopathic dermatomyositis patients

The aim of this study is to evaluate the factors associated to 1-year mortality in clinically amyopathic dermatomyositis (CADM) patients with acute interstitial lung disease (ILD). A single center of 37 cases of Chinese patients with CADM was reviewed retrospectively in Renji hospital. All CADM patients were diagnosed with ILD; there were 24 cases of acute interstitial pneumonia (AIP) and 13 cases of acute exacerbation of non-acute interstitial pneumonia non-AIP. The clinical features, including blood tests, chest high-resolution computed tomography (HRCT) score, and lung function, were analyzed, respectively. Neutrophil lymphocyte ratio (NLR), serum ferritin level, serum lactate dehydrogenase (LDH) level, and HRCT score were statistically significant factors on univariate analysis. Multivariate analysis revealed that the overall HRCT score (HR 1.134, 95 % confidence interval 1.009–1.275, P = 0.017) and serum ferritin level (HR 1.001, 95 % confidence interval 1.002–1.007, P = 0.010) were independently significant factors of 1-year mortality. C statistic value of HRCT score (c statistic value 0.867, P < 0.0001) and serum ferritin level (c statistic value 0.808, P = 0.002) were statistically significant in the classification of non-survivors. Patients with calcineurin inhibitor presented a better outcome than those without calcineurin inhibitor (log-rank test, P = 0.006). HRCT score and serum ferritin level are factors associated to the 1-year mortality of acute ILD in CADM patients. Calcineurin inhibitor might improve the outcome of CADM patients with acute ILD.