Prognostic value of peripheral blood markers in patients with myositis-associated interstitial lung diseases

Objectives: The aim of this study was to investigate the association between survival of anti-MDA5 autoantibody-positive/negative patients with myositis-associated interstitial lung disease (MA-ILD) and neutrophil–lymphocyte ratio (NLR), platelet–lymphocyte ratio (PLR), monocyte–lymphocyte ratio (MLR), C-reactive protein–albumin ratio (CAR), and erythrocyte sedimentation rate–albumin ratio (EAR).Method: The study included 104 patients diagnosed with MA-ILD between January 2017 and February 2019 at the First Affiliated Hospital, University of Science and Technology of China. The clinical and laboratory results were compared between survivors and non-survivors in anti-MDA5 autoantibody-positive and anti-MDA5 autoantibody-negative patients. Cox proportional hazard models were used for univariable and multivariate analyses to determine survival-related factors. A logistic regression model was used to establish a joint diagnosis, and the feasibility of the combined diagnosis to evaluate the prognosis of MA-ILD was explored.Results: Among 47 anti-MDA5-positive patients with MA-ILD, EAR was an independent predictor of survival. When separated into high and low subgroups, high MLR (> 0.604) and EAR (> 1.458) were predictive of survival (p < 0.05). High MLR, high EAR, and age combined with lactate dehydrogenase were the highest (0.886) in predicting the prognosis of MA-ILD, and were higher than the area under the curve diagnosed separately. In 57 anti-MDA5-negative patients with MA-ILD, NLR and high EAR (> 0.872) were independent predictors of survival (p < 0.05).Conclusion: MLR and EAR are associated with prognosis in anti-MDA5-positive patients. NLR and EAR are associated with prognosis in anti-MDA5-negative patients. Using NLR, MLR, and EAR, inflammatory conditions of MA-ILD can be predicted and possible outcomes estimated.