Combination of Prednisolone and Calcineurin Inhibitors Prevents Lung Function Decline in Patients with Anti-aminoacyl-tRNA Synthetase Antibody-Positive Polymyositis/Dermatomyositis.

Objective: Anti-aminoacyl-tRNA synthetase antibody-positive polymyositis/dermatomyositis-associ ated interstitial lung disease (ARS-ILD) has a good prognosis, with few cases progressing to respiratory failure. This study aimed to determine factors predictive of lung function changes in patients with ARS-ILD.

Methods: We retrospectively studied 49 patients with ARS-ILD treated at Kurume University Hospital Hospital between 2000 and 2018. We followed 30 patients for more than 2 years after prednisolone (PSL) therapy, with or without calcineurin inhibitors (CNIs), evaluating clinical, physiological, computed tomography, pulmonary func tion, and serological data.

Results: After treatment for 24 months, no significant differences were noted between clinical parameters and improvement in forced vital capacity (FVC), %FVC, % carbon monoxide diffusing capacity/alveolar volume (%DLCO), and %DLCO/alveolar volume. Conversely, the annual change of %FVC significantly correlated with the Medical Research Council dyspnea scale grade and %FVC at the first visit and treatment. Furthermore, the annual change of %DLCO/VA significantly correlated with the duration from the first visit to treatment initiation.

Conclusion: Compared with PSL monotherapy, combining PSL and CNI showed greater mitigation of %FVC decline. The time from onset of ARS-ILD to the first visit is critical for preventing a decline in lung function, and as such, patients should be monitored carefully.