Risk prediction model for relapse of anti-synthetase syndrome- associated interstitial lung disease in Japanese multicentre MYKO cohort study

Abstract Objectives This study aimed to establish a risk prediction model for the relapse of anti-synthetase syndrome-associated interstitial lung disease (ASyS-ILD). Methods Patients diagnosed with ASyS-ILD and treated with prednisolone and calcineurin inhibitors as remission induction therapy were enrolled in the Japanese multicentre MYKO cohort. We followed up on patients who experienced relapse of ASyS-ILD after remission induction therapy, and examined the risk factors for predicting relapse by comparing initial clinical and laboratory findings. Results Of 487 patients diagnosed with idiopathic inflammatory myopathies between 1991 and 2024, 101 patients with ASyS-ILD were included. Tacrolimus was used by 81.2% of patients and 18.8% used ciclosporin as calcineurin inhibitors for a remission induction therapy. Thirty-nine patients (38.6%) relapsed ASyS-ILD during a median follow-up of 4.3 years, and 5-year relapse rate was 45.1%. Multivariate Cox regression analyses showed that the presence of acute/subacute ILD and a lower % forced vital capacity (FVC) on admission were independently identified as risk factors for relapse in patients with ASyS-ILD. Using the receiver operating curve analysis, %FVC ≤77% was determined as the cut-off levels for indicating a poor prognosis. The 5-year relapse rate was significantly higher in patients with acute/subacute ILD, % FVC ≤77% than in those without these parameters. A risk-prediction model (RPM) based on these parameters can stratify patients into low-, moderate-, and high-risk ILD relapse groups. Conclusion Our multicentre cohort study showed that the RPM model using the presence of acute/subacute ILD and %FVC values was a useful tool for stratifying risk of ASyS-ILD relapse.