Pos1295 Poor Prognostic Factor for Relapse of Interstitial Lung Disease Complicated With Anti-Aminoacyl-Trna Synthetase Antibodies After Combination Therapy: Long-Term Follow-Up of a Single Centre Cohort

Background: Autoantibodies against aminoacyl tRNA synthetase (ARSs) are one subset of myositis-specific autoantibodies, and are associated with the complication of interstitial lung disease (ILD).[1] Patients with anti-ARS antibody-positive ILD (anti-ARS-ILD) typically respond well to immunosuppressive therapy, and have a good short-term prognosis but a high rate of long-term relapse.[2] Prednisolone (PSL) monotherapy was associated with the relapse, so treatments with PSL and calcineurin inhibitor (CNI) were recommended as maintenance therapy in anti-ARS-ILD.[3] However, some patients with anti-ARS-ILD relapsed even after receiving combination therapy.[4] Little is known about risk factors for relapsed patients with anti-ARS-ILD following combination therapy. Objectives: We evaluated poor prognostic factor for predicting relapse of anti-ARS-ILD, being treated with prednisolone and CNI over 1 years. Methods: Fifty patients with anti-ARS-ILD between October 2014 and August 2022 were enrolled in this study. We examined these patients who relapsed ILD after immunosuppressive treatment. We explored the risk factors for predicting relapse of ILD in these patients by comparing the demographic, clinical, laboratory, and radiological findings and treatments between the relapsed and non-relapsed groups on admission. Results: All patients with anti-ARS-ILD were treated with PSL and CNI as remission-induction therapy, and followed over 1 year with these combination therapy. Out of 50 patients, 19 (38%) relapsed during a median follow-up of 4.8 years. In univariate and multivariate Cox regression analysis, the presence of acute/subacute (A/S)-ILD, higher serum aldolase levels, surfactant protein-D (SP-D) levels, and lower % forced vital capacity (FVC) on admission were identified as risk factors for relapse in anti-ARS-ILD. Using the ROC analysis, aldolase ≥ 6.3 U/L, SP-D ≥ 207 ng/mL, and %FVC ≤76.8% were the best cut-off levels for indicating a poor prognosis. The 5-year relapse rate was significantly higher in patients with A/S-ILD or aldolase ≥ 6.3 U/L or SP-D ≥ 207 ng/mL or %FVC of ≤ 76.8% than in those without those. (P=0.009, 0.0005, 0.0007, 0.0004, respectively) (Figure 1A-D). Conclusion: The presence of A/S-ILD, higher serum aldolase levels, higher SP-D levels, and lower %FVC were useful indicators for predicting the relapse of anti-ARS-ILD. REFERENCES: [1] Mimori T, Imura Y, Nakashima R, et al. Autoantibodies in idiopathic inflammatory myopathy: an update on clinical and pathophysiological significance. Curr Opin Rheumatol. 2007;19(6):523-9. [2] Isoda K, Kotani T, Takeuchi T, et al. Comparison of long-term prognosis and relapse of dermatomyositis complicated with interstitial pneumonia according to autoantibodies: anti-aminoacyl tRNA synthetase antibodies versus anti-melanoma differentiation-associated gene 5 antibody. Rheumatol Int. 2017;37(8):1335-1340. [3] Nakazawa M, Kaneko Y, Takeuchi T. Risk factors for the recurrence of interstitial lung disease in patients with polymyositis and dermatomyositis: a retrospective cohort study. Clin Rheumatol. 2018;37(3):765-771. [4] Yamakawa H, Hagiwara E, Kitamura H, et al. Predictive Factors for the Long-Term Deterioration of Pulmonary Function in Interstitial Lung Disease Associated with Anti-Aminoacyl-tRNA Synthetase Antibodies. Respiration. 2018;96(3):210-221. Acknowledgements: NIL. Disclosure of Interests: None declared.