POS0295 EVALUATION OF POOR PROGNOSTIC FACTORS FOR PREDICTING RELAPSE OF INTERSTITIAL LUNG DISEASE IN MICROSCOPIC POLYANGIITIS: MULTICENTER STUDY IN JAPAN- THE REVEAL COHORT STUDY
Authors: S. Matsuda, T. Kotani, A. Okazaki, Y. Masuda, M. Shiomi, R. Watanabe, T. Taniguchi, A. Manabe, K. Kadoba, T. Yoshida, R. Hiwa, W. Yamamoto, M. Hashimoto, T. Takeuchi
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> Microscopic polyangiitis (MPA) is a subtype of ANCA-associated vasculitis that predominantly affects small vessels with few or no immune deposits involving several organs such as skin, lungs, and kidneys.[1] In Asia, interstitial lung disease (ILD) is a major pulmonary complication in myeloperoxidase-ANCA-positive MPA patients.[2] MPA complicated with ILD (MPA-ILD) is resistant to conventional therapies, including prednisolone and immu-nosuppressive therapy, and relapse of ILD was associated with death in MPA-ILD.[3] However, poor prognostic factors for relapse of ILD have not been identified in patients with MPA-ILD. <h3>Objectives:</h3> This study investigated poor prognostic factors for relapse of ILD in MPA using clinical characteristics in a multicenter cohort of Japanese patients with MPA (REVEAL cohort).[4] <h3>Methods:</h3> Patients diagnosed with MPA according to the Chapel Hill consensus definition were enrolled from 2001 to 2023 in multicenter institutes in the Kansai district of Japan. Among them, patients with MPA-ILD were identified using chest high-resolution CT on admission. We also examined these patients who relapsed ILD after immunosuppressive treatment. We explored the risk factors for predicting relapse of ILD in patients with MPA-ILD by comparing the demographic, clinical, laboratory, and radiological findings and treatments between the relapsed and non-relapsed groups on admission. <h3>Results:</h3> Out of the 243 patients with MPA, 134 had ILD. The median age was 75 years and seventy-four (55%) patients were women, and eighty-nine patients (66%) had usual interstitial pneumonia (UIP) pattern on HRCT. Among them, 28 relapsed during a mean follow-up of 4.2 years. Serum KL-6 and Sp-D levels and the prevalence of UIP pattern were significantly higher in the relapsed group than in the non-relapsed group (<i>P</i> = 0.0009, 0.001, 0.01, respectively). There were no significant differences in the median dose of prednisolone or ratio of immunosuppressive therapy between the groups. Based on these findings, we determined KL-6≥ 430 U/mL and Sp-D≥89.5 ng/mL to be the best cut-off values for predicting the relapse of ILD using receiver operating characteristic curve analysis. The 10-year relapse rate was significantly higher in patients with KL-6≥ 430 U/mL, Sp-D≥ 89.5 ng/mL, and the presence of UIP pattern than in those without (<i>P</i>&lt; 0.0001, 0.001, and 0.03, respectively) (Figure 1A-C). <h3>Conclusion:</h3> Our multicenter cohort indicated that higher KL-6 and Sp-D levels and the presence of UIP pattern on admission were useful predictors for relapse of ILD in patients with MPA. <h3>REFERENCES:</h3> [1] Jennette JC, Falk RJ, Bacon PA et al. 2012 revised International Chapel Hill Consensus Conference Nomenclature of Vasculitides. Arthritis Rheum 2013;65:1–11. [2] Sada KE, Yamamura M, Harigai M et al. Classification and characteristics of Japanese patients with antineutrophil cytoplasmic antibody-associated vas-culitis in a nationwide, prospective, inception cohort study. Arthritis Res Ther 2014;16:R101. [3] Hozumi H, Kono M, Hasegawa H et al. Clinical significance of interstitial lung disease and its acute exacerbation in microscopic polyangiitis. Chest 2021;159:2334–45. [4] Matsuda S, Kotani T, Okazaki A, et al. Prediction model for respiratory-related mortality in microscopic polyangiitis with interstitial lung disease: multicenter REVEAL cohort study. Rheumatology (Oxford). 2023. Doi:10.1093/rheumatology/kead444. Epub ahead of print. <h3>Acknowledgements:</h3> <b>NIL. None.</b> <h3>Disclosure of Interests:</h3> Shogo Matsuda Speakers bureau: Abbvie, Grant/research support:Japan Intractable Diseases Research Foundation, Takuya Kotani Speakers bureau:Abbvie, Bristol-Myers Squibb, Chugai, Eisai, Eli Lilly, Pfizer., Ayana Okazaki: None declared, Yuichi Masuda: None declared, Mayu Shiomi: None declared, Ryu Watanabe Speakers bureau:Asahi Kasei, Eli Lilly, Chugai, GSK, Sanofi, Grant/research support: AbbVie, Tomoki Taniguchi: None declared, Atsushi Manabe: None declared, Keiichiro Kadoba: None declared, Tsuneyasu Yoshida: None declared, Ryosuke Hiwa Speakers bureau:Abbvie, Asahi Kasei, Brystol-Meyers Squibb, Eisai, Eli Lilly, GSK, Kissei, Daiichi Sankyo, and Pfizer, Grant/research support: GSK, Wataru Yamamoto: None declared, Motomu Hashimoto Speakers bureau: Eli Lilly, Chugai, Tanabe-Mitsubishi, Bristol Myers Squibb, Esai, Grant/research support: AbbVie, Asahi Kasei Pharma, Astellas, Bristol Myers Squibb, Esai, Daiichi Sankyo, Eli Lilly, Novartis, Tohru Takeuchi Speakers bureau:Asahi Kasei, Chugai, Bristol-Myers Squibb, Tanabe-Mitsubishi, AbbVie, Esai., Grant/research support: Chugai.