THERAPEUTIC STRATEGIES AND LONG-TERM OUTCOME IN PATIENTS WITH INTERSTITIAL PNEUMONIA WITH AUTOIMMUNE FEATURES: A SINGLE CENTER LARGE-SCALE OBSERVATIONAL COHORT STUDY

Background: Patients with idiopathic interstitial pneumonia (IIP) may have features of connective tissue diseases (CTDs). The term interstitial pneumonia with autoimmune features (IPAF) has been recently proposed for such patients [1]. To date, only few studies have comprehensively described outcomes over a long-term period and choices of treatment [2-4]. Objectives: The aim of this study was to investigate the therapeutic strategies and long-term outcome among patients with IPAF, IIP, and CTD-ILD. Methods: Six hundreds- and seventy-two patients who had visited our department between April 2009 and March 2019 and were evaluated by chest HRCT scan. They were clinically and radiologically diagnosed as having interstitial lung disease (ILD), including IIP, CTD-ILD, undifferentiated connective tissue diseases associated ILD or other ILD. Then, we applied IPAF criteria to these patients, 68 patients were diagnosed as IPAF. We extracted the treated patients from IPAF patients. Then, the treated patients were divided into two groups, which were treated with monotherapy (glucocorticoid: GC) and with combination therapy (GC and immunosuppressant: IS). Clinical, laboratory and imaging data were collected from medical records and statistically analyzed. Results: Proportion of treatment received patients with IPAF, IIP, or CTD-ILD was 44.1%, 28.1%, and 88.0%, respectively. Then we compared long-term outcomes among patients with IPAF, IIP, and CTD-ILD, 5-year non-exacerbation rate in IPAF patients, IIP patients, and CTD-ILD patients was 53.7%, 28.3%, and 59.5%, respectively (Figure 1.). No significant difference between IPAF and CTD-ILD group was found (P=0.71). Next, we focused on IPAF and compared characteristics at diagnosis between the treatment group (n=30) and non-treatment group (n=38) in patients with IPAF. Interestingly, treatment group was significantly associated with signs of mechanic’s hands, arthritis, anti-SS-A antibody positivity, and anti-ARS antibody positivity (P=0.009, 0.05, 0.05, and 0.007). Among the treatment group, GC monotherapy was received in 46.7% (n=14), whereas GC+IS combination therapy group was 50% (n=15). When we compared long-term outcomes between two groups, 3-year non-exacerbation rate was 70.1%, 43.5%, and 83.3% (Figure 2.). No significant difference was not seen between two different treatment groups (P=0.24). Conclusion: Our large-scale cross-sectional cohort study identified that the prognosis of IPAF patients was poor as same as that of CTD patients, and even though GC mono or GC+IS combination treatment was applied for IPAF patients, prognosis was still poor and thus new intervention for IPAF should be needed to improve their prognosis. References: [1]Eur Respir J. 2016; 47:1622–1624, [2]J Rheumatol. 2013; 40:640-646, [3]Respirology. 2019 Aug 6, [4]Autoimmun Rev. 2019 Dec 12 Disclosure of Interests: Okinori Murata: None declared, Katsuya Suzuki: None declared, Nobuhito Sasaki: None declared, Tsutomu Takeuchi Grant/research support from: Eisai Co., Ltd, Astellas Pharma Inc., AbbVie GK, Asahi Kasei Pharma Corporation, Nippon Kayaku Co., Ltd, Takeda Pharmaceutical Company Ltd, UCB Pharma, Shionogi & Co., Ltd., Mitsubishi-Tanabe Pharma Corp., Daiichi Sankyo Co., Ltd., Chugai Pharmaceutical Co. Ltd., Consultant of: Chugai Pharmaceutical Co Ltd, Astellas Pharma Inc., Eli Lilly Japan KK, Speakers bureau: AbbVie GK, Eisai Co., Ltd, Mitsubishi-Tanabe Pharma Corporation, Chugai Pharmaceutical Co Ltd, Bristol-Myers Squibb Company, AYUMI Pharmaceutical Corp., Eisai Co., Ltd, Daiichi Sankyo Co., Ltd., Gilead Sciences, Inc., Novartis Pharma K.K., Pfizer Japan Inc., Sanofi K.K., Dainippon Sumitomo Co., Ltd., Makoto Maemondo: None declared