AB0661 ASSOCIATION OF ANTI-MDA-5 AUTOANTIBODY WITH AUTOIMMUNE ASSOCIATED HEMOPHAGOCYTIC SYNDROMEIN DERMATOMYOSITIS

Background Autoimmune associated hemophagocytic syndrome (AAHS) is a rare complication in dermatomyositis (DM). We previously demonstrated by multivariate analysis that one of factors associated with mortality in aAHS is DM (OR 5.57 [95% CI 1.08–28.65], P 0.05) among connective tissue diseases (1). Objectives To find out underlying immunological characteristics, we examined the DM patients with aAHS. Methods We examined 31 new onset patients with idiopathic inflammatory myopathies (IIM) including clinically amyopathic dermatomyositis (CADM) admitted to our hospital between January 2009 and December 2018. Three patients had been diagnosed as aAHS proven by bone marrow aspiration. We examined these patient clinical and laboratory characteristics. Results Two patients were diagnosed as DM and one was CADM. We found that these 3 patients were associated with interstitial pneumonia. Laboratory tests of all 3 patients showed hyperferritinemia and high titer of anti-MDA5 antibody. All patients were diagnosed as aAHS by bone marrow aspiration smears. Two of them died on the 12th and on the 75th hospital day, respectively, in spite of intensive therapies. Conclusion Anti-MDA5 may relate not only interstitial pneumonia but also aAHS. References [1] 1. Kumakura S and Murakawa Y: arthritis Rheum 2014;66:2297 Disclosure of interests Manabu Honda Speakers bureau: asahi Kasei Pharma, ono Pharm., Mayuko Moriyama: None declared, Masahiro Kondo Speakers bureau: Eisai Co., Chugai Pharma, Mitsubishi Tanabe Pharma, Bristol-Myers Squibb, Janssen Pharma, astellas Pharma, Takeda Pharma, NIPPON KAYAKU, Daiichi-Sankyo, asahi Kasei Pharma, abbVie Japan., Shunichi Kumakura: None declared, Yoshiko Sumita: None declared, Yohko Murakawa Grant/research support from: asahi Kasei Pharmaceutical Co., Ltd. Chugai Pharmaceutical Co., Ltd. Ono Pharmaceutical Co., Ltd. Daiichi Sankyo Co., Ltd. Teijin Pharma Ltd. Eisai Co., Ltd. Nippon Kayaku Co., Ltd. Mitsubishi Tanabe Pharma Corporation, Paid instructor for: Kissei Pharmaceutical Co., Ltd. Janssen Pharmaceutical K.K. Eisai Co., Ltd., Speakers bureau: ono Pharmaceutical Co., Ltd. Mitsubishi Tanabe Pharma Corporation Astellas Pharma inc. UCB Japan Co. Ltd. Chugai Pharmaceutical Co., Ltd. AbbVie GK Daiichi Sankyo Co., Ltd. AYUMI Pharmaceutical Corporation Janssen Pharmaceutical K.K. Takeda Pharmaceutical Company Limited Sanofi K.K. Teijin Pharma Ltd. Eli Lilly Japan K.K. Eisai Co., Ltd.