Satoshi Sakamoto1, Masaki Okamoto2, Shinjiro Kaieda3, Kiminori Fujimoto4, Shuji Nagata5, Masaki Tominaga6, Masayuki Nakamura7, Yoshiaki Zaizen8, Takashi Nouno9, Takuma Koga10, Tomotaka Kawayama11, Masataka Kuwana12, Hiroaki Ida13, Tomoaki Hoshino14. 1. Division of Respirology, Neurology, and Rheumatology, Department of Internal Medicine, Kurume University School of Medicine, Asahi-machi 67, Kurume, Fukuoka 830-0011, Japan. Electronic address: sakamoto_satoshi@med.kurume-u.ac.jp. 2. Division of Respirology, Neurology, and Rheumatology, Department of Internal Medicine, Kurume University School of Medicine, Asahi-machi 67, Kurume, Fukuoka 830-0011, Japan. Electronic address: okamoto_masaki@med.kurume-u.ac.jp. 3. Division of Respirology, Neurology, and Rheumatology, Department of Internal Medicine, Kurume University School of Medicine, Asahi-machi 67, Kurume, Fukuoka 830-0011, Japan. Electronic address: kaieda@med.kurume-u.ac.jp. 4. Department of Radiology and Center for Diagnostic Imaging, Kurume University School of Medicine, Asahi-machi 67, Kurume, Fukuoka 830-0011, Japan. Electronic address: kimichan@med.kurume-u.ac.jp. 5. Department of Radiology and Center for Diagnostic Imaging, Kurume University School of Medicine, Asahi-machi 67, Kurume, Fukuoka 830-0011, Japan. Electronic address: sn4735@med.kurume-u.ac.jp. 6. Division of Respirology, Neurology, and Rheumatology, Department of Internal Medicine, Kurume University School of Medicine, Asahi-machi 67, Kurume, Fukuoka 830-0011, Japan. Electronic address: tominaga_masaki@med.kurume-u.ac.jp. 7. Division of Respirology, Neurology, and Rheumatology, Department of Internal Medicine, Kurume University School of Medicine, Asahi-machi 67, Kurume, Fukuoka 830-0011, Japan. Electronic address: nakamura_masayuki@med.kurume-u.ac.jp. 8. Division of Respirology, Neurology, and Rheumatology, Department of Internal Medicine, Kurume University School of Medicine, Asahi-machi 67, Kurume, Fukuoka 830-0011, Japan. Electronic address: zaizen_yoshiaki@med.kurume-u.ac.jp. 9. Division of Respirology, Neurology, and Rheumatology, Department of Internal Medicine, Kurume University School of Medicine, Asahi-machi 67, Kurume, Fukuoka 830-0011, Japan. Electronic address: nouno_takashi@med.kurume-u.ac.jp. 10. Division of Respirology, Neurology, and Rheumatology, Department of Internal Medicine, Kurume University School of Medicine, Asahi-machi 67, Kurume, Fukuoka 830-0011, Japan. Electronic address: koga_takuma@med.kurume-u.ac.jp. 11. Division of Respirology, Neurology, and Rheumatology, Department of Internal Medicine, Kurume University School of Medicine, Asahi-machi 67, Kurume, Fukuoka 830-0011, Japan. Electronic address: kawayama_tomotaka@med.kurume-u.ac.jp. 12. Department of Allergy and Rheumatology, Nippon Medical School, Sendagi 1-1-5, Bunkyo-ku, Tokyo 113-8603, Japan. Electronic address: kuwanam@nms.ac.jp. 13. Division of Respirology, Neurology, and Rheumatology, Department of Internal Medicine, Kurume University School of Medicine, Asahi-machi 67, Kurume, Fukuoka 830-0011, Japan. Electronic address: ida@med.kurume-u.ac.jp. 14. Division of Respirology, Neurology, and Rheumatology, Department of Internal Medicine, Kurume University School of Medicine, Asahi-machi 67, Kurume, Fukuoka 830-0011, Japan. Electronic address: hoshino@med.kurume-u.ac.jp.
Abstract
BACKGROUND: Anti-melanoma differentiation-associated gene 5 antibody (anti-MDA5-Ab) is associated with fatal rapidly progressive interstitial lung disease (RP-ILD) in patients with dermatomyositis (DM). We attempted to clarify whether anti-MDA5-Ab is associated with long-term outcomes in patients with DM-ILD. METHODS: Thirty-six patients with DM-ILD were retrospectively analyzed for their serum anti-MDA5-Ab by using an enzyme-linked immunosorbent assay. We analyzed the association between clinical parameters, including the serum levels of anti-MDA5-Ab and ferritin. RESULTS: Fourteen patients (39%) were positive for anti-MDA5-Ab. The serum levels of anti-MDA5-Ab and ferritin in 7 patients with acute death were higher than those in the surviving patients. An "unclassifiable pattern" on chest computed tomography and the development of RP-ILD were also prognostic markers. The serum levels of anti-MDA5-Ab and ferritin (cut-off levels, 100 IU/mL and 899 ng/mL, respectively) were markers predictive of acute death, showing good sensitivity (86% and 83%) and specificity (97% and 100%). All 7 patients with acute death developed RP-ILD and were positive for anti-MDA5-Ab, including 6 patients with a high titer (≥100 IU/mL), whereas only 2 patients (29%) developed RP-ILD among the 7 survivors with a low titer of anti-MDA5-Ab ( < 100 IU/mL). In contrast, a low positive titer of anti-MDA5-Ab was not associated with changes in pulmonary function for 2 years. CONCLUSIONS: Although a high serum titer of anti-MDA5-Ab (≥100 IU/mL) is associated with acute death via the development of RP-ILD, outcomes in the chronic phase for patients with a low titer of anti-MDA5-Ab ( < 100 IU/mL) were similar to those of patients without anti-MDA5-Ab.
BACKGROUND: Anti-melanoma differentiation-associated gene 5 antibody (anti-MDA5-Ab) is associated with fatal rapidly progressive interstitial lung disease (RP-ILD) in patients with dermatomyositis (DM). We attempted to clarify whether anti-MDA5-Ab is associated with long-term outcomes in patients with DM-ILD. METHODS: Thirty-six patients with DM-ILD were retrospectively analyzed for their serum anti-MDA5-Ab by using an enzyme-linked immunosorbent assay. We analyzed the association between clinical parameters, including the serum levels of anti-MDA5-Ab and ferritin. RESULTS: Fourteen patients (39%) were positive for anti-MDA5-Ab. The serum levels of anti-MDA5-Ab and ferritin in 7 patients with acute death were higher than those in the surviving patients. An "unclassifiable pattern" on chest computed tomography and the development of RP-ILD were also prognostic markers. The serum levels of anti-MDA5-Ab and ferritin (cut-off levels, 100 IU/mL and 899 ng/mL, respectively) were markers predictive of acute death, showing good sensitivity (86% and 83%) and specificity (97% and 100%). All 7 patients with acute death developed RP-ILD and were positive for anti-MDA5-Ab, including 6 patients with a high titer (≥100 IU/mL), whereas only 2 patients (29%) developed RP-ILD among the 7 survivors with a low titer of anti-MDA5-Ab ( < 100 IU/mL). In contrast, a low positive titer of anti-MDA5-Ab was not associated with changes in pulmonary function for 2 years. CONCLUSIONS: Although a high serum titer of anti-MDA5-Ab (≥100 IU/mL) is associated with acute death via the development of RP-ILD, outcomes in the chronic phase for patients with a low titer of anti-MDA5-Ab ( < 100 IU/mL) were similar to those of patients without anti-MDA5-Ab.