Organ involvement in patients with anti-mitochondrial antibody-positive myositis

2022 Fiscal Year Final Research Report

• Project/Area Number: 18K07542
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 52020:Neurology-related
• Research Institution: The University of Tokyo (2020-2022); Okinaka Memorial Institute for Medical Research (2018-2019)
• Principal Investigator: Maeda Meiko 東京大学, 医学部附属病院, 助教 (20646799)
• Co-Investigator(Kenkyū-buntansha): 清水 潤 東京大学, 医学部附属病院, 届出診療医 (40260492)
• Project Period (FY): 2018-04-01 – 2023-03-31
• Keywords: 抗ミトコンドリア抗体 / 筋炎 / 心臓合併症 / 拘束性換気障害 / 質問紙

Outline of Final Research Achievements

First, we conducted a nationwide survey using a questionnaire on cardiac complications and restricted ventilatory failure in patients with anti-mitochondrial antibody (AMA)-positive myositis. The prevalence, complication frequency, and risk factors of AMA-positive myositis in Japan over the past 10 years as far as the Department of Neurology could ascertain were reported. Second, we reported the recurrence rate and organ complication rate of AMA-positive myositis during the observation period. Third, pathological findings of cardiac skeletal muscle in pathological search of autopsy cases of AMA-positive myositis were reported. Forth, a case review of past cases of AMA-positive myositis was performed. Fifth, screening for serum autoantibody associated with myocarditis or cardiomyopathy was performed in three cases of AMA-positive myositis.

Free Research Field

神経免疫学

Academic Significance and Societal Importance of the Research Achievements

抗ミトコンドリア抗体陽性筋炎は、抗ARS抗体陽性筋炎や皮膚筋炎とは異なり慢性経過をとり、心臓合併症や拘束性換気障害、骨格筋萎縮、傍脊柱筋障害を呈する頻度の高さ、診断の難しさが指摘されている。一方で早期診断、治療を行うことの重要性も指摘されていることから、本疾患の正確な臨床病理像の把握は重要であると考えられる。本研究の学術的意義は、本疾患の病理所見の観察、自己抗体解析によって病態機序解明に繋げることである。社会的意義は、難治性の希少疾患と考えられる本疾患の有病率、合併症、治療経過の把握を行うことで今後の本疾患の診断基準や治療法確立の基礎データを得るということである。