著者
西川 敦子 西野 一三
出版者
日本神経治療学会
雑誌
神経治療学 (ISSN:09168443)
巻号頁・発行日
vol.33, no.6, pp.622-626, 2017 (Released:2017-04-30)
参考文献数
41
被引用文献数
2

Immune–mediated necrotizing myopathy (IMNM) is a subgroup of idiopathic inflammatory myopathies, characterized by usually subacutely progressive course, symmetrical and proximal muscle weakness and atrophy, highly elevated serum creatine kinase levels, and muscle fiber necrosis and regeneration with little or no lymphocytic inflammatory infiltration on muscle pathology. Two major autoantibodies, anti–signal recognition particle (SRP) and anti–3–hydroxy–3–methylglutaryl–coenzyme A reductase (HMGCR) antibodies, are known to be associated with IMNM. IMNM with those antibodies were initially reported in adults but are now known to be seen also in children. Anti–SRP antibodies seem to be more frequently seen in IMNM pateints than anti–HMGCR antibodies. Although anti–HMGCR necrotizing myopathy was first found in patients who were taking statins, majority of patients do not have history of statin use. Myositis associated with anti–aminoacyl tRNA synthetases (ARS) is pathologically characterized by perifascicular necrotizing myopathy with perimysial alkaline phosphatase activity. Clinically, patients typically develop triad of interstitial lung disease, mechanic's hands, and myositis, which is sometimes called anti–synthetase syndrome or anti–ARS syndrome. Of note, necrotizing muscle pathology can also be observed in a variety of other conditions, including myositis associated with anti–mitochondria M2 autoantibodies, malignancy, viral infections (HIV and hepatitis C), and connective tissue diseases. In addition, muscular dystrophy, such as dysferlinopathy or facioscapulohumeral muscular dystrophy, may also display similar muscle pathology. Not surprisingly, it can be clinically difficult to distinguish IMNM from muscular dystrophy especially in children. As IMNM is treatable by immunosuppressive therapy, it should not be misdiagnosed. Immunohistochemical analysis including MHC class I and C5b–9 may be useful as cytoplsmic upregulation of MHC class I in non–necrotic fibers and sarcolemmal deposition of membrane attack complex (C5b–9) are often observed in IMNM but not in muscular dystrophy. This review focuses on muscle pathological features of IMNM.
著者
西川 敦子 森 まどか 岡本 智子 大矢 寧 中田 智彦 大野 欽司 村田 美穂
出版者
日本神経学会
雑誌
臨床神経学 (ISSN:0009918X)
巻号頁・発行日
vol.54, no.7, pp.561-564, 2014-07-01 (Released:2014-08-02)
参考文献数
19
被引用文献数
6

症例は26歳の女性である.出生時に呼吸不全,筋力低下があり,5歳時,顔面肩甲上腕型筋ジストロフィーと臨床診断されていた.歩行の可否などが週単位で変動した.12歳時,プロテカロール塩酸塩で変動が改善,内服を継続した.26歳時,当院受診.眼瞼下垂,顔面・体幹・四肢近位筋の筋力低下,易疲労性があり,血清CK正常,抗アセチルコリン受容体抗体と抗筋特異的チロシンキナーゼ抗体は陰性,僧帽筋の反復刺激試験でwaning現象をみとめた.DOK7遺伝子に新規変異をみとめ,先天性筋無力症候群と確定診断した.症状はアンベノニウム塩酸塩で悪化し,3,4-ジアミノピリジンで改善した.筋力低下の週から月単位の変動は診断に重要である.