著者
井上 道雄 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.37, no.2, pp.123-128, 2020 (Released:2020-08-31)
参考文献数
34

Dermatomyositis (DM) is characterized clinically by myositis and a unique set of skin eruptions and myopathologically by perifascicular atrophy and capillary C5b–9 depositions. In DM muscles, a set of proteins known to be induced by type I interferon, including myxovirus resistance protein A (MxA), are expressed. Sarcoplasmic MxA on immunohistochemistry is highly specific and sensitive for DM, and thus a useful diagnostic marker. In addition, an increasing number of reports have been recently describing the efficacy of JAK inhibitors, which block the type I interferon pathway, in patients with refractory DM. Therefore, DM can be regarded as muscle type I interferonopathy. Five DM–specific autoantibodies (DMSA) so far identified are against : TIF1–γ, MDA5, Mi–2, NXP–2, and SAE. In our cohort, 97% of DM cases confirmed by the sarcoplasmic MxA expression on muscle biopsy had one of DMSAs, suggesting that DMSA is a surrogate marker of muscle type I interferonopathy. Apparently, each DMSA is associated with a relatively specific phenotype. For example, anti–TIF1–γ autoantibodies are associated with malignancy and anti–MDA with clinically amyopathic DM. This indicates that DM may well be further subclassified by DMSA.Antisynthetase syndrome (ASS) is characterized by the presence of anti–aminoacyl t–RNA synthetases (ARS). So far, 10 anti–ARS antibodies have been identified, including Anti–Jo–1, PL–7, EJ, OJ, PL–12, and KS autoantibodies. ASS was previously classified as DM because patients typically develop skin rash such as mechanic's hand, in addition to myositis and chronic idiopathic lung disease. However, a recently proposed classification of idiopathic inflammatory myopathies (IIMs) based upon pathological and serological features, in addition to clinical information, includes ASS as a distinct subtype of IIM. Mounting evidence indicates the correlation between autoantibodies and phenotypes also in ASS. Anti–Jo–1, PL–7, EJ, OJ autoantibodies are more closely associated with myositis rather than interstitial lung disease while anti–PL–12, KS autoantibodies are more closely correlated with interstitial lung disease. ASS is pathologically characterized by perifascicular necrosis and perifascicular pathology. Perifascicular necrosis may superficially resemble perifascicular atrophy, however, MxA is not expressed in myofibers in ASS, indicating ASS and DM have different pathomechanisms. Of note, anti–OJ autoantibodies, which are seen in 27% of ASS patients who received muscle biopsy, cannot be detected by line blot assay or ELISA.
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
冨田 祐輝 松屋 合歓 成田 智子 斎藤 良彦 西野 一三 福留 隆泰
出版者
日本神経学会
雑誌
臨床神経学 (ISSN:0009918X)
巻号頁・発行日
pp.cn-001547, (Released:2021-05-20)
参考文献数
12
被引用文献数
1

一家系に3人のPOMT2遺伝子変異による常染色体性劣性遺伝の肢帯型筋ジストロフィータイプ14(limb girdle muscular dystrophy 14,以下LGMDR14と略記)の患者を経験した.症例1と症例2はPOMT2遺伝子にc.1568A>Cのホモ接合性変異,症例3は同遺伝子にc.1568A>Cとc.869C>Tのヘテロ接合性変異を有していた.c.1568A>Cは病因として新規の遺伝子変異だった.全例で進行性の歩行障害を認め知的障害を合併しており筋萎縮は大腿屈筋群に強いなど,既報告と類似していた.網膜色素変性症や近視などの眼症状は既報告では少なかったが,LGMDR14を示唆する所見と考えられた.
著者
西野 一三
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.50, no.1, pp.1-6, 2010 (Released:2010-02-08)
参考文献数
31
被引用文献数
1 2

自己貪食空胞性ミオパチー(AVM)は,筋病理学的に自己貪食空胞の出現により定義される一群の遺伝性筋疾患である.歴史的にもっとも研究が進んでいるPompe病以外に,最近2つのAVMのカテゴリーが新たに認識されつつある.一つは,Danon病を初めとする一連の筋疾患である.この筋疾患群は,特異な筋鞘膜の性質を有する自己貪食空胞(AVSF)の出現を特徴とする.AVSFでは,アセチルコリンエステラーゼをふくむ,ほぼすべての筋鞘膜蛋白質が空胞膜に発現する.Danon病はライソゾーム膜蛋白質LAMP-2の原発性欠損による.興味深いことに,本疾患におけるAVSFの数は年齢とともに増加する.AVSFミオパチーとしては,他に,最近VMA21 変異によることが明らかとなった,過剰自己貪食をともなうX連鎖性ミオパチー(XMEA)がある.もう一方のAVMは,縁取り空胞の出現を特徴とするミオパチーである.縁取り空胞は電顕的には自己貪食空胞の集塊である.もっとも良く知られた疾患として,縁取り空胞をともなう遠位型ミオパチー(DMRV)がある.本疾患は,欧米では遺伝性封入体ミオパチー(HIBM)と呼ばれる.DMRVはシアル酸生合成経路律速酵素遺伝子GNE の変異により発症する.DMRVモデルマウスにおいては,シアル酸補充療法によりほぼ完全に筋症状を抑制することができる.このことは,シアル酸低下がミオパチーの原因であることとシアル酸補充がヒトでも有効である可能性を示唆している.現時点で原因遺伝子が明らかとなっているAVSFミオパチーはともにライソゾーム機能異常を根本原因としている.一方,縁取り空胞は,DMRV/HIBMが低シアリル化を原因としているように,ライソゾーム外の異常が根本原因であり,二次的に形成されるものである.
著者
大貫 優子 鈴木 重明 重成 敦子 鈴木 進悟 鈴木 則宏 西野 一三 椎名 隆
出版者
日本組織適合性学会
雑誌
日本組織適合性学会誌 (ISSN:21869995)
巻号頁・発行日
vol.24, no.1, pp.46-53, 2017 (Released:2017-04-28)
参考文献数
17

最近,炎症性筋疾患(筋炎)に免疫介在性壊死性ミオパチー(IMNM)という新たな概念が提唱された。本疾患は,多発筋炎(PM)と類似した臨床経過を辿るが,他の筋炎とは異なり炎症細胞の浸潤が殆ど認められない特徴を持つ。筆者らによる日本人におけるHLA多型との関連解析から,特定のHLA多型(A*02:07やDRB1*08:03など)とIMNMとの関連が示唆された。将来的には,HLA多型を切り口とした本疾患発症機序の解明や診断法の開発が期待される。