Ito Mitsuru, Moriya Chie, Matsuyama Kanako, Shu En, Hamaguchi Yasuhito, Seishima Mariko
Department of Dermatology, Gifu University Graduate School of Medicine, Gifu, Japan.
Department of Molecular Pathology of Skin, Kanazawa University Graduate School of Medicine, Kanazawa, Japan.
Case Rep Dermatol. 2020 May 5;12(2):92-97. doi: 10.1159/000507504. eCollection 2020 May-Aug.
Myositis-specific autoantibodies (MSAs) including anti-Mi-2 and anti-nuclear matrix protein 2 (NXP-2) antibodies have been detected in the patients with dermatomyositis (DM), and are useful tools for identifying clinical subsets of DM. MSAs are exclusively found in DM patients. Anti-Mi-2 antibody-positive DM patients show the typical skin lesions and myositis and are rarely associated with internal malignancy and interstitial lung disease (ILD). On the other hand, adult DM patients with anti-NXP-2 antibody often show calcinosis and internal malignancy, but rarely ILD. In addition, anti-NXP-2 antibody-positive DM patients have severe phenotype with myalgia, peripheral edema, and significant dysphagia, but with mild skin lesions. Herein, we report a rare case of classic DM coexisting with both anti-Mi-2 and anti-NXP-2 antibodies, clinically, without ILD or internal malignancy. Our patient had typical skin manifestations, muscle weakness, muscle pain, and general fatigue without calcinosis, peripheral edema, or dysphagia. Thus, the clinical phenotype was similar to anti-Mi-2 antibody-positive DM.
在皮肌炎（DM）患者中已检测到包括抗Mi-2和抗核基质蛋白2（NXP-2）抗体在内的肌炎特异性自身抗体（MSA），它们是识别DM临床亚组的有用工具。MSA仅在DM患者中发现。抗Mi-2抗体阳性的DM患者表现出典型的皮肤病变和肌炎，很少与内脏恶性肿瘤和间质性肺病（ILD）相关。另一方面，抗NXP-2抗体阳性的成年DM患者常出现钙质沉着和内脏恶性肿瘤，但很少出现ILD。此外，抗NXP-2抗体阳性的DM患者具有严重的表型，伴有肌痛、外周水肿和明显的吞咽困难，但皮肤病变较轻。在此，我们报告一例罕见的经典DM病例，同时存在抗Mi-2和抗NXP-2抗体，临床上无ILD或内脏恶性肿瘤。我们的患者有典型的皮肤表现、肌肉无力、肌肉疼痛和全身疲劳，无钙质沉着、外周水肿或吞咽困难。因此，临床表型与抗Mi-2抗体阳性的DM相似。
