A Case of Dermatomyositis Coexisting with Both Anti-Mi-2 and Anti-NXP-2 Antibodies

Abstract

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.

Coexistence of Multiple Myositis-Specific Antibodies in Patients with Idiopathic Inflammatory Myopathies

“…Our results did not go against the notion that the presence of MSAs was essentially mutually exclusive in IIM [ 13 ]. The coexistence of two MSAs in an IIM patient is rare but does exist [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ].…”

“…The mutual exclusivity of MSAs has been reported before [ 13 ], which made the serology tests for MSAs more crucial for IIM subtyping. However, the coexistence of 2 or more MSAs was still found in a few case reports [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ].…”

Recognising skin manifestations of rheumatological disease

“…Serology may reveal anti-Mi-2 antibody positivity, and less commonly anti-T1F1 or anti-NXP2 antibodies, which are closely associated with internal malignancy. 22,24 The aetiology of dermatomyositis is still largely unknown. There is an established increase in the risk of malignancy in adult patients, particularly those who are amyopathic.…”