Clinical diagnosis
Case 111
【Progress】Biopsy of chest wall revealed clinically amyopathic dermatomyositis. After admission, he was given steroid pulse treatment. Unfortunately, he passed away one week later. After his death, laboratory test revealed positive anti-CADM-140/MD5 antibody.
【Discussion】
A number of patients with dermatomyositis (DM) are approximately 20,000 in Japan (1, 2). DM is seen in middle-aged or older. Clinically amyopathic dermatomyositis (CADM) is a subtype of DM and includes least symptom of myositis. CADM occurs more in Asian countries than western countries. CADM is seen in 10 – 25% of adults with DM (1-3). Further, interstitial pneumonia occurs in 50 - 70% of CADM (1-6). Our patient was 69 year-old and got interstitial pneumonia.
In patients with CADM, self-antibody named CADM-140 was first found. Then, antigen to this self-antibody was found and named melanoma-associated gene 5 (MAG5). As a result, this self-antibody is termed as anti-CADM-140/MD5 antibody (6). The patients with anti-CADM-140/MD5 antibody are known to have poor prognosis. In our case, laboratory test revealed positive anti-CADM-140/MD5 antibody and he passed away within two weeks after occurrence of dyspnea.
Symptoms of dermatitis of CADM are listed as follows; heliotrope (a kind of herb with reddish color) eyelids, Gottron’s sign (redness on digital joints), V neck erythema, shawl sign and mechanic’s hand. Of these, mechanic’s hand is known to be associated with interstitial pneumonia (1-4). In our case, medical inspection revealed the presence of butterfly erythema, V neck sign, shawl sign and mechanic’s hand.
Because laboratory result for self-anti-body takes time and CADM is rapidly progressive, imaging diagnosis is crucial for initiating treatment. The pulmonary CT findings of CADM are reported to be interstitial lung disease; non-specific interstitial pneumonia (NSIP), organizing pneumonia and diffuse alveolar damage (DAD) (7-9). Fukuda T et al. compared CT findings of CADM between two groups with rapidly progressive interstitial pneumonia (RPIP) and with non-RPIP (7). They classified CT findings into three types: crescent type, diffuse type and localized type. They found crescent ground-glass opacity (GGO) in the upper lobe in all patients with RPIP but not in patients with non-RPIP. Then they concluded that crescent GGO distributed in the upper lobe was characteristic finding in the patients with RPIP on chest CT (7). In our case, CT showed crescent GGO in the upper lobe (Figs. 2-4) and lower lobe (S6) (Figs. 2-4).
The prognosis of CADM with RPIP was very poor even if corticosteroid and immunosuppressive drugs were used (8-10). There is an ongoing protocol using three combined medicines of corticosteroid, cyclophosphamide and tacrolimus for positive anti-CADM-140/MD5 antibody patients with CADM and RPIP (11). In our case, corticosteroid pulse therapy was given but leading to early death within two weeks after the onset.
【Summary】
We present a sixty nine year-old male with clinically amyopathic dermatomyositis (CADM) & rapidly progressing interstitial pneumonia (RPIP). He suffered from persistent cough and dyspnea, and his skin inspection revealed butterfly erythema, V neck sign, shawl sign and mechanic’s hand. Chest CT revealed crescent ground-glass opacity in the pulmonary margins. Although he was given steroid-pulse therapy, he passed away within two weeks after the onset. We should keep in mind that characteristic findings of CADM & RPIP on chest CT are crescent ground glass opacity in the upper lobes. This finding might be useful to differentiate from other interstitial lung diseases such as cryptogenic organizing pneumonia (COP), chronic eosinophilic pneumonia and antineutrophil cytoplasmic antibody (ANCA) which are also interstitial lung disease in the pulmonary margins.
【References】
1.Hamaguchi Y, et al. Clinical correlations with dermatomyositis-specific autoantibodies in adult Japanese patients with dermatomyositis:a multicenter cross-sectional study. Arch Dermatol 2011;147:391-398.
2.Ikeda N, et al. Analysis of dermatomyositis-specific autoantibodies and clinical characteristics in Japanese patients. J Dermatol 2011;38:973-979.
3.Gerami P. et al. A systematic review of adult - onset clinically amyopathic dermatomyosi tis (dermatomyositis sine myositis): a missing link within the spectrum of the idiopathic inflam matory myopathies. J Am Acad Dermatol 54: 597-613, 2006．
4.Sontheimer RD et al. Potentially fatal interstitial lung disease can occur in clinically amyopathic dermatomyositis. J Am Acad Dermatol 48: 797 - 798. 2003.
5.Mukae H, et al. Clinical differences between interstitial lung disease associated with clinically amyopathic dermatomyositis and classic dermatomyositis. Chest 136:1341 - 1347, 2009.
6.Sato S, et al. Autoantibodies to a 140-kd polypeptide, CADM-140, in Japanese patients with clinically amyopathic dermatomyositis. Arthritis Rheum. 2005 May;52(5):1571-6.
7.Fukuda, S. et al. Clinically amyopathic dermatomyositis (CADM) with rapidly progressive interstitial pneumonia (RPIP); analysis of its early CT features. Poster No.: P-0026. Congress: ESTI 2016. Type: Scientific Poster. Image verification. DOI: 10.1594/esti2016/P-0026.
8.Sato S, et al. Anti-CADM-140/MDA5 autoantibody titer correlates with disease activity and predicts disease outcome in patients with dermatomyositis and rapidly progressive interstitial lung disease. Mod Rheumatol 2013; 23:496-502.
9.Ernste FC, et al. Idiopathic inflammatory myopathies: current trends in pathogenesis, clinical features, and up-to-date treatment recommendations. Mayo Clin Proc 2013; 88: 83–105. [PubMed]
10.Fujisawa T, et al. Prognostic Factors for Myositis-Associated Interstitial Lung. PLoS One. 2014; 9(6): e98824. Published online 2014 Jun 6. doi: 10.1371/journal.pone.0098824
11.抗 MDA5 抗体陽性間質性肺炎合併皮膚筋炎に対する 3 剤併用療法プロトコールの有用性. と安全性の検討. https://www.osaka-med.jrc.or.jp/aboutus/information/pdf/ethics-b_02.pdf
2018.7.4