**Interstitial Pneumonia in Dermatomyositis**

Tohru Takeuchi, Takuya Kotani and Shigeki Makino *Osaka Medical College Japan* 

#### **1. Introduction**

142 Neuromuscular Disorders

oesophagus has smooth muscle, and is more likely to be affected by scleroderma.] Because of the progressive weakness of the proximal striated oesophageal muscle, there tends to be atony and dilatation. Aspiration into the tracheobronchial tree may occur during barium swallow examination (Fig. 3a). Atony of the small intestine and colon may furthermore be a feature. It should be emphasized that involvement of the gastrointestinal is not a common

**5.1** Some of the protean radiological manifestations of dermatomyositis in childhood and

The superficial soft tissue changes may be very extensive and florid. In recent years MRI has

The effect of treatment, for example, with corticosteroids, can be monitored by four-station STIR MRI. The very extensive disease with deformities and contractures, seen previously,

Dähnert, W. 2007. *Radiology Review Manual, 6th Ed.* pp. 64-65, Wolters Kluwer, ISBN 0 7817

Hansell, D., Armstrong, P., Lynch, D., & McAdams, H. 2005. In: *Imaging of Diseases of the Chest*, pp. 581-585, Elsevier Mosby, ISBN 0 3230 36600, Philadelphia Hesla, R., Karlson, L, & McCauley, R. 1990. Milk of calcium collection in dermatomyositis :

O'Brien, J., & Kelleher, J. 2008. Calcinosis associated with dermatomyositis. *J. Belge de Radiol.,* 

Park, J., Vansant, J, Kumar, N., Gibbs, S., Curvin, M., Price, D., Partain, C., & James, A. 1990.

Resnick, D., & Kransdorf, M. 2005. *Bone and Joint Imaging, 3rd Ed.,* pp. 337-343; 349-352.

van Gelderen, W., 2007. Fluid-calcium level in the thigh versus clinical diagnosis of a soft

Dermatomyositis : correlatiive MR imaging and P-31 MR spectroscopy for quantitative characterisation of inflammatory disease. *Radiology,* 177(2), pp. 473-479

tissue abscess : ultrasound features of dermatomyositis. *Australasian Radiol,* 51, pp.

adults are illustrated, with the aid of various radiological examinations.

are now less common as a consequence of more optimal management.

ultrasound findings. *Pediatr Radiol,* 20:, pp. 344-346 Moses, S. 2008. Dermatomyositis. *Family Practice Notebook.com. 2008* 

Elsevier Saunders, ISBN 0 7216 0270 3, Philadelphia

become more important to demonstrate activity of disease.

manifestation of dermatomyositis.

6620 6, Philadelphia

91. pp. 27

B83-B85

**5. Conclusion** 

**6. References** 

Dermatomyositis (DM) and polymyositis (PM) are types of autoimmune inflammatory muscle disease that mainly damage proximal limb muscles, with DM involving characteristic skin findings such as Gottron's sign and heliotrope eruption (Bohan & Peter, 1975a, 1975b). Interstitial pneumonia (IP) is often associated with DM/PM and is one of the important prognostic factors. Above all, rapidly progressive IP (RPIP), which has the worst prognosis, is resistant to corticosteroid drugs and is strongly associated with clinical amyopathic DM (CADM), which is unlikely to show myositis (Kameda & Takeuchi, 2006). In response, combination therapies of corticosteroid drugs and immunosuppressive drugs have recently been administered early in the onset of IP, and outcomes have been improved. Here, we review the pathogenesis, the clinical and laboratory findings, and treatment of IP associated with DM/PM.

#### **2. IP Associated with DM/PM**

IP occurs in association with DM/PM in 40-50% of patients and is an important prognostic factor of DM/PM (Hidano, 1992, Marie, 2002, Fathi, 2004). In 2002, the American Thoracic Society and the European Respiratory Society jointly advocated classifying idiopathic IP into 7 types (American Thoracic Society & European Respiratory Society, 2002), which are applied to IP associated with connective tissue disease. Many cases of IP associated with DM/PM comprise one of 3 types: nonspecific interstitial pneumonia (NSIP), cryptogenic organizing pneumonia (COP), or diffuse alveolar damage (DAD) (Douglas, 2001, Fujisawa, 2005). Prognoses vary according to these types: cases of DAD are the most critical, but some cases of NSIP and COP also progress to unfortunate outcomes. IP is classified according to clinical course into 1 of 3 groups: acute/subacute IP (A/SIP) with rapidly progression over several weeks or months, chronic IP (CIP) with slowly progression over years, and asymptomatic type with only minor abnormalities on chest CT or in respiratory function tests (Frazier & Miller, 1974).

The histological features of muscle biopsies in DM and PM are different, as are the pathological features of the IP associated with each disease. PM mainly is associated with slowly progressive CIP, which histologically presents as fibrotic NSIP and which responds to corticosteroids. A/SIP also is associated with COP or cellular NSIP and shows good response to corticosteroids in many cases. In contrast, almost 50% of DM cases are associated with A/SIP, which histologically presents as fibrotic NSIP or DAD (Hirakata &

Interstitial Pneumonia in Dermatomyositis 145

than PM/DM. Patients from whom these autoantibodies are detected have respective clinical characteristics. Anti-ARS antibodies are detected in 25 to 30% of PM/DM patients, and of these anti-ARS antibodies, anti-Jo-1 antibody is most frequently detected and is closely related with myositis. Antibodies related to IP include anti-PL-12 antibody and anti-KS antibody (Friedman, 1996, Hirakata, 2007). Patients who test positive for anti-SRP antibody are considered to have fewer complications from IP (Targoff, 1990). Patients with CADM frequently complicate RPIP with poor prognosis and have been found to frequently test negative for antinuclear antibody. Recently, anti-CADM-140 (mda-5) antibody has been detected in the serum of patients with CADM (Sato, 2005). In the future, if a relation between this antibody and pathogenesis/clinical presentation is revealed, selection of

Krebs von den Lungen-6 (KL-6) and surfactant D (SpD), which are produced and secreted on the epithelial surface by alveolar type II cells and bronchial epithelial cells, are useful markers for IP. These makers increase in the serum of patients with IP associated with PM/DM. The levels of these markers are inversely correlated with DLco and are useful in judging therapeutic effect (Kubo, 2000, Bandoh, 2000, Ihn, 2002). Not all patients with IP associated with PM/DM show increases in KL-6 and SpD, and there are patients without

Fig. 1. Chest HRCT of IP associated with DM. (A) ground-glass opacity (open arrow) and consolidation (arrow); (B) subpleural curvilinear shadow (arrow); (C) Traction bronchiectasis.

treatment and prognosis are expected to improve.

increased levels of KL-6 and SpD, especially in the acute phase.

Nagai, 2000). It often evolves into corticosteroid-resistant RPIP, often progressing to acute or subacute disease in several weeks or months, and many patients die in spite of strong immunosuppressive therapies. There are many unclear points as to how certain cases evolve into RPIP. Some cases that were identified histologically as NSIP change to DAD. In addition, pathological findings can be mixed within the same patient, and the histological picture may vary according to the site of tissue sampling.
