[Interstitial lung disease in patients with polymyositis and dermatomyositis--report of three cases]

Polymyositis (PM) and dermatomyositis (DM) are connective tissue diseases (CTD) characterized by proximal muscle weakness along with changes in various internal organs, with the lungs most frequently involved. Presentation of the disease in the lungs comprises diffuse alveolar haemorrhage due to vasculitis and interstitial lung disease (ILD), which is the most frequent manifestation of CTD in the lungs and worsens the outcome and prognosis. The mechanisms involved in the ILD are not fully known, but the role of autoimmune response is unquestioned. No relationship between the severity of CTD and the changes in the lungs was observed. ILD may present at any time in the course of CTD, sometimes before the signs and symptoms of myositis occur. The more accurate imaging methods are, the more frequently changes in the lungs are detected. High resolution computed tomography (HRCT) is a gold standard in ILD imaging. Treatment of PM/DM-related ILD relays on systemic glucocorticosteroids as the first choice drugs. We present three cases of PM/DM-related ILD in middle-aged men, with a different clinical and radiological presentation. In all cases, apart from imaging (plain X-ray and HRCT of the chest) and pulmonary function tests, histological evaluation of lung changes was performed. In two cases non-specific interstitial pneumonitis (NSIP) was diagnosed, and in the third--organizing pneumonia along with sarcoid changes in the lymph nodes. Because of decreased pulmonary function all patients were treated with systemic corticosteroids and two of them additionally with azathioprine or cyclophosphamide, and the outcome was good in all of them.