Two Clinically Amyopatic Dermatomyositis with Antibody against the 140 kDa Protein Antigen who Developed Rapidly Progressive Pneumonia

Abstract

We present 2 patients with clinically amyopatic dermatomyositis (C-ADM) with antibody against the 140 kDa protein antigen. Patient 1 is a 65-year-old woman who developed erythema on her face, back and chest with general fatigue and appetite loss. Her chest X-ray and CT scan showed interstitial pneumonia (IP). She was treated with steroid therapy. Patient 2 is a 75-year-old woman, who first noticed erythema on her palms. Her chest X-ray showed slight IP, which exacerbated rapidly with dyspnea after 4 months. She was treated with 50 mg/day of prednisolone and 150 mg/day of cyclosporine A. Laboratory examinations showed high levels of KL-6, without elevation of CPK, aldolase and myoglobin in both patients’ sera. In addition, antibody against 140 kDa protein antigen was detected in sera by immunoprecipitation. Based on these findings, a diagnosis of C-ADM with rapidly progressive interstitial pneumonia was made for both patients. Although C-ADM is rarely positive for antibody against the 140 kDa protein antigen, more attention should be paid, because positive patients often develop rapidly progressive interstitial pneumonia.