The aim of this study was to follow the prevalence of pulmonary manifestations in patients with systemic rheumatic diseases. Correlation of the lung disease with the presence of autoantibodies and with clinical activity of the particular disease was performed. Methods: Patients with systemic lupus erythematosus, systemic sclerosis, poly/dermatomyositis, and mixed connective tissue disease entered in the clinical database were followed up for 5 years. Two thousand one hundred and seven patients were enrolled to the registry; from those two hundred seventy patients with systemic lupus erythematosus, 121 patients with systemic sclerosis, 104 patients with poly/dermatomyositis, and 18 patients with mixed connective tissue disease were studied. Lung manifestation was evaluated using clinical finding, pulmonary function test, radiography, and high-resolution computerized tomography when indicated. Results: Seventy-five of 270 patients with systemic lupus erythematosus had lung disease, from those 45 patients had lung manifestation not specified in detail, and 53 patients experienced pleuritis. Antinuclear antibodies were positive almost in 85% of patients, antibodies against double-stranded deoxyribonucleic acid in 45%. According to the systemic lupus erythematosus disease activity index, the disease was considered active in 75% patients. From all the patients with systemic sclerosis, 76 had lung manifestation, and more than 70% were antinuclear positive and 52% were anti-topoisomerase I positive. The activity of the disease was moderate in 36 patients. Lung manifestation was observed in 71 of 104 patients with poly/dermatomyositis, and in 3 of 18 patients with mixed connective tissue disease. Conclusions: High prevalence of lung manifestation in patients with systemic rheumatic disease has been demonstrated. It has been found most frequently in patients with poly/dermatomyositis (68.3%) and systemic sclerosis (62.8%). The lung manifestations appeared in 27.8% patients with systemic lupus erythematosus, and in 16.7% patients with mixed connective tissue disease. Frequencies of some types of lung manifestations in patients with systemic rheumatic diseases followed in the registry correspond to the data presented in the literature.

        Key words: systemic lupus erythematosus, systemic sclerosis, polydermatomyosis, mixed conective tissue disease, lung manifestation