Clinical value of KL-6 in patients with polymyositis and dermatomyositis compliated with lung disease

Abstract

Objective To investigate the clinical effect of the serum levels of KL-6 on patients with polymyositis (PM)/dermatomyositis (DM) and lung disease. Methods Among the 77 PM/DM patients, 27 cases of interstitial lung disease (ILD), 20 cases of infectious lung disease, 30 cases without lung disease. ELISA method was adopted to measure the serum KL-6 levels. The relationship between KL-6 and diagnosis, treatment, and prognosis were analyzed. Results The serum KL-6 levels in patients with ILD, patients with infectious lung disease and patients without lung diseases were (1135±649), (372±187), (231±111)U/ml, respectively. PM/DM patients with ILD had significantly higher median serum KL-6 levels than other two groups (P<0.05), but the difference between PM/DM patients with infectious lung disease and PM/DM patients without lung disease was not significant (P=0.229); While the 507 U/ml was regarded as positive standard, the sensitivity of KL-6 for PM/DM interstitial lung disease diagnosis was 96.3%, and the specificity was 89.0%. A follow-up analysis indicated that, serum KL-6 levels of 10 cases of PM/DM with ILD patients were correlated with therapeutic effect (P<0.05), and the serum KL-6 levels of 5 cases died of PM/DM with ILD were significantly higher than those of 22 cases of survived PM/DM with ILD(P<0.05). Conclusions Serum KL-6 levels can be used to identify the lung disease type in PM/DM patients, and assess clinical response to treatment, and high level of KL-6 possibly indicates poor prognosis. Key words: Polymyositis; Dermatomyositis; KL-6; Interstitial lung disease