[Clinical usefulness of KL-6 as a serum marker of idiopathic interstitial pneumonia].

KL-6 is a high-molecular-weight glycoprotein that is classified in cluster 9 among pulmonary cell antigens. Levels of KL-6 were found to be abnormally high in sera from patients with various types of interstitial pneumonitis such as idiopathic interstitial pneumonia, which can progress to pulmonary fibrosis. Levels of KL-6 in serum can be useful serum markers in the diagnosis of idiopathic interstitial pneumonia, in monitoring in the evaluation of disease activity, as a prognostic factor, and as a predictor of response to therapy.