Krebs von den Lungen-6 levels in untreated idiopathic pulmonary fibrosis.

BACKGROUND: Serum Krebs von den Lungen-6 (KL-6) has been reported to be elevated in patients with idiopathic pulmonary fibrosis (IPF). OBJECTIVE: The aim of this study was to evaluate the diagnostic value of KL-6 and whether the expression value of KL-6 could indicate the severity of the disease in IPF patients. To address this question, it is necessary to see whether the patients' physical characteristics and other clinical conditions could affect the baseline KL-6 level. DESIGN: We conducted a study of 100 patients who were diagnosed with IPF. Lung function, computed tomography (CT), and serological lab tests data were analyzed. RESULTS: The tests showed that there is a significant elevation of KL-6 in IPF patients compared with other interstitial lung disease (ILD) and healthy controls. It was noted that serum KL-6 is a stable biomarker not affected by lung infection and smoking, though IPF patients with antinuclear antibody (ANA) showed higher KL-6 levels. KL-6, in conjunction with poor pulmonary function and higher radiological fibrosis scores, indicates the severity of the disease but not poor survival. CONCLUSIONS: It is identified that serum KL-6 is a useful noninvasive biomarker to help improve the certainty of IPF diagnosis from other interstitial lung disease and assist evaluation of disease severity and prognosis.