Serum concentrations of KL-6 in patients with IPF and lung cancer and serial measurements of KL-6 in IPF patients treated with antifibrotic therapy

Abstract

Krebs von den Lungen-6 (KL-6) was suggested as ILD biomarker including idiopathic pulmonary fibrosis (IPF). Lung cancer is one of the most severe comorbidity of IPF patients. This study aimed to serially analyze KL-6 in IPF patients after 24 months of Nintedanib and to firstly investigate the biomarker behavior in IPF associated with adenocarcinoma. One hundred and forty-two ILD patients (median (IQR), 69 (63-75) years; 86 males) were retrospectively enrolled. Serial serum samples were collected from IPF patients before starting antifibrotic therapy and after 12 and 24 months. Serum KL-6 levels were measured by KL-6 reagent assay. Increased KL-6 concentrations were identified in IPF-LC patients than IPF, fibrotic hypersensitivity pneumonitis and pulmonary fibrosis associated with autoimmune disease groups. IPF patients monitored for 24 months with Nintedanib showed persisted increased levels of KL-6 with a progressive decline of FVC percentages. This preliminary study offers a first demonstration that very high serum concentrations of KL-6 in IPF-LC patients are associated with poor prognosis. Moreover, serial evaluation of serum KL-6 in IPF patients over 24 months of Nintedanib treatment revealed that most patients experienced a stabilization of lung function parameters and of serum concentrations of KL-6.