Existing and emerging biomarkers for disease progression in idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a chronic, debilitating, fibrotic lung disease leading to respiratory failure, and ultimately to death. It is characterized by marked heterogeneity regarding its clinical course. Despite significant progress in the understanding of its pathogenesis, the course of the disease and the response to treatment of an individual patient cannot be reliably predicted today. Areas covered: Non-invasive biomarkers, in particular serum biomarkers, for the (early) diagnosis, differential diagnosis, prognosis, and prediction of therapeutic response are described. The molecules are classified according to their involvement into alveolar epithelial cell injury, fibroproliferation, and matrix remodeling as well as immune regulation. Furthermore, genetic variants of TOLLIP, MUC-5B, and other genes associated with a differential response to treatment and with the development and/or the prognosis of IPF are reported. Expert commentary: The combination of multiple biomarkers may identify comprehensive biomarker signatures in IPF patients. This is a way to apply personalized medicine approach to patient affected by IPF in order to not only improve our ability to diagnose and treat disease but also offer the potential to detect disease at an earlier stage, when it is potentially easier to treat effectively.