Significance of molecular biomarkers in idiopathic pulmonary fibrosis: A mini review

Idiopathic pulmonary fibrosis (IPF) is a chronic, irreversible condition with poor prognosis that is characterized by a variable clinical course in each patient, which renders it a complex disease with unknown causes. Despite the proven efficacy of novel antifibrotic therapies, including pirfenidone and nintedanib, the diagnosis and follow-up of IPF remain challenging. Hence, the identification of molecular biomarkers for early detection of IPF and to predict biologically determined individual clinical courses, has recently piqued the interest of researchers. Previous studies have demonstrated the diagnostic and prognostic efficacy of blood proteins such as KL-6, Surfactant protein (SP)-A, and SP-D, in patients with IPF. Due to their use in clinical practice in Japan, for approximately twenty years, a significant amount of data about these biomarkers has been accumulated. This paper reviews the recent literature on molecular biomarkers for IPF that have been developed in Japan as well as other potential molecular biomarkers.