Todd JL, Neely ML, Overton R, et al. - Including 300 patients suffering idiopathic pulmonary fibrosis (IPF) from the Idiopathic Pulmonary Fibrosis Prospective Outcomes Registry and 100 individuals without known lung disease, researchers undertook this investigation to measure the circulating proteome in IPF, define differential protein expression between individuals with IPF and controls, and to determine the links between protein expression and markers of disease severity. Analysis of plasma obtained at enrolment was done using aptamer-based proteomics (1305 proteins). Between IPF and controls, significantly different levels of 551 proteins were detected, of which 47 displayed a |log₂<(fold-change)| > 0.585. Glycoproteins thrombospondin 1 and von Willebrand factor and immune-related proteins C-C motif chemokine ligand 17 and bactericidal permeability-increasing protein were included among proteins with the greatest variation in levels in patients with IPF vs controls. A distinct circulating proteome was found in patients with IPF and discrimination of these patients was allowed by a nine-protein profile. A strong association of many proteins with disease severity was also revealed. The proteins discovered may be biomarker candidates and implicate pathways for further research.