Familial and sporadic IPF: A proteomic comparison

Abstract

Background: Idiopathic Pulmonary Fibrosis (IPF) is a chronic interstitial lung disease characterized by progressive parenchymal fibrosis leading to a severe and irreversible decline of respiratory function. Familial cases of IPF have been associated with several gene mutations, that represent about 4% of total IPF population. Genetic mutations have been observed only in few sporadic IPF cases. Aims: The aim of this study is to verify different pathobiological aspects of sporadic and familial IPF forms by comparing their BronchoAleolar Lavage Fluid (BALF) proteomes. Methods: The comparative analysis of BALF obtained by sporadic and familial IPF patients was perfomed through a classical two-dimensional electrophoresis approach. The differentially expressed proteins were identified using mass spectrometry. Results of the differential analysis were then elaborated by the different Multivariate analysis systems in order to identify specific protein profiles characteristic of each condition. Results: The comparison of BALF proteomic profiles revealed 88 protein spots differentially expressed among the 2 groups. Proteins up-regulated in familial IPF than sporadic patients resulted polymeric immunoglobulin receptor, surfactant protein A, fibrinogen γ chain, transthyretin, and actin whereas isocitrate dehydrogenase, selenium binding protein1, complement factor B, andα-1-antitrypsin were down-regulated proteins in familial cohort than sporadic IPF. Conclusions: The early characterization of different IPF subtypes could help to develop more accurate and personalized therapeutic treatments. This study represents a contribution to this topic and to the analysis of the pathogenetic mechanisms and potential biomarkers of familial and sporadic IPF.