The Transciptome of BAL Cells at Acute Exacerbation of IPF reveals New Insights

Introduction: Idiopathic pulmonary fibrosis (IPF) is a heterogeneous disease with different courses. Median survival without treatment remains poor at 3 years, with acute exacerbation (AE) being a leading cause of mortality. On a histopathological level acute exacerbations shares many features of ARDS, but only very few studies investigated underlying molecular mechanisms. Objective: in order to identify key pathomechanisms of acute exacerbation of IPF we tested the transcriptome of BAL cells. Methods: The transcriptome of BAL cells from 9 IPF patients with AE and 59 patients without exacerbation was analysed using microarrays on the Agilent platform. Statistical analyses were performed on the R platform using different bioinformatics tools. We identified differentially expressed genes (DEGs) and underlying pathways in a comparative analysis. We also tested for enrichment of the identified DEGs in the BAL transcriptome signature predictive of mortality in IPF which we recently published. Results: We found 527 genes differentially expressed (DEGs, FDR Conclusions: Our data indicate that AE of IPF is not a completly different disease state rather most of the inflammatory and developmental pathways upregulated at AE are already present at baseline IPF.