Microbial and Proteomic Signature of Acute Cellular Rejection in Lung Transplants

Acute cellular rejection (ACR) is a common cause of early post lung transplant morbidity and mortality. Identification of ACR biomarkers may provide a less invasive mechanism for diagnosing ACR, improve understanding of the mechanisms behind ACR, and identify novel pathways for intervention. We aimed to determine whether unique microbial or protein signatures exist in lung transplant patients with ACR. We performed a nested case-control study utilizing bronchoalveolar lavage (BAL) fluid and plasma from 9 lung transplant cases with mild ACR (A2) paired with 9 ACR-free controls (A0) matched for time since transplant. Proteins in the plasma and BAL samples were quantified with Liquid Chromatography-Tandem Mass Spectrometry (LC-MSMS). The microbiome of the BAL samples was profiled using 16S rRNA marker gene sequencing.