Antibody responses to the host microbiome in chronic rhinosinusitis

Abstract Background The role of microbes in chronic rhinosinusitis (CRS) is poorly understood. We hypothesize that analyzing prior microbial exposures via assessing microbial protein serological reactivity in CRS versus controls may offer insights for CRS etiopathogenesis. Methods We profiled IgG and IgA antibodies to individual microbial proteins in serum samples of CRS patients and controls using a novel high‐throughput microarray protein technology, Nucleic Acid Programmable Protein Array (NAPPA). The study was conducted on 118 subjects (39 CRS, 79 controls). A CRS‐focused NAPPA array, with 1557 potentially sero‐reactive microbial proteins elected from a pre‐screening of 6500 genes of interest was constructed. It included membrane‐associated proteins from 47 bacterial species and all proteins from 43 viral strains. Differences between CRS and controls were compared across individual antimicrobial antibodies and the species. Results Chronic rhinosinusitis patients had significantly elevated antimicrobial antibodies compared with controls. One bacterium ( Staphylococcus aureus ) and three viral strains (human metapneumovirus, human herpesvirus 5, and human herpesvirus 4) were identified as sources of the proteins that showed significantly elevated sero‐reactivity in CRS patients. Within CRS, patients with polyps had elevated antibodies against S. aureus , influenza A virus (H1N1, H3N2), and rhinovirus B14. CRS patients without polyps showed more antibodies against human herpesvirus 1 and vaccinia virus WR. Conclusions Compared with healthy controls, CRS patients’ serum samples showed significantly increased sero‐reactivity to both bacterial and viral proteins, reflecting recent or current infection or active colonization. Significantly higher antibodies against S. aureus , human metapneumovirus, human herpesvirus 5, and human herpesvirus 4 in CRS need further study.