Effects of infections on lipidomic profile of Bronchial Washing (BW) and Bronchoalveolar Lavage (BAL) after lung transplantation

Lung transplantation outcomes are challenged by bacterial, viral and fungal infections, noxious triggers that could amplify or promote inflammation and chronic lung allograft dysfunction. We hypothesized the airway lipidome serves as marker of lung infection and related innate immunity. The effects of bacterial, viral and fungal infections on the BW and BAL lipidome from allografts were studied. BW (596) and BAL (199), prospectively collected from 288 pts during surveillance bronchoscopy, were assayed retrospectively by mass-spec for 25 lipid families. Microbiology info was collected. Mann Whitney test used. Bacteria were isolated in 168 BW and 49 BAL, virus in 54 BW and 22 BAL, fungi in 102 BW and 33 BAL. Virus and fungi showed greater BW and BAL total lipid concentration (p<0.05). No difference for bacteria. BW with bacteria had greater (p<0.005): cholesteryl ester (CE), sphingomyelin (SM), N-acylphosphatidylserine; no difference for BAL. BW with virus had greater (p<0.005): monoacylglicerole, ceramide, SM, DihydroSM (dhSM), monosialodihexosylganglioside (GM3), phosphatidylcholine-ether (PCE), phosphatidylethanolamine-p, lysophosphatidylethanolamine-p, lysophosphatidylinositol (LPI), BisMonoacylglyceroPhosphate (BMP); while BAL had greater (p<0.005): dhSM, Lactosylceramide (LacCer). BW with fungi had greater (p<0.005): CE, SM, dhSM, HexosylCeramide, LacCer, GM3, PCE, LPI; while no difference in BAL. The bronchial and broncho-alveolar lipidome of lung allografts is affected by the microbiologic status. Bacteria, virus and fungi have signature lipidomic profile that we speculate associates within the specific bronchial and broncho-alveolar innate immunity.