b'The Fungus Really Is Among Us:Its Role in Airway Disease, Nasal PolypsWhat is the role of fungus in allergic airway diseases? VA researchers found that many conditions, including chronic rhinosinusitis (CRS), allergic fungal rhinosinusitis, asthma, allergic bronchopulmonary mycosis/aspergillosis and cystic fibrosis (CF) have a shared immunological signature. In some cases, nasal polyps can occur.By Annette M. BoyleHOUSTONWhile the isolation of the pandemic2immuneresponse,alongwithaTh17immune increased awareness of the importance of human in- response, innate lymphoid cells (ILC) 2, production teraction and community in world beyond ourselves,of IgE antibodies and infiltrating eosinophils. thelast20yearshavetransformedunderstandingSevere forms of these disorders have long been of the importance of community interaction in therecognized as being related to hypersensitivity reac-world within ourselves. The trillions of organismstionstoenvironmentalfungi,wroteHouston VA that reside on and inside us play critical roles in theresearchersFarrahKheradmand,MD,andDavid functioning of the brain and gut, affect personalityCorry, MD, and their colleagues. Increasingly, how-and drive a wide range of immune responses. ever, environmental fungi are assuming a more pri-Until quite recently, the study of microbiota largelymary role in the etiology of these disorders, with air-focused on bacteria: how antibiotic use and misuseway mycosis, a type of non-invasive airway fungal affected intestinal and vaginal bacteria, for instance,infection, recognized as an essential driving factor or what beneficial colonies could be introduced byin at least severe subsets of allergic airway disease.fecaltransplants.Similarly,studiesofsinuscavi- The growth of fungi on the sino-mucosal surface ties and airways have sought to better understandstimulates distinct responses in line with the indi-boththeimpactofdiminishedbacterialdiversityvidualsimmunestatus.Inimmunocompromised in inflammation and the pathologic role of bacteriapeople, such as those with diabetes, invasive fungal inchronicrhinosinusitisandotherinflammatorysinusitis develops, with angioinvasion and increased diseases. riskofdamagetoendothelialcells.Inimmuno-Researchers at the Michael E. Debakey VA Centercompetent individuals, fungal balls emerge and the for Translational Research in Inflammatory Diseases,inflammation remains confined to the affected sinus alongwithcolleaguesattheMcGovernMedicalwith no tissue infiltration. School of the University of Texas Health Sciences Center and the Baylor College of Medicine, all inNasal PolypsHouston,lookedinsteadattheroleoffungusinThe third presentation, allergic fungal rhinosinusitis allergic airway diseases in a recent study. 1 (AFRS), a type of chronic rhinosinusitis with nasal They noted that many of these conditions, includ- polyps(CRWwNP),arisesinimmunocompetent ingchronicrhinosinusitis(CRS),allergicfungalpeople with an atopic background. Their hypersensi-rhinosinusitis,asthma,allergicbronchopulmonarytivity to fungal allergens generates an excessive type mycosis/aspergillosis, and cystic fibrosis (CF), have2 immune response, while a defective mucosal bar-asharedimmunologicalsignature.Allgeneraterier and fungi-activated molecular signaling contrib-a T helper type 2 (Th2) immune response or typeute to the development of nasal polyps.Continued on Page 46 u43'