Cellular changes lead to chronic allergic inflammation in the sinus

Chronic rhinosinusitis is distinct from your average case of seasonal allergies. It causes the sinuses to become inflamed and swollen for months to years at a time, leading to difficulty breathing and other symptoms that make patients feel miserable. In some people, this condition also produces tissue outgrowths known as nasal polyps, which, when severe enough, have to be removed surgically. By performing a genome-wide analysis of thousands of single cells from human patients, MIT and Brigham and Women's Hospital researchers have created the first global cellular map of a human barrier tissue during inflammation. Analysis of this data led them to propose a novel mechanism that may explain what sustains chronic rhinosinusitis. Their findings also offer an explanation for why some rhinosinusitis patients develop nasal polyps, which arise from epithelial cells that line the respiratory tract. Furthermore, their study may have broader implications for how researchers think about and treat other chronic inflammatory diseases of barrier tissues, such as asthma, eczema, and inflammatory bowel disease.