The team found that in chronic sinus infection patients, activated white blood cells (eosinophils) cluster in the nasal and sinus mucus and scatter a toxic protein (major basic protein) onto the nasal and sinus membrane. While major basic protein was not distributed in the nasal and sinus tissue, the level of this protein in the mucus of chronic sinus infection patients far exceeded that needed to damage the nasal and sinus membranes and make them more susceptible to infections such as chronic sinus infection.
To conduct this investigation, Dr. Ponikau and fellow researchers collected specimens from 22 consecutive Mayo Clinic chronic sinus infection patients undergoing endoscopic sinus surgery. The surgeons extracted the maximum possible tissue and mucus during the sinus surgery. The surgeons also extracted tissue and mucus from healthy patients undergoing septoplasty, surgery to fix a deviated septum, for comparison with the specimens from the chronic sinus infection patients. Through various forms of laboratory examination of the tissue and attached mucus, the investigators observed an abundance of major basic protein throughout the nasal and sinus mucus in all 22 specimens, but not in the tissue.
Chronic sinus infection is one of the most common chronic diseases in the United States, affecting 32 million adults, according to the National Center of Health Statistics. Chronic sinus infection produces nose and sinus problems characterized by stuffy nose, loss of sense of smell, postnasal drip, nasal discharge, and head and face pain lasting three months or longer. It notably decreases the quality of patients' lives, impairing physical and social functioning, vitality and general health, according to the Mayo Clinic researchers.