Local and systemic eosinophilia in patients undergoing endoscopic sinus surgery for chronic rhinosinusitis with and without polyposis

Eosinophils play a key role in the pathophysiology of sinonasal polyposis; their role in chronic rhinosinusitis without polyposis is less clear. To investigate this further, we biopsied diseased sinonasal tissue from 116 patients undergoing endoscopic sinus surgery and normal nasal mucosa from 24 controls. The patients were grouped, according to the nasal endoscopic appearance of their disease, into four clinical groups: chronic rhinosinusitis with no polyps, grade 1 polyps, grade 2 polyps, and grade 3 polyps. We also measured the peripheral blood eosinophil count. Histological analysis of the inflammatory cell content of the biopsies was carried out. The percentage of eosinophils in tissue from each of the clinical groups was significantly higher than that from the controls. There was no significant difference between the percentage of eosinophils in any of the clinical groups, but a trend. Peripheral eosinophil count increased with increasing severity of nasal disease.