Eosinophilic Mucin: A Predictor for Disease Severity in Chronic Rhinosinusitis

Objective: The presence of tissue eosinophilia is a determinate of disease severity in patients with chronic rhinosinusitis (CRS). The impact of eosinophilic mucin (EM) as an independent variable has not yet been elucidated. Study Design: Retrospective review. Setting: Tertiary academic clinic. Subjects Methods: CRS patients who failed medical therapy were classified by tissue eosinophilia, presence of polyps and EM. Tissue eosinophilia count per high power field (HPF) as well as the presence of EM were determined by pathologic examination of sinus tissue removed during surgery. Sinonasal Outcomes Test (SNOT-22), Lund-Mackay (LM), and Lund-Kennedy (LK) scores were compared between all groups preoperatively and postoperatively up to two and a half years (30 months). Results: 192 patients with CRS were included in the study. 87 were diagnosed with eosinophilic CRS with polyps, 58 with eosinophilic CRS without polyps, 14 with noneosinophilic CRS with polyps, and 33 with noneosinophilic CRS without polyps. Only patients with eosinophilia had EM on pathology. Of eosinophilic CRS, 50% of patients with polyps and 12% of cases without polyps demonstrated EM, respectively. EM presence portended more severe disease in patients with eosinophilia on subjective and objective scores preoperatively (P < 0.005). Postoperatively, EM patients experienced a greater improvement of symptoms, but continued to have worse endoscopy scores until 1.5 years. A tissue eosinophil count of 30 or greater per HPF was identified as a potential marker for the development of EM. Conclusions: The presence of eosinophilic mucin predicts overall worse disease severity in patients with eosinophilic CRS.