The role of preoperative blood eosinophil counts in distinguishing chronic rhinosinusitis with nasal polyps phenotypes.

BACKGROUND Chronic rhinosinusitis with nasal polyps (CRSwNP) is a common heterogenous disease in the patients with chronic airway diseases. This study investigated the role of blood eosinophil count (BEC) in the classification of CRSwNP and its recurrence in eosinophilic CRSwNP. METHODS Sixty-five patients who underwent nasal endoscopic resection of CRSwNP were recruited and divided into eosinophilic CRSwNP and non-eosinophilic CRSwNP groups based on the levels (10% cutoff) of eosinophil infiltration as indicated by hematoxylin and eosin (HE p < 0.001). We observed a statistical significance in the number of HE p < 0.001) and CRSwNP phenotypes (eosinophilic/non-eosinophilic, 28/3 vs 2/32; p < 0.001) when the cutoff value of BEC was set at 0.39 × 109 /L. The disease-free recurrence (DFR) was found to be statistically significant when the cutoff value of BEC was 0.73 × 109 /L in eosinophilic CRSwNP (p = 0.009). CONCLUSION Results indicate that BEC may be capable of distinguishing CRSwNP phenotypes as well as predicting polyp recurrence in eosinophilic CRSwNP. Given the relatively small sample size, further studies will be necessary to confirm a role for BEC as a systemic biomarker in CRSwNP.