Study On Clinical Features Of Eosinophilic Chronic Rhinosinusitis With Nasal Polyps

Objectives/Hypothesis: Chronic rhinosinusitis (CRS) is a common disease with highprevalence in population. Etiology, pathogenesis and underlying mechanism of CRS isnot fully understood. Generally based on presence or absence of nasal polyps, CRS maybe divided into two types: CRS with nasal polyps (CRSwNP) and CRS without nasalpolyps (CRSsNP). There is a predominant tissue eosinophil infiltration in some CRS,prominently in CRSwNP, and these cases can be classified as eosinophilic CRS (ECRS).There are significant differences in clinical characteristics, underly pathogenicmechanisms and treatment outcomes between ECRS and non-eosinophilic (non-ECRS).This study aims to investigate clinical features.Methods: Sixty patients with CRSwNP underwent endoscopic sinus surgery (ESS) wasincluded in this study. Based on postoperative histopathological examination and nasalpolyp tissue eosinophil count, ECRSwNP was determined as the average eosinophilcount was more than5eosinophils per high power field and non-ECRSwNP as thecount was5eosinophils or less. All patients were evaluated before ESS for theseverities of specific symptoms using VAS; the severities of nasal polyps were scoredwith endoscopic examination; the diseases of individual sinuses on CT were assessed;and blood eosinophil count and percent were measured.Results: The60patients were divided into two groups,27patients in ECRSwNP groupand33patients in non-ECRSwNP group. There was no difference in age and sexbetween two groups (p>0.05). The percentages of patients with allegic rhinitis were 74.1%in ECRSwNP group and48.5%in non-ECRSwNP group (p>0.05), and in thetwo group the percentages of patients with asthma were18.5%and12.1%(p>0.05)，respectively. Mean serum IgE levels of ECRSwNP and non-ECRSwNP groups were236.72and167.97kU/L, p>0.05. Compared to patients with non-ECRSwNP, thepatients with ECRSwNP had the increased tissue eosinophil count (33.9vs0.82cells/HPF, p<0.01), and also the increased blood eosinophil count (0.44vs0.21×109/L,p<0.01) or percent (6.49%vs3.42%. p<0.01). The patients with ECRSwNP ornon-ECRSwNP had similar severities and duration of symptoms (p>0.05). Howevercompared to the patients with non-ECRSwNP, the patients with ECRSwNPdemonstrated a higher mean score of nasal polyps (3.6vs2.1, p<0.01), with a higherincidence of bilateral polyps (92.6%vs39.4%, p<0.01) and a higher score of diseaseseverity on CT (14.4vs9.6, p<0.01) with high incidence of bilateral diseases. The tissueeosinophil count is associated with blood eosinophil count or percent in ECRSwNP, butnot in non-ECRSwNP. One-week follow-up showed the patients in each group hadsignificant improvement in the CRS-related symptoms (p<0.01)aside from smelldysfunction postoperatively, but no significant difference in improvement in symptomsbetween two groups (p>0.05).Conclusion: CRSwNP can be classified into two subtypes of ECRSwNP andnon-ECRSwNP based on tissue eosinophil infiltration. ECRSwNP differs fromnon-ECRSwNP in clinical features. Increased blood eosinophil count or percent can beused as a predictor for ECRSwNP. Subclassification of CRSwNP can be helpful to maketreatment stragety targetting different CRSwNP subtypes.