Correlation of tissue eosinophil count and modified CT olfactory cleft score and olfactory function in patients with nasal polyps

Abstract

Objective:To investigate the effect of tissue eosinophil count on olfactory function in patients with chronic sinusitis with nasal polyps（CRSwNP）. Method:We prospectively selected 59 patients with CRSwNP. All the patients were not treated with oral or topical glucocorticoids for at least 1 month at the time of enrollment. All the nasal polyps were taken under local anesthesia in the outpatient department for eosinophil count and percentage calculation. The patients were divided into eosinophilic CRSwNP（ECRS group） and non-eosinophilic CRSwNP（non-ECRS group）. Baseline data was compared between the two groups. Spearman correlation analysis was performed on tissue eosinophil count and Lund-Mackay score, modified olfactory cleft scores, Sniffin' Sticks olfactory test, olfactory evoked potential peak latency and amplitude respectively. Result:Thirty-five of 59 patients with CRSwNP completed olfactory evoked potential test, from whom we collected stable waveforms. The ECRS group had a higher olfactory cleft area CT score, ethmoid sinus CT score and blood eosinophil count and percentage; there was a significant difference between the ECRS group and the non-ECRS group in single and bilateral odor test threshold（T value）（P=0.017）. There was no significant correlation between tissue eosinophil count and subjective olfactory VAS score（P>0.05）. Tissue eosinophil count was related to the bilateral T value in Sniffin' Sticks olfactory test（r=-0.322, P=0.013）, anterior and posterior olfactory cleft area scores（r=0.431 and 0.415, respectively, P=0.001） and olfactory evoked potential N1 latency（r=0.504, P=0.001） and P2 latency（r=0.374, P=0.020）, but not related to Lund-Mackay scores. In addition, there was a significant correlation between the unilateral T score in Sniffin' Sticks test and the unilateral olfactory evoked potential N1 latency（r=-0.505, P=0.002）. Conclusion:The increase of tissue eosinophilia was closely related to olfactory disfunctions in CRSwNP. It could be reflected by modified CT olfactory cleft score, Sniffin' Sticks olfactory test T value and oERP peak latency. In addition, T value was negatively consistent with latency of oERP N1 peak.