Blood eosinophil-to-basophil ratio in patients with sinonasal polyps: does it have a clinical role?

Background In a preliminary study, eosinophil and basophil counts were recently calculated in chronic rhinosinusitis with nasal polyps (CRSwNP) using conventional histological and immunohistochemical methods: the tissue eosinophil-to-basophil ratio differed in the CRSwNP endotypes considered. Objective The aim of the present study was to compare the blood eosinophil-to-basophil ratio (bEBR) in a large series of CRSwNP with those in a control group of consecutive rhinological patients with no evidence of nasal/paranasal or systemic inflammatory disorders. Methods A retrospective study was performed on 334 CRSwNP patients, comparing the preoperative bEBR in different endotypes, and the bEBR in CRSwNP cases with those in the controls (69 cases). Results The mean bEBR was significantly higher in the CRSwNP group than in the control group (p=0.0006). The eosinophil and basophil counts were significantly and directly correlated in the CRSwNP cases (p=0.0000). The mean bEBR was significantly higher in the subcohorts of CRSwNP patients with allergy (p=0.0007), asthma (p=0.0000), and aspirin-exacerbated respiratory disease (AERD) (p=0.0153). The mean bEBR was significantly higher in the subcohort with eosinophilic CRSwNP than in the subcohort with non-eosinophilic CRSwNP (p=0.0000). Conclusion The study confirms the increasingly interesting role emerging for blood eosinophils and basophils in different CRSwNP endotypes. Blood EBR seems to be a parameter worth investigating in different CRSwNP endotypes, since it is significantly higher in patients with allergy, asthma, and AERD.