Application of eosinophil-neutrophil index eni and degree of inflammatory infiltration to assess the inflammatory process in polypous rhinosinusitis

Abstract

Introduction. Identification of the cellular composition of polyps in polypous rhinosinusitis (PRS) is important. In practice, to determine the quantitative indicators of the number and ratio of eosinophilic and neutrophilic leukocytes in polyp tissue, the eosinophil-neutrophil index (ENI) was introduced, which is equal to the ratio of the arithmetic mean number of eosinophils to the arithmetic mean number of neutrophils in 10 considered fields of view at a magnification of the microscope ×400, and the indicator degree of cellular inflammatory infiltration. Objective. To conduct a pathomorphological study of the tissue of resected nasal polyps with the determination of ENI parameters and the degree of cellular inflammatory infiltration in various PRS phenotypes and evaluate the possibility of using these indicators as predictors of PRS drug control. Materials and methods. We examined 292 people (126 men, 166 women), mean age 52.12±13.04 years, with bilateral PRS, which were divided into 4 phenotypic groups: I group: PRS without concomitant bronchial asthma (BA) and respiratory allergies; IIa group: PRS + allergic BA (aBA) and allergic rhinitis (AR); IIb group: PRS + AR without BA; III group: PRS + nonallergic BA (nBA). During pathological examination, polyps were divided into 3 histological types: «eosinophilic,» «neutrophilic,» and «mixed»; the ENI index was determined, 3 degrees of inflammatory infiltration were established: weak (I degree) when the arithmetic mean of eosinophils, lymphocytes, neutrophils, macrophages, histiocytes, and mast cells in 10 representative fields of view does not exceed 200 cells; moderate (II degree) when the arithmetic mean varies from 201 to 400 cells; and significant (III degree) where the arithmetic mean is > 400 cells. In the PRS+BA groups, the state of BA control was determined using the ACQ-7 (Asthma Control Questionnaire). An analysis of the dynamics of ENI indicators and the degree of inflammatory infiltration was carried out depending on the effectiveness of conservative therapy with topical glucocorticoids (GCs) during the observation period of 1 year. The patients were divided into 3 groups: group 1, patients with positive dynamics, with a decrease in the degree of nasal polyps; group 2, the severity of polyps remained at the same level; group 3, the prevalence of polyps was higher than a year ago. Results. In all phenotypes of PRS, the eosinophilic type of inflammation prevails. The minimum indicators of ENI (11 [6;16]) and the degree of inflammatory infiltration (1 [1; 1]) were in the PRS +AR group, the highest intensity of inflammation was found in the PRS+nBA group (2.03 [2; 2]). According to the cellular composition of polyps in group 1, eosinophilic polyps were 87%; neutrophilic, 8%; mixed type, 5%; in group 2a, 97% of eosinophilic and 3% of mixed type in the absence of neutrophilic polyps, in group 2b ORS + AR, eosinophilic polyps were detected in 100%; in group 3, eosinophilic 88%, neutrophilic 6%, and mixed polyps 6% were diagnosed. Changes in ENI parameters and the intensity of inflammatory infiltration depending on the effectiveness of conservative therapy were revealed. In the group with positive dynamics, there was a decrease in these two indicators after 6 months of using intranasal GCs, in the absence of dynamics during therapy there were no changes in these indicators, and with low drug control, their increase was noted, which after the next 12 months was manifested by aggressive growth of polyps. At the same time, a correlation was found between the increase in the magnitude of indicators of local inflammation of the tissue of nasal polyps with a deterioration in the degree of control of BA of any etiology and the absence of significant correlations between blood eosinophilia and the level of eosinophilic infiltration of polypous tissue. Conclusions. 1. During the pathological examination of the surgical material, it is necessary to establish the histological type of nasal polyps (eosinophilic, neutrophilic, and mixed) to determine the further tactics of treating patients with PRS. 2. Pathological determination of the density of the inflammatory infiltrate in the tissue of resected nasal polyps with the calculation of ENI in clinical practice is necessary to control the dynamics of the course of inflammation, predict the possibility of relapse, and adjust the treatment of patients with PRS. 3. Correlation analysis in patients with PRS did not reveal a significant relationship between the severity of tissue eosinophilic infiltration of polyp tissue and the level of eosinophils in the peripheral blood, so the determination of peripheral blood eosinophilia is not enough to characterize local inflammation in PRS. 4. A decrease in ENI and the degree of density of the inflammatory infiltrate in nasal polyps in dynamics indicates the effectiveness of the ongoing conservative therapy. 5. An increase in the intensity of inflammatory infiltration in the tissues of polyps is accompanied by a deterioration in the medical control of asthma in phenotypes of PRS in combination with aBA and nBA.