Inflammatory Profile of Chronic Rhinosinusitis With Nasal Polyp Patients in Brazil: Multicenter Study

Objectives: To determine the inflammatory profile of CRSwNP in Brazil and characterize the subgroups of CRSwNP patients in this population through cluster analysis. Study Design: Multicenter cross-sectional study involving 15 centers representing different regions of Brazil. Subjects and Methods: Clinical data of 166 patients and 80 controls, aged 18 to 70 years old, number of surgeries for CRS, history of asthma and aspirin sensitivity, and Lund-Mackay scores on CT scans. During nasal endoscopy, we obtained the Lund-Kennedy scores and collected 2 samples of nasal polyps: one for eosinophil and neutrophil tissue counts and one to quantify different cytokines. Results: 79.6% of our patients had 10 or more eosinophils/HPF. CRSwNP groups exhibited significantly lower concentrations of TNF-alpha and significantly higher concentrations of IFN-gamma, CCL11/Eotaxin, CCL24/Eotaxin-2/MPIF-2, and CCL26/Eotaxin-3 versus the control group (Kruskal-Wallis test). Comparison between CRSwNP groups (≥10 vs <10 eosinophils/HPF) showed no difference in cytokine concentration (Mann-Whitney test). Hierarchical clustering and PCA according to cytokine concentrations revealed 2 main Clusters, with a significantly higher concentration of all cytokines in Cluster 1 (n = 35) than in Cluster 2 (n = 121), except IL-6 and IL-33 (Mann-Whitney test). According to ROC curve analysis the best cut-off to differentiate the 2 clusters was 43 eosinophils/HPF. The group with ≥43 presented a higher prevalence of men and a higher Lund-Mackay score (Mann-Whitney test). Conclusions: CRSwNP patients in Brazil present mixed inflammation, with 2 distinct groups (high and low inflammatory pattern) that can be distinguished by tissue eosinophilia of ≥43 eosinophils/HPF cut-off in nasal polyps.