The Association Between Eosinophils and the Disease Process in Destructive Non-invasive Fungal Rhinosinusitis

Objective: This study aims to investigate the significance of eosinophils in the progression and prognosis of destructive non-invasive fungal rhinosinusitis. Methods: This was a retrospective study of 126 patients who were operated on for a nasal sinus disease between 2010 and 2017; of these, 56 met the inclusion criteria. These were divided into two groups: (i) Group 1, with only the destructive non-invasive sinus polyposis type, and (ii) Group 2, with all types of nasal polyposis other than the destructive non-invasive sinus fungal polyposis type. Data including demographic data, paranasal sinuses (PNS) CT scans, pre- and post-operative eosinophils count, histopathology of polyps, and fungal cultures were collected from medical records from King Abdulaziz University Hospital, Jeddah, Saudi Arabia. A nonparametric Wilcoxon signed-rank test was used to determine a significant difference of p< 0.05. We performed multivariate analysis using repeated measure analysis of covariance (ANCOVA) and adjusted for confounders such as age, sex, pre- and post-operative IgE, fungal culture, and histopathology of the disease. Interaction between age, sex, IgE, and proportion of eosinophils was assessed at a p-value of 0.05. Results: A significant difference was found between pre-and post-operative blood eosinophils levels in Group 1 (p= 0.01) after adjusting for confounders such as age, sex, fungal culture, pre and post IgE, and histopathology of the disease. However, no significant difference was found in Group 2 (p= 0.663) even after adjusting for age, sex, fungal culture, pre and post IgE, and histopathology of the disease. We did not find any significant interaction (P>0.05) between pre- and post-operative levels of eosinophils with age, sex, and fungal culture among Group 1 and Group 2. Conclusions: There is a statistically significant difference in blood eosinophils between pre- and post-operative levels in studied cases of destructive non-invasive fungal polyposis, a difference is not seen in nasal sinus polyp cases other than destructive non-invasive fungal polyposis types. High pre-operative eosinophils levels in destructive non-invasive fungal sinus polyposis types demonstrated the importance of eosinophils in the pathogenesis of this disease. The blood eosinophils can therefore be considered an important factor in the disease process and an indicator of the disease prognosis and destructive behavior.