Abstract:Objective To investigate the relationship between eosinophil infiltration (EOS) and clinical characteristics, as well as changes in IL-17 expression in patients with chronic rhinosinusitis with nasal polyps (CRSwNP).Methods A total of 100 patients diagnosed with CRSwNP between January 2020 and October 2022 at Suqian Hospital Affiliated to Xuzhou Medical University were selected. Based on the occurrence of EOS infiltration, patients were divided into a control group (55 cases without EOS infiltration) and an observation group (45 cases with EOS infiltration). Nasal endoscopy was performed on all patients, and nasal polyp tissues were collected. IL-17 levels in nasal polyp tissues and peripheral venous blood were measured. Nasal endoscopy and CT scans were used for lesion assessment with Lund-Kennedey and Lund-Mackey scores. Clinical data were collected and compared to explore factors influencing EOS infiltration and the correlation between EOS infiltration, lesion tissues, and IL-17 expression.Results There were no statistically significant differences in age, gender composition, disease duration, neutrophil percentage, lymphocyte percentage, and lesion classification between the two groups (P > 0.05). The Lund-Kennedey scores for nasal polyps, edema, and nasal discharge in the observation group were comparable to the control group (P > 0.05). However, the CT scan combined with the Lund-Mackey scores for posterior ethmoidal sinus, ostiomeatal complex, sphenoid sinus, and sphenoid recess were higher in the observation group, while the maxillary sinus score was lower than the control group (P < 0.05). The scores for anterior ethmoidal sinus and frontal sinus showed no significant differences (P > 0.05). IL-17 levels in nasal polyp tissues and serum were higher in the observation group than in the control group (P < 0.05). Serum IL-17 levels, nasal polyp tissue IL-17 levels, sphenoid recess, sphenoid sinus lesions, ostiomeatal complex, posterior ethmoidal sinus, and EOS infiltration showed a positive correlation (r = 0.859, 0.904, 0.955, 0.680, 0.281, and 0.421, all P = 0.000). Maxillary sinus lesions were negatively correlated with EOS infiltration (r = -0.700, P = 0.000), while there was no correlation between nasal discharge scores and EOS infiltration (r = 0.147, P = 0.073).Conclusion In CRSwNP with EOS infiltration, abnormal changes in IL-17 levels were observed in lesion tissues and serum. Serum IL-17 levels, nasal polyp tissue IL-17 levels, and sinus lesion conditions were associated with EOS infiltration. This study contributes to understanding the pathogenesis of CRSwNP and provides new insights for treatment, aiming to enhance diagnostic and therapeutic efficacy to improve patients' quality of life.