Abstract: Objective  To elucidate the immune cell infiltration characteristics and lipid metabolic activation in chronic rhinosinusitis with nasal polyps (CRSwNP). Methods  Eight datasets from the Gene Expression Omnibus（GEO） database containing bulk-RNA sequencing results of normal nasal mucosa and CRSwNP tissues were selected. After batch effect correction, Weighted Gene Co-expression Network Analysis (WGCNA) was performed to identify key modules associated with CRSwNP. Additionally, differentially expressed genes (DEGs) between CRSwNP tissues and the control group were analyzed, followed by functional enrichment analysis of the DEGs within the key modules. XCell analysis was used to characterize immune cell infiltration in CRSwNP tissues. The impact of varying Th2 cell infiltration levels on activation of lipid metabolic pathway  in CRSwNP was investigated, and key genes were screened for validation using real-time fluorescence polymerase chain reaction (RT-PCR). Results  Compared to the controls, DEGs in the midnight blue module of CRSwNP tissues were primarily involved in the regulation of metabolic processes. Immune infiltration analysis revealed more prominent Th2 cell infiltration in CRSwNP tissues, and lipid metabolic pathways were significantly enriched in high-type 2 CRSwNP tissues. The expression of the  key gene GDE1  was upregulated in type 2 CRSwNP tissues as measured by RT-PCR.Conclusion  GDE1 may influence disease progression by modulating the activation level of lipid metabolic pathways in type 2 CRSwNP.

Key words: chronic rhinosinusitis, immune cell infiltration, bioinformatics, type 2 inflammatory response, lipid metabolism, glycerophosphodiester phosphodiesterase 1