Identification and Functional Analysis of Key Genes Involved in Community‐Acquired Pneumonia Inflammation Based on Bioinformatics

Previous studies have revealed various treatment modalities for community-acquired pneumonia (CAP), but there is still a lack of in-depth research on inflammation-related genes (IRGs) in CAP. In this analysis, we collected clinical data from CAP patients and identified CAP differentially expressed IRGs (CAP-DE-IRGs) between healthy individuals and CAP patients. Subsequently, functional and pathway enrichment analyses were carried out on CAP-DE-IRGs. Furthermore, hub genes in IRGs were identified, with their diagnostic ability and function validated. Enrichment analyses demonstrated that these CAP-DE-IRGs were abundant in biological processes such as cytokine-cytokine receptor interaction and JAK-STAT signaling pathway. Five hub genes were selected from IRGs. Quantitative Real-time PCR (qRT-PCR) results showed that CCL5, IL7R, IL2RB, and IL10RA were significantly downregulated in CAP patients, and IL18R1 was significantly upregulated in CAP patients (p < 0.05). In the validation of the diagnostic ability of hub genes, most of the genes exhibited area under curve (AUC) values exceeding 0.7, indicating the excellent diagnostic ability of hub genes. The function prediction of hub genes unraveled that hub genes had the functions of cytokine receptor binding, immune receptor activity, response to interleukin-7, and so on. The immune infiltration analysis demonstrated that immune cell Neutrophils exhibited higher infiltration in CAP patients than in healthy individuals. The correlation analysis of hub genes and CAP-related genes manifested that the hub gene IL18R1 was positively correlated with CAP-related genes. In summary, our analysis identified a connection between CAP patients and IRGs, which is beneficial for further research on CAP.