Discovery of five diagnostic biomarkers associated with immune cell infiltration in cases of acute myocardial infarction.

Background: Acute myocardial infarction (AMI) remains one of the leading causes of mortality and morbidity worldwide.

Methods: GSE61144 and GSE66360 were the sources of microarray gene expression profiles for acute myocardial infarction patients and were acquired from the Gene Expression Omnibus (GEO) database (https://www.ncbi.nlm.nih.gov/geo/). After merging the datasets, genes that were differentially expressed were chosen.

Results: A total of 234 genes were found to have different expression levels. Of these, 206 genes were upregulated, and 28 genes were downregulated. Five coexpression modules were identified by WGCNA, with the yellow module showing a high correlation with AMI (r=0.65, P=2.0e-15). Ninety-two hub genes were selected in the yellow module by setting a threshold of module membership (MM) greater than 0.8 and gene significance (GS) higher than 0.4. By overlapping these genes with the differentially expressed genes, 81 hub genes were obtained. Five key genes (C5AR1, CXCL1, CXCL2, FPR1, and P2RY13) were identified through PPI analysis. AMI patients exhibited elevated levels of immune cell infiltration, and immune scores in AMI samples were significantly positively correlated with all five key genes. Moreover, the expression levels of these five genes were higher in AMI patients. These five genes possessed area under the curve (AUC) values exceeding 0.8 for diagnosing AMI, thereby demonstrating their efficacy as diagnostic markers.

Conclusions: C5AR1, CXCL1, CXCL2, FPR1, and P2RY13 have the potential to be useful biomarkers in diagnosing AMI and are linked to immune cell infiltration in AMI, opening up new avenues for future research into the pathogenesis of AMI.