Discovery of lipid metabolism-related diagnostic biomarkers and construction of diagnostic model in steroid-induced osteonecrosis of femoral head.

This study aimed to identify candidate diagnostic biomarkers for steroid-induced osteonecrosis of the femoral head (SONFH). Two datasets were downloaded from the Gene Expression Omnibus for analyses of differentially expressed genes (DEGs) and lipid scores in SONFH and control groups and a weighted gene co-expression network analysis. Overlap between genes in the disease-related module, DEGs, and lipid metabolism-related genes was evaluated to obtain lipid metabolism-related DEGs. A diagnostic model was constructed and evaluated using a nomogram analysis and calibration curves. Correlations between immune cells and lipid metabolism-related DEGs in the model were evaluated. In total, 1,724 DEGs were screened between the SONFH and control groups. Seven SONFH-related modules and 18 lipid metabolism-related DEGs were identified. A total of six optimized genes, CDK8, CHPT1, DPEP3, ORMDL3, PIP5K1B, and PPT2, were obtained. A model based on these genes had good diagnostic performance for SONFH in GSE123568 and GSE74089. The six genes were significantly related to two immune cell subsets, myeloid dendritic cell activated and neutrophil. These six genes may be novel biomarkers for SONFH and the combination is a potential diagnostic signature.