Abstract
<title>Abstract</title> <p>Background Sepsis is characterized by profound immune dysregulation, but the cellular distribution and immunological relevance of citrullination-related candidate biomarkers remain incompletely understood. This study aimed to define the single-cell localization of six candidate biomarkers and explore their relationship with myeloid immune remodeling in sepsis. Methods The single-cell RNA-seq dataset GSE167363 and the bulk transcriptomic dataset GSE185263 were integrated for analysis. Immune cell annotation, myeloid subcluster analysis, pseudotime trajectory inference, CellChat-based cell-cell communication analysis, and immune infiltration correlation analysis were performed to evaluate the expression distribution and potential immune relevance of LTF, MMP9, MMP8, IL10, LCN2, and S100A12. Results The six candidate biomarkers were mainly localized to myeloid cells. LTF, MMP9, MMP8, LCN2, and S100A12 were closely associated with neutrophils, whereas IL10 was enriched in CD14 + + monocytes/macrophages. Myeloid cells showed prominent differences in cellular composition and communication patterns between sepsis and control samples. Pseudotime analysis further suggested dynamic transcriptional states across myeloid subpopulations, and immune infiltration analysis supported broad associations between candidate biomarkers and myeloid-dominated immune remodeling. Conclusions These findings provide cellular-level evidence that citrullination-related candidate biomarkers are linked to neutrophil effector activation and monocyte/macrophage immune regulatory programs in sepsis. The results support further validation of these markers as potential indicators of myeloid immune remodeling.</p>