Platelet-derived sTLT-1 is associated with platelet-mediated inflammation in coronary artery disease patients

The development of coronary artery disease (CAD) depends heavily on platelet activation, and inflammation plays a major role in all stages of atherosclerosis. Platelet-specific soluble triggering receptor expressed on myeloid cells like transcript 1 (sTLT-1) facilitate clot formation and have been linked to chronic inflammation. In this study, we explored the role of platelet-derived sTLT-1 in platelet-mediated inflammation in CAD patients. Plasma levels of sTLT-1 were measured using enzyme-linked immunosorbent assay in CAD patients (n = 163) and healthy controls (n = 99). Correlation analysis was performed to determine the circulatory sTLT-1 levels with platelet activation markers, immune cells, and inflammatory cytokines/chemokines. Increased plasma sTLT-1 levels were observed in CAD patients compared with those in healthy controls (p < 0.0001). A positive correlation was observed between sTLT-1 and platelet activation markers (P-selectin, PAC-1), CD14++ CD16- cells (classical monocytes), Natural killer T (NKT) cells, and platelet-immune cell aggregates with monocytes, neutrophils, dendritic cells, CD11c+ cells, and NKT cells. In contrast, a significant negative correlation was observed with CD8 cells. Furthermore, a significant positive correlation was observed between sTLT-1 and inflammatory markers (TNF-α, IL-1β, IL-2, IL-6, IL-12p70, IL-18, CXCL-12, and CCL-11). Logistic regression analysis identified sTLT-1 and triglycerides as predictors of CAD. Receiver operating characteristic curve (ROC) analysis showed that sTLT-1 had a higher sensitivity and specificity for predicting CAD. Our findings suggest that platelet activation induces the release of sTLT-1 into the circulation in CAD patients, which aggregates with immune cells and enhances inflammatory responses.