Combined CD25, CD64, and CD69 biomarker panel for flow cytometry diagnosis of sepsis.

Sepsis is a highly prevalent syndrome in the United States. The use of cell surface markers, as an effective tool to diagnosis sepsis, has been widely investigated. However, the study of the combination of multiple biomarkers to achieve higher diagnosis accuracy is rare. This study, the panel combined with CD25, CD64, and CD69 was constructed and better diagnosis ability was observed. Septic patients (n = 40), with the mean age of 61 ± 14, were enrolled in this study, along with healthy volunteers (n = 10), included as a control group. All blood samples were measured by flow cytometry based on different subtypes of leukocytes, including neutrophils, monocytes, and lymphocytes. Antigen expression and the antigen positive cell population were reported separately based on cell types. CD64 was the best biomarker in predicting sepsis. The area under Receiver Operating Characteristic (ROC) curve (AUC) was 0.928 and 0.934 for neutrophil CD64 expression and CD64 + neutrophil population, respectively, indicating an excellent diagnosis ability for sepsis. A significant increase was also observed in the populations of CD25 + lymphocytes and CD69 + lymphocytes (p = 0.02 and 0.042, respectively; 95% confidence interval). A panel of combined CD25, CD64, and CD69 was constructed. The parameters of neutrophil CD64 expression, CD64 + neutrophil population, CD25 + lymphocyte population, and CD69 + lymphocyte population were included. The AUC of the ROC curve for this new constructed panel was 0.978. This result indicated that the combination of CD25, CD64, and CD69 outperformed each one of the single parameters in predicting sepsis alone.