Circulating endothelial cells and endothelial progenitor cells as potential predictors of acute GVHD after allogeneic hematopoietic stem cell transplantation

Objective: Acute graft-versus-host disease (aGVHD) is a major cause of treatment-related mortality after allogeneic hematopoietic stem cell transplantation. Endothelial cell damage may trigger the initiation of aGVHD. Methods: Endothelial damage and repair were evaluated by counting circulating endothelial cells (CECs) and endothelial progenitor cells (EPCs) in 17 allogeneic hematopoietic stem cell transplantation patients at pre-conditioning, day 0, day 7, day 14, day 30, and day 60 by multicolor flow cytometry. Von Willebrand factor activity was simultaneously measured. Results: Eight patients developed aGVHD and were compared to non-aGVHD patients. Patients' characteristics were not different, except for previous treatment courses. There was no difference in von Willebrand factor activity between the two groups. Both CEC and EPC counts were decreased on day 7 and day 14 and then increased thereafter. The CEC count on day 7 was significantly lower in the aGVHD group than in the non-aGVHD group (p =.0401). Restoration of the EPC count on day 60 was significantly suppressed in the aGVHD group (p =.0464). The CEC count on day 7 could predict aGVHD development (AUC 0.8214, p =.0372). Conclusion: The present results showed that CEC count on day 7 could be a predictor of aGVHD.