Circulating and progenitor endothelial cells are abnormal in patients with different types of von Willebrand disease and correlate with markers of angiogenesis.

ABSTRACT

von Willebrand disease (VWD) is the most common inherited bleeding disorder and is caused by quantitative or qualitative defects of von Willebrand factor (VWF). VWF, synthesized by endothelium and megakaryocytes (MK), circulates in plasma and is present in subendothelium and platelets. Circulating endothelial cells (CEC) and progenitor endothelial cells (EPC) have been recently proposed as markers of peripheral and bone marrow-derived angiogenesis. To evaluate the association of CEC/EPC with known inherited defects of cellular and circulating VWF, we have measured the number of CEC/EPC together with cytokines involved in angiogenesis in different VWD types. A group of 74 patients was composed by the following VWD types VWD1 (n = 22), VWD2A (n = 9), VWD2B (n = 19), VWD2M (n = 17), and VWD3 (n = 7). Healthy individuals (n = 20) were used as controls. CEC (CD146(+) , CD31(+) , and CD45(-) ) and EPC (CD34(+) , CD133(+) , and CD45(-) ) were evaluated by flow cytometry. Circulating serum levels of VEGF, E-selectin, P-selectin, EPO, and TPO were determined by ELISA. CEC, VEGF, E-selectin, and EPO were higher and EPC lower in VWD patients than in controls (P < 0.01). Among the five groups of VWD patients and controls, a significant difference was found for CEC (one-way ANOVA P = 0.005), EPC (P = 0.001), E-Selectin (P < 0.0001), EPO (P = 0.021), and TPO (P = 0.004) the latter was high in VWD3 patients. In VWD1, we found an inverse relationship between CEC and VWFAg levels (P = 0.048; R(2) = 0.19). Based on these data, CEC are increased in VWD and are associated with the high levels of cytokines involved in angiogenesis (up-regulation). EPC are decreased, suggesting down-regulation of bone marrow-derived angiogenesis in VWD.