Circulating Endothelial Cells in Kawasaki Disease

Recently, endothelial cells (EC) have been reported to be present in the circulating blood of several diseases with vascular injury, and the circulating EC (CEC) contain both the EC which become detached from the vascular wall and endothelial progenitor cells (EPC) which derive from the bone marrow. Kawasaki disease (KD) is widely known to be one type of systemic vasculitis in children. In the present study, we measured the number of CEC (mean±SE cells/ml) in 20 KD patients, who were treated with intravenous immune globulin (IVIG), using anti-EC mAb (clone P1H12)-coated magnetic beads. In 19 KD patients without coronary artery lesions (CAL), the number of CEC in the acute (pre-IVIG:15.7±1.8, post-IVIG:19.1±1.9) and subacute (14.5±1.6) phases was found to be significantly higher (P<0.05) than that in the convalescent phase (8.3+0.9) and healthy controls (HC:3.8±0.7). In one KD patient with CAL, the number of CEC was persistently high (36~44/ml) from the acute through the convalescent phase. The identity of the isolated CEC was confirmed by immunostaining methods using different anti-EC mAbs (VE-cadherin and E-selectin). Furthermore, when the CEC were stained with anti-EPC mAb (clone AC133), EPC were detected in 11 of 20 KD patients. The ratio (%) of EPC/CEC was significantly higher (P<0.05) in the post-IVIG (4.3±1.3) and subacute (5.1±1.7) phases than in both the acute (1.1±0.7) and convalescent (1.3±0.9) phases, and also the HC (0.0±0.0). These findings indicate that the increased number of CEC may be a marker which reflects the process of EC injury in KD vasculitis. Although the major origin of CEC is thought to be the shedding of EC due to vascular injury in KD, the CEC also have a small proportion of EPC which may contribute to the vasculogenesis of KD.