Circulating Endothelial Cells in Patients with Septic Shock

Abstract

The vascular endothelium has a central role in the control of microvascular tone, and it has been proposed that vascular endothelial damage occurs in septic shock, producing multiorgan failure. We have developed a method of detecting circulating endothelial cells (EC) that provides direct evidence of EC shedding in human sepsis. Human umbilical vein endothelial cells (HUVEC) were seeded in whole blood and recovered by isopycnic centrifugation to validate the technique. Blood samples were subsequently taken from 11 healthy volunteers, nine ventilated intensive care unit (ICU) control patients without sepsis, eight patients with sepsis but without shock, and 15 patients with septic shock. EC were identified by indirect immunofluorescence, using antibodies to von Willebrand factor (vWf) and the vascular endothelial growth factor receptor KDR. Mean HUVEC recovery was 86% for 20 to 100 seeded cells/ml of blood. vWf-positive EC counts per milliliter were significantly higher (analysis of variance [ANOVA], p < 0.0001) in patients with sepsis (16.1 +/- 2.7 [mean +/- SEM]) and septic shock (30.1 +/- 3.3) than in healthy (1.9 +/- 0.5) or ICU controls (2.6 +/- 0.6). KDR-positive EC counts per milliliter were also significantly higher (ANOVA, p < 0.0001) in patients with sepsis (4.2 +/- 1.1/ml) and septic shock (10.4 +/- 1.2/ml) than in healthy (0.7 +/- 0.3/ml) or ICU controls (0.5 +/- 0.2/ml). Cell counts made with anti-vWf antibody were consistently higher than those made with anti KDR antibody, but correlation between the two counts was high (r(2) = 0.93). The number of circulating KDR-positive EC was significantly higher in patients who died of septic shock than in survivors (12.0 +/- 1.6/ml versus 7.1 +/- 1.2/ml, p = 0.026). An increase in circulating EC can be identified during sepsis and septic shock. This supports the hypothesis that endothelial damage occurs in human sepsis.

Endotoxemia enhances circulating endothelial cells in humans

“…In this study, CEC counts markedly increased in patients with sepsis (850% increase) and septic shock (1580%), when compared with healthy controls, suggesting that endothelial damage precedes the clinical development of organ failure [1]. In contrast to our study, which uses the more established immunobead method of quantifying CECs, Mutunga et al [5] identified CECs by using immunohistochemistry with a polyclonal antihuman VWF. Whilst our experimental LPS endotoxemia model does provide valuable insights into host responses to gram-negative infection, it does not necessarily equate to clinical septicemia.…”

Flow cytometric evaluation of circulating endothelial cells: A new protocol for identifying endothelial cells at several stages of differentiation

“…Sickle cell disease is a vascular disease that causes tissue ischemia and exaggerated endothelial turnover, both of which are characterized by evident endothelial injury and regeneration [34]. In different patient groups, the number of ECs/mL of peripheral blood may vary between zero and 1,500; most studies found 1 to 100 circulating ECs/mL in healthy people [34][35][36][37][38][39][40]. We found much higher numbers of circulating ECs in both sickle cell patients and controls, probably due to methodological differences in sample preparation and cell quantification.…”

Endothelial cells in peripheral blood of healthy subjects and patients with metastatic carcinomas

“…The presence of mature vascular endothelial cells in the circulation may be due to a variety of factors including traumatic injury, which causes them to slough off and carried away in the circulation (14)(15)(16)(17)(18)(19).…”