Circulating endothelial and endothelial progenitor cells in patients with severe sepsis.

Elevated circulating endothelial cell (CEC) and circulating endothelial progenitor cell (CEPC) counts may indicate vascular damage and disease status, but data on these cell populations in patients with severe sepsis are limited. This study compared CEC and CEPC counts in patients with and without severe sepsis following intensive care unit (ICU) admission. Venous blood samples were collected within 24 h, 48-72 h, and 120-144 h. Baseline demographics, 28-day mortality, ICU and hospital days, and Sequential Organ Failure Assessment (SOFA) scores were recorded. Patients with (n=18) and without (n=28) severe sepsis were balanced for mean age (63.7 and 61.3 years, respectively) and gender. There were no differences in 28-day mortality, ICU days, or hospital days. Baseline SOFA scores were higher in the sepsis group. At 48-72 h, patients with severe sepsis had significantly higher median CEC counts (51.5 vs. 28.0 cells/4 ml of blood, P=0.02). CEC values for all ICU patients were significantly (P<0.05) higher than in healthy volunteers. CEPC counts in both cohorts ranged from 0 to >21 colonies/4 ml blood (mean=1.13±2.25; median=0) without significant differences at any time point. This study demonstrates the ability to quantify CECs and CEPCs using consensus methodology. Understanding the relationship between CEC/CEPC counts and outcomes may provide insight into the mechanisms of endothelial cell changes in severe sepsis.