Evaluation of endothelial damage in sepsis-related ARDS using circulating endothelial cells

Purpose: Endothelial cell activation and dysfunction are involved in the pathophysiology of ARDS. Circulating endothelial cells (CECs) may be a useful marker of endothelial dysfunction and damage but have been poorly studied in ARDS. We hypothesized that the CEC count may be elevated in patients with sepsis-related ARDS compared to those with sepsis without ARDS.Methods: ARDS was defined according to the Berlin consensus definition. The study population included 17 patients with moderate or severe ARDS, 9 with mild ARDS, 13 with sepsis and no ARDS, 13 non-septic patients, and 12 healthy volunteers. Demographic, hemodynamic, and prognostic variables, including PaO2/FiO2 ratio, 28-day survival, blood lactate, APACHE II, and SOFA score, were recorded. CECs were counted in arterial blood samples using the reference CD146 antibody-based immunomagnetic isolation and UEA1-FITC staining method. Measurements were performed 12–24 h after diagnosis of ARDS and repeated daily for 3 days.Results: The median day-1 CEC count was significantly higher in patients with moderate or severe ARDS than in mild ARDS or septic-control patients [27.2 (18.3–49.4) vs. 17.4 (11–24.5) cells/ml (p < 0.034), and 18.4 (9.1–31) cells/ml (p < 0.035), respectively]. All septic patients (with or without ARDS) had higher day-1 CEC counts than the non-septic patients [19.6 (14.2–30.6) vs. 10.8 (5.7–13.2) cells/ml, p = 0.002].Conclusion: The day-1 CEC count was significantly higher in ARDS patients than in other critically ill patients, and in moderate or severe ARDS patients compared to those with milder disease, making it a potentially useful marker of ARDS severity.