Circulating endothelial adhesion molecules in critically ill septic patients

Introduction

Recently it has been demonstrated the importance of the endothelium in the physiopathology of organ failure and death in experimental sepsis and soluble forms of adhesion molecules have been shown to be excellent markers of endothelial activation or even damage in this setting [1] But their definite role in clinical sepsis has not been clearly defined [2]. The objective of this study is to assess whether circulating concentrations of endothelial adhesion molecules [endothelial leukocyte adhesion molecule-1 (SLLAM-1) and intercellular adhesion molecule-1 (sICAM-1)] can be used to define, confirm or predict the outcome in critically ill septic patients.

Methods

Prospective, longitudinal, descriptive cohort study with no therapeutic interventions in which participated 63 patients admitted to the ICU with the clinical diagnosis of severe sepsis (21) or septic shock (42) [3] and 10 healthy adults that served as controls. Blood samples from and indwelling arterial catheter were collected from patients on days 1.3 and 7 after their admission to the ICU for measuring plasma concentrations of sELAM-1 and sICAM-1 (ELISA, R&D Systems). Additionally biological data (age, sex, APACHE II, blood leukocyte count, platelet count, coagulation, haemodynamic and blood gas variables, serum lactate levels, need of vassopressor support, culture results, SOFA score, individual organ dysfunction) and mortality were obtained. Statistical analysis was performed using Student t-test, Mann-Whitney U test. P < 0.05 was considered significant.

Results

Plasma levels of sELAM-1 and sICAM-1 on day 1 and 3 were significantly higher (P < 0.001) in septic patients than in controls. Patients with bacteremia had higher levels of ICAM-1 on day 1 (P = 0.024) and 3 (P = 0.008). Soluble levels of the molecules measured did not correlate with any other clinical or laboratory parameter at admission. With regard to outcome sELAM-1 on day 1 was significantly elevated in patients that developed coagulopa-thy and ICAM-1 on day 3 in those patients who developed shock (P = 0.007), acute renal failure (P = 0.02) or coagulopathy (P = 0.05). Both levels of sELAM-1 and ICAM-1 were similar in surviving and nonsurviving patients.

Conclusions

Plasma endothelial adhesion molecules concentrations are elevated in critically ill septic patients but their levels show a high degree of individual variation and have a poor global correlation with biological data and final outcome. sICAM-1 on day 3 might be useful for identifying the subgroup of patients who will develop multiorgan failure and therefore could benefit from a more agressive preventive or therapeutic approach.