Stephen Guy

Correlation between von Willebrand factor levels and early graft function in clinical liver transplantation

Cold preservation/reperfusion leads to sinusoidal endothelial cell (SEC) activation and damage in nearly every liver transplantation; the extent of these changes influences early graft function. Upon reperfusion, activated SEC show increased expression of adhesion molecules, including von Willebrand factor (vWF) which is released into the circulation. This study was designed to evaluate the levels of vWF measured in the caval effluent and correlate these findings with known markers of SEC damage and early graft function. Data were obtained from 35 patients undergoing orthotopic liver transplantation (LTx). Two samples were taken from each patient for measurement of vWF: a) from the portal vein immediately prior to reperfusion; and b) from the first 50 ml of the caval effluent. Commercial assays were used to measure vWF, as well as hyaluronic acid (HA), thrombomodulin (TM), IL‐1β, IL‐6, IL‐8 and TNF‐α. Patients were divided into two groups based on early graft function. Poor early graft function (PEGF) was defined as a peak aspartate transaminase (AST) or alanine transaminase (ALT) level> 2500 U/L during the first three postoperative days (POD) and a prothrombin time (PT)> 16 s on POD 2 (n=8). The remaining 27 patients had good early graft function (GEGF). In patients with GEGF, vWF levels dropped significantly between the two time points. This change was not observed in those with PEGF. A positive linear correlation was observed in the PEGF group between vWF and HA and IL‐6. The different pattern of change in vWF between the two groups, as well as the positive correlation between HA, IL‐6 and vWF in PEGF, suggest that vWF may be a useful marker of early graft function.