Hepatic allograft rejection is associated with increased levels of soluble intercellular adhesion molecule‐1

Intercellular adhesion molecule‐1 (ICAM‐1) is an adhesion molecule from the immunoglobulin super family that is recognized to be an important factor in the multistep process of cell transendothelial migration and lymphocyte adhesion during antigen recognition and effector cytolysis, mechanisms known to be involved in the pathogenesis of hepatic allograft rejection. A soluble form of ICAM‐1 (sICAM‐1) can be shed into the circulation. In this study, we examined the levels of sICAM‐1 in hepatic allograft recipients as possible markers of cellular rejection and the presence of cytomegalovirus (CMV) hepatitis. We studied three groups of patients, including eight patients with histologically documented cellular rejection, five patients with histologically documented CMV hepatitis, and a liver transplantation control population. Serum samples were obtained at the following times: baseline (1 to 3 days after transplantation), at time of diagnosis of cellular rejection, and at time of diagnosis of CMV hepatitis and 1 week after treatment of rejection episodes. The levels of sICAM‐1 were measured using an established commercial enzyme immunoassay with a sensitivity of 0.3 ng/mL. We found that serum levels of sICAM‐1 were significantly increased in liver transplant recipients who were experiencing hepatic allograft rejection but were unchanged in patients with CMV hepatitis or the time‐matched liver transplant controls. Serum levels of sICAM‐1 decreased significantly after successful treatment of the rejection episode with bolus corticosteroid therapy. We conclude that serum levels of sICAM‐1 may be useful in monitoring the occurrence of rejection and the response to antirejection therapy in liver transplant recipients.