Is regular measurement of adhesion molecules and cytokines useful to predict post-liver transplant complications?

Biomarkers for the diagnosis of acute cellular rejection in liver transplant recipients: A review

The gold standard for the diagnosis of acute cellular rejection (ACR) is a liver biopsy. The quest for an alternative non-invasive biomarkers has been long and is ongoing. However, an efficient and useful biomarker has not been developed yet. In this manuscript, we review all possible candidate biomarkers that have been studied in recent years, starting with cytokines and ending with an overview of different newly discovered "omics". Promising paths are being explored but a valid non-invasive biomarker has not been discovered yet.

Early differentiation between rejection and infection in liver transplant patients by serum and biliary cytokine patterns

BACKGROUND

Differentiation between acute liver graft rejection and infection remains a clinical challenge during the early posttransplantation period. Although cytokines play a pivotal role in mediating allograft rejection, previous studies demonstrate that most cytokines are not specific for liver graft rejection or infections. However, other studies suggest that adhesion molecules and cytokines in bile reflect the immunologic activity within the liver more closely. Therefore, we postulated that by combining cytokine patterns in serum and bile, early recognition of acute liver graft rejection and differentiation from infectious complications can be improved.

METHODS

We performed a prospective study in 45 patients who were monitored daily for clinical events and cytokine patterns in serum and bile during the first month after liver transplantation.

RESULTS

Soluble intercellular adhesion molecule-1 (sICAM-1) in serum and interleukin-8 in bile were specifically increased at the onset of acute rejection (P<0.001), whereas serum soluble tumor necrosis factor-receptor II was also significantly increased in patients with infectious complications and serum interleukin-6 only in patients with rejection during infection. In 68% of patients with increased sICAM-1, acute rejection was diagnosed within 10 days, whereas rejection occurred in only 26% of patients with low serum levels of sICAM-1. In patients with increased sICAM-1, the relative risk for rejection was 4.8 (P=0.009).

CONCLUSIONS

Cytokine patterns in bile do not provide rejection markers with higher specificity compared with serum cytokines. Daily monitoring of sICAM-1 in serum could identify patients at risk for rejection; therefore, acute liver graft rejection may be recognized earlier in those patients.

A transient increase in endogeneous erythropoietin levels after paediatric liver transplantation

We investigated whether liver transplantation affects endogeneous erythropoietin (EPO) synthesis. Serum EPO levels were measured before transplantation and during the peri-transplant period in ten consecutive paediatric patients who had received a liver allograft without recombinant EPO therapy. All patients were anaemic on post-operative day 1 (POD 1); however, the haemoglobin levels of three patients gradually increased and required phlebotomy on POD 5-9. The serum levels of EPO in all patients were within the normal range before surgery, but six of the ten patients had a transient increased level of EPO at 1248 h after transplantation. A transient increase of endogeneous EPO following paediatric liver transplantation may be associated with extramedullary erythropoiesis in human liver grafts.