The Diagnostic Impact of C4d, CD68, and NF-κB Expression in the Differentiation Between Recurrent Hepatitis C and Acute Cellular Rejection After Liver Transplantation

Liver transplantation is the selected treatment for patients with advanced liver disease and cirrhosis, mostly as a complication of hepatitis C virus (HCV). Recurrent HCV and acute cellular rejection (ACR) of the graft are the most common causes of graft failure. The distinction between the 2 conditions is essential because they are managed differently. In some cases, the clinical and histopathologic features may overlap between recurrent hepatitis C and ACR, making differentiation difficult. The aim of this study was to investigate the role of C4d, CD68, and nuclear factor kappa-B (NF-κB) in the differentiation between ACR and recurrent HCV in the post-liver-transplant biopsy using immunohistochemistry. C4d expression in endothelial cells of portal or central veins (P=0.001) and the number of macrophages highlighted by CD68 (P=0.02) were in favor of ACR, whereas NF-κB expression by hepatocytes was in favor of recurrent hepatitis C. Vascular injury demonstrated by endothelial expression of C4d and prominent macrophage infiltration identified by CD68 expression were the distinguishing criteria for ACR and representing humoral and cellular-mediated immunity as evoking factors for graft injury. The upregulation of NF-κB in the hepatocytes of recurrent hepatitis C could be an immune response to infection or it may be induced by HCV itself.