Expression of hepatic progenitor cell markers in acute cellular rejection of liver allografts-An immunohistochemical study.

Background: Hepatic progenitor cells (HPC) are induced following liver injury to facilitate regeneration. Acute cellular rejection (ACR) is a common complication after liver transplantation as a result of immune-mediated liver injury. In this study, we characterized HPC phenotype in liver allograft biopsy with ACR. We also explored the correlation between expression HPC immunophenotype and clinicopathological parameters.

Methods: Forty-four liver allograft biopsies performed between 2008 and 2016 in a single center with histologically proven ACR were examined for immunohistochemical expression of HPC markers CK19 and Sox9. The number of positive-staining cells was assessed and correlated with clinicopathological features by statistical analysis.

Results: HPC phenotype expression as denoted by CK19 and Sox9 staining was detected in the liver tissue with ACR. The numbers of CK19+ and Sox9+ cells were positively correlated. A larger number of CK19+ cells were associated with higher serum aspartate aminotransferase (AST) level at biopsy. By histological rejection score, a larger number of Sox9+ cells were associated with a higher score of bile duct damage.

Conclusion: Expression HPC markers were correlated with clinical and histological parameters in ACR. Expression of each individual marker may be more tightly associated with a particular component of the ACR process.