Acute cellular rejection versus recurrent hepatitis C after liver transplantation: Clinical and pathological features driving a rational diagnostic approach.

AIM: The aim of our study was develop and validate an algorithm system based on morphological features for finding the differences between recurrent hepatitis C virus (HCV) and acute cellular rejection (ACR) in liver biopsies of HCV-transplanted patients. METHODS: Two hundred and eighty-eight liver biopsies were analyzed from 121 patients transplanted for HCV. A diagnostic consensus was reached between clinicians and pathologists in 214 biopsies for the diagnosis of recurrent HCV or ACR. A random sample of 114 liver biopsies (derivation cohort) was taken to generate the diagnostic tree and was subsequently evaluated using the validation cohort in 100 liver biopsies by recursive partitioning analysis of morphological variables and time since transplantation. RESULTS: The presence of endotheliitis together with a time of less than 6 weeks since LT definitely excluded recurrent HCV. After obtaining the regression tree, diagnostic accuracy was 96% and 93% in the derivation and validation cohort, respectively. Both cases surpassed the pathologist's original diagnosis, which had a diagnostic accuracy of 91% (P < 0.05, for both comparisons). CONCLUSION: A recursive partitioning analysis of the morphological features in liver biopsies from HCV-transplanted patients may be useful for easily distinguishing between recurrent HCV and ACR.

Influence of human leukocyte antigen mismatching on rejection development and allograft survival in liver transplantation: is the relevance of HLA-A locus matching being underestimated?

The influence of HLA matching on liver transplant is still controversial, as studies have failed to demonstrate an adverse effect of HLA mismatching on transplant outcome. We examined the effect of HLA mismatching on transplant outcome in a series of 342 consecutive liver transplants (224 finally analyzed). HLA typing was performed by serological and molecular methods. HLA-A matching was associated with an increased chronic rejection incidence (P=0.04). Indeed, HLA-A match also demonstrated a significant impact on allograft survival (P=0.03), confirming previous observation concerning to rejection, as complete HLA-A mismatching favored a better liver transplant outcome. Analysis of HLA-A+B+DR matching also demonstrated a significant impact on graft survival (P<0.05). Multivariate Cox regression analysis confirmed the effect of HLA-A and DPB1 matching as independent risk factors for graft loss. Another independent factor was a positive pre-transplant crossmatch. In conclusion, liver transplant outcome has not been found to be improved by HLA matching, however a poorer HLA compatibility favored a better graft survival and decreased rejection incidence, with a special relevance for HLA-A matching.