DR Antigens Influence Graft Outcome and HCV Recurrence After Liver Transplantation

Recurrent diseases following liver transplantation: current concepts

PURPOSE OF REVIEW

Liver transplantation is the treatment of choice for patients with chronic end-stage liver disease. The posttransplant setting is complex, and an improved long-term graft and patient survival adds to the complexity. There are often multiple causes of graft dysfunction and the associated morbidity and disorder are varied. This review focuses on the current concepts of several recurrent diseases, emphasizing the interpretation of the posttransplant liver biopsies in long-term survivors as challenging and clinically more relevant then ever. It confirms the importance and the necessity of clinico-pathologic correlation in the posttransplant setting.

RECENT FINDINGS

The long-term graft and patient survival following liver transplantation has improved significantly over the past decade. The spectrum of histopathologic patterns seen in liver biopsies and our understanding of them have evolved and expanded considerably, so much so, that both pathologists and clinicians alike now recognize new and emerging disease patterns not previously encountered in the nontransplant setting.

SUMMARY

Typical histopathologic features are usually easily identified and interpreted in liver biopsies. There are, however, a number of atypical histopathologic patterns, especially in the setting of recurrent diseases, often modified by immunosuppression, or altered by other immune-mediated processes, autoimmunity, or hepatotoxicity. Several conditions and entities, especially in the late posttransplant setting, including atypical allograft rejection, idiopathic posttransplant hepatitis, the spectrum of changes seen in recurrent hepatitis C, nodular regenerative hyperplasia, and de-novo disease occurrence, to name a few, have all been recognized in the past several years.

Recurrent viral liver disease (hepatitis B and C) after liver transplantation

Hepatitis C represents more than 35% of liver transplant candidates worldwide. Meanwhile, hepatitis B continues to be an important cause of end-stage liver disease and hepatocellular carcinoma in Asia and Africa. Recurrent viral liver disease is a significant event after liver transplantation and continues to be one of the main causes of graft dysfunction and loss in the middle and long-term follow-up. Mechanisms of liver reinfection and disease recurrence vary between these two viruses and pre-emptive as well as the therapeutic approaches are different. Hepatitis B patients can be managed with immune globulin immediately after liver transplant and various agents such as nucleotide and nucleoside analogues can be associated. As a result, disease recurrence has been delayed or prevented in these patients. Individuals transplanted for hepatitis C are known to have universal reinfection and a high rate of disease recurrence has been reported in the literature. Strategies to treat hepatitis C recurrence are limited to the use of pegylated interferon and ribavirin when disease is demonstrated histologically and biochemically, although other strategies have been described with limited or no success. We herein review the mechanisms of disease recurrence and the current as well as the future therapeutic approaches to prevent and to treat these diseases.

Predictors of graft and patient survival in hepatitis C virus (HCV) recipients: model to predict HCV cirrhosis after liver transplantation

BACKGROUND

Hepatitis C virus (HCV) recurrence after liver transplantation (LT) is almost universal, but the natural history of recurrent HCV in the allograft is highly variable. Our study had two aims: 1) to assess the impact of different pre- and postLT factors on graft and patient survival in HCV transplant recipients and 2) to create a model which may predict the patients at risk for HCV-related graft cirrhosis at 5 years postLT.

METHODS

A total of 168 LTs were considered for this study. Univariate and multivariate Cox proportional hazards regression model was used, as well as logistic regression analysis to create a model of prediction of HCV cirrhosis within 5 years after LT.

RESULTS

Predictive factors for both decreased graft and patient survival included patients recently transplanted (2000-2004), induction without azathioprine, short-term therapy with mycophenolate mofetil and prednisone (< or =6 months), presence of early cholestasis, histologically proven early recurrence of hepatitis C. Recipient human leukocyte antigen DR3 positivity, presence of early cholestasis, and donor age >50 years were identified as independent predictors of graft cirrhosis within 5 years. A predictive model was established in order to calculate at 6 months a risk score for graft HCV cirrhosis within 5 years postLT using a formula that included the identified independent predictors. The area under receiver operating characteristic curve was 0.83, indicating a good ability to predict medium-term HCV allograft cirrhosis.

CONCLUSION

This model may be a useful tool for better identifying high-risk HCV patients who should be selected for early initiation of antiviral therapy.

Patterns of recurrent hepatitis C after liver transplantation in a recent cohort of patients

Clinicopathologic trends of recurrent hepatitis C after liver transplantation (LT) in hepatitis C (HCV) patients seem to have changed in recent years. Our aims were to define the current post-LT patterns of HCV recurrence and identify features of diagnostic and/or prognostic significance. Detailed analysis was performed on 92 HCV patients who underwent LT from June 1999 to December 2003 and survived early post-LT period. The study patients were grouped, as follows: no histologic recurrence (n = 31), "typical" recurrent HCV (n = 52), and post-LT autoimmune-like hepatitis ("AIH-like") (n = 9). The typical and AIH-like groups had mostly common features with post-LT progressive fibrosis (stage > or =2) more frequent in the latter. Based on post-LT progressive fibrosis (stage > or =2), the 2 post-LT hepatitis categories were regrouped as progressive (n = 24) and nonprogressive (n = 37). High viral counts, HCV genotype 1, and native liver inflammation grade 2 or higher with plasmacytic periseptitis were more frequent in progressive cases than nonprogressive or nonrecurrent cases. Sex mismatch of male recipient and female donor was more common in nonrecurrent group. Overall, death rate was comparable in all groups; however, post-LT HCV-related deaths were more common in progressive cases. In conclusion (1) two thirds (66.2%) of HCV patients developed histologic hepatitis after LT with either typical or AIH-like features; (2) progressive fibrosis was seen in 39.3% of patients with post-LT hepatitis and 26% of the entire study group and was more frequent in AIH-like cases; (3) inflammation grade 2 or higher with plasmacytic periseptitis in native livers may be a predictor of post-LT progressive fibrosis; and (4) male recipient/female donor combination was more common in nonrecurrent cases.

Early recurrence of hepatitis C virus infection after liver transplantation

1. Early recurrence of hepatitis C is universal. 2. Typical histopathologic features of hepatitis C virus (HCV) and acute allograft rejection (AAR) exist. 3. Early recurrent HCV may be differentiated from AAR. 4. Liver biopsy plays a role in diagnosing HCV and AAR. 5. Risk factors for recurrent HCV should be known. 6. The natural history of recurrent HCV should be known. 7. The future role of ancillary studies beyond liver biopsy is assessed.

Allograft TNFbeta and IL16 polymorphisms influence HCV recurrence and severity after liver transplantation

Hepatitis C (HCV) recurrence after liver transplantation is universal although severity varies. We explored whether certain donor cytokine gene polymorphisms may be useful markers of susceptibility to severe recurrence. Allograft tumor necrosis factor (TNF) beta and interleukin (IL) 16 gene polymorphisms were correlated with l-yr clinical outcome among HCV+ recipients. Recipients of donor TNFbeta(2,2) (n = 8) experienced less recurrence (50% vs. 71%, P < 0.05), less fibrosis (25% vs. 76%, P < 0.01), and less rejection (25% vs. 71%, P < 0.01) than donor TNFbeta(1,1) (n = 19). Recipients of donor TNFbeta(1,2) (n = 27) demonstrated an intermediate picture with less fibrosis (56%, P < 0.01) and less rejection (37%, P < 0.01) than TNFbeta(1,1). Recipients with donor IL16(TC) (n = 22) showed less recurrence (65% vs. 78%, P = 0.05), less fibrosis (53% vs. 67%, P = 0.06), and less rejection (41% vs. 55%, P = 0.06) than IL16(TT) (n = 32) genotype. Recipients of the combination TNFbeta(2,2)/IL16(TC) donor genotype had the most benign clinical outcome with less recurrence (33% vs. 75%, P < 0.01), no fibrosis (0% vs. 50%, P < 0.001), and fewer rejections (33% vs. 75%, P < 0.01) than donor TNFbeta(1,1)/IL16(TT) genotype. In vitro production of cytokines correlated with genotype. Release of soluble TNFbeta for TNFbeta(1,1) vs. TNFbeta(1,2) and TNFbeta(2,2) was 4803 +/- 2142 pg/mL vs. 5629 +/- 3106 (P = not significant [ns]) and 7180 +/- 3005 (P = ns). Release of soluble IL16 for IL16(TT) vs. IL16(TC) was 437 +/- 86 pg/mL vs. 554 +/- 39 (P = 0.06). In conclusion, allograft TNFbeta and IL16 gene polymorphisms may be useful markers to predict the severity of disease recurrence among HCV+ patients after liver transplantation.