Clinical, virological, and histologic evolution of hepatitis C virus infection in liver transplant recipients

Molecular Interactions between Pathogens and the Circadian Clock

The daily periodicity of the Earth's rotation around the Sun, referred to as circadian (Latin "circa" = about, and "diem" = day), is also mirrored in the behavior and metabolism of living beings. The discovery that dedicated cellular genes control various aspects of this periodicity has led to studies of the molecular mechanism of the circadian response at the cellular level. It is now established that the circadian genes impact on a large network of hormonal, metabolic, and immunological pathways, affecting multiple aspects of biology. Recent studies have extended the role of the circadian system to the regulation of infection, host-pathogen interaction, and the resultant disease outcome. This critical review summarizes our current knowledge of circadian-pathogen interaction at both systemic and cellular levels, but with emphasis on the molecular aspects of the regulation. Wherever applicable, the potential of a direct interaction between circadian factors and pathogenic macromolecules is also explored. Finally, this review offers new directions and guidelines for future research in this area, which should facilitate progress.

Influence of antiviral therapy in the long-term outcome of recurrent hepatitis C virus infection following liver transplantation

INTRODUCTION

Severity of recurrent hepatitis C virus (HCV) infection in liver transplant recipients (LTR) is variable and the influence of different factors, including the administration of antiviral therapy in the long-term outcome is controversial.

METHODS

We analyzed the outcome of a cohort of HCV-infected LTR who were transplanted in our institution. Patients were divided into 2 groups (severe and non-severe HCV disease) depending on the presence of a fibrosis score of F ≥ 2 in the Scheuer index and/or fibrosing cholestasic hepatitis (FCH) in a graft biopsy. Risk factors were studied using logistic regression analysis. Survival of patients was estimated using Kaplan-Meier plots. A total of 146 patients were followed for a mean of 58 months.

RESULTS

Fifty-six (34%) patients developed severe HCV disease and showed shorter survival (P < 0.024). Donor age (odds ratio [OR]: 1.04; 95% confidence interval [CI]: 1.02-1.06) and pre-transplant viral load (VL) >10(6) UI/mL (OR: 3.5; 95% CI: 1.42-10.61) were the only factors associated with severe HCV infection. Over-immunosuppression (OR: 2.3; 95% CI: 1.2-4.41) was specifically associated with the development of FCH. Overall, patient survival in recipients who received a full course of anti-HCV therapy was higher than in patients who did not complete antiviral therapy (P = 0.004) or received no treatment (P = 0.007). Patients with non-severe HCV infection have a higher probability of receiving a full course of antiviral therapy (P = 0.033).

CONCLUSION

In conclusion, donor age, pre-transplant VL, and over-immunosuppression were associated with the long-term development of severe HCV recurrence in liver grafts. Administration of a full course of antiviral therapy was associated with better survival.

Evolution of hepatitis C virus in liver allografts

1. Hepatitis C virus (HCV) RNA+ liver allograft recipients invariably reinfect the liver allograft within hours after transplantation, and the majority (>70%) develop chronic hepatitis. The rate at which these patients experience progression to cirrhosis and the overall percentage are significantly increased in comparison with HCV infection in the nontransplant setting. 2. Core needle biopsy evaluation is used to establish the diagnosis of recurrent HCV, which can be difficult to distinguish from acute cellular rejection and other causes of allograft dysfunction. In the vast majority of cases, however, distinguishing recurrent HCV from other posttransplant syndromes is reliably achieved by a careful examination of hematoxylin and eosin-stained sections and correlation with clinical and serological data. 3. Recurrent HCV often coexists with other causes of liver allograft dysfunction, and the determination of the most important cause of injury and whether other causes of injury are present is important. Included are residual changes of preservation/reperfusion injury, biliary sludging/structuring, acute cellular and chronic rejection, and autoimmune hepatitis. 4. The complex interplay between immunosuppression management, viral replication, and the recipient immune system results in distinct patterns of recurrent chronic HCV in the liver allograft: (1) conventional or usual acute and chronic HCV, which resembles that seen in the general population with HCV; (2) fibrosing cholestatic hepatitis; and (3) plasma cell-rich HCV, which might represent a variant of, or overlap with, autoimmune hepatitis and rejection. 5. The variable but usually hastened histopathological progression toward cirrhosis in HCV+ allografts is similar to that seen in the nontransplant setting, but in allografts, the overall severity of lymphocytic inflammation is less, and ductular reactions, stellate cell activation, and subsinusoidal fibrosis are accentuated. Hepatic stressors and causes of an impaired ability of hepatocytes to replicate include persistently high levels of viral replication, HCV-specific CD4+ T responses, advanced donor age, high levels or rapid withdrawal of immunosuppression, and coexistent liver damage from preservation/reperfusion injury, biliary structuring, or coexistent cytomegalovirus or herpes 6 viral infection. 6. Immunological effector mechanisms involved in the rejection and control of HCV replication/HCV elimination show significant overlap. Patients with very high levels of HCV RNA rarely show significant clinically significant acute or chronic rejection, whereas their occurrence is frequently associated with very low levels or clearance of HCV RNA. Studying the evolution from recurrent HCV to acute rejection in patients treated with interferon and/or weaned from immunosuppression might provide valuable insights into the relationship between these 2 processes as well as liver allograft acceptance.

Morphologic Features of Hepatitis C Recurrence in Patients After Orthotopic Liver Transplantation-Preliminary Analysis of our Case Observations

INTRODUCTION

Hepatitis C virus (HCV) recurrence is almost universal in patients after liver transplantation. The diagnosis of reinfection is more difficult than that of a primary process, as shown by our pathomorphologic analysis of cases of HCV recurrence.

MATERIAL

During 5.5 years, 240 liver biopsies included 54 obtained from liver transplant recipients with primary HCV infections, among whom 26 (56.5%) had clinical signs and symptoms of hepatitis. Nineteen patients from this population underwent 30 liver biopsies. In addition, seven biopsies were performed in five patients without clinical signs of reinfection.

RESULTS

In 44.2% of patients with HCV recurrence and 15% without reinfection, the intensity of the primary process in the native livers was assessed as high. Reinfection was found in all patients with liver carcinoma and 67% with hepatocyte dysplasia. Histologic signs of infection were estimated as minimal (n = 4), mild (n = 19), or moderate (n = 4). In five patients with reinfections and one without recurrence, histologic manifestations of acute rejection were also observed. In conclusion, HCV was the indication for liver transplantation in 22.4% cases. Clinical manifestation of recurrence was found in 56.5% of the patients, who tended to be older than those without disease recurrence. Upon microscopy, lobular lesions predominated over the portal changes. Factors predisposing to HCV recurrence were coexistence of other liver disorders, a high intensity of the inflammatory process, hepatocyte dysplasia, and/or hepatocellular carcinoma in the native liver and acute rejection episodes.

Recipient HLA-DR3, tumour necrosis factor-alpha promoter allele-2 (tumour necrosis factor-2) and cytomegalovirus infection are interrelated risk factors for chronic rejection of liver grafts

BACKGROUND/AIMS

The tumour necrosis factor (TNF)-2 promoter allele, which elicits elevated expression of TNF-alpha, is in linkage disequilibrium with the extended haplotype HLA-A1-B8-DR3-DQ2. TNF-2 and HLA-DR3 have been implicated in renal and cardiac graft rejection and loss. Cytomegalovirus (CMV) infection has been associated with chronic allograft rejection. We examined the relationship between HLA-DR3, promoter allele TNF-2 and cytomegalovirus in relation to chronic rejection following liver transplantation.

METHODS

(i) Retrospective analysis of HLA-DR3 was performed in 307 liver transplant recipients and 283 donors. (ii) Prospective analysis of TNF-alpha promoter allele status, HLA-DR3 status and cytomegalovirus infection was assessed in 123 recipients.

RESULTS

(i) Retrospective analysis. Recipient HLA-DR3 (relative risk 1.9; 95% C.I. 1.01-3.58) was a risk factor for chronic rejection. (ii) Prospective analysis. Recipient HLA-DR3 was a risk factor for chronic rejection (relative risk 3.41; 95% C.I. 1.66-7.03) which was elevated further by superimposed CMV infection (relative risk 5.01; 95% C.I. 2-12.55). Recipient TNF-2 was associated with chronic rejection (relative risk 2.29; 95% C.I. 0.9-5.83) through linkage to HLA-DR3.

CONCLUSIONS

Recipient HLA-DR3, TNF-2 status and CMV infection were inter-related risk factors for chronic rejection of liver grafts.

Banff schema for grading liver allograft rejection: utility in clinical practice

An accurate and functional system for grading acute liver allograft rejection is important for patient management, research, and communication. The Banff schema is a consensus document designed to provide an internationally accepted standard for this purpose. The aim of this study is to determine if application of the Banff schema would significantly alter the grading of acute liver allograft rejection compared with the Birmingham system. One hundred twenty-four post-liver transplantation biopsies performed by the Western Australian Liver Transplantation Service between 1992 and 1997 were retrospectively analyzed by a pathologist and a hepatologist. Each was supplied with a brief clinical history before applying the Banff and Birmingham criteria. Results were compared with each other and to the diagnosis made at the time of the biopsy, which was based on the European grading system. Rejection was diagnosed by the reviewers in 61 of 124 biopsy specimens according to the criteria of Snover. The Banff schema and Birmingham system agreed on the grade of rejection in 22 of the 61 biopsy specimens. The Banff schema elevated the grade of rejection in 39 specimens by an increment of one. In no instance did the Banff schema reduce the grade. Comparison between the Banff schema and diagnosis made at the time of biopsy showed agreement in 39 specimens, whereas the Banff schema elevated the grade in 15 specimens and reduced the grade in 23 specimens. In comparison to the Birmingham system, the Banff schema elevated the grade of liver allograft rejection in the majority of biopsy specimens, and this has the potential to alter clinical management with the adoption of the Banff schema or if the systems are used interchangeably.

Cirrhosis of the Liver in Long-Term Marrow Transplant Survivors

Patients who survive hematopoietic cell transplantation (HCT) have multiple risk factors for chronic liver disease, including hepatitis virus infection, iron overload, and chronic graft-versus-host disease (GVHD). We studied 3,721 patients who had survived 1 or more years after HCT at a single center and identified patients with histologic or clinical evidence of cirrhosis. Risk factors for the development of cirrhosis were evaluated and compared with a group of matched control subjects. Cirrhosis was identified in 31 of 3,721 patients surviving 1 or more years after HCT, 23 of 1,850 patients surviving 5 or more years, and in 19 of 860 patients surviving 10 or more years. Cumulative incidence after 10 years was estimated to be 0.6% and after 20 years was 3.8%. The median time from HCT to the diagnosis of cirrhosis was 10.1 years (range, 1.2 to 24.9 years). Twenty-three patients presented with complications of portal hypertension, and 1 presented with hepatocellular carcinoma. Thirteen patients have died from complications of liver disease, and 2 died of other causes. Three patients have undergone orthotopic liver transplantation. Hepatitis C virus infection was present in 25 of 31 (81%) of patients with cirrhosis and in 14 of 31 (45%) of controls (P = .01). Cirrhosis was attibutable to hepatitis C infection in 15 of 16 patients presenting more than 10 years after HCT. There was no difference in the prevalence of acute or chronic GVHD, duration of posttransplant immunosuppression, or posttransplant marrow iron stores between cases and controls. Cirrhosis is an important late complication of hematopoietic cell transplantation and in most cases is due to chronic hepatitis C. Long-term survivors should be evaluated for the presence of abnormal liver function and hepatitis virus infection.