The influence of hepatitis C virus genotypes on the outcome of liver transplantation

Management of hepatitis c genotype 4 in the liver transplant setting

End-stage liver disease secondary to hepatitis C virus (HCV) infection is the major indication for orthotopic liver transplantation (OLT) worldwide. The percentage of HCV patients infected with genotype 4 (G4) among recipients of OLT varies depending on geographic location. In the Middle East, including Saudi Arabia, G4 infection is the most common genotype among transplant recipients. Due to the low prevalence of HCV-G4 in Europe and the United States, this genotype has not been adequately studied in prospective trials evaluating treatment outcomes and remains the least studied variant. The aim of this review is to summarize the natural history and treatment outcome of HCV-G4 following liver transplantation, with particular attention to new HCV therapies. This review incorporates all published studies and abstracts including HCV-G4 patients.

Living-donor liver transplantation and hepatitis C

Hepatitis-C-virus- (HCV-) related end-stage cirrhosis is the primary indication for liver transplantation in many countries. Unfortunately, however, HCV is not eliminated by transplantation and graft reinfection is universal, resulting in fibrosis, cirrhosis, and finally graft decompression. In areas with low deceased-donor organ availability like Japan, living-donor liver transplantation (LDLT) is similarly indicated for HCV cirrhosis as deceased-donor liver transplantation (DDLT) in Western countries and accepted as an established treatment for HCV-cirrhosis, and the results are equivalent to those of DDLT. To prevent graft failure due to recurrent hepatitis C, antiviral treatment with pegylated-interferon and ribavirin is currently considered the most promising regimen with a sustained viral response rate of around 30% to 35%, although the survival benefit of this regimen remains to be investigated. In contrast to DDLT, many Japanese LDLT centers have reported modified treatment regimens as best efforts to secure first graft, such as aggressive preemptive antiviral treatment, escalation of dosages, and elongation of treatment duration.

Liver transplantation and hepatitis C

Hepatitis-C-virus- (HCV-) related end-stage cirrhosis is the primary indication for liver transplantation in many countries. Unfortunately, however, HCV is not eliminated by transplantation and graft reinfection is universal, resulting in fibrosis, cirrhosis, and finally graft decompensation. The use of poor quality organs, particularly from older donors, has a highly negative impact on the severity of recurrence and patient/graft survival. Although immunosuppressive regimens have a considerable impact on the outcome, the optimal regimen after liver transplantation for HCV-infected patients remains unclear. Disease progression monitoring with protocol biopsy and new noninvasive methods is essential for predicting patient/graft outcome and starting antiviral treatment with the appropriate timing. Antiviral treatment with pegylated interferon and ribavirin is currently considered the most promising regimen with a sustained viral response rate of around 30% to 35%, although the survival benefit of this regimen remains to be investigated. Living-donor liver transplantation is now widely accepted as an established treatment for HCV cirrhosis and the results are equivalent to those of deceased donor liver transplantation.

HCV in liver transplantation

HCV-related cirrhosis represents the leading indication for liver transplantation in the Western countries. HCV reinfection after liver transplantation occurs in virtually all patients transplanted for HCV-related liver disease Histological evidence of chronic HCV infection develops in 50 to 90 % of patients by 12 months after liver transplantation, and cirrhosis occurs in about 20 % of patients within 5 years after transplant. Several studies have evaluated host, viral, and transplant-related factors that might be associated with the severity of HCV recurrence. Among host factors, immunosuppression is one of the major factors that accounts for accelerated HCV recurrence and it has been an area of extensive research and controversy. Donor age, steatosis, and immunogenetic factors are also relevant in determining the outcome in patients transplanted for HCV-related cirrhosis. A major step to prevent complications of HCV recurrence related to the rapid fibrosis is the posttransplant antiviral treatment. Two strategies have been tried: pre-emptive or other strategies as soon as possible after liver transplantation or elective therapy once there is histological evidence of recurrent hepatitis C. Retransplantation due to graft failure from recurrent hepatitis C is rarely an option in the era of organ shortage as it is associated with poor outcome, but many case needs to be considered early in the evolution of disease. New antivirals may change the outcome dramatically of patients transplanted for HCV cirrhosis.

Steroid-free living donor liver transplantation for HCV--a multicenter prospective cohort study in Japan

This prospective, non-randomized, multicenter cohort study analyzed the safety and efficacy of a steroid-free immunosuppressive (IS) protocol for hepatitis C virus (HCV)-positive living donor liver transplant (LDLT) recipients in Japan. Of 68 patients enrolled from 13 transplant centers, 56 fulfilled the inclusion/exclusion criteria; 27 were assigned the steroid-free IS protocol (Fr group) and 29 the traditional steroid-containing IS protocol (St group). Serum HCV RNA levels increased over time and were higher in the St group until postoperative day 90 (POD 14, p=0.013). Preemptive anti-HCV therapy was started in a higher percentage of recipients (59.3%) in the Fr group than in the St group (31.0%, p=0.031), mainly due to early HCV recurrence. The incidence of HCV recurrence at one yr was lower in the Fr group (22.2%) than in the St group (41.4%; p=0.066). The incidence of acute cellular rejection was similar between groups. New onset diabetes after transplant, cytomegalovirus infection, and renal dysfunction were significantly less frequent in the Fr group than in the St group (p=0.022, p<0.0001, p=0.012, respectively). The steroid-free IS protocol safely reduced postoperative morbidity and effectively suppressed both the HCV viral load in the early post-transplant period and HCV recurrence in HCV-positive LDLT recipients.

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.

Hepatitis C recurrence after liver transplantation: has the human leukocyte antigen mismatching at individual loci a role?

BACKGROUND AND AIM

The objective of this 11-year cohort retrospective study conducted in adult patients with chronic hepatitis C virus (HCV) who underwent liver transplantation (LT) was to identify whether human leukocyte antigen (HLA) mismatching is associated with the recurrence of HCV and with the time to recurrence of HCV.

METHODS

Among the 181 patients (74% men; mean age: 54 years, range 25-71) who underwent a LT between 1995 and 2006 in the study center, 163 had relevant data in their medical chart documenting HCV recurrence, and 107 (65.64%) reported a histological evidence of HCV recurrence.

RESULTS

Survival was 78% at 5 years. There was no significant relationship between the total score of HLA-mismatches and the recurrence of HCV. Similarly, there was no significant relationship between the total score of HLA mismatches and the time to recurrence of HCV. For the analyses at each individual locus, a significant relationship between the individual scores of HLA-mismatches and the recurrence of HCV were observed. Out of the 40 patients who experienced a rejection, the rate of recurrence was not different according to the severity of the rejection (75% mild, 64% moderate and 64% for severe rejection).

CONCLUSIONS

In conclusion, this large study did not demonstrate any relationship between the total score of HLA mismatches and HCV-recurrence. Contrarily a significant relationship between the individual scores of HLA mismatches (HLA-A3, HLA-B35, HLA-DR3, HLA-DR7, HLA-DQ2, HLA-DQ2-0) and the recurrence of HCV were observed.

Clinical outcome of HCV-related graft cirrhosis and prognostic value of hepatic venous pressure gradient

Hepatitis C virus (HCV) allograft cirrhosis may progress rapidly requiring re-transplantation but its course is little studied. We evaluated serially biopsied patients who developed HCV-related allograft cirrhosis. We assessed outcome of graft cirrhosis in 55 out of 234 consecutive patients and predictors of decompensation and mortality, including hepatic venous pressure gradient (HVPG) in 38. Allograft cirrhosis (Ishak stage 6, 60%; stage 5, 40%) was diagnosed between 12 and 172 months (median, 52) from transplantation; subsequent follow up was 22 (1-78) months. Faster development (<or=48 months) was associated with tacrolimus and nonuse of azathioprine and prednisolone. Decompensation occurred in 22% with a probability of not developing decompensation reaching 60% at 5 years. Survival among compensated patients was 77% at 5 years, but fell rapidly after decompensation (12% at 1 year). Decompensation and mortality were independently associated with HVPG >or= 10 mmHg, Child-Pugh score >or= 7, and albumin levels <or= 32 g/dl but not with fibrosis stage 5 or 6, HCV genotype (1b, 34%) or immunosuppression used after diagnosis of cirrhosis. In conclusion, Ishak stage 5 and 6 HCV-related cirrhosis have similar prognosis after liver transplantation. An HVPG >or= 10 mmHg, in addition to liver dysfunction, gives independent prognostic information prior to decompensation, allowing early relisting before prognosis becomes extremely poor.

Long-term outcome of human leukocyte antigen mismatching in liver transplantation: results of the National Institute of Diabetes and Digestive and Kidney Diseases Liver Transplantation Database

A perfect or nearly perfect human leukocyte antigen (HLA) match has been associated with better immediate and long-term survival of diseased donor kidney transplants. However, the effect of HLA matching for hepatic allografts remains poorly defined. Using data from the National Institutes of Diabetes and Digestive and Kidney Diseases Liver Transplantation Database, we investigated the association between HLA mismatches and hepatic allograft survival, disease recurrence, and immunosuppression interactions. A, B, and DR loci were used to calculate total mismatch scores of 0 (no mismatches in any loci) to 6 (mismatches in all loci). Seven hundred ninety-nine adults (male, 55%; female, 45%) underwent 883 liver transplants. The 10-year graft survival according to total mismatch score was as follows: 0-2, 60%; 3-4, 54%; and 5-6, 57%. There was a negative effect of mismatching at the A locus on patient survival, with shorter survival for patients with 1 or 2 mismatches compared with 0 mismatches [P = 0.05, hazard ratio (HR) = 1.6]. Patients on tacrolimus with 1 or 2 mismatches at B or DR loci appeared to have increased rates of patient and graft survival compared to patients with 0 mismatches, with the appearance of a protective effect of tacrolimus (HR = 0.67). The effect of HLA mismatching was more pronounced on certain disease recurrences. DR-locus mismatch increased recurrence of autoimmune hepatitis (P = 0.01, HR = 4.2) and primary biliary cirrhosis (P = 0.04, HR = 2). Mismatch in the A locus was associated with more recurrence of hepatitis C virus (P = 0.01, HR = 1.6) and primary sclerosing cholangitis (P = 0.03, HR = 2.9).

CONCLUSION

Mismatching at the A locus decreases patient survival in liver transplant recipients, and mismatching at the DR and A loci affects recurrence of autoimmune liver diseases and hepatitis C, respectively.

The impact of donor variables on the outcome of orthotopic liver transplantation for hepatitis C

Morphologic characteristics of the graft have been proposed as a major contributor to the long-term outcomes in orthotopic liver transplantation (OLT). Our objective was to determine the impact of donor variables, including donor age, donor-recipient HLA match, and type of donation (DCD vs donation after brain death [DBD]), on the outcome of OLT in 192 patients with hepatitis C virus (HCV). Fourteen patients underwent OLT from donation after cardiac death (DCD) donors and 188 from DBD donors. Mean donor age, warm ischemia time at recovery, and cold ischemia time were similar between the groups. Overall graft survival rate at 1 year (55% DCD vs 85% DBD) and 5 years (46% DCD vs 78% DBD) was significantly lower in the DCD group (P = .0003). Similarly, patient survival rate at 1 year (62% DCD vs 93% DBD) and 5 years (62% DCD vs 82% DBD) was significantly lower in the DCD group (P = .0295). Incidences of hepatic artery thrombosis, portal vein thrombosis, and primary nonfunction were similar between the DCD and DBD groups. The incidence of liver abscess with ischemic-type biliary stricture was higher in recipients from DCD as compared with DBD (42% vs 2%). A trend toward lower graft survival was noted in recipients from donors older than 60 years of age in the HCV population (P = .07), with statistically lower patient survival (P = .02). Donor- recipient HLA matching did not appear to correlate with OLT outcome in patients with HCV. DCD donors and donors older than 60 years of age significantly impact patient and graft survival. Lower graft and patient survival in recipients from DCD donors does not appear to be related to early disease recurrence.

Risk factors for hepatitis C recurrence after liver transplantation

Hepatitis C virus (HCV)-related end-stage liver disease is the main indication for liver transplantation performed in Europe and the United States. Recurrence of hepatitis C in the graft is universal and may lead to chronic hepatitis in most patients and to cirrhosis in 20-30% of patients within 5-10 years of transplantation. The natural history of HCV recurrence is highly variable but leads to a lower survival rate than other recurrent liver diseases. The immunosuppressed status and several other factors have been linked with the pattern and severity of recurrence. What remains controversial are those factors associated with fibrosis progression and how these could be modified to improve outcome of recurrent hepatitis C. No single factor but a combination of several factors is associated with fibrosis progression on the graft. The major factors associated with accelerated disease recurrence include: high viral load pre- (>10(6) IU / mL) and / or early post-transplantation (>10(7) IU / mL at 4 months), donor older than 40-50 years, prolonged ischaemic time, cytomegalovirus coinfection, over immunosuppression and / or abrupt changes in immunosuppression, HIV coinfection, infection by genotype 1b. Cautious follow-up of the pathology of the graft is mandatory including routine biopsies and / or noninvasive monitoring of fibrosis.

Outcomes after lung transplantation in patients with chronic hepatitis C virus infection

BACKGROUND

Hepatitis C virus (HCV) infects 4 million people in the USA, with a prevalence of 1.4%. The seropositivity rate among potential lung transplant candidates is 1.9%, yet little information is available regarding outcomes of lung transplantation in HCV-positive lung transplant recipients. Our study reports outcomes of lung transplantation in HCV-positive recipients and compares them to HCV-negative controls.

METHODS

A retrospective analysis of the Cleveland Clinic Foundation's lung transplant database (465 patients) identified six HCV-positive patients. Demographic data, etiology of HCV infection, HCV viral load pre- and post-transplant, pre-transplant hepatic pathology, serial transaminases, incidence of acute hepatitis, graft function data and patient survival data were obtained by chart extraction.

RESULTS

Five HCV-positive recipients had a pre-transplant liver biopsy, none of whom had evidence of cirrhosis pre-transplant. Although HCV RNA levels markedly increased post-transplant, no concomitant increase in transaminases was noted. There was no significant difference in the incidence of acute rejection at 1 year in our HCV-positive cohort compared with the HCV-negative lung transplant recipients from our institution. One patient developed bronchiolitis obliterans syndrome (BOS) during the follow-up period. Two patient deaths occurred, one at 8 months and the other at 2 years post-transplant. No evidence of hepatic dysfunction was noted in either deceased patient. The four surviving patients are alive at a median 3.2 years (range 1 to 6 years).

CONCLUSIONS

No significant difference in patient or graft survival was noted between the HCV-positive lung transplant recipients and the HCV-negative recipients.

Approach to recurrent hepatitis C following liver transplantation

Hepatitis C-associated liver failure is the most common indication for liver transplantation. Histologic evidence of recurrence is apparent in approximately 50% of hepatitis C virus (HCV)-infected recipients in the first postoperative year. Approximately 10% of HCV-infected recipients will die or lose their allograft due to hepatitis C-associated allograft failure. HCV-infected recipients who undergo retransplantation have 5-year patient and graft survival rates that are broadly similar to those for transplant recipients who are not HCV infected. Although the choice of calcineurin inhibitor, mycophenolate mofetil, or both has not been clearly shown to affect histologic recurrence of hepatitis C, higher cumulative exposure to corticosteroids is associated with increased mortality and more severe histologic recurrence. In contrast to treatment of non-HCV-infected recipients, treatment of HCV-infected transplant recipients for acute cellular rejection is associated with attenuated patient survival. Steroid-resistant rejection with or without the use of T-cell-depleting therapies is associated with a greater than fivefold increased risk of mortality in HCV-infected liver transplant recipients. Pegylated interferon with or without ribavirin should be considered for treatment of recipients with histologically apparent recurrence of hepatitis C before total bilirubin exceeds 3 mg/dL. The role of hepatitis C immunoglobulin and new immunosuppressive agents in the management of hepatitis C after transplant continues to evolve.

Detection of HCV antigens in liver graft: relevance to the management of recurrent post-liver transplant hepatitis C

The aim of this study was to evaluate how the immunohistochemical detection of liver hepatitis C virus (HCV) antigens (HCV-Ag) could support the histologic diagnosis and influence the clinical management of post-liver transplantation (LT) liver disease. A total of 215 liver specimens from 152 HCV-positive patients with post-LT liver disease were studied. Histologic coding was: hepatitis (126), rejection (34), undefined (24; coexisting rejection grade I and hepatitis), or other (31). The percentage of HCV-Ag infected hepatocytes were evaluated, on frozen sections, by an immunoperoxidase technique. HCV-Ag were detectable early in 57% of cases within 30 days post-LT, 92% of cases between 31 and 180 days, and 74% of cases after more than 180 days. Overall, HCV-Ag were detected more frequently in histologic hepatitis as compared to rejection (P < 0.0001) with a higher percentage of positive hepatocytes (P < 0.00001). In 16 patients with a high number of HCV-Ag-positive hepatocytes (65%; range 40-90%) a clinical diagnosis of recurrent hepatitis (RHC) was made despite inconclusive histopathologic diagnosis. Multivariate analysis identified the percentage of HCV-Ag-positive hepatocytes and the time post-LT as independent predictors for RHC (P = 0.008 and P = 0.041, respectively) and the number of HCV-Ag-positive hepatocytes >/=50% as the only independent predictor for nonresponse (P < 0.001) in 26 patients treated with alpha-interferon plus ribavirin. In conclusion, HCV reinfection occurs early post-LT, reaching its peak within 6 months. Immunohistochemical detection of post-LT HCV reinfection support the diagnosis of hepatitis when the histologic features are not conclusive. A high number of infected cells, independently from the genotype, represents a negative predictive factor of response to antiviral treatment.

Infections after Living-Donor Liver Transplantation

BACKGROUND

Despite greater awareness of organ donation among the general public, the supply of cadaveric organs has fallen short of identified needs. Living-donor liver transplantation (LDLT) is an effective means of overcoming the shortage of adult organs, as outcomes are now comparable to those of cadaveric donor liver transplantation.

METHODS

From January, 2002 through January, 2006, 40 LDLTs were performed at our center. With two exceptions, the donor was a first-degree relative of the recipient; all donors were in excellent health with good hepatic function and morphology. All but two donors contributed the right lobe. Infections in the donors and recipients were analyzed.

RESULTS

Clinically relevant infections occurred in three donors. In the recipients, the infections did not differ significantly from those experienced by recipients of cadaveric organs in terms of risk factors (e.g., poor graft function, re-transplantation, surgical complications such as bile duct stenosis, or vascular anastomotic stenosis) or type of infection. Cholangitis was the most frequent infection, leading to septic shock in five of the 14 patients with infections; intra-abdominal infections related to surgical complications led to septic shock in three additional patients. The other most commonly observed infections were urinary tract infections (n=10) and pneumonia (n=3).

CONCLUSIONS

Living-donor liver transplantation offers hope to patients with end-stage liver disease in geographic areas where the waiting time mortality is high and available organs from deceased donors fall short of the population's need.

HLA-DRB1 donor-recipient mismatch affects the outcome of hepatitis C disease recurrence after liver transplantation

BACKGROUND & AIMS

This study extends our previously reported observations that various immunological factors are associated with the occurrence of histologically proven recurrent hepatitis C. The two specific issues investigated were to confirm the associations of MHC alleles and donor/recipient mismatch with the occurrence of recurrent hepatitis C in an independent cohort of newly transplanted patients and to look for immunologic and nonimmunologic variables affecting the severity of the recurrent disease.

METHODS

Two separate cohorts of consecutive patients were studied: a look-back cohort (LC) of 120 patients and a cohort for studying the disease progression (CSDP) of 190 patients. Protocol liver biopsies were obtained at least 1, 3, 5, 7, and 10 years after liver transplantation (LT).

RESULTS

A fully mismatched donor/recipient pair at the DRB1 locus was confirmed to be associated with both the recurrence of histologic hepatitis in the LC (59% vs 23%, P = .0002) and its progression beyond stage 3 in the CSPD (71.4% vs 39.3%, P = .0003). Relevant immunologic and nonimmunologic variables were included into a multivariate Cox proportional model and three variables, namely, donor age, full HLA-DRB1 donor-recipient mismatch, and HLA B14, resulted in independent risk factors for the development of severe fibrosis.

CONCLUSION

This study provides evidence that DRB1 donor-recipient mismatch affects both the occurrence and progression of recurrent hepatitis C disease. This information is clinically relevant as it may help to better allocate organs and to recognize patients at risk for progression so that specific interventions can be implemented.

Antithymocyte globulin induction therapy in hepatitis C-positive liver transplant recipients

It is unclear whether antithymocyte globulin (ATG) induction therapy in hepatitis C-positive (HCV-positive) liver transplant recipients influences the risk of developing recurrent HCV disease. Multiple acute rejection episodes and high-dose steroids and/or OKT3 used to treat acute rejection increase the risk of graft loss from HCV. We studied the impact of ATG induction on graft and patient survival in HCV-positive liver transplants performed since 1990. Recipients who died or lost their grafts within 1 month of transplantation were excluded. Second, third, and fourth grafts were excluded, as were patients with stage III or IV hepatocellular carcinoma. There were 443 cadaveric liver transplants in adult recipients, of whom 142 (32%) were HCV positive. The incidence of biopsy-proven acute rejection was less in patients who received ATG induction, 34.2% (ATG induction) versus 66.6% (no ATG induction) (P<or=.01). ATG induction did not influence the risk of graft loss from HCV-related disease (P=.75). When only HCV-related graft loss was considered, 10-year graft survival for HCV-positive recipients was 74% (ATG induction) versus 68.2% (no ATG induction). Whether ATG induction was given or not had no significant impact on either overall graft survival (P=.39) or patient survival (P=.11) in HCV-positive recipients.

Management of hepatitis C virus infection in the setting of liver transplantation

1. Posttransplantation recurrence of hepatitis C virus infection is a universal phenomenon with a highly variable natural history. 2. Approximately 10% to 25% of hepatitis C virus- infected recipients of liver allografts will develop cirrhosis within 5 years' after transplantation. 3. The 1-year actuarial risk of hepatic decompensation after recurrence of cirrhosis approximates 42%. 4. Some of the factors associated with aggressive recurrence include donor and recipient age, recent year of transplantation, recipient gender and race, the use of antithymocyte globulin, and high dose of corticosteroids. 5. Highly aggressive recurrent hepatitis C virus infection leading to cirrhosis fares poorly after retransplantation in the presence of hyperbilirubinemia and renal failure, with a 1-year survival of approximately 40%. 6. Elevated serum aminotransferases are a poor indicator or recurrent disease. 7. Current sustained virological response after combination pegylated alpha interferon and ribavirin treatment is approximately 25%. 8. There is no consensus on initiation time point, duration of treatment, or dosage. Given immunosuppression, at least 48 weeks of therapy is a reasonable approach. 9. Treatment for 48 weeks is cost effective. Incremental cost-effectiveness ratio for men aged 55 years is $29,100 per life-year saved.

Progression of liver fibrosis in patients with chronic hepatitis C after orthotopic liver transplantation

BACKGROUND

Hepatitis C virus (HCV)-related cirrhosis is the leading indication for orthotopic liver transplantation (OLTx). HCV recurrence is universal after OLTx, with a highly variable course. This study aimed to find factors that affect progression of fibrosis in recurrent HCV.

METHODS

Fifty-eight HCV patients underwent OLTx at our center who were selected on the basis of available preOLTx serum or explanted liver sample and liver biopsy obtained at least 6 months postOLTx. All liver biopsies were performed when clinically indicated and were scored using the modified Hepatitis Activity Index (HAI). Primary immunosuppression consisted of tacrolimus and prednisone.

RESULTS

The group included 41 males (mean age 49.6 years). HCV genotype distribution was 1a, 31 (53%); 1b, 16 (28%), and others 11 (19%). The mean follow-up was 53.1 months. Patients with genotype 1a (n=31; mean 46.3 months) had significantly lower fibrosis-free survival analyzed by the presence of fibrosis stages 5 and 6 when compared with other genotypes (n=27; mean 60.1 months; P=0.0088, log rank test). Mean HAI scores were significantly higher in HCV genotype 1a, although there were no differences in survival between genotypes. Similarly, patients with cytomegalovirus (CMV) infection postOLTx (n=4) had a higher fibrosis progression rate compared with those without CMV (n=54) (mean fibrosis-free survival 29.0 vs. 53.0 months P=0.0004, log-rank test). Human leukocyte antigen matching and rate of acute rejection did not influence progression of fibrosis.

CONCLUSION

Patients with HCV genotype 1a and those developing CMV postOLTx have a higher rate of hepatic fibrosis progression after OLTx for HCV-related chronic liver disease.

Host and donor risk factors before and after liver transplantation that impact HCV recurrence

1. The natural history of hepatitis C after liver transplantation is variable. Several factors, including those related to the virus, the host, the environment and the donor, are probably implicated in the outcome. 2. The immune status per se likely represents the main significant variable in influencing disease severity in hepatitis C virus-infected patients. Findings that support this statement include the higher aggressivity of hepatitis C in immunocompromised liver transplant recipients as compared with that observed in immunocompetent patients, both before and after the development of compensated cirrhosis, and the significant association described between the degree of immunosuppression and disease severity. 3. Similar to that observed in the immunocompetent population, the age at the time of infection (age of the donor) strongly affects posttransplantation hepatitis C virus-related disease progression. 4. Hepatitis C-related disease progression is faster in patients who underwent transplantation in recent years as compared with those who underwent transplantation in earlier cohorts. The increasing age of the donor and the use of stronger immunosuppression may, in part, explain the worse outcomes seen in recent years. 5. Additional host-related variables predictive of outcome include the immunogenetic background, the timing of recurrence, and the early histologic findings.

Living donor liver transplantation and hepatitis C

Preliminary results indicate that living donor liver transplantation patients infected with hepatitis C virus (HCV) develop earlier and more severe recurrence than their cadaveric counterparts. The mechanisms underlying this observation are unknown, but could include hepatic regeneration, differences in living donor liver transplantation recipient demographics, immune homology between donor and recipients, or other factors not previously considered. The optimum clinical approach is to only consider living donor liver transplantation in HCV-infected recipients as a life-saving procedure and to attempt to eradicate HCV before transplantation to prevent recurrent infection.

Recurrent hepatitis C following liver transplant: diagnosis, natural history, and therapeutic options

Hepatitis C virus (HCV) related cirrhosis is the most common indication for orthotopic liver transplantation (OLT). Updated data suggest worse long-term outcomes for those transplanted with HCV than those transplanted for other indications. Re-infection with HCV post-OLT is universal, therefore diagnosis of recurrence should be based on histological findings in the setting of persistent viremia. Variables associated with worse outcome of recurrent disease include early recurrence, degree of immunosuppression, and donor age. Antiviral therapy has been used in the prevention and treatment of recurrent disease, and can be initiated prior to transplantation, prophylactically after transplantation, and during recurrence. Preliminary studies of pre-transplantation treatment demonstrate virological responses, but tolerance is common. Higher efficacy has been associated with combination therapy for recurrent disease. Adverse effects limit its widespread use.

Outcome of liver transplantation for patients infected by hepatitis C, including those infected by genotype 4

Predictors of hepatitis C virus (HCV)-related liver disease posttransplantation are still unclear. The impact of HCV genotype on outcome of transplantation has been studied, but conclusions are not in agreement. The role of HCV genotype 4 on the result of liver transplantation requires further study. The aim of this study is to examine the outcome of liver transplantation for patients with HCV genotype-4 infection. The study group included 128 patients who underwent transplantation for HCV infection: 28 patients, genotype 1; 11 patients, genotype 2; 19 patients, genotype 3; and 32 patients, genotype 4. For 64 of 128 patients, genotype was known and an assessable histological specimen was available. Median interval from transplantation to biopsy was 1.92 years (range, 0.24 to 11.48 years). Twenty-six percent of HCV genotype-4 patients developed either severe fibrosis or cirrhosis versus 6.7% in the genotype non-4 group (P =.04). A statistically significant greater fibrosis progression rate was observed in genotype-4 than genotype non-4 patients. In univariate and multivariate analysis, rapid liver fibrosis was associated with the presence of HCV genotype-4 infection. In addition, donor and recipient age and graft warm ischemic time also were associated with rate of fibrosis progression. Five-year cumulative rates for the development of cirrhosis or severe liver fibrosis were 84% in genotype-4 and 24% in genotype non-4 patients (P =.02). Five-year survival rates for patients with genotypes 1, 2/3, and 4 were 72%, 80%, and 79%, respectively (P =.8). In conclusion, 5-year survival for patients who underwent transplantation for HCV genotype-4 infection was similar to that of genotype non-4 patients; however, more severe fibrosis and rapid fibrosis progression was observed after transplantation in patients with genotype-4 infection.

Immunosuppression in hepatitis B virus and hepatitis C virus transplants: special considerations

The management of the immunosuppression treatment must take account its consequences on viral replication. Such treatment operates on the emerging balance between the recurrence of the virus on the graft and the immune response of the host. Randomized and prospective trials are currently ongoing with the purpose of determining the opportunity and relevance of each immunosuppressive agent in the treatment. In HBV patients, good control of HBV reinfection by prophylactic strategies using HBIG, lamivudine, or both have decreased the impact of immunosuppression on HBV recurrence. In contrast, HCV recurrence is now a major problem. The mechanisms of viral recurrence need to be deepened thus requiring new studies. The absence of in vitro and in vivo systems to study HCV reinfection is a lack in the comprehension of the relation between HCV and immunosuppression. It will allow adapting the effectiveness of the immunosuppression treatment. The treatment's primary target is to avoid graft rejection, and its secondary objective is to limit the risk of viral recurrence.

Significance of immune status, genotype and viral load in the severity of chronic hepatitis C in HIV infected haemophilia patients

Chronic hepatitis C is associated with more severe liver disease in patients coinfected with HIV, but the pathogenic mechanism of this more aggressive course is still unclear. The aim of this study was to assess the relationship of HCV genotype, viral load and epidemiological factors with the histological severity of chronic hepatitis in haemophilia patients with HCV/HIV coinfection, taking into consideration the immune status of the patients. Twenty-one HIV/HCV coinfected haemophilia patients, with mean age +/- SD 35.7 +/- 8.7 years, underwent transcutaneous liver biopsy 6-15 years (median 12 years) after HIV and 6-32 (median 21.5 years) years after HCV infection. Twelve patients were stage A (CDC), six stage B and three stage C. CD4 cells were < 50 microL(-1) in three patients (14.3%), 50-200 in 11(52.4%) and > 200 in 7(33.3%). Mean +/- SD log(10) HCV-RNA was 6.87 +/- 0.7 copies mL(-1) (range 5.4-7.9), and mean +/- SD log(10) HIV-RNA was 3.75 +/- 0.98 copies mL(-1) (range 2.7-6), at the time of liver biopsy. Minimal hepatitis was diagnosed in five patients (24%), mild in 10 (48%) and moderate in six (28%). Hepatitis stage 0-2 was found in seven cases (33%) and cirrhosis in six (29%). Statistical analysis showed a significant association of CD4 count < 50 with minimal hepatitis and of CD > 200 with mild and moderate hepatitis (P = 0.033). In addition, minimal hepatitis was found only in patients with stage C, while the majority of subjects with HIV stage A showed mild and moderate hepatitis (P = 0.003). Moreover genotype 1 was independently associated with advanced hepatitis stage (P = 0.04). No relationship was found between hepatitis severity, HIV or HCV RNA levels, patient's age and duration of HIV or HCV infection. Our results suggest that HCV/HIV coinfection may aggravate the course of hepatitis in the phase of immunocompetence, most probably through an immune mediated process. Genotype 1 seems to be associated with advanced liver disease.

Treatment of posttransplantation recurrence of hepatitis C with interferon and ribavirin: lessons on tolerability and efficacy

Recurrence of hepatitis C virus (HCV) infection after orthotopic liver transplantation is a major cause of graft failure. The aim of our study was to determine the safety, efficacy, and tolerability of combination therapy with interferon and ribavirin in the treatment of recurrent hepatitis after liver transplantation. Twenty-six patients (18 men) with histologically established HCV recurrence after liver transplantation for cirrhosis secondary to chronic HCV infection were treated with a combination of interferon alfa-2b (3 million units three times weekly) and ribavirin (800 to 1,000 mg/d). Dosage modifications were according to a standard protocol incorporating laboratory values and clinical side effects. Fifty percent of patients completed 1 year or more of therapy. On an intention-to-treat basis, nine patients (35%) showed an end-of-treatment virological response. Six of these nine patients completed greater than 6 additional months of follow-up, and all have had sustained virological responses. A histological response (decrease in histological activity index > or = 2) was seen in 75% of virological responders and 67% of nonresponders. Adverse events requiring dose modification or cessation of therapy occurred in 66% of patients. Adjuvant therapies used to support hemoglobin levels included erythropoietin and red blood cell transfusions. There were no independent pretreatment predictors of a virological response, perhaps because of the small sample size. Combination therapy with interferon and ribavirin may be beneficial in patients with recurrent HCV after liver transplantation. The majority of patients require dose modifications because of side effects. Histological response is common in virological nonresponders.

Interactions between cytomegalovirus, human herpesvirus-6, and the recurrence of hepatitis C after liver transplantation

Recurrence of hepatitis C (HCV) following liver transplantation is common. Herpesvirus reactivation following transplant may have an immunomodulatory effect resulting in increased HCV replication. We studied whether cytomegalovirus (CMV) and human herpesvirus-6 (HHV-6) may be associated with HCV recurrence and viral load after transplant. We prospectively followed 66 HCV liver-transplant recipients with serial viral load testing for CMV and HHV-6. Infection and viral load were correlated with the development of biopsy-proven HCV recurrence and HCV viral loads. Histologic recurrence of HCV occurred in 41/66 (62.1%) patients. In the primary analysis, CMV infection and disease, and HHV-6 infection were not associated with HCV recurrence. Peak CMV and HHV-6 viral loads were not significantly different in patients with and without recurrence. No correlation was observed between HCV viral loads at 1 and 3 months post-transplant and peak HHV-6 or CMV viral loads. In a subgroup analysis, HHV-6 infection was associated with the development of more severe recurrence (hepatitis and/or fibrosis score > or = 2) (p = 0.01). Also, fibrosis scores at last follow up were higher in patients with CMV disease (1.67 vs. 0.56; p = 0.016) and in patients with HHV-6 infection (1.18 vs. 0.55; p = 0.031). In conclusion, HHV-6 and CMV infection and viral load were not associated with increased overall rates of HCV recurrence or HCV viral load after liver transplantation but may be associated with more severe forms of recurrence.

A pilot study of the tolerability and efficacy of antiviral therapy in hepatitis C virus-infected patients awaiting liver transplantation

Decompensated liver disease associated with chronic hepatitis C virus (HCV) infection is the most common indication for liver transplantation. It was shown previously that greater pretransplantation HCV titers are associated with relatively poor patient and graft survival. The tolerability and efficacy of antiviral therapy in patients with decompensated liver disease are not known. We conducted a pilot study to determine the likely tolerability and efficacy of pretransplantation antiviral therapy with interferon alfa-2b, with or without ribavirin. HCV RNA-positive patients at or near the top of their respective waiting lists were randomly assigned to one of three treatment regimens until the time of liver transplantation: (1) group A, interferon alfa-2b, 1 x 10(6) U/d; (2) group B, interferon alfa-2b, 3 x 10(6) U three times weekly; or (3) group C, interferon alfa-2b, 1 x 10(6) U/d, plus ribavirin, 400 mg twice daily. Less than half the patients screened met entry criteria, with thrombocytopenia and leukopenia the most common reasons for exclusion. Fifteen patients were administered antiviral therapy; three patients in group A and six patients each in groups B and C. Loss of detectable HCV RNA was seen in 33% of patients, whereas 55% had a decrease in viral titers on therapy. Twenty-three adverse events occurred, including 20 serious adverse events. Thrombocytopenia was the most common adverse event. Two infectious complications occurred; one of these had a fatal outcome. We conclude that although pretransplantation antiviral therapy may reduce HCV titers in a minority of patients who meet treatment initiation criteria, adverse events associated with therapy are frequent and often severe in patients with Child's class B and C cirrhosis.

Timing of reinfection and mechanisms of hepatocellular damage in transplanted hepatitis C virus-reinfected liver

Pathogenic mechanisms and dynamics of hepatitis C virus (HCV) reinfection in orthotopic liver transplantation (OLT) are poorly defined. This study focuses on these aspects by studying 55 frozen biopsy specimens from transplant recipients with various histological diagnoses obtained from 4 days to 4 years post-OLT and 10 patients with HCV-related chronic hepatitis. The percentage of HCV-infected hepatocytes, number and distribution of CD8 and natural killer cells, and rates of hepatocellular apoptosis and proliferation were quantified by immunohistochemistry. HCV antigens were detected in 37% of biopsy specimens obtained within 20 days and 90% of biopsy specimens obtained from 21 days to 6 months after OLT. The number of HCV-infected hepatocytes was never less than 40% in acute hepatitis specimens and never greater than 30% in the other cases. Hepatocellular apoptosis was high in biopsy specimens of acute hepatitis and moderate in those from transplant recipients with normal histological characteristics, but still greater than in specimens of chronic active hepatitis. Proliferation correlated significantly with apoptosis. Lymphocyte infiltration was high and similar among cases of acute hepatitis, chronic hepatitis, and rejection. These data: (1) show that the detection of liver HCV antigens is sensitive enough to be used in clinical practice as a diagnostic tool to detect infection of the transplanted liver and might be useful, combined with conventional histological evaluation to detect hepatitic damage, for therapeutic decision making; (2) suggest direct cytotoxicity of HCV, as well as immunologic mechanisms possibly prevalent in chronic hepatitis and rejection, at least in the phase of acute massive liver infection; and (3) show that hepatocellular apoptosis and regeneration might be active enough to lead to replacement of the entire transplanted liver in 2 weeks.

Management of recurrent hepatitis C after liver transplantation: a concise review

Recurrent hepatitis C infection and subsequent graft failure are increasingly recognized problems after orthotopic liver transplantation. Although many prospective therapeutic, controlled trials in primary hepatitis C disease have been reported, large-scale studies are yet to be performed in patients with posttransplant recurrent hepatitis C after liver transplantation. In this review, we summarize the current literature on the therapeutic approaches for recurrent hepatitis C and discuss the results of published studies on therapy with ribavirin or interferon (IFN) alone and on combination therapy with IFN plus ribavirin. Further, we discuss results of prophylactic approaches to the problem of recurrent hepatitis C after transplant. Finally, we discuss additional aspects of anti-hepatitis C virus therapy after liver transplantation.

Viral hepatitis in the liver transplant recipient

Understanding and management of HBV and HCV infection in the OLT recipient has evolved rapidly in the last decade. The spontaneous risk for viral recurrence after transplantation is high, but has been decreased effectively in hepatitis B-positive recipients with the use of HBIG and lamivudine. HCV recurrence as defined by histologic injury is almost universal, although graft or patient outcomes for the first 8 years after OLT do not appear to be limited by HCV serostatus. However, effective prophylactic regimens that alter the natural history of HCV reinfection do not currently exist, and with longer follow-up into the second decade, the prevalence of HCV-related graft failure is likely to increase.

Recurrent hepatitis C after liver transplantation

Cirrhosis due to hepatitis C is now the commonest indication for liver transplantation in Western Europe and in the United States. Graft reinfection is almost universal. The natural history of recurrent hepatitis C ranges from minimal damage to cirrhosis in a few months or years. Different virus and host immune factors are involved in the pathogenesis of hepatitis and are determinants of the outcome. The association between immunosuppression and severity of HCV recurrence is conflicting and remains to be evaluated fully. The treatment of recurrent HCV disease with IFN or ribavirin, as monotherapy, is ineffective. Preliminary results from combination therapy, however, are encouraging. Currently, a reasonable approach would be to treat patients with histological and clinical disease progression. New approaches for the prophylaxis of recurrent hepatitis C are under evaluation but whether this treatment will influence the severity of liver disease or the outcome of recurrence is still unknown.

Comparative allograft histology after liver transplantation for cryptogenic cirrhosis, alcohol, hepatitis C, and cholestatic liver diseases

BACKGROUND

End-stage liver disease for which no cause can be identified, cryptogenic cirrhosis, is a common indication for liver transplantation. Allograft inflammation and fibrosis have been reported to recur with similar frequencies after liver transplantation for cryptogenic cirrhosis and hepatitis C (HCV).

METHODS

We determined sequential posttransplant allograft histology in four groups of recipients: 31 transplanted for cryptogenic cirrhosis, 70 for cholestatic etiologies, 40 for alcoholic liver disease, and 56 for HCV. Modified hepatitis activity index (HAI) and fibrosis stage were determined at 4 months, 1 year, and at most recent biopsy posttransplantation.

RESULTS

The prevalence of HAI > or = 2 among cryptogenic recipients was similar to that of cholestatic and alcoholic recipients at 4 months, 1 year, and at most recent evaluation (mean 45+/-17 months posttransplantation). For HCV-infected recipients, the frequency of HAI > or = 2 was more than for cryptogenic recipients at 1 year (52 vs. 29%, P=0.04) and at most recent evaluation (64 vs. 15%, P=0.003). Fibrosis scores for cryptogenic, cholestatic, and alcoholic recipients were similar at all timepoints. The proportion of HCV-infected recipients with fibrosis stage >2 was more than that of cryptogenic recipients at 4 months (29 vs. 12%, P=0.05), 1 years (46 vs. 7%, P=0.0002), and at most recent evaluation (42 vs. 15%, P=0.06). None of the cryptogenic recipients developed cirrhosis.

RESULTS

The frequency of elevated HAI and fibrosis stage in recipients who undergo transplantation for cryptogenic cirrhosis is similar to that of recipients who undergo transplantation for cholestatic etiologies and significantly less than that of HCV-infected recipients. Fibrosis stage and HAI are generally stable after transplantation for cryptogenic cirrhosis. These data do not suggest a viral etiology of liver disease in the majority of patients with cryptogenic cirrhosis.

Influence of immunogenetic background on the outcome of recurrent hepatitis C after liver transplantation

In immunocompetent patients, specific human leukocyte antigen (HLA) class II alleles have been associated with the severity of hepatitis C virus (HCV)-related disease, in particular, HLA-DRB1*11 has been found to exert a protective effect. The authors have analyzed the role of HLA class I and II alleles in determining the frequency, timing, and progression of histologically proven recurrent hepatitis C in 89 patients who underwent a liver transplant for HCV-related cirrhosis. In addition, the influence of HLA mismatch between donor and recipient, HCV genotype, and use of steroid pulses was also evaluated. Median patient follow up was 35 months (range 4-119). HLA-DRB1 typing was performed by genomic analysis in all cases. Liver biopsies were obtained routinely and at least at yearly intervals. Histologically proven recurrent hepatitis was observed in 46 patients (52%), 10 patients progressing to stage 5-6 fibrosis in most cases within 2 years after transplant. By univariate analysis, 3 variables, HLA-B14, HLA-DRB1*04, and HLA-DRB1 donor/recipient mismatch, showed a significant effect on time to recurrent hepatitis C disease. These parameters were included in a multivariate regression model along with HCV genotype, treatment with steroid pulses and DRB1*11. HLA-B14, HLA-DRB1*04, and HLA-DRB1 donor/recipient mismatch were confirmed to provide a significant and independent contribution to the risk of hepatitic disease recurrence. As for the severity of the disease, none of the 10 patients with stage 5-6 hepatitis carried the HLA-DRB1*11 allele, in line with what was observed in nontransplant subjects. Our results suggest that in posttransplant recurrent hepatitis C, immunogenetic factors are relevant in determining HCV infection outcome.

Indications for liver transplantation in patients with chronic hepatitis B and C virus infection and hepatocellular carcinoma

Patients with chronic hepatitis B virus (HBV) infection were not accepted for liver transplantation in Asia in the past because the hepatitis B immune globulin (HBIG) used to prevent post-transplantation recurrence was very expensive and it was generally believed that Asians with hepatitis B fared worse than Caucasians after liver transplantation. The availability of lamivudine has altered the indication of liver transplantation for these patients. Twenty-five Chinese patients with chronic HBV infection were given lamivudine as primary prophylaxis against HBV re-infection before transplantation. Five patients died within 40 days of transplantation. After a median follow-up period of 14 months (range, 5-39), 17 patients had lost serum HBsAg from 4 days to 27 months post transplantation, but it reappeared in three patients 4-12 months later. Antibody to HBsAg was detected periodically in the serum of 1 patients who had lost HBsAg. At the last follow-up, six patients were HBsAg-positive and HBV DNA was detected in only one of them. The indication for liver transplantation for chronic hepatitis C virus (HCV) infection is not as strict as for patients with chronic HBV infection because the long-term survival is similar to that of non-hepatitis C patients, even though re-infection by HCV in the recipients is nearly universal. The main issue in the selection of patients with HCV for liver transplantation is therefore identification of criteria that can predict re-infection and development of cirrhosis. These include factors such as multiple episodes of rejection, use of OKT3, pre-transplant viral load and genotype, but reports are not consistent and so there are no well-defined selection criteria. The selection criteria for patients with hepatocellular carcinoma are now well defined. Many studies have confirmed that a tumour > 5 cm, and showing vascular invasion, and poor differentiation adversely affects survival. In practice, only patients with a tumour < 5 cm and Child's C cirrhosis are accepted for liver transplantation. Transarterial oily chemoembolization and intralesional alcohol injection are used to control or down-stage the tumour while patients wait for a cadaveric liver graft.

Liver transplantation for hepatitis C virus related cirrhosis

Hepatitis C virus (HCV) related chronic liver disease is now the leading cause for liver transplantation in many centres. Virological recurrence is inevitable following liver transplantation. Excellent patient and graft survival are seen in the short-term, equivalent to that in patients transplanted for other causes of liver disease. However, histological evidence of disease recurrence or hepatitis is present in over half the patients within a year of transplantation, although a small percentage develop progressive cholestatic hepatitis with graft loss within a year. Cirrhosis can develop in the first year after transplantation and 28% of patients have evidence of cirrhosis by 5 years. There is little agreement over the factors that predict the recurrence of disease, development of cirrhosis within the graft and graft or patient survival. Graft loss due to HCV occurs in up to 9% at 5 years and the long-term prognosis may not be comparable to groups transplanted for other diseases. Patients with hepatocellular carcinoma may benefit from liver transplantation if the tumour is small and without vascular invasion. There are, as yet, no clear guidelines regarding the best combination of immunosuppressants in patients with HCV but viral clearance has been achieved with the use of interferon and ribavirin therapy post-operatively.

Recurrent hepatitis C after liver transplantation: clinical and therapeutical issues

Hepatitis C virus (HCV) reinfection after liver transplantation is almost constant, assessed by the persistence of HCV RNA in 90% of cases. Acute hepatitis appeared in 75% of patients at a median of 4 months' post-transplantation. The 5-year actuarial rate of acute and chronic hepatitis on the graft is 75% and 60%, respectively. The rate of HCV cirrhosis on the graft is variable from 8 to 25% at 5 years. After transplantation, HCV viraemia is dramatically increased and correlates with the occurrence of acute hepatitis on the graft. Intrahepatic levels of HCV are high at the time of acute hepatitis, and decrease with constitution of chronic graft hepatitis lesions, implying an immunological response to the viral infection. A relationship between genotype 1b and the prevalence of HCV hepatitis on the graft has been suggested in European but not American series. The influence of the age of the recipient, quasispecies, viral compartmentalization, immunosuppressive treatment, and of HLA matching is being evaluated. The 5-year patient survival is around 65-80%. However, the occurrence of cirrhosis with a risk of graft failure may decrease the 10 and 15-year patient survival. Attempts to give prophylactic post-transplant antiviral treatment are under evaluation. Antiviral treatment of post-transplant graft lesions with combination therapy interferon-ribavirin gave promising results but indications and duration of treatment should be evaluated. In conclusion, HCV reinfection is frequent, but medium-term survival is good. However, the long-term graft and patient survival remains unknown, and efficient prevention and treatment of HCV graft is mandatory.

Increased late hepatic artery thrombosis rate and decreased graft survival after liver transplants with zero cross-reactive group mismatches

The use of broad-specificity cross-reactive groups (CREGs) at the A and B HLA loci has been proposed as a means to improve both access and outcome for renal transplantation but has not yet been studied for liver transplantation. We retrospectively analyzed our results for all adult liver transplantations performed at our center between 1989 and 1996 for which HLA typing and complete 3-year follow-up data were available. Two hundred eight transplantations were studied, with a mean follow-up of 66 +/- 2 months (range, 36 to 110 months); A and B loci were converted to CREGs by the method of Rodey. Thirteen percent of the patients with 0 CREG mismatches had hepatic artery thrombosis versus 2% for those with 1 or more mismatches (odds ratio, 6.7; 95% confidence interval, 2.6 to 17.3 by univariate analysis; odds ratio, 3.5; 95% confidence interval, 1.1 to 11.7 by logistic regression analysis). These events occurred significantly later in the 0-CREG mismatch group (21 +/- 7 v 4 +/- 2 months posttransplantation; P =.04 by Student's t-test). Graft survival rates were significantly lower for patients with 0 CREG mismatches (56% v 68% at end of study; P =.05 by Cox-Mantel test). The number of CREG mismatches had no effect on the frequency of rejection, steroid-resistant rejection, or infectious complications, including cytomegalovirus. Neither total nor individual A, B, or DR HLA matching had an effect on outcome. There appears to be little evidence that intentional CREG matching would improve outcomes for liver transplantation and, under some circumstances, could be deleterious.