Does tacrolimus offer virtual freedom from chronic rejection after primary liver transplantation? Risk and prognostic factors in 1,048 liver transplantations with a mean follow-up of 6 years

The absence of chronic rejection in pediatric primary liver transplant patients who are maintained on tacrolimus-based immunosuppression: a long-term analysis

BACKGROUND

Although the outcome of liver transplantation has improved significantly during the past two decades, graft loss caused by chronic rejection after liver transplantation still occurs in 2% to 20% of recipients. The overall incidence of chronic rejection is also reported to be low in adult recipients, and risk factors have been identified. Chronic rejection is associated with the inability to maintain baseline immunosuppression. Additionally, the diagnoses of primary biliary cirrhosis, primary sclerosing cholangitis, autoimmune hepatitis, hepatitis B virus, and hepatitis C virus, common indications for liver transplantation in adults, are associated with a higher incidence of chronic rejection. Fortunately, these diagnoses are rarely seen in children. Little is known about chronic rejection in long-term pediatric liver transplant survivors. The purpose of this longitudinal study was to examine the incidence of biopsy-proven chronic rejection in long-term survivors of primary pediatric liver transplantation under tacrolimus-based immunosuppression.

METHODS

From October 1989 to December 1992, 166 children (boys=95, girls=71; mean age=5.0+/-2.9 years) received a primary liver transplant. These patients were followed until March 2000 with a mean follow-up of 9+/-0.8 (range, 7.4-10.4) years. All liver biopsy specimens and explanted grafts were evaluated for evidence of chronic rejection using the International Banff Criteria.

RESULTS

The mortality rate during the follow-up period was 15% (n=25). Retransplantation was required in 11% (n=18) of recipients. Actuarial patient and graft survival rates at 10 years were 84.9% and 80.1%, respectively. There were 535 liver biopsy samples available for evaluation, including the 18 explanted allografts. Biopsy specimens of three other functioning allografts showed evidence of chronic rejection. Immunosuppression had been discontinued or drastically reduced in these recipients because of life-threatening infections, noncompliance, or both. On restoring baseline immunosuppression, all three children had normalized liver function and the allografts were maintained; the liver transplant patients who are alive currently have normal liver functions.

CONCLUSION

The findings of this study suggest that chronic rejection does not occur in pediatric liver transplant recipients receiving tacrolimus-based immunosuppression, provided baseline immunosuppression is maintained.

Real-time monitoring of acute liver-allograft rejection using the Banff schema

BACKGROUND

The Banff schema is the internationally accepted standard for grading acute liver-allograft rejection, but it has not been prospectively tested.

METHODS

Complete Banff grading was prospectively applied to 2,038 liver-allograft biopsies from 901 adult tacrolimus-treated primary hepatic allograft recipients between August 1995 and September 2001. Histopathologic data was melded with demographic, clinical, and laboratory data into a database on an ongoing basis using locally developed software.

RESULTS

Acute rejection developed in 575 of 901 (64%) patients and the worst grade was mild in 422 of 575 (73%). At least one episode of moderate or severe acute rejection developed in 153 of 901 (17%) patients and most episodes, irrespective of severity, occurred within the first year after transplantation. Patients with moderate or severe acute rejection showed higher alanine aminotransferase (P =0.007) and aspartate aminotransferase ( P=0.07) levels and were more likely to develop perivenular fibrosis on follow-up biopsies (P =0.001) and graft failure from acute or chronic rejection ( P=0.004) than those with mild rejection. Regardless of severity, 80% of patients with acute rejection did not develop significant fibrosis in follow-up biopsies, and graft failure from acute or chronic rejection occurred in only 11 of 901 (1%) allografts.

CONCLUSIONS

Most acute-rejection episodes are mild and do not lead to clinically significant architectural sequelae. When tested prospectively under real-life and -time conditions, the Banff schema can be used to identify those few patients who are potentially at risk for more significant problems. Creation, capture, and integration of non-free text, or "digital," pathology data can be used to prospectively conduct outcomes-based research in transplantation.

Tacrolimus versus microemulsified ciclosporin in liver transplantation: the TMC randomised controlled trial

BACKGROUND

Calcineurin inhibitors are the most commonly used immunosuppressive drugs in liver transplantation, but the optimum initial immunosuppression regimen is not known. The aim of our study was to compare tacrolimus with microemulsified ciclosporin, in a regimen with standardised concomitant immunosuppressive therapy.

METHODS

In all liver transplant centres in the UK and Republic of Ireland, 606 patients undergoing a first orthotopic liver transplantation were randomly assigned open-label tacrolimus or microemulsified ciclosporin. Primary outcome was the combined frequency (whichever occurred first) of death, retransplantation, or treatment failure for immunological reasons, analysed by intention to treat.

FINDINGS

96% of patients received the treatment allocated to them. The primary outcome was reached in 62 (21%) of 301 patients in the tacrolimus group versus 99 (32%) of 305 allocated microemulsified ciclosporin (relative risk 0.63 [95% CI 0.48-0.84], p=0.001; time-to-event analysis log-rank test p=0.002): deaths (50 [17%] vs 72 [24%]); retransplantations (11 [4%] vs 31 [10%]) treatment failure for immunological reasons (6 [2%] vs 12 [4%]). The relative risk for the composite outcome was in favour of tacrolimus. The main causes of death in both trial groups were sepsis and multiple organ failure (31 [10%] vs 30 [10%]), and the main cause for retransplantation was hepatic artery thrombosis (6 [2%] vs 17 [6%]). Renal dysfunction and the need for antihypertensive therapy were much the same in both groups. Tacrolimus was more diabetogenic.

INTERPRETATION

Clinical outcome at 1 year was better with tacrolimus-based immunosuppression than with microemulsified ciclosporin during the first year after liver transplantation. Tacrolimus should be the first choice of calcineurin inhibitor for patients receiving their first liver graft.

Pediatric liver transplantation. A single center experience spanning 20 years

BACKGROUND

Survival after liver transplantation has improved significantly over the last decade with pediatric recipients faring better than adults. The 20-year experience of pediatric liver transplantation at Children's Hospital of Pittsburgh is reported in terms of patient survival; graft survival in relation to age, gender, and immunosuppressive protocols; causes of death; and indications for retransplantation.

METHOD

From March 1981 to April 1998, 808 children received liver transplants at Children's Hospital of Pittsburgh. All patients were followed until March 2001, with a mean follow-up of 12.2+/-3.9 years (median=12.6; range=2.9-20). There were 405 female (50.2%) and 403 male (49.8%) pediatric recipients. Mean age at transplant was 5.3+/-4.9 years (mean=3.3; range 0.04-17.95), with 285 children (25.3%) being less than 2 years of age at transplant. Cyclosporine (CsA)-based immunosuppression was used before November 1989 in 482 children (50.7%), and the subsequent 326 recipients (40.3%) were treated with tacrolimus-based immunosuppression. Actuarial survival was calculated using the Kaplan-Meier statistical method. Differences in survival were calculated by log-rank analysis.

RESULTS

Overall patient survival at 1, 5, 10, 15, and 20 years was 77.1%, 72.6%, 69.4%, 65.8%, and 64.4%, respectively. There was no difference in survival for male or female patients at any time point. At up to 10 years posttransplant, the survival for children greater than 2 years of age (79.5%, 75.7%, and 71.6% at 1, 5, and 10 years, respectively) was slightly higher than those at less than 2 years of age (72.6%, 66.9%, and 65.3% at 1, 5, and 10 years, respectively). However, at 15 and 20 years posttransplant, survival rates were similar (>2 years=67.3% and 65.8%; <2 years=64.1% and 64.1%). A significant difference in survival was seen in CsA-based immunosuppression (71.2%, 68.1%, 65.4%, and 61%) versus tacrolimus-based immunosuppression (85.8%, 84.7%, 83.3%, and 82.9%) at 1, 3, 5, and 10 years, respectively (P=0.0001). The maximum difference in survival was noted in the first 3 months between CsA and tacrolimus; thus, indicating there may have been other factors (nonimmunological factors) involved in terms of donor and recipient selection and technical issues. The mean annual death rate beyond 2 years posttransplant was 0.47%, with the mean annual death rate for patients who received tacrolimus-based immunosuppression being significantly lower than those who received CsA-based immunosuppression (0.14% vs. 0.8%; P=0.001). The most common etiologies of graft loss were hepatic artery thrombosis (33.4%), acute or chronic rejection (26.6%), and primary nonfunction (16.7%). Of note, retransplantation for graft loss because of acute or chronic rejection occurred only in those patients who received CsA-based immuno-suppression.

CONCLUSION

The overall 20-year actuarial survival for pediatric liver transplantation is 64%. Survival has increased by 20% in the last 12 years with tacrolimus-based immunosuppression. Although this improvement may be the result of several factors, retransplantation as a result of acute or chronic rejection has been completely eliminated in patients treated with tacrolimus.

Late hepatic allograft dysfunction

1. Lifelong monitoring of graft function, immunosuppressive levels, and screening for drug toxicity is required in all liver recipients. 2. Late hepatic allograft dysfunction is common and is caused by a variety of etiologies including rejection, infection, biliary/vascular abnormalities, recurrence of disease, and drug hepatotoxicity. 3. In all patients with late hepatic allograft dysfunction, liver biopsy should be performed to assess for the presence of rejection, and to thus avoid excessive use of bolus corticosteroid therapy and guide appropriate immunosuppressive management. 4. Recurrence of disease is the most common cause of late hepatic allograft dysfunction. 5. Hepatitis C universally reinfects the hepatic allograft, and is associated with decreased patient and graft survival and leads to the recurrence of cirrhosis in 28% of patients within 5 years of transplantation. 6. Major advances have been made in preventing recurrence of hepatitis B by the use of hepatitis B immune globulin in combination with lamivudine therapy. 7. Autoimmune liver diseases such as primary biliary cirrhosis, primary sclerosing cholangitis, and autoimmune hepatitis have a recurrence rate of approximately 20% to 30%. 8. In patients developing recurrence of autoimmune hepatitis, steroid withdrawal is the most common cause. 9. Recurrent hepatocellular cancer can be markedly reduced if strict guidelines are adhered to in selecting patients. 10. Drug hepatotoxicity must always be considered in the differential diagnosis of late hepatic allograft dysfunction.