Rudolf Steininger

A prospective randomised, open-labeled, trial comparing sirolimus-containing versus mTOR-inhibitor-free immunosuppression in patients undergoing liver transplantation for hepatocellular carcinoma

BackgroundThe potential anti-cancer effects of mammalian target of rapamycin (mTOR) inhibitors are being intensively studied. To date, however, few randomised clinical trials (RCT) have been performed to demonstrate anti-neoplastic effects in the pure oncology setting, and at present, no oncology endpoint-directed RCT has been reported in the high-malignancy risk population of immunosuppressed transplant recipients. Interestingly, since mTOR inhibitors have both immunosuppressive and anti-cancer effects, they have the potential to simultaneously protect against immunologic graft loss and tumour development. Therefore, we designed a prospective RCT to determine if the mTOR inhibitor sirolimus can improve hepatocellular carcinoma (HCC)-free patient survival in liver transplant (LT) recipients with a pre-transplant diagnosis of HCC.Methods/DesignThe study is an open-labelled, randomised, RCT comparing sirolimus-containing versus mTOR-inhibitor-free immunosuppression in patients undergoing LT for HCC. Patients with a histologically confirmed HCC diagnosis are randomised into 2 groups within 4-6 weeks after LT; one arm is maintained on a centre-specific mTOR-inhibitor-free immunosuppressive protocol and the second arm is maintained on a centre-specific mTOR-inhibitor-free immunosuppressive protocol for the first 4-6 weeks, at which time sirolimus is initiated. A 21/2 -year recruitment phase is planned with a 5-year follow-up, testing HCC-free survival as the primary endpoint. Our hypothesis is that sirolimus use in the second arm of the study will improve HCC-free survival. The study is a non-commercial investigator-initiated trial (IIT) sponsored by the University Hospital Regensburg and is endorsed by the European Liver and Intestine Transplant Association; 13 countries within Europe, Canada and Australia are participating.DiscussionIf our hypothesis is correct that mTOR inhibition can reduce HCC tumour growth while simultaneously providing immunosuppression to protect the liver allograft from rejection, patients should experience less post-transplant problems with HCC recurrence, and therefore could expect a longer and better quality of life. A positive outcome will likely change the standard of posttransplant immunosuppressive care for LT patients with HCC.Trial RegisterTrial registered at http://www.clinicaltrials.gov: NCT00355862(EudraCT Number: 2005-005362-36)

Efficacy of liver transplantation for alcoholic cirrhosis with respect to recidivism and compliance.

Many transplant centers are reluctant to accept alcoholic patients for OLT because of their supposed potential for alcoholic recidivism and poor compliance with the required immunosuppressive regimen, both of which result in graft failure. Only inconclusive data related to these arguments are available. From May 1982 to January 1993, 58 patients received OLT at our institution for end-stage cirrhosis, where alcohol was the only toxic component. The indication for OLT in these patients was considered with particular attention to recidivism and compliance. Overall survival in this group was 71% and 63% at 1 and 5 years, respectively, with an average survival time of 78 months. Actuarial survival of patients transplanted since January 1989 (n = 37) was 86% and 83% at 1 and 2 years (average survival 42 months). Nonfatal clinical endpoints were analyzed in those patients surviving at least 3 months (n = 44). Return to alcohol abuse has been documented in 14 persons at routine short-term outpatient checkups. The estimated risk for alcoholic recidivism amounts to 31%, with a median follow-up of 33 months. Compliance with immunosuppressive regimen was expressed as a dependent value of acute rejection episodes (0.3 per patient, median follow-up 33 months), chronic rejection (occurred in none of the patients), and measurements of CsA HPLC blood trough level (92.2% within the target range). The preversus postoperative improvement of employment, marital, and social status after OLT showed a statistically significant difference. Unwillingness to offer OLT to individuals with alcoholic liver disease because of failure to demonstrate 100% long-term abstinence appears difficult to defend in the face of good results in survival, compliance, and social rehabilitation.

Arginase release following liver reperfusion : evidence of hemodynamic action of arginase infusions

Immediately after hepatic reperfusion in human or-thotopic liver transplantation, high amounts of arginase are released from the graft, thereby influencing nitric oxide metabolism. This metabolic alteration may be one component of the ischemia-reperfusion syndrome in OLT with its hemodynamic disturbances (e.g., systemic hypotension, pulmonary hypertension). The aim of this study was to compare hemodynamic and metabolic changes following OLT in the pigs with those obtained under arginase infusions in catheterized, anesthetized pigs. Following liver revascularization in the pigs, plasma arginase concentrations increased from 48±19 IU/L to 2613 ±944 IU/L, resulting in a drop in plasma levels of L-arginine (-87%) and in a drop in nitrite (-82%) and nitrate (-53%) concentrations. Of the measured organspecific hemodynamic alterations, the mean pulmonary arterial pressure increased from 17±2 mmHg to 30±5 mmHg, whereas the flow/pressure index of the portal vein decreased about 60%. A primed continuous infusion of arginase (25,000 IU) increased plasma arginase levels to a maximum of 3,690±962 IU and evoked a decrease of L-arginine, but did not alter plasma nitrite or nitrate levels. The administration of arginase in healthy pigs did not influence cardiac output, mean arterial pressure, heart rate, or total peripheral resistance, but led to an increase of mean pulmonary arterial pressure from 19±3 to 48±5 mmHg and to a reduction of arterial hepatic blood flow from 229±65 ml/min to 154±41 ml/min. From this we conclude that high levels of liver arginase cause hemodynamic alterations in the lung and the liver. We hypothesize that the pulmonary hypertension and the reduced hepatic blood flow found during the immediate reperfusion period after OLT are possibly related to the increased arginase release due to the hepatic damage of the graft.

Sirolimus Use in Liver Transplant Recipients With Hepatocellular Carcinoma: A Randomized, Multicenter, Open-Label Phase 3 Trial.

Background We investigated whether sirolimus-based immunosuppression improves outcomes in liver transplantation (LTx) candidates with hepatocellular carcinoma (HCC). Methods In a prospective-randomized open-label international trial, 525 LTx recipients with HCC initially receiving mammalian target of rapamycin inhibitor–free immunosuppression were randomized 4 to 6 weeks after transplantation into a group on mammalian target of rapamycin inhibitor–free immunosuppression (group A: 264 patients) or a group incorporating sirolimus (group B: 261). The primary endpoint was recurrence-free survival (RFS); intention-to-treat (ITT) analysis was conducted after 8 years. Overall survival (OS) was a secondary endpoint. Results Recurrence-free survival was 64.5% in group A and 70.2% in group B at study end, this difference was not significant (P = 0.28; hazard ratio [HR], 0.84; 95% confidence interval [95% CI], 0.62; 1.15). In a planned analysis of RFS rates at yearly intervals, group B showed better outcomes 3 years after transplantation (HR, 0.7; 95% CI, 0.48-1.00). Similarly, OS (P = 0.21; HR, 0.81; 95% CI, 0.58-1.13) was not statistically better in group B at study end, but yearly analyses showed improvement out to 5 years (HR, 0.7; 95% CI, 0.49-1.00). Interestingly, subgroup (Milan Criteria-based) analyses revealed that low-risk, rather than high-risk, patients benefited most from sirolimus; furthermore, younger recipients (age ⩽60) also benefited, as well sirolimus monotherapy patients. Serious adverse event numbers were alike in groups A (860) and B (874). Conclusions Sirolimus in LTx recipients with HCC does not improve long-term RFS beyond 5 years. However, a RFS and OS benefit is evident in the first 3 to 5 years, especially in low-risk patients. This trial provides the first high-level evidence base for selecting immunosuppression in LTx recipients with HCC.

L-arginine deficiency after liver transplantation as an effect of arginase efflux from the graft : influence on nitric oxide metabolism

L-Arginine plays an important role in protecting animals against ammonia intoxication, enhances immune function, stimulates wound healing, and is the precursor for the endothelium-derived relaxing factor, recently recognized as nitric oxide (NO). In this study, we investigated the influence of hepatic reperfusion on amino acid metabolism after human OLT. After 10 sec of reperfusion, the arterial plasma levels of L-arginine dropped from 105 +/- 12 mumol/L to 3.8 +/- 0.6 mumol/L (P < 0.001), whereas plasma ornithine increased from 40 +/- 5.5 mumol/L to 129 +/- 15 mumol/L (P < 0.001). The reduced L-arginine levels remained subnormal for several hours after OLT. This drop in plasma L-arginine was due to an arginase release from the implanted graft. Immediately after reperfusion, the plasma concentrations of arginase increased from pretransplantation values of 18 +/- 13 IU/L to 2384 +/- 1456 IU/L (P < 0.01). Measurement of plasma nitrite (NO2-) and nitrate (NO3-), which are the stable end products of NO, revealed that NO2- decreased about 50% after reperfusion (from 1.64 +/- 0.32 mumol/L to 0.80 +/- 0.17 mumol/L; P < 0.001), whereas NO3- levels remained unchanged (76 +/- 23 mumol/L vs. 63 +/- 8 mumol/L). We conclude that hepatic reperfusion causes L-arginine deficiency by liberating high amounts of arginase from the implanted graft. This L-arginine depletion may influence the NO synthesis in patients after OLT.

Patient and Graft Survival in Older Kidney Transplant Recipients: Does Age Matter?

An increasing gap between supply and demand of donor kidneys for transplantation exists. There is concern regarding the allocation of scarce organs to elderly patients, because the benefit obtained by the transplant may be less in elderly compared with younger recipients. It was the objective of this study to determine differences in patient and organ survival between organ recipients >65 yr and 50 to 64 yr of age at transplantation. A retrospective cohort of 627 patients >50 yr who received a kidney transplant between 1993 and 2000 was assembled. Detailed information on patient demographics, comorbidities, and immunological and donor characteristics was ascertained before transplantation. Five-year patient and graft survival were evaluated by Kaplan-Meier survival curves and multivariate Cox proportional-hazard models. Five-year patient mortality was similar between patients aged >65 and 60 to 64 at transplantation (relative risk [RR] = 1.07; 95% confidence interval [CI], 0.66 to 1.74). Patients aged 50 to 59 yr showed a clear trend toward lower 5-yr mortality (RR = 0.66; 95% CI, 0.43 to 1.03). Compared with patients >65 yr, 5-yr graft loss was not different in patients aged 60 to 64 (RR = 1.28; 95% CI, 0.82 to 2.02) or those aged 50 to 59 yr at transplantation (RR = 1.02; 95% CI, 0.68 to 1.53). After thorough control for confounding, 5-yr graft survival was not materially different by age group. Discrimination against older candidates for kidney transplantation on age-related grounds alone is not warranted.

Intraoperative estimation of endotoxin, TNFα, and IL-6 in orthotopic liver transplantation and their relation to rejection and postoperative infection

The course of endotoxemia, TNF alpha, and IL-6 during orthotopic liver transplantation was studied in 28 transplantations performed in 27 patients to evaluate their impact on early postoperative rejection and infection. The preoperative levels of endotoxin, TNF alpha, and IL-6 were not different in patients who did or did not develop postoperative rejection and/or infection within the first 10 postoperative days. At the end of surgery, TNF alpha levels increased in patients who developed rejection (median 100 pg/ml vs. 11.5 pg/ml, P = 0.004). A TNF alpha level of greater than 100 pg/ml at the end of transplantation predicted rejection in 82% of the patients. During surgery, IL-6 levels increased significantly in patients with subsequent postoperative infection, reaching significance after revascularization of the graft (median 975 pg/ml vs. 185 pg/ml, P = 0.006). An IL-6 cutoff level of 800 pg/ml predicted postoperative infection in 75% of the patients. Endotoxins were elevated intraoperatively in patients with postoperative infection, but the difference did not reach significance. There was no prognostic relevance with respect to the intraoperative values of TNF alpha and infection or IL-6 values and rejection. An intraoperative elevation of TNF alpha seems to precede early postoperative rejection, and highly increased IL-6 may be a predictor of subsequent infection in human liver transplantation.

Combination of extended donor criteria and changes in the Model for End-Stage Liver Disease score predict patient survival and primary dysfunction in liver transplantation: a retrospective analysis.

Background. The purpose of this study was to analyze the impact of extended donor criteria (EDC) and of changes in the Model for End-Stage Liver Disease (MELD) score while waiting for liver-transplantation (&Dgr;-MELD) on patient survival and initial graft function. Methods. We included 386 consecutive patients with end-stage liver disease who underwent orthotopic liver transplantation at the Medical University Vienna between 1997 and 2003. Primary outcome was patient survival and secondary outcome was initial graft function. EDC included: age >60 years, >4 days intensive medical care, cold ischemia time >10 hr, need for noradrenalin >0.2 &mgr;g/kg/min or doputamin >6 &mgr;g/kg/min, a donor peak serum sodium >155 mEq/L, a donor serum creatinine >1.2 mg/100 mL, and a body mass index >30. Results. &Dgr;-MELD was significantly higher in the nonsurvivor population (P=0.01) and EDC showed a significant influence on initial graft function (P=0.01). Worsening in either &Dgr;-MELD or the presence of at least two EDC was not associated with an increased risk of primary graft dysfunction and death. Worsening in &Dgr;-MELD and the presence of at least two EDC was significantly associated with primary graft dysfunction (P=0.01) and death (P=0.008). Conclusion. The combination of a liver recipient with worsening &Dgr;-MELD and a potential donor with at least two EDC should be avoided.

Short-term induction therapy with anti-thymocyte globulin and delayed use of calcineurin inhibitors in orthotopic liver transplantation.

The appropriate time point for starting immunosuppressive treatment with calcineurin inhibitors after orthotopic liver transplantation (OLT) has been a subject of debate. The aim of the study was to analyze the effects of anti‐thymocyte globulin (ATG) induction therapy on rejection, renal function, infection, tumor rate, and survival. We retrospectively analyzed 391 patients after OLT who had either received calcineurin inhibitors immediately after OLT (n = 129) or after an initial short‐term Thymoglobulin induction therapy (n = 262). The 1‐year acute rejection rate was 14.5% vs. 31.8% in favor of ATG (P = 0.0008). Rejection grades and the need for treatment also differed significantly (7.3% vs. 23.3%; P = 0.001). Serum creatinine at transplantation was similar in both groups (1.14 mg/dL vs.1.18 mg/dL; P = NS). Postoperative hemofiltration was less frequently seen after induction therapy (P < 0.05). Reduced renal function at 1 year was commonly observed, but serum creatinine (1.26 mg/dL vs. 1.37mg/dL; P = 0.015) and glomerular filtration rate (81 mL/min vs. 75 mL/min; P = 0.02) were far better in the ATG group. Undesired side effects occurred at a similar rate in both groups. Five‐year patient survival was also similar in the 2 groups (70.1% and 74.3%; P > 0.05). Short‐term ATG induction therapy with delayed administration of calcineurin inhibitors led to a more favorable rejection rate and an improved clinical course in case of a rejection episode. It has beneficial effects on renal function immediately after OLT as well as later, and no additional harmful effects. Liver Transpl 13:1039–1044, 2007.

Influence of cumulative number of marginal donor criteria on primary organ dysfunction in liver recipients.

Abstract:u2002 Background:u2002 The aim of this cohort study was to assess the cumulative effect of marginal donor criteria on initial graft function and patient survival after liver transplantation.