Langzeit-Outcome nach Lebertransplantation

[Specific infections in organ transplantation]

This article is concerned with the important topic of infections associated with organ transplantation and includes a discussion on four subtopics. The first section describes the current options in the prevention and therapy of viral hepatitis in association with liver transplantation. Infections with hepatitis B, C, D (delta) and E are discussed with special emphasis on the interferon-free treatment of hepatitis C with the new antiviral drugs.The second section deals with Pseudomonas aeruginosa (PA) infections following lung transplantation (LuTx), which is one of the most frequently detected pathogens in the airway after LuTx. Patients with cystic fibrosis are particularly affected. This is important because studies have shown a clear correlation between chronic PA infections after LuTx and development of chronic transplant failure. Even if the data are still sparse, recommendations on prevention and therapeutic strategies are given. The theme of the third section is the high importance of viral infections after kidney transplantation. In addition to acquired infections, the transplanted organ as well as the recipient can be the source of the infection. The better the transplanted organ is tolerated under moderate immunosuppression, the less common and severe virus infections are. The focus of this section is on three common pathogens: cytomegalovirus, polyomavirus BK and hepatitis viruses.The final section deals with Aspergillus infections following transplantation of various organs. In this context Aspergillus spp. are one of the most commonly occurring fungal diseases. The epidemiology, risk factors, diagnostics, prophylaxis and therapy of invasive aspergillosis are presented.

(Cleaved) CK18 serum and tissue expression levels differentiate acute HCV reinfection from acute rejection in liver allografts

BACKGROUND & AIMS

Orthotopic liver transplantation (OLT) is the sole therapeutic option to cure end-stage liver diseases including HCV-related cirrhosis. Timely and precise differentiation of relevant acute HCV reinfection from acute rejection after OLT is vital for appropriate therapy. Aim of this study was to evaluate the usefulness of (non-) invasive apoptosis (M30) and necrosis (M65) determination in the differential diagnosis of acute (and chronic) HCV reinfection vs. acute rejection in liver allografts.

METHODS

Serum samples and liver biopsy tissues were available from 76 patients including a control group (19× NAFL, 19× NASH, 16× acute rejection, 11× acute and 11× chronic HCV reinfection) and were analysed using M30- and M65 ELISAs (M30S, M65S) and M30-immunohistochemistry (M30H). Clinical and serological data were collected.

RESULTS

M30S, M65S and M30H were highly correlated with diagnostic groups in the total cohort (all P < 0.0001). M30S, M65S and M30H were independently able to differentiate acute HCV reinfection from acute rejection (P = 0.048, P = 0.001, P = 0.010) with moderate to excellent diagnostic accuracy (sensitivity, specificity, cut-off-value in M30S: 70%, 75%, 1025 U/L; M65S: 100%, 92%, 1308 U/L; M30H: 73%, 88%, 0.3%).

CONCLUSIONS

M30-, M65-ELISAs and M30-immunohistochemistry are potential useful tools in differentiating acute HCV reinfection from acute rejection facilitating both speed and accuracy of the diagnostic process for the clinician and hepatopathologist. In this context, M65S provided superior diagnostic characteristics compared to M30-based methods. However, being the first analysis of (cleaved) CK18 serum and tissue expression levels in this context, the results need to be verified in further studies.

Outcome stagnation of liver transplantation for primary sclerosing cholangitis in the Model for End-Stage Liver Disease era

PURPOSE

Survival after liver transplantation (LTX) has decreased in Germany since the implementation of Model for end-stage liver disease (MELD)-based liver allocation. Primary sclerosing cholangitis (PSC) is known for its otherwise excellent outcome after LTX. The influence of MELD-based liver allocation and subsequent allocation policy alterations on the outcome of LTX for PSC is analyzed.

METHODS

This is a retrospective observational study including 126 consecutive patients treated with LTX for PSC between January 1, 1999 and August 31, 2012. The PSC cohort was further compared to all other indications for LTX in the study period (n=1420) with a mean follow-up of 7.9 years (SD 3.2). Multivariate risk-adjusted analyses were performed. Alterations of allocation policy have been taken into account systematically.

RESULTS

Transplant recipients suffering from PSC are significantly younger (p<0.001), can be discharged earlier (p=0.018), and have lower 3-month mortality than patients with other indications (p=0.044). The observed time on the waiting list is significantly longer for patients with PSC (p<0.001), and there is a trend toward lower match MELD points in the PSC cohort (p=0.052). No improvement in means of short-term mortality could be shown in relation to alterations of allocation policy within the MELD era (p=0.375). Survival rates of the pre-MELD era did not differ significantly from those of the MELD era (p=0.097) in multivariate risk-adjusted analysis. Patients in the MELD era suffered pre-transplant significantly more frequently from dominant bile duct stenosis (p=0.071, p=0.059, p=0.048, respectively; chi2).

CONCLUSIONS

Progress is stagnating in LTX for PSC. Current liver allocation for PSC patients should be reconsidered.

Technical feasibility of liver transplantation without cold storage

PURPOSE

The success of liver transplantation (LT) is accompanied by an increased need for organs. The wider use of older donors and marginal organs with risk factors such as steatosis has lead to a new interest to improve the outcome with marginal organs. We herewith report a novel technique for LT with in situ preparation and immediate warm-ischemia liver transplantation (WI-LT). The aim of our study was to demonstrate the technical feasibility and report the transplant course.

METHODS

Six patients underwent WI-LT at our institution. Hepatectomies during procurement and LT were both performed in parallel by different surgical teams. Technical factors and postoperative allograft function were analyzed.

RESULTS

All six WI-LTs were performed without intraoperative complications with a mean warm-ischemia time (WIT) of 29.0 min. No patient developed primary non-function or required retransplantation. Mean alanine aminotransferase (194.0 ± 170.4 U/l) and aspartate aminotransferase (316.3 ± 222.1 U/l) values on the first postoperative day were low, indicating a low ischemia/reperfusion injury and an excellent liver function.

CONCLUSIONS

These results demonstrate that WI-LT is a safe and technically feasible approach for LT with possibly reduced IRI and an excellent postoperative allograft quality. WI-LT may therefore be considered in individual patients especially with extended criteria donors to eventually improve postoperative allograft quality.

Perioperative risk factors for prolonged mechanical ventilation after liver transplantation due to acute liver failure

Background

Acute liver failure (ALF) is a rapidly progressing and fatal disease for which liver transplantation (LT) is the only treatment. Posttransplant mechanical ventilation tends to be more prolonged in patients with ALF than in other LT patients. The present study examined the clinical effects of prolonged posttransplant mechanical ventilation (PMV), and identified risk factors for PMV following LT for ALF.

Methods

We reviewed data of patients undergoing LT for ALF between January 2005 and June 2011. After grouping patients according to administration of PMV (≥ 24 h), donor and recipient perioperative variables were compared between the groups with and without PMV. Potentially significant factors (P < 0.1) from the univariate intergroup comparison were entered into a multivariate logistic regression to establish a predictive model for PMV.

Results

Twenty-four (25.3%) of 95 patients with ALF who received PMV had a higher mortality rate (29.2% vs 11.3%, P = 0.038) and longer intensive care unit stay (12.9 ± 10.4 vs 7.1 ± 2.7 days, P = 0.012) than patients without PMV. The intergroup comparisons revealed worse preoperative hepatic conditions, more supportive therapy, and more intraoperative fluctuations in vital signs and less urine output in the with- compared with the without-PMV group. The multivariate analysis revealed that preoperative hepatic encephalopathy (≥ grade III), intraoperative blood pressure fluctuation, and oliguria (< 0.5 ml/kg/h) were independent risk factors for PMV.

Conclusions

PMV was associated with deleterious outcomes. Besides care for known risk factors including hepatic encephalopathy, meticulous attention to managing intraoperative hemodynamic circulatory status is required to avoid PMV and improve the posttransplant prognosis in ALF patients.

Influence of hepatitis C virus infection and high virus serum load on biliary complications in liver transplantation

BACKGROUND

Biliary complications (BCs) and recurrent hepatitis C virus (HCV) infection are among the major causes of morbidity and graft loss following liver transplantation. The influence of HCV on BCs has not been definitely clarified.

PATIENTS AND METHODS

We performed a retrospective cohort study to analyze risk factors and outcome of post orthotopic liver transplantation (OLT) BCs in 352 liver transplant recipients over 12 years in Munich, Germany (n = 84 with HCV; living donor and re-OLT were excluded). BCs diagnosed with imaging techniques and abnormal liver enzyme pattern, requiring an intervention, were considered.

RESULTS

In a multivariate analysis, HCV serostatus and a high pre-and post-surgery HCV RNA serum load were independent risk factors for anastomotic strictures. HCV positivity and BCs alone did not alter graft loss. HCV-positive patients with BCs, however, had a significantly worse graft outcome (P = 0.02). Non-anastomotic strictures, bile leaks, and the number of interventions needed to treat bile leaks led to worse graft outcome in all patients.

CONCLUSION

HCV positivity and a high HCV RNA serum load were risk factors for anastomotic strictures. BCs and HCV had an additive effect on graft loss.

Metabolic preconditioning with fructose prior to organ recovery attenuates ischemia-reperfusion injury in the isolated perfused rat liver

OBJECTIVE

Ischemia-reperfusion injury is associated with a high rate of primary organ dysfunction and thereby contributes substantially to morbidity and mortality in the course of liver transplantation. In the present study, the impact of metabolic preconditioning with fructose on ischemia-reperfusion injury in the isolated perfused rat liver model is evaluated.

METHODS

Fasted rats received a single intravenous fructose injection to induce metabolic preconditioning (fructose group) or a volume equivalent of normal saline (control group) 10 min before liver explantation. After 26 h of cold storage, livers were reperfused for 90 min at 37°C with Krebs-Henseleit buffer. The parameters used to quantify ischemia-reperfusion injury included hepatic oxygen consumption, enzyme release, and cell viability.

RESULTS

During reperfusion, livers in the fructose group consumed more oxygen than livers in the control group (p < 0.005), indicating ATP synthesis as a result of glycolytic fructose degradation. Moreover, cell injury was reduced by fructose administration, as reflected by a lower enzyme release during both cold ischemia and reperfusion (p < 0.05). Finally, hepatocyte viability at the end of reperfusion was significantly higher in the fructose group (p < 0.01). However, there was no significant difference between the two experimental groups in reference to the viability of endothelial cells.

CONCLUSION

In clinical use, metabolic preconditioning with fructose prior to organ recovery might contribute to a reduction in the incidence of primary organ dysfunction after liver transplantation.

High intrahepatic HHV-6 virus loads but neither CMV nor EBV are associated with decreased graft survival after diagnosis of graft hepatitis

BACKGROUND & AIMS

In liver transplant recipients with graft hepatitis, the relevance of herpesviruses is not well defined.

METHODS

Viral loads of CMV, EBV, and HHV-6 were determined in blood and liver biopsies of 170 liver transplant recipients with graft hepatitis by quantitative PCR.

RESULTS

HHV-6-, CMV-, and EBV-DNA were detected in 58%, 14%, and 44% of the biopsies, respectively, with coinfections in 34%. High intrahepatic HHV-6 DNA levels (>75th percentile, 11.27 copies/1000 cells) and detection of HHV-6 DNAemia were significantly associated with decreased graft survival after diagnosis of graft hepatitis (p=0.014 and p=0.003, respectively, median follow-up was 23.8 months). Multivariate analysis confirmed high intrahepatic HHV-6 loads as an independent factor associated with reduced graft survival (adjusted hazard ratio 2.61, 95%confidence interval 1.16-5.87). Low concentrations of HHV6 DNA in the liver, indicating latent infection, did not influence graft survival. Neither CMV nor EBV (qualitative detection and high virus loads) nor acute rejection (according to the BANFF score) affected graft survival. However, patients had been treated for CMV reactivations and acute rejections in this retrospective study. High age and high bilirubin levels were the other independent factors associated with reduced graft survival (adjusted hazard ratio 3.56CI 1.52-8.34 and 3.23CI 1.50-6.96, respectively).

CONCLUSIONS

High intrahepatic HHV-6-DNA levels are associated with decreased graft survival in liver transplant recipients with graft hepatitis. The significance of HHV-6 as potential etiology of graft hepatitis needs further evaluation.

Availability, characteristics, and barriers of rehabilitation programs in organ transplant populations across Canada

Rehabilitation is receiving increasingly more attention from the medical community in the management of individuals' pre- and post-organ transplantation. A cross-sectional descriptive survey was administered to all known transplant programs across Canada to explore the availability, characteristics, and barriers of rehabilitation programs pre- and post-heart, lung, kidney, and liver transplantation. Of the 58 programs surveyed, 35 agreed to participate (nine heart, six lung, 13 kidney, seven liver), and six refused for a response rate of 71%. Twelve transplant programs that offered rehabilitation were identified (six heart, five lung, one liver). All rehabilitation programs identified included aerobic exercises, strength training, and education and involved a multidisciplinary team. The Six Minute Walk Test and the Medical Outcomes Short Form-36 questionnaire were the most commonly used outcome measures. In kidney and liver transplant programs, over 50% of respondents from these programs cited lack of funding, shortage of health care personnel, and a low volume of patients in a centralized region as barriers to providing rehabilitation programs. Rehabilitation can play an integral role in pre- and post-transplantation management, and barriers to access and provision of rehabilitation for organ transplant populations should be examined further.

Multidrug donor preconditioning prevents cold liver preservation and reperfusion injury

PURPOSE

Primary graft dysfunction still represents a major challenge in liver transplantation. We herein studied in an isolated rat liver perfusion model whether a multidrug donor preconditioning (MDDP) can not only reduce but also completely prevent cold ischemia-reperfusion injury.

METHODS

MDDP included curcumin, simvastatin, N-acetylcysteine, erythropoietin, pentoxyphylline, melatonin, glycine, and methylprednisolone. Postischemic reperfusion was performed after 24 h cold storage in histidine-tryptophan-ketoglutarate solution with 37°C Krebs Henseleit bicarbonate buffer.

RESULTS

Cold hepatic ischemia-reperfusion resulted in a massive K(+) release, protein loss, and aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase elevation. This was associated with increased malondialdehyde formation, enhanced tumor necrosis factor-alpha and interleukin-6 production, pronounced leukocytic tissue infiltration, and apoptotic cell death.

CONCLUSIONS

MDDP abolished the inflammation response and was capable of completely preventing the manifestation of parenchymal injury. Thus, MDDP potentiates the protective effects reported after single-drug donor preconditioning and may therefore be an interesting approach to improve the outcome in clinical liver transplantation.

Hepatitis E virus infection as a cause of graft hepatitis in liver transplant recipients

Hepatitis E virus (HEV) infection induces self-limiting liver disease in immunocompetent individuals. Cases of chronic hepatitis E have recently been identified in organ transplant recipients. We questioned if chronic hepatitis E plays a role in graft hepatitis after liver transplantation in a low endemic area. Two hundred twenty-six liver transplant recipients, 129 nontransplanted patients with chronic liver disease, and 108 healthy controls were tested for HEV antibodies. HEV RNA was investigated in all sera from transplanted patients. HEV antibodies were detected in 1 healthy control (1%), 4 patients with chronic liver disease (3%), and 10 liver transplant recipients (4%). Three liver transplant patients also tested positive for HEV RNA. Two of them developed persistent viremia with HEV genotype 3. The patients were anti-HEV immunoglobulin G-negative and HEV RNA-negative before transplantation and had an episode of acute hepatitis 5 or 7 months after transplantation, which led to advanced liver fibrosis after 22 months in 1 patient. Seroconversion to anti-HEV occurred not before 4 months after the first detection of HEV RNA. The possibility of reverse zoonotic transmission was experimentally confirmed by the infection of 5 pigs with a patient's serum. The pigs showed histological inflammation in the liver, and HEV RNA was detectable in different organs, including muscle. In conclusion, the prevalence of HEV infection in Central European liver transplant recipients is low; however, chronic hepatitis E may occur and needs to be considered in the differential diagnosis of graft hepatitis. The diagnosis of HEV infection should be based on HEV RNA determination in immunosuppressed patients. We suggest that immunocompromised individuals should avoid eating uncooked meat and contact with possibly HEV-infected animals.

[Liver transplantation: indications and results]

After around 64,000 transplantations in Europe since 1988 liver transplantation has emerged as a standard treatment option for otherwise incurable chronic liver diseases. Cirrhosis of different etiologies represents the most frequent transplant indication. Overall survival in this group amounts to 72% after 5 years, and 62% after 10 years. In Germany, the main indications include alcoholic liver cirrhosis, tumors with increasing numbers in recent years, as well as viral diseases leading to cirrhosis. Since December 2006 the priority for liver transplantation is determined by the model for end stage liver disease (MELD) and not by the length of waiting time. MELD is a statistical model based on serum creatinine, serum bilirubin and coagulation, which describes the probability of 3-month mortality of a potential transplant candidate. Not all liver diseases are adequately represented by MELD necessitating the additional use of a defined number of standard exceptions that have been last updated in 2008. As a consequence of these developments indications, selection of recipients and the management of the waiting list have seen profound change.

Aftercare for patients with transplanted organs

BACKGROUND

The postoperative management following solid organ transplantation requires close cooperation between family doctors, internists, the local hospital, and the transplant center.

METHODS

Selective analysis of current national and international guidelines and relevant review articles.

RESULTS/CONCLUSION

In the early phase post transplantation, aftercare involves inpatient treatment and outpatient or inpatient rehabilitation with the aim of complete social and professional reintegration. Early diagnosis and treatment of typical general complications such as post-transplant diabetes, hyperlipidemia, arterial hypertension, osteoporosis, and kidney failure is essential. Early detection and treatment of malignant disease and opportunistic infections in patients with long-term immunosuppression is desirable. Moreover, organ-specific factors have to be taken into account. In the event of transplant dysfunction, recurrence of the underlying disease in the transplant, chronic or acute rejection, and organ-specific infections and drug toxicity have to be considered.