Harald Schrem

Liver transplantation after organ preservation with normothermic extracorporeal perfusion.

ObjectiveTo study normothermic extracorporeal liver perfusion (NELP) as a means to preserve livers for transplantation and to reverse warm ischemic injury.Summary Background DataThe authors provide experimental evidence that successful transplantation after 4 hours of normothermic extracorporeal liver perfusion is possible and as reliable as 4 hours of cold preservation in University of Wisconsin solution. NELP preserves liver function completely and can reverse 60 minutes of warm ischemic injury in non–heart-beating donors.MethodsThirty-six German Landrace pigs received transplants in six groups. Group 1 animals received direct transplantation. Group 2 received transplants after 4 hours of cold preservation with University of Wisconsin solution and Group 3 animals after 4 hours of NELP. Group 4 animals sustained 1 hour of warm ischemia before transplantation. Group 5 animals received transplants after 1 hour of warm ischemia and 4 hours of cold preservation and Group 6 animals after 1 hour of warm ischemia and 4 hours of NELP.ResultsAll animals receiving livers treated by NELP survived more than 7 days after the transplant (Groups 3 and 6). In contrast, all animals in Group 5 developed primary graft nonfunction within 24 hours after transplantation.ConclusionThe technique of NELP holds the potential to keep a mammalian liver outside the body completely functional, possibly for more than 4 hours. NELP can be used for liver preservation before transplantation or for the use of organs from non–heart-beating donors.

Liver-Enriched Transcription Factors in Liver Function and Development. Part II: the C/EBPs and D Site-Binding Protein in Cell Cycle Control, Carcinogenesis, Circadian Gene Regulation, Liver Regeneration, Apoptosis, and Liver-Specific Gene Regulation

In the first part of our review (see Pharmacol Rev 2002;54:129-158), we discussed the basic principles of gene transcription and the complex interactions within the network of hepatocyte nuclear factors, coactivators, ligands, and corepressors in targeted liver-specific gene expression. Now we summarize the role of basic region/leucine zipper protein family members and particularly the albumin D site-binding protein (DBP) and the CAAT/enhancer-binding proteins (C/EBPs) for their importance in liver-specific gene expression and their role in liver function and development. Specifically, regulatory networks and molecular interactions were examined in detail, and the experimental findings summarized in this review point to pivotal roles of DBP and C/EBPs in cell cycle control, carcinogenesis, circadian gene regulation, liver regeneration, apoptosis, and liver-specific gene regulation. These regulatory proteins are therefore of great importance in liver physiology, liver disease, and liver development. Furthermore, interpretation of the vast data generated by novel genomic platform technologies requires a thorough understanding of regulatory networks and particularly the hierarchies that govern transcription and translation of proteins as well as intracellular protein modifications. Thus, this review aims to stimulate discussions on directions of future research and particularly the identification of molecular targets for pharmacological intervention of liver disease.

Surgical treatment and outcome of iatrogenic bile duct lesions after cholecystectomy and the impact of different clinical classification systems.

Different injury patterns of iatrogenic bile duct lesions after cholecystectomy have prompted the proposal of several different clinical classification systems. The aim of this study was to validate these systems comparatively.

Magnetic resonance imaging of focal liver lesions. Comparison of the superparamagnetic iron oxide resovist versus gadolinium-DTPA in the same patient

RATIONALE AND OBJECTIVES The authors assess the efficacy of static and dynamic magnetic resonance (MR) imaging using the superparamagnetic iron oxide SHU-555A (Resovist) versus standard dose of gadolinium (Gd)-DTPA in patients with focal liver lesions. METHODS Magnetic resonance imaging was performed in 30 patients suffering from histopathologically verified malignant (n = 22) and benign (n = 8) liver lesions. T2-weighted conventional and fat-suppressed as well as T1-weighted sequences were used before, during, and after fast intravenous administration of Resovist (1 mL/minute) at three doses of 4, 8, and 16 mumol/kg body weight. One week before the Resovist-enhanced MR imaging study 20 patients underwent Gd-DTPA-enhanced MR imaging. RESULTS Detection rate was improved for metastatic lesions revealing 36 lesions unenhanced versus 53 focal lesions using Resovist-enhanced MR imaging. Gadolinium-DTPA-enhanced scans showed no additional lesion versus unenhanced and Resovist-enhanced MR imaging. Static and dynamic imaging demonstrated no measurable percentage signal intensity loss (PSIL) using Resovist-enhanced MR imaging versus a percentage enhancement of 79.7% in Gd-DTPA enhanced scans. In the dynamic T2-weighted sequences, hepatocellular carcinoma nodules (n = 4) showed a rapid decrease in signal intensity starting at 44 seconds. Postinfusion of Resovist followed by a low, constant increase in signal intensity. Gadolinium-DTPA enhanced scans showed a percentage enhancement of 73.4 focal nodular hyperplasia (FNH) and hemangioma revealed a strong and early dose-dependent PSIL 44 to 60 seconds postinfusion with a prolonged signal loss for the FNH in the late study. Statistical evaluation revealed a statistically significant superiority of Resovist-enhanced MR imaging concerning the detection and delineation of focal liver lesions compared with unenhanced and Gd-DTPA enhanced scans (P < 0.05). CONCLUSIONS The fast infusion of the new superparamagnetic contrast agent Resovist shows advantages for dynamic and static MR imaging of focal liver lesions.

Large-Scale Isolation of Human Hepatocytes for Therapeutic Application:

During the last decade, hepatocyte transplantation has been suggested as a safe and potentially effective clinical option for the treatment of acute or decompensating chronic liver failure as well as for hereditary liver disease. Currently, one of the major limiting factors for clinical application is the insufficient access to suitable liver cell preparations. In cooperation with the German and Catalane organ procurement organizations, a routine procedure for the isolation of hepatocytes from donor organs rejected for transplantation (n = 117) has been established. The process is performed according to the current EC Guidelines for Good Manufacturing Practice (cGMP) and all corresponding national laws and regulations concerning donor organ and tissue procurement. In about 50% of the cases (n = 58) the three-step perfusion procedure has been completed with an average total cell yield of 5.9 × 109 cells per organ, the cell preparations displaying a mean viability of 64%. The mean specific yield was 3.6 × 106 total and 2.6 × 106 viable cells per gram liver tissue, respectively. Specific cell yields from three infantile donor livers were considerably higher. No correlation between isolation efficiency and cold ischemia time or donor age was found within the adult organ donors. In contrast, organs with a severe steatosis generally did not result in successful cell isolation. Results of sterility and endotoxin determination are also presented. In summary, a standardized and cGMP conform method of hepatocyte isolation from nontransplantable liver organs was established, which reproducibly yields large amounts of hepatocytes suitable for therapeutic application.

Incidence and long‐term risk of de novo malignancies after liver transplantation with implications for prevention and detection

The goal of this study was the characterization of long‐term cancer risks after liver transplantation (LT) with implications for prevention and detection. Site‐specific cancer incidence rates and characteristics were compared retrospectively for 2000 LT patients from a single institution (January 1, 1983 to December 31, 2010) and the general German population with standardized incidence ratios (SIRs); the total follow‐up at December 31, 2011 was 14,490 person‐years. The cancer incidence rates for the LT recipients were almost twice as high as those for the age‐ and sex‐matched general population (SIR = 1.94, 95% CI = 1.63‐2.31). Significantly increased SIRs were observed for vulvar carcinoma (SIR = 23.80), posttransplant lymphoproliferative disorder/non‐Hodgkin lymphoma (SIR = 10.95), renal cell carcinoma (SIR = 2.65), lung cancer (SIR = 1.85), and colorectal cancer (SIR = 1.41). The mean time between transplantation and diagnosis was 6.8 years. The mean age at the time of diagnosis was significantly lower for the cohort versus the general population with similar malignancies [50 years (both sexes) versus 69 and 68 years (males and females), P ≤ 0.006]. Tumors were diagnosed at more advanced stages, and there was a trend of higher grading, which suggested more aggressive tumor growth. Tumor treatment was performed according to accepted guidelines. Surprisingly, 5‐year survival was slightly better in the study cohort versus the general population for renal cell carcinoma, lung cancer, colorectal cancer, and thyroid cancer. Long‐term immunosuppression with different protocols did not lead to significantly different SIRs, although patients treated with mycophenolate mofetil had the lowest SIR for de novo cancers (1.65, 95% CI = 1.2‐2.4). Alcoholic liver disease (SIR = 2.30) and primary sclerosing cholangitis (SIR = 3.40) as indications for LT were associated with an increased risk of de novo malignancies. In conclusion, risk‐adapted cancer surveillance is proposed. Tumor treatment performed according to accepted guidelines appears adequate. Mycophenolate may lead to lower long‐term risks for de novo cancers. Liver Transpl 19:1252–1261, 2013.

The Donor-Risk-Index, ECD-Score and D-MELD-Score all fail to predict short-term outcome after liver transplantation with acceptable sensitivity and specificity

BACKGROUND Expansion of the donor pool by the use of grafts with extended donor criteria reduces waiting list mortality with an increased risk for graft and patient survival after liver transplantation. This study investigates the ability of the Donor-Risk-Index (DRI), the Extended-Criteria-Donor-Score (ECD-score) and the D-MELD-score to predict early outcome after liver transplantation. MATERIAL/METHODS 291 consecutive adult liver transplants (01.01.2007-31.12.2010) were analysed in a single centre study with ongoing data collection. Primary study endpoints were 30-day mortality, 3-month mortality, 3-month patient and graft survival and the necessity of acute retransplantation within 30 days. For the primary study endpoints ROC-curve analysis was performed to calculate the sensitivity, specificity, and overall model correctness of the Donor-Risk-Index (DRI), Extended-Criteria-Donor-Score (ECD-score) and the D-MELD-Score as predictive models. Cut-off values were selected with the best Youden index. RESULTS ROC-curve analysis showed areas under the curve (AUROCs) <0.7 for the DRI, the ECD-Score and the D-MELD-Score as models for the prediction of 30-day mortality, 3-month mortality, 3-month patient survival, 3-month graft survival as well as the necessity of acute retransplantation within 30 days after transplantation with unacceptable low levels of overall model correctness (<62%) and specificity (<56%). CONCLUSIONS The DRI, the ECD-Score and the D-MELD-Score all fail to predict short-term outcome after liver transplantation with acceptable overall model correctness in a current European transplant setting.

Low incidence of p53 mutations in European hepatocellular carcinomas with heterogeneous mutation as a rare event

BACKGROUND/AIMS The aim of this study was to evaluate the role of p53 mutations in European hepatocarcinogenesis. METHODS DNA extracts from 20 microdissected tumor samples were investigated. Nucleotide sequence analysis of subcloned polymerase chain reaction-fragments of the conserved domain exons 5-8 was performed in order to detect heterogeneous distribution of p53 mutated cells within the tumors. In a screening procedure four clones of each exon 5-8 were analyzed. To confirm the observed mutations polymerase chain reaction and subcloning was repeated. RESULTS Sequence analysis confirmed a mutation in only two cases (10%). One at codon 220 (exon 6) was a homogeneous transition in nearly all clones from TAT to TGT. The other mutation was a transition from cGG to CAG at the known hot spot codon 248 (exon 7). It was found in 30% of the clones. We conclude that the other mutations from the first step were artefacts due to the infidelity of the taq-polymerase. All tumors had wild type sequence at the reported hot spot codon 249. The minor importance of p53 gene alterations in European hepatocarcinogenesis was further confirmed at the protein level by immunohistochemistry. Only the tumors with the heterogeneous p53 mutation at codon 248 showed a p53 overexpression in nearly 30% of the nuclei. None of the other tumors showed higher levels of p53 expression. CONCLUSIONS We therefore conclude that the incidence of p53 mutations in European hepatocellular carcinomas is very low. Generally there may be no heterogeneous distribution of p53 mutated cells within a tumor. The contribution of this genetic alteration to hepatocarcinogenesis in Europe seems of little importance.

Living donor liver transplantation: effect of the type of liver graft donation on donor mortality and morbidity

To investigate the influence of the type of liver graft donation on donor mortality and morbidity. The clinical course of 87 living liver donors operated on at our center between 2002 and 2009 was retrospectively analysed and data pertaining to all complications were retrieved. No donor mortality was observed and no donor suffered any life‐threatening complication. Four donors (4.6%) developed biliary leakage, nine (10.3%) had to be readmitted to hospital and six (6.9%) required some or other type of reoperation related to the previous liver donation. Reoperations included incisional or diaphragmatic hernia repair (n = 4), biliary leakage repair (n = 1) and segmental colon resection combined with diaphragmatic hernia repair (n = 1). There was a statistically significant difference in hospital stay (P < 0.001), autologous blood transfusions (P < 0.001) and operating time (P < 0.005) when right lobe donations (Segments V–VIII) were compared with left lobe (Segments II–IV) and left lateral lobe (Segments II–III) donations, whereas no difference was found between these groups regarding hospital readmission, operative revisions and the incidence or severity of complications. Right lobe donation was associated with prolonged hospital stay, increased blood transfusions and prolonged operating time when compared with left and left lateral lobe donation, whereas donor mortality and morbidity did not differ between these groups.

Langzeit-Outcome nach Lebertransplantation

Liver transplantation has been reported to reach excellent results for selected indications. We analysed the results of liver transplantation in our centre over a period of 23 years, with a total of 2,114 consecutive liver transplants in 1,773 patients (eras I-III 5.5 years each, era IV 6.5 years). Overall 20-year survival after liver transplantation was 29.8%. The most frequent leading causes of death were infections of various origins (30%), tumour recurrence (14.2%), and pneumonia (8.4%). The most frequent leading causes for graft loss were infection of various origins (19.6%), initial nonfunction of the graft (14.6%), and tumour recurrence (9.6%). Both long-term patient and graft survival were significantly better after primary liver transplantation than after first retransplantation (P<0.001). Patient and graft long-term survival improved significantly across all four consecutive eras (P<0.001). In era IV, the most recent, 5-year patient survival reached 96% for PBC, 89.4% for PSC, 78.5% for biliary atresia, 70% for acute liver failure, 69.1% for HBV-related cirrhosis, 61.3% for hepatocellular carcinoma, and 56% for HCV-related cirrhosis.