2-Step-Scores with optional nephropathology for the prediction of adverse outcomes for brain-dead donor kidneys in Eurotransplant.

BACKGROUND AND HYPOTHESIS: The decision for acceptance or discard of the increasingly rare and marginal brain-dead donor kidneys in Eurotransplant (ET) countries has to be made without solid evidence. Thus, we developed and validated flexible clinicopathological scores called 2-Step Scores for the prognosis of delayed graft function (DGF) and one-year death-censored transplant loss (1y-tl) reflecting the current practice of six ET countries including Croatia and Belgium. METHODS: The training set was n=620 for DGF and n=711 for 1y-tl, with validation sets n=158 and n=162. In step 1, stepwise logistic regression models including only clinical predictors were used to estimate the risks. In step 2, risk estimates were updated for statistically relevant intermediate risk percentiles with nephropathology. RESULTS: Step 1 revealed an increased risk of DGF with increased cold ischaemia time, donor and recipient BMI, dialysis vintage, number of HLA-DR mismatches or recipient CMV IgG positivity. On the training and validation set, c-statistics were 0.672 and 0.704, respectively. At a range between 18% and 36%, accuracy of DGF-prognostication improved with nephropathology including number of glomeruli and Banff cv (updated overall c statistics of 0.696 and 0.701, respectively).Risk of 1y-tl increased in recipients with cold ischaemia time, sum of HLA-A. -B, -DR mismatches and donor age. On training and validation sets, c-statistics were 0.700 and 0.769, respectively. Accuracy of 1y-tl prediction improved (c-statistics = 0.706 and 0.765) with Banff ct. Overall, calibration was good on the training, but moderate on the validation set; discrimination was at least as good as established scores when applied to the validation set. CONCLUSION: Our flexible 2-Step Scores with optional inclusion of time-consuming and often unavailable nephropathology should yield good results for clinical practice in ET, and may be superior to established scores. Our scores are adaptable to donation after cardiac death and perfusion pump use.

Declined Organs for Liver Transplantation: A Right Decision or a Missed Opportunity for Patients with Hepatocellular Carcinoma?

BACKGROUND: Liver transplantation is the only promising treatment for end-stage liver disease and patients with hepatocellular carcinoma. However, too many organs are rejected for transplantation. METHODS: We analyzed the factors involved in organ allocation in our transplant center and reviewed all livers that were declined for transplantation. Reasons for declining organs for transplantation were categorized as major extended donor criteria (maEDC), size mismatch and vascular problems, medical reasons and risk of disease transmission, and other reasons. The fate of the declined organs was analyzed. RESULTS: 1086 declined organs were offered 1200 times. A total of 31% of the livers were declined because of maEDC, 35.5% because of size mismatch and vascular problems, 15.8% because of medical reasons and risk of disease transmission, and 20.7% because of other reasons. A total of 40% of the declined organs were allocated and transplanted. A total of 50% of the organs were completely discarded, and significantly more of these grafts had maEDC than grafts that were eventually allocated (37.5% vs. 17.7%, p < 0.001). CONCLUSION: Most organs were declined because of poor organ quality. Donor-recipient matching at time of allocation and organ preservation must be improved by allocating maEDC grafts using individualized algorithms that avoid high-risk donor-recipient combinations and unnecessary organ declination.

[Impact of the SARS-CoV-2 Pandemic on Liver Surgery and Liver Transplantations in Germany]. / Einfluss der Coronapandemie auf die Leberchirurgie und Lebertransplantationen in Deutschland.

BACKGROUND: The SARS-CoV-2 pandemic has led to restrictions in surgical care worldwide and therefore also posed new challenges to liver surgery. The respective procedures often entail high perioperative risks and resource requirements. However, the indication for liver surgery is frequently without alternatives. To date, there is little knowledge about the impact of the pandemic on liver surgery in Germany. METHODS: A retrospective data analysis of liver surgery procedures in Germany as well as transplantations was conducted. Evaluations were based on procedure codes recorded between 2010 and 2020 according to diagnosis-related groups (DRG) by the Federal Statistical Office of Germany (Destatis) and data from the German Organ Procurement Organization (Deutsche Stiftung Organtransplantation; DSO). RESULTS: According to DRG procedure codes relating to liver surgery recorded between 2010 and 2020 in Germany, the annual fluctuation for the first year of the pandemic 2020 remained comparable to previous years. Furthermore, the development of post-mortem liver transplantations as well as living liver donations remained stable in Germany in 2020 and 2021. CONCLUSIONS: The number of liver surgery procedures in Germany was subject to a dynamic development until 2020, without apparent changes in the first year of the SARS-CoV-2 pandemic. The most frequently performed liver procedures, as well as liver transplantations, remained stable with respect to their annually recorded numbers. Publication of data regarding procedures in liver surgery and transplantation in 2021 need to be awaited and analyzed to evaluate whether the observations presented in this article prove stable any further.

[Education of Abdominal Organ Procurement Surgeons in Germany - Challenges and Possible Solutions]. / Ausbildung von Entnahmechirurgen abdomineller Organe in Deutschland ­ Herausforderungen und Lösungsansätze.

The procurement of abdominal organs is a highly specialised operation, which marks the first important step for a successful transplantation. The article gives an overview of the organisation and the current state of the education of procurement surgeons in Germany. We comment on current challenges and discuss these in an international context.

[Declined Liver Grafts - Analysis of the German Donor Population from 2010 to 2018]. / Nicht transplantierte Spenderorgane ­ eine bundesweite Auswertung aller Organangebote für die Lebertransplantation von 2010 bis 2018.

BACKGROUND: The lack of suitable allografts limits the availability of liver transplantation in Germany. The quality of potentially available German donor livers has to date not been analyzed. METHODS: Analysis of all donors for potential liver transplantations reported to the Eurotransplant by the German Organ Transplantation Foundation from 2010 to 2018. Categorization of transplanted and discarded organs utilizing available histopathological reports and predefined extended criteria for organ donation. RESULTS: A total of 8594 livers were offered for transplantation, of which 15.2 % were discarded. During the analysis period the proportion of donor livers from extended criteria donors increased from 65 % to 70 % (p = 0.005). In 2018, 21.3 % of offered donor livers were discarded, more than half (56.4 %) of these organs came from donors meeting multiple extended criteria. Livers were significantly more likely to be not transplanted, when from donors of older age (> 65 years; 41 vs. 28 %), BMI > 30 kg/m2 (29 vs. 14 %) or elevated transaminase levels (all p < 0,001). CONCLUSION: Despite the consistent organ scarcity in Germany, a relevant amount of livers cannot be transplanted due to a multitude of organ quality limitations. This should stimulate the search for concepts such as normothermic ex vivo machine perfusion to evaluate, protect and potentially improve organ quality.

Expanding pancreas donor pool by evaluation of unallocated organs after brain death: Study protocol clinical trial (SPIRIT Compliant).

BACKGROUND: Pancreas graft quality directly affects morbidity and mortality rates after pancreas transplantation (PTx). The criteria for pancreas graft allocation are restricted, which has decreased the number of available organs. Suitable pancreatic allografts are selected based on donor demographics, medical history, and the transplant surgeon's assessment of organ quality during procurement. Quality is assessed based on macroscopic appearance, which is biased by individual experience and personal skills. Therefore, we aim to assess the histopathological quality of unallocated pancreas organs to determine how many unallocated organs are potentially of suitable quality for PTx. METHODS AND ANALYSIS: This is a multicenter cross-sectional explorative study. The demographic data and medical history of donor and cause of rejection of the allocation of graft will be recorded. Organs of included donors will be explanted and macroscopic features such as weight, color, size, and stiffness will be recorded by 2 independent transplant surgeons. A tissue sample of the organ will be fixed for further microscopic assessments. Histopathologic assessments will be performed as soon as a biopsy can be obtained. We will evaluate up to 100 pancreata in this study. RESULT: This study will evaluate the histopathological quality of unallocated pancreas organs from brain-dead donors to determine how many of these unallocated organs were potentially suitable for transplantation based on a histopathologic evaluation of organ quality. CONCLUSION: The comprehensive findings of this study could help to increase the pancreas graft pool, overcome organ shortage, reduce the waiting time, and also increase the number of PTx in the future. Registration number: ClinicalTrials.gov: NCT04127266.

German recommendations for pretransplantation donor kidney biopsies.

PURPOSE: This manuscript reviews the data about the histopathologic and develops recommendations to standardise and improve the biopsy procedure, the biopsy handling, the histopathological evaluation, the communication of results and the collection of data from pretransplantation kidney biopsies of deceased donors in Germany. METHODS: The recommendations are based on this literature review, on discussions at two workshops held by the German Society of Pathology and the German Organ Transplantation Foundation and on personal experiences of the authors. RESULTS: These German recommendations advocate the use of punch biopsies, paraffin embedding and detailed descriptive reporting of histopathological findings. CONCLUSIONS: These recommendations constitute only a starting point. Periodical revisions will help to simplify and optimise the recommendations with the ultimate goal to prospectively gather data for the elaboration of a computer-based algorithm that allows the exact prediction of transplantation outcome for a given match of donor and recipient.

Influence of Deceased Donor and Pretransplant Recipient Parameters on Early Overall Kidney Graft-Survival in Germany.

Background. Scarcity of grafts for kidney transplantation (KTX) caused an increased consideration of deceased donors with substantial risk factors. There is no agreement on which ones are detrimental for overall graft-survival. Therefore, we investigated in a nationwide multicentre study the impact of donor and recipient related risks known before KTX on graft-survival based on the original data used for allocation and graft acceptance. Methods. A nationwide deidentified multicenter study-database was created of data concerning kidneys donated and transplanted in Germany between 2006 and 2008 as provided by the national organ procurement organization (Deutsche Stiftung Organtransplantation) and BQS Institute. Multiple Cox regression (significance level 5%, hazard ratio [95% CI]) was conducted (n = 4411, isolated KTX). Results. Risk factors associated with graft-survival were donor age (1.020 [1.013-1.027] per year), donor size (0.985 [0.977-0.993] per cm), donor's creatinine at admission (1.002 [1.001-1.004] per µmol/L), donor treatment with catecholamine (0.757 [0.635-0.901]), and reduced graft-quality at procurement (1.549 [1.217-1.973]), as well as recipient age (1.012 [1.003-1.021] per year), actual panel reactive antibodies (1.007 [1.002-1.011] per percent), retransplantation (1.850 [1.484-2.306]), recipient's cardiovascular comorbidity (1.436 [1.212-1.701]), and use of IL2-receptor antibodies for induction (0.741 [0.619-0.887]). Conclusion. Some donor characteristics persist to impact graft-survival (e.g., age) while the effect of others could be mitigated by elaborate donor-recipient match and care.

Poor organ quality and donor-recipient age mismatch rather than poor donation rates account for the decrease in deceased kidney transplantation rates in a Germany Transplant Center.

Kidney transplantation is limited not by technical or immunological challenges but by lack of donor organs. Whereas the number of patients on waiting list increased, the transplantation rate decreased. We analyzed the development of decline rates and reasons as well as the fate of declined organs. In total, 1403 organs offered to 1950 patients between 2001 and 2010 were included. Of 440 organs offered between 2009 and 2011 that were declined, we investigated whether these organs were transplanted elsewhere and requested delayed graft function, creatinine, graft and patient survival. Data were compared to results of transplantations at the same time at our center. Decline rate increased from 47% to 87%. Main reasons were poor organ quality and donor-recipient age or size mismatch. Of the rejected organs, 55% were transplanted at other centers with function, graft and patient survival equivalent to patients transplanted at our center during that period. The number of decline has increased over time mainly due to a growing number of marginal donors accounting for poor organ quality or a mismatch of donor and recipient. If proper donor-recipient selection is performed, many organs that would otherwise be discarded can be transplanted successfully.

Aorto-hepatic bypass in liver transplantation in the MELD-era: outcomes after supraceliac and infrarenal bypasses.

PURPOSE: Poor arterial inflow during orthotopic liver transplantation (OLT) may necessitate arterial revascularisation using aorto-hepatic bypasses with supraceliac (SC) or infrarenal (IR) allografts. This study compared both techniques focusing on the patients' preoperative conditions, postoperative graft/organ function, complications and survival. METHODS: Fifteen out of 114 OLT patients underwent revascularisation (7 IR/8 SC) between 2005 and 2008 and were included in the study. The patients' records were reviewed retrospectively. RESULTS: IR patients presented with a higher BMI, received more male donor organs and their reperfusion sequence was predominately portal venous (SC: primary arterial). SC patients presented a significantly worse preoperative creatinine clearance and a trend towards a higher MELD score. The postoperative graft/organ function, morbidity and mortality did not differ between the groups despite a trend towards a worse survival in the SC group. A deteriorated preoperative creatinine clearance and higher MELD score negatively impacted the survival. Postoperative bleeding episodes and major re-interventions also affected the outcome. CONCLUSIONS: We found no evidence for superiority of either bypass technique in our OLT patients. The trend toward a worse survival in SC patients was most likely caused by the worse preoperative conditions of these patients and highlights the importance of the impact of the MELD score on the outcome after OLT.

Pancreatoduodenectomy--current status of surgical and perioperative techniques in Germany.

BACKGROUND: Pancreatoduodenectomy in Germany is performed by a broad range of hospitals. A diversity of operative techniques is employed as no guidelines exist for intra- and perioperative management. We carried out a national survey to determine the de facto German standards for pancreatoduodenectomy, assess quality assurance measures, and identify relevant issues for further investigation. METHODS: A questionnaire evaluating major outcome variables, case load, preferred surgical procedures, and perioperative management during pancreatoduodenectomy was developed and sent to 211 German hospitals performing >12 pancreatoduodenectomies per year (requirement for certification as a pancreas center). Statistical analysis was carried out using the Fisher Exact, Mann-Whitney U, and Spearman tests. RESULTS: The final response rate was 86 % (182/211). The preferred technique and de facto German standard for pancreatoduodenectomy was pylorus-preserving pancreatoduodenectomy with pancreatojejunostomy carried out via duct-to-mucosa anastomosis with interrupted sutures using PDS 4.0. The minority of German pancreas centers were certified (18-48 %). The certification rate increased with higher capacity levels and case load (P < 0.05); however, significant correlations between the fistula rate and hospital case load, hospital capacity level, or hospital certification status were not seen. CONCLUSION: This study revealed a distinct variety of management strategies for pancreatic surgery and available evidence-based data was not necessarily translated into clinical practice. The limited certification rate represented a shortcoming of quality assurance. The data emphasize the need for further trials to answer the questions whether hospital certifications and omission of drains improve outcome after pancreatoduodenectomy and for the establishment of guidelines for pancreatoduodenectomy.

Impact of failed allograft nephrectomy on initial function and graft survival after kidney retransplantation.

The management of an asymptomatic failed renal graft remains controversial. The aim of our study was to explore the effect of failed allograft nephrectomy on kidney retransplantation by comparing the outcome of recipients who underwent graft nephrectomy prior to retransplantation with those who did not. Retrospective comparison of patients undergoing kidney retransplantation with (group A, n = 121) and without (group B, n = 45) preliminary nephrectomy was performed, including subgroup analysis with reference to patients with multiple (≥2) retransplantations and patients of the European Senior Program (ESP). Nephrectomy leads to increased panel reactive antibody (PRA) levels prior to retransplantation and is associated with significantly increased rates of primary nonfunction (PNF; P = 0.05) and acute rejection (P = 0.04). Overall graft survival after retransplantation was significantly worse in group A compared with group B (P = 0.03). Among the subgroups especially ESP patients showed a shorter graft survival after previous allograft nephrectomy. On the multivariate analysis, pretransplant graft nephrectomy and PRA >70% were independent and significant risk factors associated with graft loss after kidney retransplantation. Nephrectomy of the failed allograft was not beneficial for retransplant outcome in our series. Patients with failed graft nephrectomy tended to have a higher risk of PNF and acute rejection after retransplantation. The possibility that the graft nephrectomy has a negative impact on graft function and survival after retransplantation is worth studying further.

Analyzing miRNAs in ductal adenocarcinomas of the pancreas.

BACKGROUND: MicroRNAs (miRNAs) have gained attention as an epigenetic component involved in the development of pancreatic ductal adenocarcinoma (PDAC). Several methods for miRNA profiling are in common use, but the validity of these methods is not defined. The aim of this study was to define the optimal method for miRNA detection in PDAC. METHODS: miRNA expression was determined using different and partially redundant methods (miRNA microarray, TaqMan low density array (TLDA), single tube quantitative RT-PCR). The data from different methods were statistically evaluated and tested for intermethodic consistency and reliability of the results. Finally, the miRNA expression status and the cell lines' ability to metastasize were correlated. RESULTS: Comparing low and high metastatic cells, miRNA-microarrays identified fewer differentially expressed and only upregulated miRNAs (n=27; 27 up-regulated) compared with TLDAs (n=54; 19 up- and 35 down-regulated). Evaluating miRNAs that target tumor suppressor genes, expression of all single tube quantitative real-time reverse transcriptase PCR (qRT-PCR) validated miRNAs was detected to be significantly altered in TLDA analysis (100%). MiRNA microarrays detected only 25% of qRT-PCR validated miRNAs. Furthermore, results from TLDA analysis correlated well with data from qRT-PCR and presented ΔΔCt values from 3.5±1.86 (range 0.8-5.62) compared with 3.74±1.86 (range 0.78-5.95) in qRT-PCR. CONCLUSION: Notable differences comparing data obtained from different screening methods were found. While TLDA and qRT-PCR correlated well in quantity and quality of the measured miRNAs, several tumor suppressor gene targeting and down-regulated miRNAs were not detected by miRNA-microarrays. This heterogeneity shows that care must be exercised when comparing results from different methods in PDAC.

Role of tumor microenvironment on gene expression in pancreatic cancer tumor models.

OBJECTIVES: The microenvironment is known to be a relevant factor of influence on tumor growth and metastasis in pancreatic ductal adenocarcinoma (PDAC). To determine the influence of the microenvironment on changes in gene expression, we analyzed gene expression in different PDAC tissues. METHODS: Four human PDAC cell lines were introduced into a murine PDAC model with two insertion techniques: injection and implantation. Gene expression profiles of the cell lines growing in vitro and in vivo (ectopically and orthotopically) were established by microarray and validated by RT-PCR. RESULTS: Significant differences were found in the gene expression profiles of the in vitro versus in vivo tissues (P < 0.05), while no differences were found between the in vivo tissues. Analyzing the orthotopic tumors derived from the injection and implantation methods, similar gene expression patterns with 0%-18% significantly differentially expressed genes between tumors of the two different methods were observed (analysis of variance [ANOVA]; P < 0.0001). CONCLUSIONS: Gene expression from cell lines growing in vitro differed from the expression patterns of the same cells growing in vivo, while the localization of the growing tumor cells did not significantly alter gene expression. These data demonstrate that the implantation and injection techniques used in this study yield similar results and may be compared with each other.

EP300--a miRNA-regulated metastasis suppressor gene in ductal adenocarcinomas of the pancreas.

Genetic and epigenetic alterations during development of pancreatic ductal adenocarcinomas (PDACs) are well known. This study investigates genetic and epigenetic data together with tumor biology to find specific alterations responsible for metastasis formation. Using 16 human PDAC cell lines in a murine orthotopic PDAC model, local infiltration and metastatic spread were assessed by standardized dissemination scores. The cell lines were further classified into 3 hierarchical groups according to their metastatic potential. Their mRNA and microRNA (miRNA) expression was profiled via mRNA-microarray as well as Taqman Low Density Array, and validated by single quantitative RT-PCR and Western blotting. In the highly metastatic group, a significant induction of EP300 targeting miRNAs miR-194 (fold change: 26.88), miR-200b (fold change: 61.65), miR-200c (fold change: 19.44) and miR-429 (fold change: 21.67) (p < 0.05) was detected. Corresponding to this, decreased expression of EP300 mRNA (p < 0.0001) and protein (p < 0.05) were detected in the highly metastatic PDAC cell lines with liver metastases compared to the nonmetastatic or marginally metastatic cell lines, while no correlation with local tumor growth was found. In conclusion, epigenetic alterations with upregulated EP300 targeting miRNAs miR-194, miR-200b, miR-200c and miR-429 are related to reduced EP300 mRNA and protein in PDAC. These results demonstrate that miRNAs might be able to modulate the expression of metastasis-specific suppressor genes and metastatic behavior in PDAC, suggesting diagnostic and therapeutic opportunities for EP300 and its targeting miRNAs in PDAC.

Involvement of CD40 targeting miR-224 and miR-486 on the progression of pancreatic ductal adenocarcinomas.

BACKGROUND: Genetic and epigenetic alterations during development of pancreatic ductal adenocarcinomas (PDAC) are well known. Genetic and epigenetic data were correlated with tumor biology to find specific alterations responsible for invasion and metastasis in pancreatic ductal adenocarcinomas. METHODS: A total of 16 human PDAC cell lines were used in murine orthotopic PDAC models. By means of standardized dissemination scores, local invasion and metastatic spread were assessed. mRNA and microRNA expression were studied by microarray and TaqMan low-density array. Quantitative real-time-polymerase chain reaction and flow cytometry were used for expression validation. RESULTS: CD40 was detected as a relevant target gene for differentially expressed miRNAs observed in highly invasive and metastatic PDAC only. A significant overexpression (P < .05) of CD40-related miRNAs miR-224 and miR-486 was detected in highly invasive and metastatic PDAC, whereas CD40 mRNA expression was not significantly altered. Instead, CD40 protein expression at cell surfaces of these highly invasive and metastatic PDAC was significantly reduced (P < .01). CONCLUSIONS: Epigenetic alterations with upregulated CD40-targeting miR-224 and miR-486 are related to downregulated CD40 protein expression at cell surfaces in highly invasive and metastatic PDAC. Thus, miRNA-regulated CD40 expression seems to play an important role in progression of PDAC. These data suggest a diagnostic and therapeutic potential for CD40 and/or its targeting miRNAs in PDAC.