Steve White

Pancreatectomy with islet autotransplantation for the treatment of severe chronic pancreatitis: the first 40 patients at the leicester general hospital.

Background. Surgical resection of the pancreas is considered a final resort in the treatment of chronic pancreatitis. However, the opportunity to perform an islet autotransplant at the same time provides the potential to prevent the onset of diabetes. Methods. Pancreatectomy together with islet autotransplantation has been offered in our center since 1994. A total of 40 patients have now undergone this procedure. The follow‐up times range from 6 months to 7 years. The data presented here include the annual postoperative oral glucose tolerance test and glycosylated hemoglobin (HbA1c) results, together with insulin and opiate requirements. Results. Nineteen male and 21 female patients (median age 44, range 21‐65) have been transplanted. Pancreatitis was related to alcohol in 45% and was idiopathic in 40%. A median of 130,108 (24,332‐1, 165,538) islet equivalent (IEQ) were transplanted, which related to 2,020 (320‐23,311) IEQ per kilogram of body weight. At 2 years posttransplant, 18 patients had a median HbA1c of 6.6% (5.2‐19.3%), fasting C‐peptide of 0.66 ng/mL (0.26‐2.65 ng/mL), and required a median of 12 (0‐45) units of insulin per day. At 6 years, these figures were 8% (6.1‐11.1%), 1.68 ng/mL (0.9‐2.78 ng/ml) and 43 U/day (6‐86 U/day), respectively. The majority of patients no longer require opiate analgesia, 68% have been able to return to work, and one patient has had a baby. Conclusions. Islet autotransplantation offers a valuable addition to surgical resection of the pancreas, as a treatment for chronic pancreatitis; and even in cases in which insulin independence is not achieved, the potential beneficial effects of C‐peptide make the procedure worthwhile.

A case-control comparison of the results of renal transplantation from heart-beating and non-heart-beating donors.

Introduction. The decline in heart-beating brainstem dead organ donors has necessitated the search for other organ sources. In the field of renal transplantation one alternative source currently available, but little used, is that of kidneys from non-heart-beating donors (NHBD). Reticence to use NHBD kidneys is in part due to concerns over the effect that warm ischemic may have subsequent graft function. Presented here are the results of the NHBD renal transplants at the Leicester transplant unit, and compared with matched heart-beating donor transplants as a case control analysis. Methods. In order to analyze any differences in graft performance between the two organ sources, the confounding effect of other variables known to influence the outcome of renal transplantation was minimized by matching NHBD and HBD transplants for the following criteria: donor age and sex, first or re-transplant, anastomosis and cold times, tissue match and PRA sensitisation. Transplant performance was assessed primarily by graft survival, the statistical evaluation of which was by log rank analysis of Kaplan-Meier curves. Results. 72 NHBD and 192 HBD transplants were performed over an eight year period. Of the 192 HBD transplants, 105 matched one or more of the NHBD by the criteria outlined above, and thus constituted the control group for comparison. There was no significant difference in overall graft survival between the two groups. The 5 year survival for the NHBD was 73% compared with 65% for HBD kidneys. When death with a functioning graft is treated as censored data, then these figures become 75% and 81% respectively, again without statistical significance. Conclusion. NHBD kidneys are a valuable additional source of organs for transplantation, with long-term survival, comparable to transplants from HBD.

Differential DNA methylation of genes involved in fibrosis progression in non-alcoholic fatty liver disease and alcoholic liver disease.

BackgroundChronic liver injury can lead to the development of liver fibrosis and cirrhosis but only in a minority of patients. Currently, it is not clear which factors determine progression to fibrosis. We investigated whether DNA\methylation profile as determined by pyrosequencing can distinguish patients with mild from those with advanced/severe fibrosis in non-alcoholic liver disease (NAFLD) and alcoholic liver disease (ALD). To this end, paraffin-embedded liver biopsies were collected from patients with biopsy-proven NAFLD or ALD, as well as paraffin-embedded normal liver resections, genomic DNA isolated, bisulfite converted and pyrosequencing assays used to quantify DNA methylation at specific CpGs within PPARα, PPARα, TGFβ1, Collagen 1A1 and PDGFα genes. Furthermore, we assessed the impact of age, gender and anatomical location within the liver on patterns of DNA methylation in the same panel of genes.ResultsDNA methylation at specific CpGs within genes known to affect fibrogenesis distinguishes between patients with mild from those with severe fibrosis in both NAFLD and ALD, although same CpGs are not equally represented in both etiologies. In normal liver, age, gender or anatomical location had no significant impact on DNA methylation patterns in the liver.ConclusionsDNA methylation status at specific CpGs may be useful as part of a wider set of patient data for predicting progression to liver fibrosis.

Plasma DNA methylation: a potential biomarker for stratification of liver fibrosis in non-alcoholic fatty liver disease

Objective Liver biopsy is currently the most reliable way of evaluating liver fibrosis in patients with non-alcoholic fatty liver disease (NAFLD). Its inherent risks limit its widespread use. Differential liver DNA methylation of peroxisome proliferator-activated receptor gamma (PPARγ) gene promoter has recently been shown to stratify patients in terms of fibrosis severity but requires access to liver tissue. The aim of this study was to assess whether DNA methylation of circulating DNA could be detected in human plasma and potentially used to stratify liver fibrosis severity in patients with NAFLD. Design Patients with biopsy-proven NAFLD and age-matched controls were recruited from the liver and gastroenterology clinics at the Newcastle upon Tyne Hospitals NHS Foundation Trust. Plasma cell-free circulating DNA methylation of PPARγ was quantitatively assessed by pyrosequencing. Liver DNA methylation was quantitatively assessed by pyrosequencing NAFLD explant tissue, subjected to laser capture microdissection (LCM). Patients with alcoholic liver disease (ALD) were also subjected to plasma DNA and LCM pyrosequencing. Results 26 patients with biopsy-proven NAFLD were included. Quantitative plasma DNA methylation of PPARγ stratified patients into mild (Kleiner 1–2) and severe (Kleiner 3–4) fibrosis (CpG1: 63% vs 86%, p<0.05; CpG2: 51% vs 65% p>0.05). Hypermethylation at the PPARγ promoter of plasma DNA correlated with changes in hepatocellular rather than myofibroblast DNA methylation. Similar results were demonstrated in patients with ALD cirrhosis. Conclusions Differential DNA methylation at the PPARγ promoter can be detected within the pool of cell-free DNA of human plasma. With further validation, plasma DNA methylation of PPARγ could potentially be used to non-invasively stratify liver fibrosis severity in patients with NAFLD. Plasma DNA methylation signatures reflect the molecular pathology associated with fibrotic liver disease.

Expression of Mesenchymal and α-Cell Phenotypic Markers in Islet β-Cells in Recently Diagnosed Diabetes

OBJECTIVE Relative contributions of reversible β-cell dysfunction and true decrease in β-cell mass in type 2 diabetes remain unclear. Definitive rodent lineage-tracing studies have identified β-cell dedifferentiation and subsequent reprogramming to α-cell fate as a novel mechanism underlying β-cell failure. The aim was to determine whether phenotypes of β-cell dedifferentiation and plasticity are present in human diabetes. RESEARCH DESIGN AND METHODS Immunofluorescence colocalization studies using classical endocrine and mesenchymal phenotypic markers were undertaken using pancreatic sections and isolated islets from three individuals with diabetes and five nondiabetic control subjects. RESULTS Intraislet cytoplasmic coexpression of insulin and vimentin, insulin and glucagon, and vimentin and glucagon were demonstrated in all cases. These phenotypes were not present in nondiabetic control subjects. CONCLUSIONS Coexpression of mesenchymal and α-cell phenotypic markers in human diabetic islet β-cells has been confirmed, providing circumstantial evidence for β-cell dedifferentiation and possible reprogramming to α-cells in clinical diabetes.

Alcohol directly stimulates epigenetic modifications in hepatic stellate cells.

BACKGROUND & AIMS Alcohol is a primary cause of liver disease and an important co-morbidity factor in other causes of liver disease. A common feature of progressive liver disease is fibrosis, which results from the net deposition of fibril-forming extracellular matrix (ECM). The hepatic stellate cell (HSC) is widely considered to be the major cellular source of fibrotic ECM. We determined if HSCs are responsive to direct stimulation by alcohol. METHODS HSCs undergoing transdifferentiation were incubated with ethanol and expression of fibrogenic genes and epigenetic regulators was measured. Mechanisms responsible for recorded changes were investigated using ChIP-Seq and bioinformatics analysis. Ethanol induced changes were confirmed using HSCs isolated from a mouse alcohol model and from ALD patients liver and through precision cut liver slices. RESULTS HSCs responded to ethanol exposure by increasing profibrogenic and ECM gene expression including elastin. Ethanol induced an altered expression of multiple epigenetic regulators, indicative of a potential to modulate chromatin structure during HSC transdifferentiation. MLL1, a histone 3 lysine 4 (H3K4) methyltransferase, was induced by ethanol and recruited to the elastin gene promoter where it was associated with enriched H3K4me3, a mark of active chromatin. Chromatin immunoprecipitation sequencing (ChIPseq) revealed that ethanol has broad effects on the HSC epigenome and identified 41 gene loci at which both MML1 and its H3K4me3 mark were enriched in response to ethanol. CONCLUSIONS Ethanol directly influences HSC transdifferentiation by stimulating global changes in chromatin structure, resulting in the increased expression of ECM proteins. The ability of alcohol to remodel the epigenome during HSC transdifferentiation provides mechanisms for it to act as a co-morbidity factor in liver disease.

Successful Treatment of De Novo Posttransplant Thrombotic Microangiopathy With Eculizumab

Atypical hemolytic uremic syndrome (aHUS) is a disease characterized by complement hyperactivation secondary to defects in complement genes and acquired autoantibodies against complement regulatory proteins (1). The clinical features include thrombotic microangiopathy (TMA), hemolytic anemia, thromb

Prognostic factors and survival after resection of colorectal liver metastasis in the era of preoperative chemotherapy: an 11-year single-centre study.

Introduction: A variety of factors have been identified in the literature which influence survival following resection of colorectal liver metastases (CRLM). Much of this literature is historical, and its relevance to contemporary practice is not known. The aim of this study was to identify those factors which influence survival during the era of preoperative chemotherapy in patients undergoing resection of CRLM in a UK centre. Methods: All patients having liver resection for CRLM during an 11-year period up to 2011 were identified from a prospectively maintained database. Prognostic factors analysed included tumour size (≥5 or <5 cm), lymph node status of the primary tumour, margin positivity (R1; <1 mm), neo-adjuvant chemotherapy (for liver), tumour differentiation, number of liver metastases (≥4), preoperative carcinoembryonic antigen (CEA; ≥200 ng/ml) and whether metastases were synchronous (i.e. diagnosed within 12 months of colorectal resection) or metachronous to the primary tumour. Overall survival (OS) was compared using Kaplan-Meier plots and a log rank test for significance. Multivariate analysis was performed using a Cox regression model. Statistical analysis was performed in SPSS v19, and p < 0.05 was considered to be significant. Results: 432 patients underwent resection of CRLM during this period (67% male; mean age 64.5 years), and of these, 54 (13.5%) had re-resections. The overall 5-year survival in this series was 43% with an actuarial 10-year survival of 40%. A preoperative CEA ≥200 ng/ml was present in 10% of patients and was associated with a poorer 5-year OS (24 vs. 45%; p < 0.001). A positive resection margin <1 mm was present in 16% of patients, and this had a negative impact on 5-year OS (15 vs. 47%; p < 0.001). Tumour differentiation, number, biliary or vascular invasion, size, relationship to primary disease, nodal status of the primary disease or the use of neo-adjuvant chemotherapy had no impact on OS. Multivariate analysis identified only the presence of a positive resection margin (OR 1.75; p < 0.05) and a preoperative CEA ≥200 ng/ml (OR 1.88; p < 0.01) as independent predictors of poor OS. Conclusion: Despite the wide variety of prognostic factors reported in the literature, this study was only able to identify a preoperative CEA ≥200 ng/ml and the presence of tumour within 1 mm of the resection margin as being of value in predicting survival. These variables are likely to identify patients who may benefit from intensive follow-up to enable early aggressive treatment of recurrent disease.

Preservation of the donor pancreas for whole pancreas and islet transplantation

Ridgway D, Manas D, Shaw J, White S. Preservation of the donor pancreas for whole pancreas and islet transplantation.
Clin Transplant 2010: 24: 1–19.

The role of pancreatic stellate cells in pancreatic cancer

BACKGROUND The prognosis of pancreatic cancer remains desperately poor, with little progress made over the past 30 years despite the development of new combination chemotherapy regimens. Stromal activity is especially prominent in the tissue surrounding pancreatic tumours, and has a profound influence in dictating tumour development and dissemination. Pancreatic stellate cells (PaSCs) have a key role in this tumour microenvironment, and have been the subject of much research in the past decade. This review examines the relationship between PaSCs and cancer cells. METHODS A comprehensive literature search was performed of multiple databases up to March 2014, including Medline, Pubmed and Google Scholar. RESULTS A complex bidirectional interplay exists between PaSCs and cancer cells, resulting in a perpetuating loop of increased activity and an overriding pro-tumorigenic effect. This involves a number of signalling pathways that also impacts on other stromal components and vasculature, contributing to chemoresistance. The Reverse Warburg Effect is also introduced as a novel concept in tumour stroma. CONCLUSION This review highlights the pancreatic tumour microenvironment, and in particular PaSCs, as an ideal target for therapeutics. There are a number of cellular processes involving PaSCs which could hold the key to more effectively treating pancreatic cancer. The feasibility of targeting these pathways warrant further in depth investigation, with the aim of reducing the aggressiveness of pancreatic cancer and improving chemodelivery.