Stephen R. Munn

Sequential Changes in the Metabolic Response to Orthotopic Liver Transplantation During the First Year After Surgery

ObjectiveTo quantify the sequential changes in the metabolic response occurring in patients with end-stage liver disease after orthotopic liver transplantation (OLT). Summary Background DataDetailed quantification of the changes in energy expenditure, body composition, and physiologic function that occur in patients after OLT has not been performed. Understanding these changes is essential for the optimal management of these patients. MethodsFourteen patients who underwent OLT for end-stage liver disease had measurements of resting energy expenditure, body composition, and physiologic function immediately before surgery and 5, 10, 15, 30, 90, 180, and 360 days later. ResultsResting energy expenditure was significantly elevated after surgery (24% above predicted), peaking around day 10 after OLT, when it averaged 42% above predicted. A significant degree of hypermetabolism was still present at 6 months, but at 12 months measured resting energy expenditure was close to predicted values. Before surgery, measured total body protein was 82% of estimated preillness total body protein. During the first 10 days after OLT, a further 1.0 kg (10%) of total body protein was lost, mostly from skeletal muscle. Only 54% of this loss was restored by 12 months. Significant overhydration of the fat-free body was seen before OLT, and it was still present 12 months later. Although significant losses of body fat and bone mineral occurred during the early postoperative period, only body fat stores were restored at 12 months. Both subjective fatigue score and voluntary hand grip strength improved rapidly after OLT to exceed preoperative levels at 3 months. At 12 months grip strength was close to values predicted for these patients when well. Respiratory muscle strength improved less markedly and was significantly lower than predicted normal levels at 12 months. ConclusionsBefore surgery, these patients were significantly protein-depleted, overhydrated, and hypermetabolic. After surgery, the period of hypermetabolism was prolonged, restoration of body protein stores was gradual and incomplete, and respiratory muscle strength failed to reach expected normal values. Our measurements indicate that OLT does not normalize body composition and function and imply that a continuing metabolic stress persists for at least 12 months after surgery.

Associations between HLA Class I Alleles and Escape Mutations in the Hepatitis B Virus Core Gene in New Zealand-Resident Tongans

ABSTRACT The full repertoire of hepatitis B virus (HBV) peptides that bind to the common HLA class I molecules found in areas with a high prevalence of chronic HBV infection has not been determined. This information may be useful for designing immunotherapies for chronic hepatitis B. We identified amino acid residues under positive selection pressure in the HBV core gene by phylogenetic analysis of cloned DNA sequences obtained from HBV DNA extracted from the sera of Tongan subjects with inactive, HBeAg-negative chronic HBV infections. The repertoires of positively selected sites in groups of subjects who were homozygous for either HLA-B*4001 (n = 10) or HLA-B*5602 (n = 7) were compared. We identified 13 amino acid sites under positive selection pressure. A significant association between an HLA class I allele and the presence of nonsynonymous mutations was found at five of these sites. HLA-B*4001 was associated with mutations at E77 (P = 0.05) and E113 (P = 0.002), and HLA-B*5602 was associated with mutations at S21 (P = 0.02). In addition, amino acid mutations at V13 (P = 0.03) and E14 (P = 0.01) were more common in the seven subjects with an HLA-A*02 allele. In summary, we have developed an assay that can identify associations between HLA class I alleles and HBV core gene amino acids that mutate in response to selection pressure. This is consistent with published evidence that CD8+ T cells have a role in suppressing viral replication in inactive, HBeAg-negative chronic HBV infection. This assay may be useful for identifying the clinically significant HBV peptides that bind to common HLA class I molecules.

Biliary complications following orthotopic liver transplantation: a 10-year audit

BACKGROUND Biliary complications following liver transplantation result in major morbidity. We undertook a 10-year audit of the incidence, management and outcomes of post-transplant biliary complications at the New Zealand Liver Transplant Unit. METHODS Prospectively collected data on 348 consecutive liver transplants performed between February 1998 and October 2008 were reviewed. The minimum follow-up was 6 months. RESULTS A total of 309 adult and 39 paediatric transplants were performed over the study period. Of these, 296 (85%) were whole liver grafts and 52 (15%) were partial liver grafts (24 split-liver, eight reduced-size and 20 live-donor grafts). There were 80 biliary complications, which included 63 (18%) strictures and 17 (5%) bile leaks. Partial graft, a paediatric recipient and a Roux-en-Y biliary anastomosis were independent predictors of biliary strictures. Twenty-five (40%) strictures were successfully managed non-operatively and 38 (60%) required surgery (31 biliary reconstructions, three segmental resections and four retransplants). Seven (41%) bile leaks required surgical revision and 10 (59%) were managed non-operatively. There was no mortality related directly to biliary complications. CONCLUSIONS Biliary complications affected one in five transplant recipients. Paediatric status, partial graft and Roux-en-Y anastomosis were independently associated with the occurrence of biliary strictures. Over half of the affected patients required surgical revision, but no mortality resulted from biliary complications.

Poorer survival in patients whose explanted hepatocellular carcinoma (HCC) exceeds Milan or UCSF Criteria. An analysis of liver transplantation in HCC in Australia and New Zealand

BACKGROUND Milan and University of California San Francisco (UCSF) Criteria have been used for selection of patients with hepatocellular carcinoma (HCC) for liver transplantation (LTx). The aims of this study were to analyse the results of LTx for HCC in Australia and New Zealand with emphasis on the effects of discordance between pre-LTx radiological and post-LTx pathological staging. METHODS A total of 186 LTx for HCC carried out between July 1985 and August 2003 were included. Patients were categorized according to the Milan and UCSF Criteria. RESULTS The median follow-up was 6.55 years (range 2.96-20.93 years). Pre-LTx factors associated with better survival include tumour size < or = 5 cm, number of tumours < or = 3, staging within Milan and UCSF Criteria and more recent transplantation (1996-2003). In all, 14 patients had a pre-LTx stage outside the Milan but within the UCSF Criteria. One- and 5-year patient survival rates were, respectively, 88% and 74% within the Milan Criteria, and 87% and 73% within the UCSF Criteria. Vascular invasion, capsular invasion, lymph node invasion and pathological stage outside UCSF Criteria were associated with poor outcome. Of patients within the Milan and UCSF Criteria pre-LTx, 24% and 18%, respectively, were outside the same criteria post-LTx. These patients had poorer survival rates. CONCLUSIONS The use of the UCSF Criteria in this cohort increased the number of patients eligible for LTx without compromising 5-year survival rates. Patients whose explant tumours were outside the Milan or UCSF Criteria had poorer outcomes compared with those whose explants remained within these criteria.

The effect of somatostatin 201-995 on the early course of porcine pancreaticoduodenal allotransplantation.

This study was undertaken to determine the effects of somatostatin 201-995 (SMS) on the maintenance dose of intravenous cyclosporine and on graft blood flow, exocrine secretion, and rejection after porcine pancreaticoduodenal allotransplantation (PDA). For seven days, 12 pigs (6 control, 6 SMS-treated) were studied to determine the effects of SMS on serum CsA concentrations. Twenty-six pigs (14 control, 12 SMS) with streptozocin-induced diabetes underwent PDA. Blood flow was measured through graft celiac and superior mesenteric arteries 15 and 60 min after reperfusion. SMS (75 micrograms s.c.) was given after the 15-min blood-flow measurement in the SMS group. Sixteen pigs (8 control, 8 SMS) were followed postoperatively with daily measurements of serum glucose and amylase concentrations, and urine amylase and trypsin activities. All pigs were immunosuppressed with azathioprine, prednisone, and i.v. CsA. SMS pigs also received SMS (75 micrograms s.c.) every 8 hr. SMS had no effect on maintenance dose of CsA or on serum amylase, urine amylase, or urine trypsin activities. Mean days to rejection were also not affected. Intraoperative graft blood flow was significantly decreased by SMS, but incidence of graft thrombosis was unchanged. These results suggest that in the porcine PDA model, SMS does not appear to inhibit exocrine secretion and potentially may adversely affect the early course of PDA by decreasing graft blood flow.

Liver transplantation in Australia and New Zealand

Liver transplantation (LT) in Australia and New Zealand began in 1985. Over this time until December 2014, LT took place in 3700 adults and 800 children. LT is regulated with 1 unit, supported by the government, per state or region. Currently approximately 270 transplants take place per year. Organ donation rates are moderate in Australia (17 per 1 million of population) but very low in New Zealand (11 per 1 million of population). All the units share organ donors for fulminant hepatic failure cases (status 1). Recipient listing criteria and organ allocation criteria are commonly agreed to via National and Trans‐Tasman agreements, which are published online. Current survival rates indicate approximately 94% 1‐year survival with median survival in adults of approximately 20 years, whereas 75% of children are alive at 20 years. All units collaborate in research projects via the Australia and New Zealand Liver Transplant Registry and have published highly cited articles particularly on the prevention of hepatitis B virus recurrence. Outcomes for indigenous populations have also been analyzed. In conclusion, LT in Australia and New Zealand is well developed with transparent processes related to criteria for listing and organ allocation together with publication of outcomes. Liver Transplantation 22 830–838 2016 AASLD.

Nature and outcomes of the increased incidence of colorectal malignancy after liver transplantation in Australasia.

Objectives: To examine whether incidence of colorectal malignancy is increased in Australasian liver transplant recipients compared with the general population of Australia, and to assess the characteristics and outcomes of colorectal malignancy in this patient group.

Genetic Diversity and Linkage Disequilibrium in the Polynesian Population of Niue Island

ABSTRACT Isolated populations that recently have been derived from small homogeneous groups of founders should have low genetic diversity and high levels of linkage disequilibrium and should be ideal for mapping ancestral polymorphisms that influence complex genetic disease susceptibility. Populations that fulfill these criteria have been difficult to identify. We have been looking for Polynesian populations with these characteristics, because Polynesians have high rates of complex genetic diseases. In Niue Islanders all ancestral female (mitochondrial HSV1 sequence) and 90.4% of ancestral male (Y-chromosome haplogroup) lineages are of Southeast Asian origin. The frequency of European Y-chromosome haplogroups is 7.2%. The diversities of mitochondrial HSV1 sequences (h = 0.18 ±0.05) and Y-chromosome haplo-groups (h = 0.18 ±0.05) are lower than values published for any other population. Ten autosomal microsatellites spaced over 5.8 cM show low allele numbers in Niue Islanders relative to Europeans (55 vs. 88 total alleles, respectively) and a modest reduction in heterozygous loci (0.71 ±0.02 vs. 0.78 ±0.02, p =0.04). The higher linkage disequilibrium (d2) between these loci in Niue Islanders relative to Europeans (p = 0.001) is negatively correlated (r = −0.47, p =0.01) with genetic distance. In summary, Niue Islanders are genetically isolated and have a homogeneous Southeast Asian ancestry. They have reduced autosomal genetic diversity and high levels of linkage disequilibrium that are consistent with the influence of genetic drift mechanisms, such as a founder effect or bottlenecks. High-powered linkage disequilibrium studies designed to map ancestral polymorphisms that influence complex genetic disease susceptibility may be feasible in this population.

The kinetics of CD154 (CD40L) expression in peripheral blood mononuclear cells of healthy subjects in liver allograft recipients and X-linked hyper-IgM syndrome.

The costimulatory pathways play a key role in T cell activation during allograft rejection (AR). Inhibition of the T cell costimulatory molecule CD154 (CD40 ligand) has been effective in producing long‐term allograft survival in rodents and non‐human primates. The role of the CD40‐CD154 pathway in human orthotopic liver transplantation (OLT) has not been examined. 
Aim: To describe the patterns of CD154, CD69 and CD152 (CTLA4) expression in OLT recipients and to determine their temporal relationship to AR. 
Methods: Peripheral blood mononuclear cells (PBMCs) were isolated from 15 OLT allograft recipients just prior to and for seven consecutive days postoperatively. Gene and protein expression of CD154, CD69 and CD154 were examined by reverse transcription‐polymerase chain reaction (RT‐PCR) and flow cytometry (FC), respectively. 
Results: FC failed to demonstrate an up‐regulation of CD154 and CD152 protein expression during the first postoperative week. Intracellular FC did not increase the sensitivity. There was an increased level of CD3+CD8+ T cells expressing CD69 at the time of rejection compared to that on day 0. RT‐PCR demonstrated a sporadic expression of CD154 and CD69 mRNA, with no correlation to episodes of acute cellular rejection. In vitro stimulation of PBMCs revealed an impaired up‐regulation of CD154 in patients receiving conventional immunosuppression compared to healthy controls. The assays were validated using positive and negative controls, including a family with X‐linked hyper‐IgM syndrome. 
Conclusion: We found no evidence of spontaneous CD154 gene or protein expression in PBMCs associated with acute rejection episodes following OLT. Immunosuppression resulted in impaired responses to ex vivo stimulation. 
Lymphocyte costimulatory pathways play a critical role in mediating acute allograft rejection. However, we found no evidence of spontaneous CD154 gene or protein expression in PBMCs associated with acute rejection episodes following OLT. Furthermore, stimulation in vitro resulted in less up‐regulation of CD154 than for healthy controls.

Evidence for reduced selection pressure on the hepatitis B virus core gene in hepatitis B e antigen-negative chronic hepatitis B

The mechanisms underlying the high levels of hepatitis B virus (HBV) replication that cause hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (e-CHB) are unknown. Impaired anti-HBV immunity, which may be measurable as a relaxation of selection pressure on the virus, is possible. A group of Tongans (n = 345) with a chronic HBV infection, including seven with e-CHB, were genotyped at HLA class I. The repertoire of HBV core-gene codons under positive selection pressure was defined by phylogenetic analysis (by using the paml program) of 708 cloned sequences extracted from the 67 of these 345 subjects with the same repertoire of HLA class I alleles as the seven e-CHB individuals and matched controls (see below). The frequency of non-synonymous mutations at these codons was measured in longitudinal data from 15 subjects. Finally, the number of non-synonymous mutations at these codons was compared in seven groups comprised of one subject with e-CHB and 1-3 HLA class I-matched controls with an inactive, HBeAg-negative chronic HBV infection (e-InD). Nineteen codons in the core gene were under positive selection pressure. There was a high frequency of new non-synonymous mutations at these codons (P<0.0001) in longitudinal data. The mean number of these 19 codons with non-synonymous mutations was lower (P = 0.02) in HBV from subjects with e-CHB (4.4±0.5 codons per subject) versus those with e-InD (6.4±0.4 codons per subject). There is a subtle relaxation in selection pressure on the HBV core gene in e-CHB. This may be due to impaired antiviral immunity, and could contribute to the high levels of viral replication that cause liver inflammation in this disease.