Trans-ancestral fine-mapping of MHC reveals key amino acids associated with spontaneous clearance of hepatitis C in HLA-DQß1.

Spontaneous clearance of acute hepatitis C virus (HCV) infection is associated with single nucleotide polymorphisms (SNPs) on the MHC class II. We fine-mapped the MHC region in European (n = 1,600; 594 HCV clearance/1,006 HCV persistence) and African (n = 1,869; 340 HCV clearance/1,529 HCV persistence) ancestry individuals and evaluated HCV peptide binding affinity of classical alleles. In both populations, HLA-DQß1Leu26 (p valueMeta = 1.24 × 10-14) located in pocket 4 was negatively associated with HCV spontaneous clearance and HLA-DQß1Pro55 (p valueMeta = 8.23 × 10-11) located in the peptide binding region was positively associated, independently of HLA-DQß1Leu26. These two amino acids are not in linkage disequilibrium (r2 < 0.1) and explain the SNPs and classical allele associations represented by rs2647011, rs9274711, HLA-DQB1∗03:01, and HLA-DRB1∗01:01. Additionally, HCV persistence classical alleles tagged by HLA-DQß1Leu26 had fewer HCV binding epitopes and lower predicted binding affinities compared to clearance alleles (geometric mean of combined IC50 nM of persistence versus clearance; 2,321 nM versus 761.7 nM, p value = 1.35 × 10-38). In summary, MHC class II fine-mapping revealed key amino acids in HLA-DQß1 explaining allelic and SNP associations with HCV outcomes. This mechanistic advance in understanding of natural recovery and immunogenetics of HCV might set the stage for much needed enhancement and design of vaccine to promote spontaneous clearance of HCV infection.

Real-World Outcomes of Direct-Acting Antiviral Treatment and Retreatment in United Kingdom-Based Patients Infected With Hepatitis C Virus Genotypes/Subtypes Endemic in Africa.

BACKGROUND: Chronic hepatitis C virus (HCV) infection affects 71 million individuals, mostly residing in low- and middle-income countries (LMICs). Direct-acting antivirals (DAAs) give high rates of sustained virological response (SVR) in high-income countries where a restricted range of HCV genotypes/subtypes circulate. METHODS: We studied United Kingdom-resident patients born in Africa to examine DAA effectiveness in LMICs where there is far greater breadth of HCV genotypes/subtypes. Viral genome sequences were determined from 233 patients. RESULTS: Full-length viral genomic sequences for 26 known subtypes and 5 previously unidentified isolates covering 5 HCV genotypes were determined. From 149 patients who received DAA treatment/retreatment, the overall SVR was 93%. Treatment failure was associated primarily with 2 subtypes, gt1l and gt4r, using sofosbuvir/ledipasvir. These subtypes contain natural resistance-associated variants that likely contribute to poor efficacy with this drug combination. Treatment failure was also significantly associated with hepatocellular carcinoma. CONCLUSIONS: DAA combinations give high SVR rates despite the high HCV diversity across the African continent except for subtypes gt1l and gt4r, which respond poorly to sofosbuvir/ledipasvir. These subtypes are widely distributed across Western, Central, and Eastern Africa. Thus, in circumstances where accurate genotyping is absent, ledipasvir and its generic compounds should not be considered as a recommended treatment option.

A UK survey on variation in the practice of management of choledocholithiasis and laparoscopic common bile duct exploration (ALiCE Survey).

BACKGROUND: The practice of managing suspected/confirmed common bile duct stones (CBDS) can vary significantly in the UK. We aimed to assess this variability in practice and challenges to form a basis for future consensus. METHODS: An electronic survey containing 40 questions on various aspects of management of CBDS was sent to surgeons who perform cholecystectomies via five surgical associations. RESULTS: A total of 132 surgeons responded to the survey. The speciality of surgeons includes upper gastro-intestinal (68%), general (18%), colorectal (12%), and others (2%). For patients with suspected CBD stones, 80% would choose magnetic resonance cholangio-pancreatography, and 14.4% would proceed to intra-operative imaging. Most surgeons preferred intra-operative cholangiogram over intra-operative ultrasound (83% vs 17%). For the treatment, 62.1% preferred a two-stage approach [endoscopic retrograde cholangio-pancreatography (ERCP) followed by laparoscopic cholecystectomy (LC)] and 33.4% chose a single-stage approach [LC + laparoscopic common bile duct exploration (LCBDE)]. Eighty (60.6%) responders performed LCBDE, and 19 (23.8%) of them performed > 10 LCBDEs in a year. Two third of surgeons (62.5%) preferred a trans-choledochal approach to CBDS. Half of the surgeons that perform LCBDE use a T-tube selectively and 1.6% routinely. The "availability of very good ERCP service" and "lack of formal training" were the two main reasons for surgeons not performing LCBDE. Both surgeons' speciality and whether they perform other complex laparoscopic surgery were significantly associated with choosing a two-stage approach over a one-stage approach (χ2 test, speciality p = 0.033, complex surgery p = 0.011). CONCLUSION: Our survey confirms the significant variability in the diagnosis and management of CBDS. The two-stage approach is still the most common way of managing CBDS in the UK. The main reasons for the low uptake of the single-stage approach are the availability of good ERCP service, lack of equipment and lack of formal training in the technique of LCBDE.

A Multiancestry Sex-Stratified Genome-Wide Association Study of Spontaneous Clearance of Hepatitis C Virus.

BACKGROUND: Spontaneous clearance of acute hepatitis C virus (HCV) infection is more common in women than in men, independent of known risk factors. METHODS: To identify sex-specific genetic loci, we studied 4423 HCV-infected individuals (2903 male, 1520 female) of European, African, and Hispanic ancestry. We performed autosomal, and X chromosome sex-stratified and combined association analyses in each ancestry group. RESULTS: A male-specific region near the adenosine diphosphate-ribosylation factor-like 5B (ARL5B) gene was identified. Individuals with the C allele of rs76398191 were about 30% more likely to have chronic HCV infection than individuals with the T allele (OR, 0.69; P = 1.98 × 10-07), and this was not seen in females. The ARL5B gene encodes an interferon-stimulated gene that inhibits immune response to double-stranded RNA viruses. We also identified suggestive associations near septin 6 and ribosomal protein L39 genes on the X chromosome. In box sexes, allele G of rs12852885 was associated with a 40% increase in HCV clearance compared with the A allele (OR, 1.4; P = 2.46 × 10-06). Septin 6 facilitates HCV replication via interaction with the HCV NS5b protein, and ribosomal protein L39 acts as an HCV core interactor. CONCLUSIONS: These novel gene associations support differential mechanisms of HCV clearance between the sexes and provide biological targets for treatment or vaccine development.

Unacceptable failures: the final report of the Lancet Commission into liver disease in the UK.

This final report of the Lancet Commission into liver disease in the UK stresses the continuing increase in burden of liver disease from excess alcohol consumption and obesity, with high levels of hospital admissions which are worsening in deprived areas. Only with comprehensive food and alcohol strategies based on fiscal and regulatory measures (including a minimum unit price for alcohol, the alcohol duty escalator, and an extension of the sugar levy on food content) can the disease burden be curtailed. Following introduction of minimum unit pricing in Scotland, alcohol sales fell by 3%, with the greatest effect on heavy drinkers of low-cost alcohol products. We also discuss the major contribution of obesity and alcohol to the ten most common cancers as well as measures outlined by the departing Chief Medical Officer to combat rising levels of obesity-the highest of any country in the west. Mortality of severely ill patients with liver disease in district general hospitals is unacceptably high, indicating the need to develop a masterplan for improving hospital care. We propose a plan based around specialist hospital centres that are linked to district general hospitals by operational delivery networks. This plan has received strong backing from the British Association for Study of the Liver and British Society of Gastroenterology, but is held up at NHS England. The value of so-called day-case care bundles to reduce high hospital readmission rates with greater care in the community is described, along with examples of locally derived schemes for the early detection of disease and, in particular, schemes to allow general practitioners to refer patients directly for elastography assessment. New funding arrangements for general practitioners will be required if these proposals are to be taken up more widely around the country. Understanding of the harm to health from lifestyle causes among the general population is low, with a poor knowledge of alcohol consumption and dietary guidelines. The Lancet Commission has serious doubts about whether the initiatives described in the Prevention Green Paper, with the onus placed on the individual based on the use of information technology and the latest in behavioural science, will be effective. We call for greater coordination between official and non-official bodies that have highlighted the unacceptable disease burden from liver disease in England in order to present a single, strong voice to the higher echelons of government.

Intermediate Monocytes in Acute Alcoholic Hepatitis Are Functionally Activated and Induce IL-17 Expression in CD4+ T Cells.

In humans, the three main circulating monocyte subsets are defined by their relative cell surface expression of CD14 and CD16. They are all challenging to study because their characteristics are strongly context specific, and this has led to a range of conflicting reports about their function, which is especially so for CD14++CD16+ (intermediate) monocytes. Ex vivo cultures are also often confounded by the concomitant use of immunosuppressive drugs. We therefore sought to characterize the phenotype and function of intermediate monocytes in the setting of acute inflammation prior to treatment in a cohort of 41 patients with acute alcoholic hepatitis (AH). Circulating intermediate monocytes were enriched in patients with AH and had an activated phenotype with enhanced expression of CCR2 and CD206 compared with healthy controls. Proinflammatory cytokine expression, including IL-1ß and IL-23, was also higher than in healthy controls, but both classical (CD14++CD16-) and intermediate monocytes in AH were refractory to TLR stimulation. Compared with healthy controls, both AH monocyte subsets had greater phagocytic capacity, enhanced ability to drive memory T cell proliferation in coculture, and skewed CD4+ T cells to express an increased ratio of IL-17/IFN-γ. Furthermore, liver tissue from AH patients demonstrated an enrichment of monocytes including the intermediate subset compared with controls. These data demonstrate that intermediate monocytes are expanded, functionally activated, induce CD4+ T cell IL-17 expression, and are enriched in the liver of patients with AH.

Multi-ancestry fine mapping of interferon lambda and the outcome of acute hepatitis C virus infection.

Clearance of acute infection with hepatitis C virus (HCV) is associated with the chr19q13.13 region containing the rs368234815 (TT/ΔG) polymorphism. We fine-mapped this region to detect possible causal variants that may contribute to HCV clearance. First, we performed sequencing of IFNL1-IFNL4 region in 64 individuals sampled according to rs368234815 genotype: TT/clearance (N = 16) and ΔG/persistent (N = 15) (genotype-outcome concordant) or TT/persistent (N = 19) and ΔG/clearance (N = 14) (discordant). 25 SNPs had a difference in counts of alternative allele >5 between clearance and persistence individuals. Then, we evaluated those markers in an association analysis of HCV clearance conditioning on rs368234815 in two groups of European (692 clearance/1 025 persistence) and African ancestry (320 clearance/1 515 persistence) individuals. 10/25 variants were associated (P < 0.05) in the conditioned analysis leaded by rs4803221 (P value = 4.9 × 10-04) and rs8099917 (P value = 5.5 × 10-04). In the European ancestry group, individuals with the haplotype rs368234815ΔG/rs4803221C were 1.7× more likely to clear than those with the rs368234815ΔG/rs4803221G haplotype (P value = 3.6 × 10-05). For another nearby SNP, the haplotype of rs368234815ΔG/rs8099917T was associated with HCV clearance compared to rs368234815ΔG/rs8099917G (OR: 1.6, P value = 1.8 × 10-04). We identified four possible causal variants: rs368234815, rs12982533, rs10612351 and rs4803221. Our results suggest a main signal of association represented by rs368234815, with contributions from rs4803221, and/or nearby SNPs including rs8099917.

Applicability, safety, and biological activity of regulatory T cell therapy in liver transplantation.

Regulatory T cells (Tregs) are a lymphocyte subset with intrinsic immunosuppressive properties that can be expanded in large numbers ex vivo and have been shown to prevent allograft rejection and promote tolerance in animal models. To investigate the safety, applicability, and biological activity of autologous Treg adoptive transfer in humans, we conducted an open-label, dose-escalation, Phase I clinical trial in liver transplantation. Patients were enrolled while awaiting liver transplantation or 6-12 months posttransplant. Circulating Tregs were isolated from blood or leukapheresis, expanded under good manufacturing practices (GMP) conditions, and administered intravenously at either 0.5-1 million Tregs/kg or 3-4.5 million Tregs/kg. The primary endpoint was the rate of dose- limiting toxicities occurring within 4 weeks of infusion. The applicability of the clinical protocol was poor unless patient recruitment was deferred until 6-12 months posttransplant. Thus, only 3 of the 17 patients who consented while awaiting liver transplantation were dosed. In contrast, all six patients who consented 6-12 months posttransplant received the cell infusion. Treg transfer was safe, transiently increased the pool of circulating Tregs and reduced anti-donor T cell responses. Our study opens the door to employing Treg immunotherapy to facilitate the reduction or complete discontinuation of immunosuppression following liver transplantation.

Multi-Ancestry Genome-Wide Association Study of Spontaneous Clearance of Hepatitis C Virus.

BACKGROUND & AIMS: Spontaneous clearance of hepatitis C virus (HCV) occurs in approximately 30% of infected persons and less often in populations of African ancestry. Variants in major histocompatibility complex (MHC) and in interferon lambda genes are associated with spontaneous HCV clearance, but there have been few studies of these variants in persons of African ancestry. We performed a dense multi-ancestry genome-wide association study of spontaneous clearance of HCV, focusing on individuals of African ancestry. METHODS: We performed genotype analyses of 4423 people from 3 ancestry groups: 2201 persons of African ancestry (445 with HCV clearance and 1756 with HCV persistence), 1739 persons of European ancestry (701 with HCV clearance and 1036 with HCV persistence), and 486 multi-ancestry Hispanic persons (173 with HCV clearance and 313 with HCV persistence). Samples were genotyped using Illumina (San Diego, CA) arrays and statistically imputed to the 1000 Genomes Project. For each ancestry group, the association of single-nucleotide polymorphisms with HCV clearance was tested by log-additive analysis, and then a meta-analysis was performed. RESULTS: In the meta-analysis, significant associations with HCV clearance were confirmed at the interferon lambda gene locus IFNL4-IFNL3 (19q13.2) (P = 5.99 × 10-50) and the MHC locus 6p21.32 (P = 1.15 × 10-21). We also associated HCV clearance with polymorphisms in the G-protein-coupled receptor 158 gene (GPR158) at 10p12.1 (P = 1.80 × 10-07). These 3 loci had independent, additive effects of HCV clearance, and account for 6.8% and 5.9% of the variance of HCV clearance in persons of European and African ancestry, respectively. Persons of African or European ancestry carrying all 6 variants were 24-fold and 11-fold, respectively, more likely to clear HCV infection compared with individuals carrying none or 1 of the clearance-associated variants. CONCLUSIONS: In a meta-analysis of data from 3 studies, we found variants in MHC genes, IFNL4-IFNL3, and GPR158 to increase odds of HCV clearance in patients of European and African ancestry. These findings could increase our understanding of immune response to and clearance of HCV infection.

Sofosbuvir/velpatasvir for 12 weeks in hepatitis C virus-infected patients with end-stage renal disease undergoing dialysis.

BACKGROUND & AIMS: Although off-label use of sofosbuvir-containing regimens occurs regularly in patients with hepatitis C virus (HCV) infection undergoing dialysis for severe renal impairment or end-stage renal disease (ESRD), these regimens are not licensed for this indication, and there is an absence of dosing recommendations in this population. This study evaluated the safety and efficacy of sofosbuvir/velpatasvir in patients with HCV infection with ESRD undergoing dialysis. METHODS: In this phase II, single-arm study, 59 patients with genotype 1-6 HCV infection with ESRD undergoing hemodialysis or peritoneal dialysis received open-label sofosbuvir/velpatasvir (400 mg/100 mg) once daily for 12 weeks. Patients were HCV treatment naive or treatment experienced without cirrhosis or with compensated cirrhosis. Patients previously treated with any HCV NS5A inhibitor were not eligible. The primary efficacy endpoint was the proportion of patients achieving sustained virologic response (SVR) 12 weeks after discontinuation of treatment (SVR12). The primary safety endpoint was the proportion of patients who discontinued study drug due to adverse events. RESULTS: Overall, 56 of 59 patients achieved SVR12 (95%; 95% CI 86-99%). Of the 3 patients who did not achieve SVR12, 2 patients had virologic relapse determined at post-treatment Week 4 (including 1 who prematurely discontinued study treatment), and 1 patient died from suicide after achieving SVR through post-treatment Week 4. The most common adverse events were headache (17%), fatigue (14%), nausea (14%), and vomiting (14%). Serious adverse events were reported for 11 patients (19%), and all were deemed to be unrelated to sofosbuvir/velpatasvir. CONCLUSIONS: Treatment with sofosbuvir/velpatasvir for 12 weeks was safe and effective in patients with ESRD undergoing dialysis. LAY SUMMARY: Sofosbuvir/velpatasvir is a combination direct-acting antiviral that is approved for treatment of patients with hepatitis C virus (HCV) infection. Despite the lack of dosing recommendations, sofosbuvir-containing regimens (including sofosbuvir/velpatasvir) are frequently used for HCV-infected patients undergoing dialysis. This study evaluated the safety and efficacy of sofosbuvir/velpatasvir for 12 weeks in patients with HCV infection who were undergoing dialysis. Treatment with sofosbuvir/velpatasvir was safe and well tolerated, resulting in a cure rate of 95% in patients with HCV infection and end-stage renal disease. Clinical Trial Number: NCT03036852.

Gathering momentum for the way ahead: fifth report of the Lancet Standing Commission on Liver Disease in the UK.

This report presents further evidence on the escalating alcohol consumption in the UK and the burden of liver disease associated with this major risk factor, as well as the effects on hospital and primary care. We reiterate the need for fiscal regulation by the UK Government if overall alcohol consumption is to be reduced sufficiently to improve health outcomes. We also draw attention to the effects of drastic cuts in public services for alcohol treatment, the repeated failures of voluntary agreements with the drinks industry, and the influence of the industry through its lobbying activities. We continue to press for reintroduction of the alcohol duty escalator, which was highly effective during the 5 years it was in place, and the introduction of minimum unit pricing in England, targeted at the heaviest drinkers. Results from the introduction of minimum unit pricing in Scotland, with results from Wales to follow, are likely to seriously expose the weakness of England's position. The increasing prevalence of obesity-related liver disease, the rising number of people diagnosed with type 2 diabetes and its complications, and increasing number of cases of end-stage liver disease and primary liver cancers from non-alcoholic fatty liver disease make apparent the need for an obesity strategy for adults. We also discuss the important effects of obesity and alcohol on disease progression, and the increased risk of the ten most common cancers (including breast and colon cancers). A new in-depth analysis of the UK National Health Service (NHS) and total societal costs shows the extraordinarily large expenditures that could be saved or redeployed elsewhere in the NHS. Excellent results have been reported for new antiviral drugs for hepatitis C virus infection, making elimination of chronic infection a real possibility ahead of the WHO 2030 target. However, the extent of unidentified cases remains a problem, and will also apply when new curative drugs for hepatitis B virus become available. We also describe efforts to improve standards of hospital care for liver disease with better understanding of current service deficiencies and a new accreditation process for hospitals providing liver services. New commissioning arrangements for primary and community care represent progress, in terms of effective screening of high-risk subjects and the early detection of liver disease.

Disease burden and costs from excess alcohol consumption, obesity, and viral hepatitis: fourth report of the Lancet Standing Commission on Liver Disease in the UK.

This report contains new and follow-up metric data relating to the eight main recommendations of the Lancet Standing Commission on Liver Disease in the UK, which aim to reduce the unacceptable harmful consequences of excess alcohol consumption, obesity, and viral hepatitis. For alcohol, we provide data on alcohol dependence, damage to families, and the documented increase in alcohol consumption since removal of the above-inflation alcohol duty escalator. Alcoholic liver disease will shortly overtake ischaemic heart disease with regard to years of working life lost. The rising prevalence of overweight and obesity, affecting more than 60% of adults in the UK, is leading to an increasing liver disease burden. Favourable responses by industry to the UK Government's soft drinks industry levy have been seen, but the government cannot continue to ignore the number of adults being affected by diabetes, hypertension, and liver disease. New direct-acting antiviral drugs for the treatment of chronic hepatitis C virus infection have reduced mortality and the number of patients requiring liver transplantation, but more screening campaigns are needed for identification of infected people in high-risk migrant communities, prisons, and addiction centres. Provision of care continues to be worst in regions with the greatest socioeconomic deprivation, and deficiencies exist in training programmes in hepatology for specialist registrars. Firm guidance is needed for primary care on the use of liver blood tests in detection of early disease and the need for specialist referral. This report also brings together all the evidence on costs to the National Health Service and wider society, in addition to the loss of tax revenue, with alcohol misuse in England and Wales costing £21 billion a year (possibly up to £52 billion) and obesity costing £27 billion a year (treasury estimates are as high as £46 billion). Voluntary restraints by the food and drinks industry have had little effect on disease burden, and concerted regulatory and fiscal action by the UK Government is essential if the scale of the medical problem, with an estimated 63 000 preventable deaths over the next 5 years, is to be addressed.

Elbasvir/grazoprevir and sofosbuvir for hepatitis C virus genotype 3 infection with compensated cirrhosis: A randomized trial.

Many direct-acting antiviral regimens have reduced activity in people with hepatitis C virus (HCV) genotype (GT) 3 infection and cirrhosis. The C-ISLE study assessed the efficacy and safety of elbasvir/grazoprevir (EBR/GZR) plus sofosbuvir (SOF) with and without ribavirin (RBV) in compensated cirrhotic participants with GT3 infection. This was a phase 2, randomized, open-label study. Treatment-naive participants received EBR/GZR + SOF + RBV for 8 weeks or EBR/GZR + SOF for 12 weeks, and peginterferon/RBV treatment-experienced participants received EBR/GZR + SOF ± RBV for 12 weeks or EBR/GZR + SOF for 16 weeks. The primary endpoint was HCV RNA <15 IU/mL 12 weeks after the end of treatment (sustained virologic response at 12 weeks [SVR12]). Among treatment-naive participants, SVR12 was 91% (21/23) in those treated with RBV for 8 weeks and 96% (23/24) in those treated for 12 weeks. Among treatment-experienced participants, SVR12 was 94% (17/18) and 100% (17/17) in the 12-week arm, with and without RBV, respectively, and 94% (17/18) in the 16-week arm. Five participants failed to achieve SVR: 2 relapsed (both in the 8-week arm), 1 discontinued due to vomiting/cellulitis (16-week arm), and 2 discontinued (consent withdrawn/lost to follow-up). SVR12 was not affected by the presence of resistance-associated substitutions (RASs). There was no consistent change in insulin resistance, and 5 participants reported serious adverse events (pneumonia, chest pain, opiate overdose, cellulitis, decreased creatinine). High efficacy was demonstrated in participants with HCV GT3 infection and cirrhosis. Treatment beyond 12 weeks was not required, and efficacy was maintained regardless of baseline RASs. CONCLUSION: Data from this study support the use of EBR/GZR plus SOF for 12 weeks without RBV for treatment-naive and peginterferon/RBV-experienced people with GT3 infection and cirrhosis (ClinicalTrials.gov NCT02601573). (Hepatology 2018;67:2113-2126).

Haplotype analysis finds linkage disequilibrium in the IL-12 gene in patients with HCV.

HCV is a major cause of liver disease worldwide. IL-12 plays an essential role in the balance of T helper 1 (Th1) differentiation versus a T helper 2 (Th2) driven response from its naïve precursor. Linkage disequilibrium measures the degree to which alleles at two loci are associated and the non-random associations between alleles at two loci. Haplotypes of the three IL-12B loci studied were determined in the patient cases and the normal healthy control subjects. The frequency of the 12 possible IL-12B haplotypes on the 3 loci was determined in subjects heterozygous at only one of the loci within the studied haplotype. Haplotype frequencies were compared between the patient groups and controls (n = 49) to determine if any preferential combination of markers occurred using chi-squared and applying the Bonferroni correction. 45 HCV RNA negative patients; 88 HCV RNA positive patients; and 15 uninfected cases at high risk of HCV infection (EU) were studied. The haplotype "C" SNP of the 3'UTR with the "E" 4 bp deletion of the intron 4 region was in linkage disequilibrium (χ(2) = 45.15, P < 0.001, 95% CL). The haplotype analysis of the insertion allele of the promoter with the deletion allele of the intron 4("E") IL-12B polymorphism showed linkage disequilibrium (χ(2) = 5.64, P = 0.02). Linkage disequilibrium of polymorphisms is reported in the IL-12 gene in patients with HCV infection and contributes to the understanding of patient genotype and expected production of IL-12, responding to infection.

Impaired functional capacity in potential liver transplant candidates predicts short-term mortality before transplantation.

Liver transplantation (LT) is a lifesaving treatment. Because of the shortage of donor organs, some patients will not survive long enough to receive a transplant. The identification of LT candidates at increased risk of short-term mortality without transplantation may affect listing decisions. Functional capacity, determined with cardiopulmonary exercise testing (CPET), is a measure of cardiorespiratory reserve and predicts perioperative outcomes. This study examined the association between functional capacity and short-term survival before LT and the potential for CPET to predict 90-day mortality without transplantation. A total of 176 patients who were assessed for nonacute LT underwent CPET. Ninety days after the assessment, 10 of the 164 patients who had not undergone transplantation were deceased (mortality rate = 6.1%). According to a comparison of survivors and nonsurvivors, the Model for End-Stage Liver Disease score, UK Model for End-Stage Liver Disease (UKELD) score, age, anaerobic threshold, and peak oxygen uptake (VO(2)) were significant univariate predictors of 90-day mortality without transplantation, but only the UKELD score and peak VO(2) retained significance in a multivariate analysis. The mean peak VO(2) was significantly lower for nonsurvivors versus survivors (15.2 ± 3.3 versus 21.2 ± 5.3 mL/minute/kg, P < 0.001). According to a receiver operating characteristic (ROC) curve analysis, peak VO(2) performed well as a diagnostic test (area under the ROC curve = 0.84, 95% confidence interval = 0.76-0.92, sensitivity = 0.90, specificity = 0.74, P < 0.001). The optimal cutoff value for predicting mortality was ≤17.6 mL/minute/kg. The positive predictive value of a peak VO(2) ≤ 17.6 mL/minute/kg for 90-day mortality was greatest for patients with high UKELD scores: 38% of the patients with a UKELD score ≥ 57 and a peak VO(2) ≤ 17.6 mL/minute/kg died, whereas only 6% of the patients with a UKELD score ≥ 57 and a peak VO(2) > 17.6 mL/minute/kg died (P = 0.03). In conclusion, patients assessed for LT with an impaired functional capacity have poorer short-term survival; this is particularly true for individuals with worse liver disease severity.

Polymorphic differences in SOD-2 may influence HCV viral clearance.

Hepatitis C virus (HCV) is a pathogen causing chronic hepatitis, cirrhosis, and liver cancer occurring in about 3% of the world's population. Most individuals infected with HCV develop persistent viremia. Oxidative stress may play an important role in the pathogenesis of a number of diseases including HCV infection and diabetes mellitus. Polymorphisms in the antioxidant genes may determine cellular oxidative stress levels as a primary pathogenic role in HCV and/or in its complications. Patients with HCV and normal, healthy controls were investigated for a superoxide dismutase (SOD-2) polymorphism in the mitochondrial targeting sequence with Ala/Val (C-9T) substitution. Polymorphisms in antioxidant gene SOD-2 were carried out by PCR, restriction fragment length polymorphism assays and by polyacrylamide gel electrophoresis. For the SOD-2 polymorphism, the RNA positive group showed a higher percentage of "CT" genotype than the RNA negative group (89.3% vs. 66.1%, P = 0.001, χ(2) = 11.9). The RNA negative group had more TT genotypes than the RNA positive group (27.4% vs. 6.80%, P = 0.01, χ(2) = 11.6). The exposed uninfected group had an increased frequency of the "CT" genotype (86.2% vs. 66.1%, P = 0.02, χ(2) = 5.5). The RNA positives had a higher frequency of the "CT" from the normal controls (72.1% vs. 89.2%, P = 0.005, χ(2) = 7.8).

CD81 sequence and susceptibility to hepatitis C infection.

Several cell surface molecules have hepatitis C virus (HCV) binding properties and may serve as receptors facilitating viral entry into cells. The large extracellular loop (LEL) of CD81 has been shown to bind the HCV envelope protein E2 with several critical residues for the CD81-HCV-E2 interaction. It was hypothesised that variation in the CD81 LEL sequence may modify susceptibility to HCV infection. HCV RNA negative patients with spontaneous viral clearance (RNA -ve); HCV RNA positive cases, who are affected chronically (RNA +ve); and patients at high risk of HCV infection, exposed but uninfected patients (EU) were studied. Genomic DNA was extracted from whole blood samples and four exons of the CD81 LEL gene were amplified by PCR and sequenced. The cDNA derived from CD81 (≈700 bp) was sequenced following RNA extraction from peripheral blood mononuclear cells. Patients, who are RNA positive, RNA negative, and exposed uninfected were sequenced for four DNA sections (A, B, C, and D). Sixty-two (43M:19F) patients, from all the patient cohorts, were sequenced and compared for the C section alone (which encompasses the important binding region of the molecule for envelope protein) including 21 (14M:7F) HCV RNA negative, 15 (10M:5F) HCV RNA positive and 26 (20M:6F) exposed uninfected and no sequence differences were observed. The entire CD81 sequence from cDNA was obtained in 23 cases-11 RNA -ve, 5 RNA +ve and 7 EU. In 7 of the 23 cases, the nucleotides were confirmed with the genomic sequence (4 RNA -ve and 3 EU cases). No sequence variation was found in any of the patients studied by either method, including gene sections encoding the residues most important for CD81-HCV E2 binding. The LEL of CD81 is a molecule that is highly conserved. No differences in nucleotide sequence influencing susceptibility to, or outcome of HCV infection or evidence of methylation of the gene were found.

Synergism of tapasin and human leukocyte antigens in resolving hepatitis C virus infection.

UNLABELLED: CD8+ T-cell responses to hepatitis C virus (HCV) are important in generating a successful immune response and spontaneously clearing infection. Human leukocyte antigen (HLA) class I presents viral peptides to CD8+ T cells to permit detection of infected cells, and tapasin is an important component of the peptide loading complex for HLA class I. We sought to determine if tapasin polymorphisms affected the outcome of HCV infection. Patients with resolved or chronic HCV infection were genotyped for the known G/C coding polymorphism in exon 4 of the tapasin gene. In a European, but not a US, Caucasian population, the tapasin G allele was significantly associated with the outcome of HCV infection, being found in 82.5% of resolvers versus 71.3% of persistently infected individuals (P = 0.02, odds ratio [OR] = 1.90 95% confidence interval [CI] = 1.11-3.23). This was more marked at the HLA-B locus at which heterozygosity of both tapasin and HLA-B was protective (P < 0.03). Individuals with an HLA-B allele with an aspartate at residue 114 and the tapasin G allele were more likely to spontaneously resolve HCV infection (P < 0.00003, OR = 3.2 95% CI = 1.6-6.6). Additionally, individuals with chronic HCV and the combination of an HLA-B allele with an aspartate at residue 114 and the tapasin G allele also had stronger CD8+ T-cell responses (P = 0.02, OR = 2.58, 95% CI-1.05-6.5). CONCLUSION: Tapasin alleles contribute to the outcome of HCV infection by synergizing with polymorphisms at HLA-B in a population-specific manner. This polymorphism may be relevant for peptide vaccination strategies against HCV infection.