Therapeutic plasma-exchange improves systemic inflammation and survival in acute-on-chronic liver failure: A propensity-score matched study from AARC

BACKGROUND AND AIM

Plasma-exchange (PE) has improved survival in acute liver failure by ameliorating systemic inflammatory response syndrome (SIRS). We evaluated PE and compared it to Fractional Plasma Separation and Adsorption (FPSA) and standard medical treatment (SMT) in a large multinational cohort of ACLF patients.

METHODS

Data were prospectively collected from the AARC database and analysed. Matching by propensity risk score (PRS) was performed. Competing risk survival analysis was done to identify deaths because of multiorgan failure (MOF). In a subset of 10 patients, we also evaluated the mechanistic basis of response to PE.

RESULTS

ACLF patients (n = 1866, mean age 44.3 ± 12.3 yrs, 93% males, 65% alcoholics) received either artificial liver support (ALS) (n = 162); [PE (n = 131), FPSA (n = 31)] or were continued on standard medical therapy (SMT) (n = 1704). In the PRS-matched cohort (n = 208, [ALS-119; PE-94, FPSA-25)], SMT-89). ALS therapies were associated with a significantly higher resolution of SIRS (Odd's ratio 9.23,3.42-24.8), lower and delayed development of MOF (Hazard ratio 7.1, 4.5-11.1), and lower liver-failure-related deaths as compared to FPSA and SMT (P < .05). PE cleared inflammatory cytokines, damage-associated molecular patterns, and endotoxin in all patients. Responders improved monocyte phagocytic function and mitochondrial respiration and increased the anti-inflammatory cytokine interleukin-1 receptor antagonist (IL-1RA) compared to non-responders. PE was associated with lesser adverse effects as compared to FPSA.

CONCLUSIONS

PE improves systemic inflammation and lowers the development of MOF in patients with ACLF. Plasma-exchange provides significant survival benefit over FPSA and could be a preferred modality of liver support for ACLF patients.

Liver diseases in the Asia-Pacific region: a Lancet Gastroenterology & Hepatology Commission

The Asia-Pacific region is home to more than half of the global population and accounted for 62·6% of global deaths due to liver diseases in 2015. 54·3% of global deaths due to cirrhosis, 72·7% of global deaths due to hepatocellular carcinoma, and more than two-thirds of the global burden of acute viral hepatitis occurred in this region in 2015. Chronic hepatitis B virus (HBV) infection caused more than half of the deaths due to cirrhosis in the region, followed by alcohol consumption (20·8%), non-alcoholic fatty liver disease (NAFLD; 12·1%), and chronic infection with hepatitis C virus (HCV; 15·7%). In 2015, HBV accounted for about half the cases of hepatocellular carcinoma in the region. Preventive strategies for viral hepatitis-related liver disease include increasing access to clean drinking water and sanitation. HBV vaccination programmes for neonates have been implemented by all countries, although birth-dose coverage is extremely suboptimal in some. Availability of screening tests for blood and tissue, donor recall policies, and harm reduction strategies are in their initial stages in most countries. Many governments have put HBV and HCV drugs on their essential medicines lists and the availability of generic versions of these drugs has reduced costs. Efforts to eliminate viral hepatitis as a public health threat, together with the rapid increase in per-capita alcohol consumption in countries and the epidemic of obesity, are expected to change the spectrum of liver diseases in the Asia-Pacific region in the near future. The increasing burden of alcohol-related liver diseases can be contained through government policies to limit consumption and promote less harmful patterns of alcohol use, which are in place in some countries but need to be enforced more strictly. Steps are needed to control obesity and NAFLD, including policies to promote healthy lifestyles and regulate the food industry. Inadequate infrastructure and insufficient health-care personnel trained in liver diseases are issues that also need to be addressed in the Asia-Pacific region. The policy response of most governments to liver diseases has thus far been inadequate and poorly funded. There must be a renewed focus on prevention, early detection, timely referral, and research into the best means to introduce and improve health interventions to reduce the burden of liver diseases in the Asia-Pacific region.

Correction to: Acute-on-chronic liver failure: consensus recommendations of the Asian Pacific association for the study of the liver (APASL): an update

The article Acute-on-chronic liver failure: consensus recommendations of the Asian Pacific association for the study of the liver (APASL): an update, written by [Shiv Sarin], was originally published electronically on the publisher's internet portal (currently SpringerLink) on June 06, 2019 without open access.

Acute-on-chronic liver failure: consensus recommendations of the Asian Pacific association for the study of the liver (APASL): an update

The first consensus report of the working party of the Asian Pacific Association for the Study of the Liver (APASL) set up in 2004 on acute-on-chronic liver failure (ACLF) was published in 2009. With international groups volunteering to join, the "APASL ACLF Research Consortium (AARC)" was formed in 2012, which continued to collect prospective ACLF patient data. Based on the prospective data analysis of nearly 1400 patients, the AARC consensus was published in 2014. In the past nearly four-and-a-half years, the AARC database has been enriched to about 5200 cases by major hepatology centers across Asia. The data published during the interim period were carefully analyzed and areas of contention and new developments in the field of ACLF were prioritized in a systematic manner. The AARC database was also approached for answering some of the issues where published data were limited, such as liver failure grading, its impact on the 'Golden Therapeutic Window', extrahepatic organ dysfunction and failure, development of sepsis, distinctive features of acute decompensation from ACLF and pediatric ACLF and the issues were analyzed. These initiatives concluded in a two-day meeting in October 2018 at New Delhi with finalization of the new AARC consensus. Only those statements, which were based on evidence using the Grade System and were unanimously recommended, were accepted. Finalized statements were again circulated to all the experts and subsequently presented at the AARC investigators meeting at the AASLD in November 2018. The suggestions from the experts were used to revise and finalize the consensus. After detailed deliberations and data analysis, the original definition of ACLF was found to withstand the test of time and be able to identify a homogenous group of patients presenting with liver failure. New management options including the algorithms for the management of coagulation disorders, renal replacement therapy, sepsis, variceal bleed, antivirals and criteria for liver transplantation for ACLF patients were proposed. The final consensus statements along with the relevant background information and areas requiring future studies are presented here.

Liver Disease in Singapore

Liver disease is a significant health issue in Singapore. In the Singapore Burden of Disease Survey, liver cancer and liver cirrhosis contributed 3.2 and 0.9% of years of life lost (YLL) out of 182,753 YLL respectively. Liver cancer was ranked 8th and liver cirrhosis was ranked 20th in YLL. Liver cancer is the 5th most common cancer in males, and has an age-adjusted rate of 17.6 per 100,000 population. The underlying etiology of liver cirrhosis is chronic hepatitis B (CHB) in 63.3%, alcohol in 11.2%, cryptogenic in 9%, and chronic hepatitis C (CHC) in 6.9%. The overall seroprevalence rate of CHB is 3.6%, while CHC is approximately 0.1%. The trend in prevalence of liver cancer is gradually reducing as is CHB. However, less is known about alcoholic liver disease and fatty liver disease and there is some evidence that the latter is increasing. Singapore has a multilayered health care system designed to provide basic health care needs to the population. There are various schemes available that provide subsidized and assisted health care for treatment of hepatitis B and C as well as liver transplantation. Health policy with regard to a national action plan has not yet been developed and there is room for health care specialists, government and nongovernment agencies to work together to tackle liver disease in Singapore. How to cite this article: Muthiah M, Chong CH, Lim SG. Liver Disease in Singapore. Euroasian J Hepato-Gastroenterol 2018;8(1):66-68.

Predictors of response to tenofovir disoproxil fumarate plus peginterferon alfa-2a combination therapy for chronic hepatitis B

BACKGROUND

In patients with chronic hepatitis B, tenofovir disoproxil fumarate (TDF) plus pegylated interferon (PEG-IFN) for 48-weeks results in higher rates of hepatitis B surface antigen (HBsAg) loss than either monotherapy.

AIM

To identify baseline and on-treatment factors associated with HBsAg loss at Week 72 and provide a model for predicting HBsAg loss in patients receiving combination therapy for 48 weeks.

METHODS

A secondary analysis of data from an open-label study where patients were randomised to TDF (300 mg/day, oral) plus PEG-IFN (PI, 180 μg/week, subcutaneous) for 48 weeks (TDF/PI-48w); TDF plus PEG-IFN for 16 weeks, TDF for 32 weeks (TDF/PI-16w+TDF-32w); TDF for 120 weeks (TDF-120w) or PEG-IFN for 48 weeks (PI-48w). Logistic regression methods were used to identify models that best predicted HBsAg loss at Week 72.

RESULTS

Rates of HBsAg loss at Week 72 were significantly higher in the TDF/PI-48w group (6.5%) than in the TDF/PI-16w+TDF-32w (0.5%), TDF-120w (0%) and PI-48w (2.2%) groups (P = 0.09). The only baseline factor associated with response was genotype A. HBsAg decline at Week 12 or 24 of treatment was associated with HBsAg loss at Week 72 (P < 0.001). HBsAg decline >3.5 log₁₀ IU/mL at Week 24 in the TDF/PI-48w group resulted in a positive predictive value of 85% and a negative predictive value of 99% for HBsAg loss at Week 72.

CONCLUSIONS

HBsAg decline at Week 24 of TDF plus PEG-IFN combination therapy may identify patients who, after completing 48 weeks of treatment, have a better chance of achieving HBsAg loss at Week 72.

Asian-Pacific clinical practice guidelines on the management of hepatitis B: a 2015 update

Worldwide, some 240 million people have chronic hepatitis B virus (HBV), with the highest rates of infection in Africa and Asia. Our understanding of the natural history of HBV infection and the potential for therapy of the resultant disease is continuously improving. New data have become available since the previous APASL guidelines for management of HBV infection were published in 2012. The objective of this manuscript is to update the recommendations for the optimal management of chronic HBV infection. The 2015 guidelines were developed by a panel of Asian experts chosen by the APASL. The clinical practice guidelines are based on evidence from existing publications or, if evidence was unavailable, on the experts' personal experience and opinion after deliberations. Manuscripts and abstracts of important meetings published through January 2015 have been evaluated. This guideline covers the full spectrum of care of patients infected with hepatitis B, including new terminology, natural history, screening, vaccination, counseling, diagnosis, assessment of the stage of liver disease, the indications, timing, choice and duration of single or combination of antiviral drugs, screening for HCC, management in special situations like childhood, pregnancy, coinfections, renal impairment and pre- and post-liver transplant, and policy guidelines. However, areas of uncertainty still exist, and clinicians, patients, and public health authorities must therefore continue to make choices on the basis of the evolving evidence. The final clinical practice guidelines and recommendations are presented here, along with the relevant background information.

Resolution of adefovir-related nephrotoxicity by adefovir dose-reduction in patients with chronic hepatitis B

BACKGROUND

Chronic hepatitis B patients (CHB) treated with adefovir were followed up to evaluate nephrotoxicity and its outcome.

AIM

To assess the incidence of renal dysfunction during adefovir therapy in Asian patients and factors associated with it, and evaluate strategies to improve adefovir-related renal dysfunction and their impact on viral suppression.

METHODS

Chronic hepatitis B clinic patients from a tertiary hospital on adefovir treatment, with their clinical and laboratory parameters were extracted from the hospital electronic clinical database in an observational study design. Patients were excluded if they had liver/renal transplant, baseline renal impairment or were on dialysis. Adefovir-related renal dysfunction was defined as adefovir-related abnormal serum creatinine (ARASC) > 125 μmol/L (males), >90 μmol/L (females); adefovir-related abnormal GFR <60 mL/min; and adefovir-related increased serum creatinine >0.5 mg/dL, without other known causes of nephrotoxicity.

RESULTS

A total of 271/383 adefovir-treated patients were suitable for analysis and 33(12%) patients developed abnormal serum creatinine. Cumulative increase in proportion of patients with ARASC was 33.8% and GFR ≤60 mL/min was 38.3% by 6 years, while serum creatinine increase ≥0.5 mg/dL was 21.48% by 5 years. Using multivariate analysis, the only independent baseline predictor of ARASC was GFR ≤76.1 mL/min. Patients who had ARASC had similar levels of viral suppression to those who did not have ARASC. Those who had ARASC either continued adefovir (24%), switched therapy (24%) or had adefovir dose reduction (52%). ARASC resolved and GFR normalised in almost all patients after either switching therapy or reducing adefovir dose, with no difference between the two strategies (P = 0.737). Those with adefovir dose reduction had no significant increase in HBV DNA (P = 0.170).

CONCLUSIONS

Adefovir-related renal dysfunction occurred in a significant number of adefovir-treated patients, but reduction of the dose led to renal improvement without compromising treatment efficacy.

Open-label phase 1b pilot study to assess the antiviral efficacy of simvastatin combined with sertraline in chronic hepatitis C patients

BACKGROUND

3-Hydroxy-3-methyl-glutaryl coenzyme A reductase inhibitors inhibit HCV replication in vitro. The combination of sertraline and simvastatin has synergistic antiviral activity in vitro, but there are no prior in vivo studies. Our aims were to prospectively assess the antiviral efficacy and safety of this drug combination in chronic hepatitis C (CHC) patients.

METHODS

A total of 15 CHC adults (including 1 control subject) that were treatment-naive or prior partial responders/relapsers to standard-of-care therapy were enrolled at four centres (2 in Singapore and 2 in the US). Patients received simvastatin 40 mg once daily and sertraline 50 mg once daily for 7 days, and then 80 mg once daily and 100 mg once daily, respectively, for another 21 days with a 14-day follow-up.

RESULTS

Of the 15 CHC patients, 13 completed the study. Subjects were mostly Caucasian (8/15), mean age 49.1 ±9 years and the genotype distribution was 1=10, 2=2 and 3=3. No subject discontinued dosing due to adverse events. Mean HCV RNA change from baseline was from -0.005 to -0.236 log(10) IU/ml across study intervals. Three subjects had transient >1 log(10) HCV RNA declines. No subject achieved >2 log(10) HCV RNA decline.

CONCLUSIONS

The combination of sertraline and simvastatin is well-tolerated over the short-term, but has no significant antiviral or anti-inflammatory response in CHC patients. This may reflect in vivo differences in synergy between statin and/or selective serotonin reuptake inhibitors and incomplete inhibition of membrane protein prenylation with statin therapy.

Baseline characteristics and early on-treatment response predict the outcomes of 2 years of telbivudine treatment of chronic hepatitis B

BACKGROUND/AIMS

In the GLOBE trial, telbivudine treatment was identified as a significant, independent predictor of better outcomes at 2 years. We analyzed all telbivudine recipients in this trial to determine the predictors of optimal outcomes.

METHODS

The intent-to-treat population comprised 458 HBeAg-positive and 222 HBeAg-negative telbivudine-treated patients. Multivariate logistic regression analyses were employed to evaluate baseline and/or early on-treatment variables.

RESULTS

Baseline HBV DNA<9 log(10)copies/mL, or ALT levels > or = 2x above normal were strong pretreatment predictors for HBeAg-positive, but not for HBeAg-negative patients. However, non-detectable serum HBV DNA at treatment week 24 (TW24) was the strongest predictor for better outcomes for both groups. A combination of pretreatment characteristics plus TW24 response identified subgroups with the best outcomes: (1) HBeAg-positive patients with baseline HBV DNA<9 log(10)copies/mL, ALT > or = 2x above normal and non-detectable HBV DNA at TW24 achieved at 2 years: non-detectable HBV DNA in 89%, HBeAg seroconversion in 52%, telbivudine resistance in 1.8%; and (2) HBeAg-negative patients with baseline HBV DNA<7 log(10)copies/mL and non-detectable serum HBV DNA at TW24 achieved at 2 years: non-detectable HBV DNA in 91%, telbivudine resistance in 2.3%.

CONCLUSION

During telbivudine treatment, non-detectable serum HBV DNA at treatment week 24 is the strongest predictor for optimal outcomes at 2 years.

Role of the miR-106b-25 microRNA cluster in hepatocellular carcinoma

MicroRNAs are tiny RNA molecules which serve as important post-transcriptional regulators of gene expression. Dysregulated expression of microRNAs has been observed in human cancers, indicating that microRNAs may function as oncogenes or as tumor suppressors. To date, the microRNAs encoded by the oncogenic miR-17-92 cluster, and its paralog the miR-106b-25 cluster, are among those which are differentially expressed in human cancers. In this study, we examined and confirmed the over-expression of these clusters in hepatocellular carcinoma and in hepatoma-derived cells. At least 50% of the tumor samples showed a greater than two-fold increase in the expression for miR-18 and for the miR-106b-25 cluster when compared with the corresponding paired non-tumor samples. Knock-down studies for the miR-106b-25 cluster, which includes miR-106b, miR-93 and miR-25, showed that the expression of the cluster is necessary for cell proliferation and for anchorage-independent growth. In tumors with high expression of this cluster, reduced expression of the BH3-only protein Bim, a miR-25 target, was observed. We further identified the transcription factor E2F1 as a target gene for miR-106b and miR-93 and it is likely that one of the roles of the miR-106b-25 cluster is to prevent excessively high E2F1 expression, which may then cause apoptosis. We conclude that there is aberrant expression of microRNAs encoded by the oncogenic miR-17-92 cluster and the miR-106b-25 cluster in hepatocellular carcinoma. The consistent overexpression of the miR-106b-25 cluster and its role in cell proliferation and anchorage-independent growth points to the oncogenic potential of this cluster.

Cultural adaptation and validation of a questionnaire for use in hepatitis B patients

Health-related quality of life (HRQoL) is an important aspect of the overall management of hepatitis B virus (HBV) infection. The major challenge is to find a valid and reliable disease-specific HRQoL instrument designed specifically for measuring health status in hepatitis B patient. Consequently, this study was undertaken to adapt culturally the Hepatitis Quality of Life Questionnaire (HQLQ) and assess its suitability for use in English-speaking hepatitis B virus-infected (HBV) patients in Singapore. Two patient focus groups were conducted to facilitate the cultural adaptation of the HQLQ. Reliability was assessed using Cronbach's alpha coefficients and intraclass correlation coefficients. Item-to-scale correlation was assessed using Spearman's rank correlations (rho) between scale scores and their constituent items. Convergent and divergent construct validities were tested in three and two a priori hypotheses, respectively, and the correlations were assessed using Spearman's rank correlation coefficients (rho). The culturally adapted questionnaire was tested in 298 HBV patients. The test-retest reliability was supported with 10 of the 12 scales showing acceptable correlation coefficients (i.e. alpha>0.7). Item-to-scale correlations were good with most items highly correlated with their hypothesized scales. Convergent and divergent construct validities were supported by the presence of hypothesized correlations between the HQLQ and the EQ-5D domains (eight of 10 sub-hypotheses for convergent construct validity and all hypotheses for divergent construct validity were fulfilled). In conclusion, our results showed that the culturally adapted HQLQ has good validity and reliability, making it a potentially useful outcome measure in the evaluation of HBV patients in Singapore.

How big is the financial burden of hepatitis B to society? A cost-of-illness study of hepatitis B infection in Singapore

Hepatitis B virus (HBV) infection is the most common cause of chronic viral liver disease in Singapore. Nevertheless, very little data exist on the financial burden of HBV infection to the society as a whole. The aim of this study was therefore to assess the direct and indirect cost of HBV infection in a cost-of-illness analysis. The combined data from the direct and indirect cost with the estimated prevalence for different disease stages of HBV infection would represent the annual financial burden of HBV infection to the Singaporean society as a whole. The estimated total annual cost of chronic HBV infection and its associated complications in Singapore was US$279 million (range US$34-941 million when allowing various assumptions as tested by the sensitivity analyses), with 58% or US$161 million attributable to direct cost. Based on the base-case estimation, total direct cost alone is equivalent to 12% of the national healthcare expenditure for 2003. The total cost incurred by chronic hepatitis B patients represents the biggest cost component, followed by decompensated cirrhosis (DC) patients. The ratio of direct to indirect costs based on the base-case estimation increased with disease severity, with the highest ratio obtained for the post-liver transplants (40.2:1), followed by hepatocellular carcinoma (7.4:1) and DC patients (2.7:1). The results of this study suggest that the management of HBV infection poses more than a medical challenge as it is a sizeable economic burden from both the payer and societal perspectives.

Zidovudine treatment for anti-HIV positive haemophiliacs

Twenty haemophiliacs (17 CDC group IV and 3 CDC group II) were treated with zidovudine for a median of 37 weeks (range 10-66). Eight (40%) tolerated zidovudine without a dose change. Two patients died and five patients (29%) developed opportunist infections. Haematological toxicity occurred in ten CDC IV patients (59%) but only one case of sepsis occurred in 101 episodes of documented granulocytopenia. Thrombocytopenia responded to treatment with zidovudine in four of five patients. It is concluded that zidovudine is beneficial for symptomatic haemophiliacs and although the haematological toxicity is high, it is mostly asymptomatic, reversible and well tolerated. Two of the three CDC II patients treated with zidovudine progressed to CDC IV, but had low initial T4 lymphocyte counts and were P24 antigen positive.

Antibodies to platelet glycoproteins in haemophiliacs infected with HIV

The techniques of Western blotting and the monoclonal antibody specific immobilization of platelet antigen (MAIPA) assay were used to detect antibodies to platelet glycoproteins in 43 samples of serum from 23 anti-HIV positive haemophiliacs (8 with severe thrombocytopenia, 6 with moderate thrombocytopenia, and 9 with a normal platelet count), six anti-HIV negative haemophiliacs and ten controls. Antibodies were present in the majority of anti-HIV positive patients' sera even before the onset of thrombocytopenia. Thrombocytopenia was associated with an increase in the incidence of antibodies to GPIIIa and GPIb, whereas the antigen most frequently recognized in patients without thrombocytopenia was GPIIb. Anti-GPIIb and/or GPIIIa reactivity was also seen in three out of the six anti-HIV negative patients. There was no correlation between the absolute platelet count and the detection of antibodies in either assay. Effective therapy for thrombocytopenia with zidovudine, interferon or splenectomy did not influence the presence of antibody. Eight of nine patients with AIDS were negative in the MAIPA assay, consistent with their depressed immune status. It is concluded that the production of antibodies to platelet membrane glycoprotein in anti-HIV positive haemophiliacs is influenced by factors other than HIV. The presence of such antibodies is independent of the platelet count and is therefore unlikely to play a causative role in HIV-related thrombocytopenia.

The treatment of HIV associated thrombocytopenia in haemophiliacs

HIV associated thrombocytopenia occurs in 5-10% of asymptomatic individuals, and 25-45% of people with AIDS. A variety of treatments are available but the inherited bleeding disorder in addition to the thrombocytopenia makes management in haemophiliacs a special problem. The management of this double coagulopathy is described in seven patients. IV gammaglobulin and steroids were useful only in the short term; zidovudine produced a good response, could be taken orally, had anti-HIV activity and was well tolerated in asymptomatic HIV positive patients. Interferon was an alternative when zidovudine was ineffective or produced intolerable side-effects. Splenectomy was considered only after failure of other treatments because of the increased risks of bleeding.

Clinical trial: a phase II, randomized study evaluating the safety, pharmacokinetics and anti-viral activity of clevudine for 12 weeks in patients with chronic hepatitis B

BACKGROUND

Clevudine is a polymerase inhibitor that has the unusual feature of delayed viral rebound after therapy in some patients which may be related to its pharmacokinetics.

AIM

To characterize pharmacokinetic and pharmacodynamic profile of clevudine, a potent hepatitis B polymerase inhibitor.

METHODS

A multicenter, randomized study comparing 10, 30 and 50 mg clevudine once daily for 12 weeks with 24 weeks off-treatment follow-up. Patients had chronic HBV infection, were nucleoside-naïve without co-infection. HBV viral load (VL) was assayed using Digene Hybrid Capture II with a lower limit of detection of 4700 copies/mL (940 IU/mL). Clevudine levels were measured using a liquid chromatography/mass spectrometery method.

RESULTS

A total of 31 patients were enrolled into the 10 mg (n = 10), 30 mg (n = 11) and 50 mg (n = 10) groups, respectively. At week 12, the median VL change was -3.2, -3.7 and -4.2 log(10) copies/mL (-0.64, -0.74 and -0.84 log(10) IU/mL) in the 10, 30 and 50 mg groups, respectively (P = 0.012). At week 12, one of 10, five of 11 and two of 10 patients had VL below the assay lower limit of detection. Clevudine was well tolerated with no severe/serious adverse events. The mean plasma half-life of clevudine was 70 h and consequently is not the cause of the delayed viral rebound seen in some patients. Through modelling, 97% of the maximal treatment effect was reached with a 30 mg daily dose. Six patients had genomic changes without viral rebound.

CONCLUSION

Clevudine appears to be a potent and tolerable (over 12 weeks) anti-viral and the optimal dosage appears to be 30 mg once daily.

Clinical trial: effects of adefovir dipivoxil therapy in Asian and Caucasian patients with chronic hepatitis B

BACKGROUND

Two-thirds of the 350 million people infected with chronic hepatitis B virus live in the Asia-Pacific region. AIM To compare the effects of adefovir dipivoxil therapy between Asian and Caucasian patients with chronic hepatitis B.

METHODS

The safety and efficacy of 10 mg of adefovir dipivoxil was compared to placebo in 501 Asian (n = 259) or Caucasian (n = 242) HBeAg+ and HBeAg- chronic hepatitis B virus patients treated for 48 weeks in two randomized, double-blind, placebo-controlled studies.

RESULTS

At week 48, histological improvement was observed in 60% and 56% of Caucasian and Asian patients, respectively. Change in serum hepatitis B virus DNA from baseline to week 48 for the adefovir dipivoxil-treated patients was -3.89 and -3.70 log(10) copies/mL in Caucasian and Asian patients, respectively, while 34 per cent of Caucasian patients and 39 per cent of Asian patients had undetectable serum hepatitis B virus DNA (<400 copies/mL) at week 48. The percentage of patients achieving alanine aminotransferase (ALT) normalization at week 48 was similar in both groups (Caucasian 64 per cent, Asian 63 per cent). No patients developed resistance through week 48. No differences in adverse events or grade 3 or 4 laboratory abnormalities were observed between groups.

CONCLUSIONS

There were no significant differences in treatment response between Asians and Caucasians. Adefovir dipivoxil was well tolerated and no resistance developed up to week 48 in both racial groups.

Report of an international workshop: Roadmap for management of patients receiving oral therapy for chronic hepatitis B

An international group of experienced hepatologists and virologists conducted a single-day workshop to review the management of patients with chronic hepatitis B receiving treatment with oral nucleosides or nucleotides. Guidelines regarding on-treatment management and available published data on the importance of serum hepatitis B virus (HBV) DNA as a marker of outcomes were reviewed. On-treatment monitoring strategies to define early virologic responses that might be predictive of better outcomes and a reduced risk of viral resistance were proposed for further study. This treatment plan, labeled the roadmap concept, recommends monitoring of serum HBV DNA levels to identify outcomes of therapy. Primary treatment failure was defined as a reduction of serum HBV DNA levels by less than 1 log10 IU/mL from baseline at week 12. Measurement of the HBV DNA level at week 24 was considered essential to characterize virologic responses as complete, partial, or inadequate. Complete virologic response was defined as negative HBV DNA by a sensitive assay (<60 IU/mL or <300 copies/mL); partial virologic response was defined as HBV DNA levels less than 2000 IU/mL (4 log10 copies/mL), and inadequate virologic response was defined as HBV DNA levels of 2000 IU/mL or greater (4 log10 copies/mL). Strategies are proposed for managing patients in each of these categories, depending in part on the rapidity with which HBV DNA suppression is achieved and the emergence of genotypic mutations that reduce the effectiveness of a specific drug. Future studies of the use of the roadmap concept in improving outcomes of chronic hepatitis B are warranted.

Liver transplantation for hepatocellular carcinoma in Singapore

INTRODUCTION

The prognosis of patients with hepatocellular carcinoma (HCC) is poor. Surgical resection offers the benefit of removal of the tumour but is associated with liver decompensation and tumour recurrence, even after successful surgery. Liver transplantation offers the benefits of complete tumour removal with prevention of both decompensation and recurrence post-operation. This paper aims to review results of liver transplantation for patients with HCC in Singapore.

METHODS

All adult patients with HCC accepted on the waiting list for liver transplantation (based on the Milan criteria) from 1996 to 2004 in Singapore were reviewed. Patients' HCC were managed with either transarterial chemoembolisation or percutaneous radiofrequency ablation while they were on the waiting list. Post-transplant survival and factors associated with mortality were analysed by Cox regression analysis.

RESULTS

41 patients with HCC were accepted onto the waiting list over the nine-year period. 22 underwent transplantation and 19 did not, with a one-year survival of 91 percent versus 24 percent, respectively. (p-value is less than 0.001). Mean waiting time for transplant was 39 weeks. Post-transplant HCC recurrence was 2/22 (nine percent). Among all patients, mortality was significantly related to baseline white cell counts, prothrombin time, age, alpha-foetoprotein level, Child-Pugh score, and whether patients underwent transplant.

CONCLUSION

Despite the relatively long waiting time of a mean of 39 weeks, post-transplant recurrence of HCC was relatively low at nine percent. Liver transplant is an effective treatment for patients with a HCC, with a reasonable long-term survival.

Referral patterns and waiting times for liver transplantation in Singapore

INTRODUCTION

Referral patterns, waiting times, waiting list, and mortality provide information on how effectively a transplant programme deals with referred patients. This paper aims to review these parameters in the Singapore National Liver Transplant Programme.

METHODS

Data of all patients referred to the Singapore National Liver Transplant Programme since its inception were captured and outcomes were retrieved and described.

RESULTS

562 patients were referred for liver transplant evaluation from 1990-2004, consisting of 457 adults and 105 children. The main indications for referral were hepatitis B liver disease and hepatocellular carcinoma in adults, and biliary atresia in children. Most patients were of United Network of Organ Sharing (UNOS) status 3 or 4 at the time of referral. 114 (20.28 percent) patients had transplants, consisting of 66 adults (14.44 percent) and 48 (45.71 percent) children. 138 adults and ten children were rejected for transplant, mainly for the reason of being "too early". The median waiting time for adults who had transplants was 3.3 months while adults still on the waiting list had been waiting for 16.2 months. The overall waiting list mortality was 44.3 percent, being 52.5 percent in adults and 23.2 percent in children.

CONCLUSION

The overall transplantation rate is low and the waiting list mortality is high as a result of low availability of organs, particularly in adults. Paediatric liver transplant appears to have been better at dealing with referred patients but this is probably due to availability of living-related liver transplant. Improvement in these may result from the Human Organ Transplant Act.

Long-term post-liver transplant complications of renal impairment and diabetes mellitus: data from Singapore

INTRODUCTION

Patients who survive the initial post-liver transplantation period face the development of chronic diseases in the long run. We studied two important complications of liver transplantation, namely: renal impairment and diabetes mellitus.

METHODS

We analysed adult patients followed-up for more than one year using data from our liver transplant clinical records. Long-term post-transplant renal impairment (RI) was defined as glomerular filtration rate (GFR) less than 60 ml/min/1.73 square metres and long-term post-transplant diabetes mellitus (DM) was defined as fasting blood glucose more than 7.8 mmol/L, that existed at least one year after liver transplantation. Pre- and post-transplant factors that could be associated with these conditions were examined.

RESULTS

Altogether, 35 patients were evaluated. Mean age at transplant was 50 years. Mean duration of follow-up was 58.4 months. There was 11.4 percent of pre-transplant RI and 17.0 percent of pre-transplant DM. Prevalence of post-transplant RI was 43.5 percent at one year and 45.0 percent at four years. Long-term post-transplant RI was associated with renal impairment at six months post-transplant (p-value is 0.033). Prevalence of severe post-transplant RI (GFR is less than 30 ml/min/1.73 square metres) at four years was 5.7 percent. Prevalence of post-transplant DM was 45.5 percent at two years but declined to 5.3 percent at four years.

CONCLUSION

Post-transplant renal impairment appears to be a potential long-term problem while post-transplant diabetes mellitus appears to improve with time.

MELD may not be the better system for organ allocation in liver transplantation patients in Singapore

INTRODUCTION

The Model for End-Stage Liver Disease (MELD) score is a good predictor of mortality on the liver transplant waiting list and is the current system of organ allocation in the USA. However, a higher MELD may be associated with poorer outcome post-liver transplantation. The aim of this study was to determine if MELD should be implemented as the system for organ allocation for liver transplantation in Singapore.

METHODS

There were 46 adult patients who underwent primary liver transplantation at the National University Hospital, Singapore from January 1996 to December 2002. We applied the MELD score to patients who were transplanted and looked for a correlation with survival post-transplant. Patients were followed-up until the most recent visit or death. Survival analysis was performed using Cox regression and Kaplan-Meier method.

RESULTS

The mean age at transplant was 52.7 (SD 2.34) years. The majority of the patients transplanted had Hepatitis B (43 percent). The median MELD score at transplantation was 17 (7-42) and the median Child's score was 11 (6-15). There was a significant correlation between pre-transplant MELD and survival at six months (p-value is 0.037, 95 percent confidence interval [CI] is 1.004-1.13) but not at one year (p-value is 0.065, 95 percent CI is 0.99-1.12). There were no differences in the pre-transplant MELD (odds-ratio [OR] 1, 95 percent CI 0.9-1) as well as survival for patients with and without Hepatitis B (OR 0.72, 95 percent CI 0.22-2.35).

CONCLUSION

MELD allows livers to be allocated to the patients with the greatest medical urgency but its influence on post-transplant survival should be further clarified so that post-transplant survival is not compromised.

Liver transplantation in Singapore 1990-2004

INTRODUCTION

Liver transplantation is the accepted standard of care for patients with hepatocellular carcinoma, decompensated liver cirrhosis, and acute liver failure. Since the first liver transplant done in Singapore in 1990, results have been improving. We review the overall results of liver transplantation over the last 15 years.

METHODS

All transplant cases from 1990 to 2004 were reviewed retrospectively.

RESULTS

100 liver transplants were performed over the last 15 years; four in the first five years and 96 in the subsequent ten years. Overall one- and five-year survival rates were 80 percent and 78 percent, respectively. 44 were paediatric transplants, of which biliary atresia was the commonest indication for paediatric transplant. 56 were adult transplants of which hepatocellular carcinoma and decompensated hepatitis B cirrhosis were the commonest indications for adult transplant. Infection remained the commonest cause of mortality.

CONCLUSION

The number of transplants carried out per year was small due to the low cadaveric donation rate, but the survival of liver transplant patients was comparable to well-established liver transplant centres.

Long-term results of liver transplant in patients with chronic viral hepatitis-related liver disease in Singapore

INTRODUCTION

Liver disease from chronic hepatitis B (CHB) and C (CHC) constitutes 57 percent of adult liver transplant in Singapore. Their long-term results post-transplant may be affected by recurrence of the viral illness. This study aims to evaluate the long-term results and survival in patients transplanted for CHB- and CHC-related liver disease.

METHODS

Patients transplanted for CHB- and CHC-related disease from 1990 until March 2004, which included decompensated cirrhosis and hepatocellular carcinoma (HCC), were reviewed and analysed.

RESULTS

25 patients were transplanted for CHB-related liver disease, with mean follow-up of 153 +/- 25 weeks. Two- and four-year survival rates were 75 percent and 69 percent, respectively. Hepatitis B recurrence from YMDD mutants occurred in five patients, and four were treated successfully with adefovir dipivoxil, with resolution in transaminases and/or improvement in histology. One patient became non-compliant with follow-up and medications, and died 173 weeks post-transplant from reactivation of the wild-type hepatitis B virus. Nine patients were transplanted for CHC-related liver disease, with mean follow-up of 188 +/- 40 weeks, and two- and four-year survival rates of 89 percent and 76 percent, respectively. Two patients developed hepatitis C recurrence and were treated with interferon and ribavarin. One responded with sustained response but the other remained viraemic and died of HCC recurrence two years post-transplant.

CONCLUSION

Long-term results from CHB- and CHC-related liver diseases were satisfactory and comparable to major transplant centres in the USA and Europe. Recurrence of viral hepatitis post-transplant is controllable with current antiviral therapy.

Treatment of steroid-resistant acute liver transplant rejection with basiliximab

Current rescue therapies for acute steroid-resistant rejection, such as OKT3 and high-dose tacrolimus, are not uncommonly associated with side effects that contribute to significant morbidity of the patient. Basiliximab is a chimeric monoclonal antibody that acts as an interleukin-2 receptor antagonist on the surface of activated T lymphocytes. It has until now only been used as immunoprophylaxis in adult liver transplant patients. In this report, we describe the use of Basiliximab as rescue therapy in a case of acute steroid-resistant rejection in an adult living related liver transplant recipient.

Successful listing of patients for liver transplant was related to participation of referring doctor in the transplant program

INTRODUCTION

Experience with liver transplantation is limited in many parts of Asia. Therefore, patients from nontransplant centers may not be referred in a timely fashion for transplants. Our aim was to evaluate the pattern of referral for liver transplantation and their outcomes in Singapore.

METHODS

Consecutive patients referred from 1990 to 2001 were reviewed. Patients from any hospital in Singapore (or the region) could be referred to the program. They were discussed at the weekly meetings. Appropriate patients were placed on the waiting list. "Pending" indicated that the disease was early or there were unsettled medical or social issues. Unsuitable patients were "rejected" for transplant.

RESULTS

There were 385 patients referred over a 12-year period. Hepatitis B cirrhosis and hepatocellular carcinoma (HCC) were the most common indications among adults, whereas biliary atresia was the most common for children. Pediatric patients were more likely than adult patients to be listed for transplant (53/76 vs 106/309, P < .001). Patients referred by regular attendees of the program were more likely to be accepted than nonattendees (38% vs 25%, P = .04). "Disease too early", "advanced HCC", and "refusal by family members" were the most common reasons for rejection.

CONCLUSION

Members of the Liver Transplant Program were more likely to refer suitable patients for transplant at the appropriate time. Better interaction between gastroenterologists inside and outside the transplant program would help to improve the timing of referrals for liver transplantation, and hence, patient survival.

The MELD score may help to determine optimum time for liver transplantation

BACKGROUND

The model for end-stage liver disease (MELD) score is a good predictor of mortality on the waiting list and short-term survival post liver transplantation.

AIM

Our aim was to determine if there is a pretransplant MELD score beyond which liver transplantation is prohibitive.

PATIENTS AND METHODS

Forty-six adult patients underwent primary liver transplantation from January 1996 to December 2002. Patients followed to the most recent visit or death underwent survival analysis using Cox regression and Kaplan Meier methods.

RESULTS

There was a significant correlation between the pretransplant MELD score and survival at 6 months posttransplant (P=.037 95% CI: 1.004-1.13). Patients with pretransplant MELD score greater than or equal to 32 showed significantly greater mortality compared with those less than 32 (HR 9.18, 95%CI=1.16-72.44).

CONCLUSION

Pretransplant MELD may help to determine the optimum time for liver transplantation.

A cost comparison of management of chronic hepatitis B and its associated complications in Hong Kong and Singapore

GOALS

To estimate and compare the direct medical cost in the management of chronic hepatitis B (CHB) infection and its complications from the perspective of public health organizations in Hong Kong and Singapore.

BACKGROUND

Hong Kong and Singapore are endemic hepatitis B virus areas with about 10% and 5%, respectively, of the population estimated as hepatitis B virus infected.

STUDY

The medical histories of 660 patients with CHB who received medical services over 5 years from three major public hospitals in Hong Kong and Singapore were studied retrospectively. Costs were analyzed according to the five disease states and estimated in Hong Kong dollars (HKD) and Singapore dollars (SGD).

RESULTS

In both Hong Kong and Singapore, the per-patient total annual cost increased with the severity of the disease. CHB cost HKD 6318 (US 810 dollars) in Hong Kong and SGD 718.15 (US 410.37 dollars) in Singapore. Compensated cirrhosis cost HKD 10,304 (US 1321 dollars) in Hong Kong and SGD 1,175.34 (US 671.62 dollars) in Singapore. Decompensated cirrhosis cost HKD 58,428 (US 7490 dollars) in Hong Kong and SGD 15,389.84 (US 8794.19 dollars) in Singapore. Hepatocellular carcinoma cost HKD 121,822 (US 15,618 dollars) in Hong Kong and SGD 12314.04 (US 7036.59 dollars) in Singapore. Each case of liver transplant was estimated to cost HKD 514,498 (US 65,961 dollars) in Hong Kong and SGD 86,369.28 (US 49,353.87 dollars) in Singapore. CHB in Hong Kong accounted for about 4% of the healthcare expenditure.

CONCLUSION

This study confirms that CHB and its liver disease complications are a significant economic burden to the healthcare budgets of Hong Kong and Singapore, and indicates that effective therapy that arrests or reverses the progression of liver disease would be highly cost-effective.

The majority of hepatitis B carriers are not on regular surveillance in Singapore

INTRODUCTION

Carriers of hepatitis B virus (HBV) are at risk of developing long-term complications. Regular surveillance helps detect treatable chronic hepatitis, cirrhosis and liver cancer, and is recommended by practice guidelines in the United States, Europe and Singapore. However, there have been few studies evaluating the follow-up of HBV carriers. This study seeks to determine the proportion of HBV carriers on regular follow-up in Singapore and the impact on hepatitis B disease.

METHODS

An advertisement was taken in local newspapers advertising for free screening to HBV carriers. 387 persons answered the advertisement. The screening comprised history-taking, physical examination, blood tests (liver panel, alphafoetoprotein, hepatitis B surface antigen (Ag) and hepatitis B eAg) and ultrasonography of liver. Further evaluation was conducted if the screening results were abnormal.

RESULTS

Of the 387 HBV carriers, 346 (89 percent) were male and 375 (97 percent) were Chinese. Their mean age was 39 years (range 20-60 years) and 36 percent were positive for HBeAg. 247 (64 percent) were not on regular screening over the past 12 months. 19 (5.4 percent) patients were diagnosed to have complications, namely: 13 had HBeAg-positive chronic hepatitis, two had HBeAg-negative chronic hepatitis, one had early liver cancer who recovered well after a curative resection and three had compensated cirrhosis.

CONCLUSION

Our screening programme diagnosed 5.4 percent of complications among 387 asymptomatic HBV carriers. However, 64 percent of the study subjects were not screened regularly and may pose an important public health threat if they develop long-term complications. Further studies are needed to evaluate and improve patient compliance for screening.

Genome-wide expression profiling of RNA interference of hepatitis B virus gene expression and replication

Small interfering RNA (siRNA) has been used repeatedly to down-regulate viral gene expression and inhibit viral replication in mammalian cells. In this study, we showed that siRNAs specific for two conserved regions within the hepatitis B S antigen (HBsAg) gene can inhibit antigen production in two human liver cell lines which constitutively produce and secrete HBsAg. The inhibitory effect was concentration dependent for both PLC/PRF/5 and 2.2.15 cells. Decreases in the corresponding viral transcript levels were observed. The inhibitory effect was observed within 24 h and was still evident 7 days after the initial treatment with siRNA. A significant reduction in virion production was also observed for the 2.2.15 cells. A critical consideration in this study was the specificity of the siRNA-mediated inhibition. To address this, we first examined the effects on cell growth and viability. These were not affected in either cell line. cDNA microarrays were also used to examine genome-wide changes in gene regulation. No significant off-target gene regulation was observed in either cell line. Our findings thus indicate that siRNA can specifically mediate the down-regulation of viral gene expression leading to a reduction in virion production.

Successful treatment of Xylohypha bantiana brain abscess mimicking invasive cerebral aspergillosis in a liver transplant recipient

Invasive aspergillosis is a highly lethal disease in immunocompromised hosts especially with central nervous system involvement. In a review of 2380 liver transplants performed over 14 years, 13 out of 15 fungal brain abscesses were due to Aspergillus species and only one patient survived [Arch Surg, 132 (1997) 304]. Dematiaceous fungi while less readily recognised, often have a more favorable outcome [Transplantation, 63 (1997) 160]. We report a Xylophypha bantiana cerebral abscess in a liver transplant recipient initially identified as a branching mould on histology that had a successful outcome due to aggressive appropriate treatment.

Prophylactic lamivudine prevents hepatitis B reactivation in chemotherapy patients

BACKGROUND

Chronic hepatitis B virus carriers receiving chemotherapy develop a high hepatitis B virus reactivation rate (38-53%) with a high mortality (37-60%). Few studies have characterized the efficacy of lamivudine in the treatment of chemotherapy-induced hepatitis B virus reactivation.

AIM

To determine whether lamivudine prophylaxis reduces chemotherapy-induced hepatitis B virus reactivation and mortality.

METHODS

The medical records of all hepatitis B surface antigen-positive patients with malignancy treated with chemotherapy since 1995 at the National University Hospital of Singapore were identified, and divided into those who received lamivudine prophylaxis before chemotherapy (P) and those who did not (NP). The parameters examined included gender, age, malignancy type, steroid usage, number of chemotherapy courses and regimens, follow-up duration and hepatitis B virus status. The outcome measures were hepatitis B virus reactivation (abrupt rise of serum alanine aminotransferase to > 200 IU/L) and reactivation death. Patients with primary hepatoma or liver metastasis were excluded.

RESULTS

Thirty-five patients were identified: 16 in the P group and 19 in the NP group. The baseline characteristics of the two groups were similar. Seven of the 19 patients in the NP group and none of the 16 patients in the P group developed reactivation (36.8% vs. 0%, P=0.009). Six of the seven patients in the NP group who developed reactivation received lamivudine at that time, but five died (mortality, 71.4%), whilst no patient in the P group died from reactivation (P=0.064).

CONCLUSIONS

Prophylactic lamivudine appears to prevent hepatitis B virus reactivation and its associated mortality in patients treated with chemotherapy. This should be confirmed with prospective studies.

Fatal hepatitis B reactivation following discontinuation of nucleoside analogues for chronic hepatitis B

BACKGROUND

Nucleoside analogues such as lamivudine for chronic hepatitis B have an excellent safety profile while patients are on therapy but reactivation flares occur in 19-50% of patients after stopping therapy, some of whom develop liver decompensation.

AIMS

To describe and report three cases who developed fatal hepatitis B reactivation after stopping nucleoside analogue therapy.

SUBJECTS AND RESULTS

Three patients are described who developed hepatitis B reactivation and liver decompensation after stopping therapy. One of the three patients was participating in a famciclovir trial and the other two were receiving lamivudine therapy for active hepatitis B infection. All three patients had documented hepatitis B flares, and all had hepatitis B virus DNA detected at that time. All patients developed decompensated liver disease despite one patient having had a prior liver biopsy showing absence of cirrhosis. Reintroduction of lamivudine therapy failed to halt progression of liver decompensation even after hepatitis B virus DNA had been demonstrated to be absent. Sequencing for lamivudine resistant mutants in two cases where serum was available failed to show evidence of mutations associated with lamivudine resistance.

CONCLUSION

Hepatitis B virus reactivation, leading to decompensation and death, are possible complications of treatment withdrawal and patients should be monitored closely if therapy is ceased.

Identification and molecular characterisation of the complete genome of a Singapore isolate of hepatitis C virus: sequence comparison with other strains and phylogenetic analysis

The complete genomic sequence of a Singapore isolate of the hepatitis C virus (HCV) was obtained from serum of an individual chronically infected with HCV. Nine overlapping cDNA clones covering the entire viral genome was amplified by reverse-transcription-polymerase chain reaction (RT-PCR), This isolate (HCV-S1) comprised 9,609 nucleotides (nt), including 341 nt of the complete 5' untranslated region (5' UTR), a single open reading frame of 3,011 amino acids (aa) and 235 nt of the complete 3' UTR. Its genotype was identified as type lb from analyses of its sequences in the 5' UTR, NS3 and NS5B regions. When compared against nine reported HCV isolates, the overall aa homology of HCV-SI was closest with an Australian strain, HCV-A (94%) and a Japanese strain, HCV-JT (93.9%). Phylogenetic analysis revealed that it was most closely related to the Taiwan strain, HCV-TW and another Japanese strain, HCV-K1-R1.

The hepatitis C virus core protein interacts with NS5A and activates its caspase-mediated proteolytic cleavage

Viral proteins interact with one another during viral replication, assembly, and maturation. Systematic interaction assays of the hepatitis C virus (HCV) proteins using the yeast two-hybrid method have uncovered a novel interaction between core and NS5A. This interaction was confirmed by in vitro binding assays, and coimmunoprecipitation in mammalian cells. Core and NS5A are also colocalized in COS-7 cells. Interestingly, NS5A is cleaved to give specific-size fragments, when core is coexpressed in mammalian cells. Overexpression of core produced many dying and rounded cells and effects such as DNA laddering and the truncation of poly(ADP-ribose) polymerase 1 (PARP1), both indicators of apoptosis. These observations led us to investigate the link between the induction of apoptosis by core and the cleavage of NS5A. The proteolysis of NS5A and these apoptotic events can be inhibited by caspase inhibitor, Z-VAD, indicating that core induces apoptosis and the cleavage of NS5A by caspases. In cells infected by the HCV, core may provide the intrinsic apoptotic signal, which produces truncated forms of NS5A. The biological function of core-NS5A interaction and the downstream effect of NS5A cleavage are discussed.

Extended lamivudine treatment in patients with chronic hepatitis B enhances hepatitis B e antigen seroconversion rates: results after 3 years of therapy

A study in Chinese patients with chronic hepatitis B showed that treatment with lamivudine for 1 year significantly improves liver histology and enhances hepatitis B e antigen (HBeAg) seroconversion compared with placebo. Fifty-eight patients from this 1-year study have received long-term treatment with lamivudine 100 mg; the outcome of 3 years of lamivudine is reported here. Before treatment, all patients had detectable HBeAg. HBeAg seroconversion (HBeAg-negative, anti-HBe-positive), hepatitis B virus (HBV)-DNA suppression, alanine transaminase (ALT) normalization, emergence of YMDD variant HBV, liver histology, and long-term safety were assessed. After 3 years of continuous treatment with lamivudine 100 mg daily, 40% (23 of 58) of patients achieved HBeAg seroconversion. In patients with baseline serum ALT >2 x upper limit of normal (ULN), the rate of HBeAg seroconversion was 65% (17 of 26). Median serum HBV-DNA concentrations were below the level of detection, and median ALT concentrations were within the normal range throughout 3 years of treatment. YMDD variant HBV emerged in 33 of 58 (57%) patients during the 3 years, of whom 9 (27%) achieved HBeAg seroconversion (6 after emergence of YMDD variant HBV). ALT levels and histologic scores after emergence of YMDD variant HBV did not show major deterioration. Lamivudine was well tolerated during 3 years of therapy. In conclusion, these data in Chinese patients with chronic hepatitis B show enhanced seroconversion rates with extended lamivudine treatment. Up to two thirds of patients with moderately elevated pretreatment ALT achieved HBeAg seroconversion after 3 years of therapy.

Palliation of malignant gastric outlet obstruction caused by gastric cancer with self-expandable metal stents

Gastric carcinoma is among the most common cancers worldwide. Surgery remains the mainstay of potentially curative treatments. Unfortunately, most patients have an advanced form of the disease. We evaluated our experience in palliating malignant gastric outlet obstruction caused by gastric cancer with expandable metal stents (Wallstent Enteral; Boston Scientific, Singapore). Six patients with a median age of 68 years (range, 45-88) underwent the procedure. Three had metastatic gastric cancer; two recurrent gastric cancer; and one locally advanced gastric cancer with poor comorbid status. After the procedure, five of the six patients were able to resume an oral feeding within 24 hours. One patient with gastric dysmotility caused by linitus plastica required nasogastric tube feeding. Three patients died during a median follow-up period of 4 weeks (range, 2-8). The other three patients were still well at a median follow-up period of 10 weeks (range, 5-12). There was no procedure-related mortality or morbidity, nor was there any stent migration or blockage in any of these patients. In conclusion, palliation of malignant gastric outlet strictures caused by gastric cancer with expandable metal stents is an effective and safe alternative to surgery, particularly in patients with postgastrectomy anastomotic recurrence and in those who are poor candidates for surgery. Patients who are not expected to survive beyond 1 month and those with linitus plastica and associated gastric dysmotility may not be appropriate candidates for such a procedure.

Mutations that affect dimer formation and helicase activity of the hepatitis C virus helicase

Interaction between viral proteins is necessary for viral replication and viral particle assembly. We used the yeast two-hybrid assay to identify interactions among all the mature proteins of the hepatitis C virus. The interaction between NS3 and NS3 was one of the strongest viral protein-protein interactions detected. The minimal region required for this interaction was mapped to a specific subdomain of 174 amino acids in the N terminus of the helicase region. Random mutations in the minimal region were generated by PCR, and mutants that failed to interact with a wild-type minimal fragment were isolated using the yeast two-hybrid assay as a screen. Three of these mutations resulted in a reduction or a loss of interaction between helicases. Analytical gel filtration showed that in the presence of an oligonucleotide, wild-type helicases form dimers whereas the mutants remain mostly monomeric. All three mutants were partially or almost inactive when assayed for helicase activity in vitro. Mixing a mutant helicase (Y267S) with wild-type helicase did not dramatically affect helicase activity. These data indicate that dimerization of the helicase is important for helicase activity. The mutations that reduce self-association of the helicase may define the key residues involved in NS3-NS3 dimerization.