Incidence and prediction of HBsAg seroclearance in a prospective multi-ethnic HBeAg-negative chronic hepatitis B cohort

BACKGROUND AND AIMS

Achieving HBsAg loss is an important landmark in the natural history of chronic hepatitis B (CHB). A more personalized approach to prediction of HBsAg loss is relevant in counseling patients. This study sought to develop and validate a prediction model for HBsAg loss based on quantitative HBsAg levels (qHBsAg) and other baseline characteristics.

METHODS

The Hepatitis B Research Network (HBRN) is a prospective cohort including 1240 untreated HBeAg-negative patients (1150 adults, 90 children) with median follow-up of 5.5 years. Incidence rates of HBsAg loss and hepatitis B surface antibody (anti-HBs) acquisition were determined, and a predictor score of HBsAg loss using readily available variables was developed and externally validated.

RESULTS

Crude incidence rates of HBsAg loss and anti-HBs acquisition were 1.6 and 1.1 per 100 person-years (PY); 67 achieved sustained HBsAg loss for an incidence rate of 1.2 per 100 PY. Increased HBsAg loss was significantly associated with older age, non-Asian race, HBV phenotype (inactive CHB vs. others), HBV genotype A, lower HBV-DNA levels, and lower and greater change in qHBsAg. The HBRN-SQuARe (sex,∆quantHBsAg, age, race) score predicted HBsAg loss over time with area under the receiver operating characteristic curve (AUROC) (95% CIs) at 1 and 3 years of 0.99 (95% CI: 0.987-1.00) and 0.95 (95% CI 0.91-1.00), respectively. In validation in another cohort of 1253 HBeAg-negative patients with median follow-up of 3.1 years, HBRN SQuARe predicted HBsAg loss at 1 and 3 years with AUROC values of 0.99 (0.98-1.00) and 0.88 (0.77-0.99), respectively.

CONCLUSION

HBsAg loss in predominantly untreated patients with HBeAg-negative CHB can be accurately predicted over a 3-year horizon using a simple validated score (HBRN SQuARe). This prognostication tool can be used to support patient care and counseling.

Coagulopathy, Bleeding Events, and Outcome According to Rotational Thromboelastometry in Patients With Acute Liver Injury/Failure

BACKGROUND AND AIMS

Patients with acute liver injury or failure (ALI/ALF) experience bleeding complications uncommonly despite an abnormal hemostatic profile. Rotational thromboelastometry (ROTEM), which assesses clot formation in whole blood, was used to determine the nature of abnormal hemostasis and whether it contributes to bleeding events, illness severity, or survival.

APPROACH AND RESULTS

A total of 200 patients were recruited from sites of the ALF Study Group. Blood collected daily for up to 5 days was analyzed using ROTEM delta devices. Consistent with standard laboratory evidence of hypocoagulability (median international normalized ratio = 2.9 and platelet count = 144 × 109 /L), patients frequently exhibited ROTEM parameters outside the normal range (73% and 62% had abnormalities in clot formation from extrinsic and intrinsic clotting cascades, respectively); however, measures of clot stability were generally normal. Eighteen patients (9%) experienced bleeding events, in whom clot initiation, assembly, and firmness were more severely deranged than patients without bleeding. Abnormal ROTEM parameters were more frequently observed in patients with non-acetaminophen ALI/ALF than those with acetaminophen ALI/ALF (clot initiation [P < 0.001], assembly [P = 0.02], firmness at 10 minutes [P = 0.05], and maximal firmness [P = 0.06]). Patients with more severe systemic complications (high-grade hepatic encephalopathy and need for renal replacement therapy) also had a higher incidence of abnormal ROTEM parameters. Finally, more hypocoagulable ROTEM parameters (clot initiation (P = 0.005), stiffness at 10 minutes (P = 0.05), and maximal stiffness by fibrin assembly (P = 0.004)) were observed in patients who died or underwent liver transplantation than those who survived with their native liver.

CONCLUSIONS

In patients with ALI/ALF, abnormal ROTEM parameters are frequent and proportional to disease severity. Whether the increased bleeding risk associated with abnormal ROTEM indicates hemostatic failure or is a proxy for disease severity requires additional study.

The higher prevalence of truncal obesity and diabetes in American than Chinese patients with chronic hepatitis C might contribute to more rapid progression to advanced liver disease

BACKGROUND

Chronic hepatitis C virus (HCV) infection is the leading cause of cirrhosis and hepatocellular carcinoma (HCC) in the United States (US) and an emerging cause in China.

AIM

To compare the clinical characteristics of hepatitis C patients in the US and China, and factors influencing disease stage.

METHODS

Prospective study of 2 cohorts of HCV patients recruited at 1 site in the US and 3 sites in China. Standardised questionnaire on risk factors and medical history were used and diagnosis of cirrhosis and HCC was based on pre-defined criteria.

RESULTS

One thousand nine hundred and fifty seven patients (1000 US and 957 China) were enrolled. US patients were more likely to be men (61.4% vs 48.5%), older (median age 57 vs 53 years), obese (38.4% vs 16.8%) and diabetic (21.8% vs 10.8%). A significantly higher per cent of US patients had cirrhosis (38.2% vs 16.0%) and HCC (14.1% vs 2.7%). Investigator estimated time at infection in US was 10 years earlier than in Chinese patients but US patients were more likely to have advanced disease even after stratifying for duration of infection. Study site in the US, older age, truncal obesity, diabetes and prior HCV treatment were significant predictors of advanced disease on multivariate analysis.

CONCLUSIONS

HCV patients in the US had more advanced liver disease than those in China. We speculate that underlying fatty liver disease may be a major contributor to this difference, and management of glycometabolic abnormalities should occur in parallel with anti-viral therapy to achieve optimal outcomes.

Comparative analysis of portal hepatic infiltrating leucocytes in acute drug-induced liver injury, idiopathic autoimmune and viral hepatitis

Drug-induced liver injury (DILI) is often caused by innate and adaptive host immune responses. Characterization of inflammatory infiltrates in the liver may improve understanding of the underlying pathogenesis of DILI. This study aimed to enumerate and characterize leucocytes infiltrating liver tissue from subjects with acute DILI (n = 32) versus non-DILI causes of acute liver injury (n = 25). Immunostains for CD11b/CD4 (Kupffer and T helper cells), CD3/CD20 (T and B cells) and CD8/CD56 [T cytotoxic and natural killer (NK) cells] were evaluated in biopsies from subjects with acute DILI, either immunoallergic (IAD) or autoimmune (AID) and idiopathic autoimmune (AIH) and viral hepatitis (VH) and correlated with clinical and pathological features. All biopsies showed numerous CD8(+) T cells and macrophages. DILI cases had significantly fewer B lymphocytes than AIH and VH and significantly fewer NK cells than VH. Prominent plasma cells were unusual in IAD (three of 10 cases), but were associated strongly with AIH (eight of nine) and also observed in most with AID (six of nine). They were also found in five of 10 cases with VH. Liver biopsies from subjects with DILI were characterized by low counts of mature B cells and NK cells in portal triads in contrast to VH. NK cells were found only in cases of VH, whereas AIH and VH both showed higher counts of B cells than DILI. Plasma cells were associated most strongly with AIH and less so with AID, but were uncommon in IAD.

Changes in characteristics of hepatitis C patients seen in a liver centre in the United States during the last decade

With the approval of 2 direct-acting antivirals (DAAs) in 2011 and anticipation of interferon (IFN)-free regimens, more hepatitis C virus (HCV) chronically infected patients are now seeking treatment. To describe the characteristics of newly referred HCV patients in 2011-2012 (Era-2) and compare them to those seen in 1998-1999 (Era-1). Retrospective data were collected from HCV patients newly referred to our tertiary liver clinics. Advanced liver disease was defined as cirrhosis (based on histology or Aspartate aminotransferase-platelet-ratio index (APRI) >2), hepatic decompensation or hepatocellular carcinoma (HCC). A total of 1348 patients (538 in Era-1, 810 in Era-2) were included. Compared to Era-1, Era-2 patients were older (median age 56 vs 45 years), more likely to be black (17.2% vs 11.6%) and had a longer interval between diagnosis and referral (median 4 vs 2 years). Genotype (GT) 1 predominated in both Eras with a significant increase in GT1a from 39.9% in Era-1 to 53.8% in Era-2. A higher per cent of patients in Era-2 were treatment experienced, but 77% had never received treatment. Era-2 patients were more likely to have advanced disease at referral (61.6% vs 51.5%, P < 0.001), with an eightfold higher prevalence of HCC (21.6% vs 2.6%, P < 0.001). HCV patients newly referred in recent years were older, predominantly infected with GT1a and had more advanced liver disease yet only a quarter had received HCV treatment. Reduction in HCV disease burden will require development of treatment regimens targeted towards patients in the current Era as well as increase in diagnosis and referral of patients for treatment.

Meta-analysis: the impact of oral anti-viral agents on the incidence of hepatocellular carcinoma in chronic hepatitis B

BACKGROUND

Five oral nucleos(t)ide analogues are available to treat chronic hepatitis B (CHB). With the availability of newer agents, their efficacy on incidence of hepatocellular carcinoma (HCC) is not well described.

AIM

To determine the efficacy of oral anti-viral agents in reducing HCC risk in relationship with other known factors.

METHODS

Published studies of at least 20 CHB patients treated with an oral anti-viral agent and followed for >2 years were analysed for incidence of HCC per 100 person years follow-up.

RESULTS

Pooled homogeneous data from six studies showed lamivudine (LAM) treatment (n = 3306) to reduce HCC risk by 51% compared with no treatment (n = 3585) (3.3 vs. 9.7 per 100 person years, P < 0.0001). Pooled data from 49 studies (23 with LAM; 16 with adefovir; and 10 with entecavir, tenofovir or telbivudine) of 10 025 treated patients showed HCC incidence of 1.3 per 100 person years, independent of the agent used. Patient age >50 years and hepatitis B virus-DNA detectability at HCC diagnosis increased risk of HCC by twofold with a 10-fold higher risk among patients with cirrhosis compared with chronic hepatitis. Meta-regression showed patient age, study location (Eastern vs. Western) and type of study (randomised or not) contributed to heterogeneity.

CONCLUSIONS

Lamivudine treatment significantly reduces the incidence of HCC compared with no treatment. However, HCC still develops at a rate of 1.3 per 100 patient years in CHB patients receiving an oral anti-viral agent. This finding highlights the need for continued HCC surveillance, particularly in CHB patients with inadequate viral suppression, older age and cirrhosis.

Sofosbuvir and daclatasvir combination therapy in a liver transplant recipient with severe recurrent cholestatic hepatitis C

Recurrent HCV infection following liver transplantation can lead to accelerated allograft injury that is difficult to treat with interferon. The aim of this study is to describe the first ever use of an interferon-free, all oral regimen in a liver transplant recipient with severe recurrent HCV. A 54-year-old male with HCV genotype 1b developed severe cholestatic HCV at 6 months posttransplant with ascites, AST 503 IU/mL, alkaline phosphatase of 298 IU/mL, HCV RNA of 12 000 000 IU/mL, and histological cholestasis with pericellular fibrosis. Sofosbuvir, an HCV polymerase inhibitor (400 mg/day), and daclatasvir, an HCV NS5A replication complex inhibitor (60 mg/day), were co-administered for 24 weeks. Within 4 weeks of initiating treatment, serum HCV RNA levels became undetectable and liver biochemistries normalized with concomitant resolution of ascites. The patient achieved a sustained virological response with undetectable HCV RNA at 9 months posttreatment. During and following treatment, the daily dose and blood level of tacrolimus remained stable and unchanged. The rapid and sustained suppression of HCV replication in this liver transplant recipient provides great promise for the use of combination oral antiviral regimens in other immunosuppressed and interferon refractory HCV patients.

IL-28B polymorphisms and the response to antiviral therapy in HCV genotype 2 and 3 varies by ethnicity: a meta-analysis

Studies of IL-28B genotype in patients with hepatitis C virus (HCV) genotype 2/3 infection have yielded conflicting results. The aim of this meta-analysis was to obtain a pooled odds ratio (OR) of the impact of IL-28B genotype on achieving sustained virologic response (SVR) in patients with HCV genotype 2/3 infection treated with pegIFN and ribavirin. A meta-analysis with a random effects model was performed, and study heterogeneity and publication bias were assessed. Forty-three percent of the Caucasians (11 studies) and 86% of Asians (five studies) had the favourable IL-28B genotype. In Caucasians, the pooled OR of SVR with the favourable IL-28B genotype was 1.36 (95%CI: 0.98-1.88, P = 0.07) in all patients and 1.55 (95%CI: 1.10-2.18, P = 0.01) in patients treated with pegIFN and ribavirin for ≥24 weeks. In Asians, the pooled OR of SVR in patients with the favourable IL-28B genotype was 1.99 (95%CI: 0.94-4.25, P = 0.07). The favourable IL-28B genotype was also significantly associated with rapid virologic response (RVR) in both groups (Caucasians: OR: 1.82, 95%CI: 1.12-2.96, P = 0.02; Asians: 2.39, 95%CI: 1.39-4.11, P = 0.002), as well as the likelihood of an SVR in a subgroup of 350 Caucasian patients without an RVR (OR: 3.29, 95%CI: 1.67-6.51, P = 0.001). The favourable IL-28B genotype is a statistically significant predictor of SVR and RVR in Caucasian patients treated with pegIFN and ribavirin for 24 weeks. In contrast, the favourable IL-28B genotype is associated with RVR, but not SVR in Asian HCV genotype 2 patients.

Meta-analysis: IL-28B genotype and sustained viral clearance in HCV genotype 1 patients

BACKGROUND

Polymorphisms in the IL-28B region are a strong predictor of sustained virologic response (SVR) in individual studies of HCV genotype 1 patients receiving peginterferon (pegIFN) and ribavirin.

AIM

To obtain a pooled odds ratio (OR) of SVR in patients of varying race with the favourable IL-28B genotype compared to those with the unfavourable genotype.

METHODS

A literature search was conducted using online databases and a review of conference abstracts. A random effects meta-analysis was performed and study heterogeneity and publication bias were assessed.

RESULTS

There were 21 individual studies of HCV genotype 1 patients of varying ethnicity treated with pegIFN and ribavirin. The pooled prevalence of the favourable IL-28B genotype varied by race (73% vs. 41% vs. 13% in 2612 Asians, 3110 Caucasians and 452 African-Americans, respectively, P < 0.001). However, the strength of association of the IL-28B genotype with SVR was similar in all three racial groups (Caucasians: odds ratio (OR) 3.88, 2.75-5.49, African-Americans: OR 4.63, 2.52-8.50 and Asians OR 5.66, 3.99-8.02, all P < 0.001). The IL-28B genotype was also associated with SVR in 263 HIV/HCV co-infected Caucasians (OR 5.49, 3.02-9.96, P < 0.001). Study quality score and anti-viral treatment regimen did not impact the strength of the association in patient subgroups nor in the pooled population.

CONCLUSIONS

IL-28B genotype is significantly associated with SVR in HCV genotype 1 patients of varying race, as well as in HIV co-infected patients, receiving pegIFN and ribavirin. IL-28B testing in conjunction with other pre-treatment parameters may prove useful in counselling HCV patients.

Adherence to nucleos(t)ide analogues for chronic hepatitis B in clinical practice and correlation with virological breakthroughs

Medication adherence is important for the success of nucleos(t)ide analogue (NUC) treatment for chronic hepatitis B. The aims of this study were to determine adherence to NUCs and factors associated with NUC adherence and to correlate NUC adherence with the occurrence of virological breakthroughs in patients with chronic hepatitis B. Consecutive patients with chronic hepatitis B receiving NUC were asked to complete a survey every 3 months. Adherence was also assessed by healthcare providers in the clinic. Adherence rate was defined as the per cent of days the patients took their hepatitis B virus medications during the last 30 days. A total of 111 patients were studied. The mean age was 47.7 years, 73.9% were men, 57.7% were Asian, 42.3% had postgraduate education and 80% had private insurance. Sixty-nine (74.1%) patients reported 100% adherence in the survey, while 78 (83.9%) reported 100% adherence to their healthcare providers. Patients with 100% adherence based on the survey were older (P = 0.02), more likely to be men (P = 0.006), and had higher annual household income (P = 0.04) than those with <100% adherence. In the 80 patients who completed three surveys, viral breakthrough was observed in 1/46 (2.2%) with 100% adherence on all three surveys, 1/18 (5.6%) with <100% adherence on one survey and 3/16 (18.8%) with <100% adherence on ≥2 surveys, (P = 0.06). In conclusion, adherence to NUC therapy in our patients with chronic hepatitis B was high but self-reporting of adherence to healthcare providers may be inflated. Patients with chronic hepatitis B with better adherence to NUC therapy had a trend towards a lower rate of viral breakthroughs.

Serum proteomic profiling in patients with drug-induced liver injury

BACKGROUND

Idiosyncratic drug-induced liver injury (DILI) is a complex disorder that is difficult to predict, diagnose and treat.

AIM

To describe the global serum proteome of patients with DILI and controls.

METHODS

A label-free, mass spectrometry-based quantitative proteomic approach was used to explore protein expression in serum samples from 74 DILI patients (collected within 14 days of DILI onset) and 40 controls. A longitudinal analysis was conducted in a subset of 21 DILI patients with available 6-month follow-up serum samples.

RESULTS

Comparison of DILI patients based on pattern, severity and causality assessment of liver injury revealed many differentially expressed priority 1 proteins among groups. Expression of fumarylacetoacetase was correlated with alanine aminotransferase (ALT; r = 0.237; P = 0.047), aspartate aminotransferase (AST; r = 0.389; P = 0.001) and alkaline phosphatase (r = -0.240; P = 0.043), and this was the only protein with significant differential expression when comparing patients with hepatocellular vs. cholestatic or mixed injury. In the longitudinal analysis, expression of 53 priority 1 proteins changed significantly from onset of DILI to 6-month follow-up, and nearly all proteins returned to expression levels comparable to control subjects. Ninety-two serum priority 1 proteins with significant differential expression were identified when comparing the DILI and control groups. Pattern analysis revealed proteins that are components of inflammation, immune system activation and several hepatotoxicity-specific pathways. Apolipoprotein E expression had the greatest power to differentiate DILI patients from controls (89% correct classification; AUROC = 0.97).

CONCLUSION

This proteomic analysis identified differentially expressed proteins that are components of pathways previously implicated in the pathogenesis of idiosyncratic drug-induced liver injury.

Meta-analysis: oral anti-viral agents in adults with decompensated hepatitis B virus cirrhosis

BACKGROUND

The optimal oral anti-viral agent to use in patients with decompensated HBV cirrhosis remains unclear.

AIM

We performed a meta-analysis of the oral nucleos(t)ide analogues in patients with decompensated HBV cirrhosis.

METHODS

One year efficacy and safety outcomes in 22 studies published in English between '95 and 2010 were analysed.

RESULTS

Substantial heterogeneity was noted in the inclusion/exclusion criteria, controls, and sensitivity of the HBV DNA assay used. Pooled 1-year data showed benefit favouring lamivudine (LAM) vs. untreated controls for Child-Turcotte-Pugh (CTP) score improvement by ≥2 (OR: 117 (15 921), P ≤ 0.0001) and transplant-free survival (OR: 3.2 (1.2, 9), P = 0.022). Adefovir (ADV) led to undetectable HBV DNA at 1-year in 41% compared to 83% with LAM and 80% with entecavir (ETV). Overall, 1-year transplant-free survival rates varied from 78% with LAM to 95% and 94% with Tenofovir (TDF) and Telbivudine (TBV), respectively. The 1-year incidence of drug resistant HBV was 0% with ADV, ETV and TDF and 11% with LAM although TBV was associated with a 29% incidence at 2 years. Drug-related adverse events were infrequently reported.

CONCLUSIONS

All the oral anti-viral agents were associated with improved virological, biochemical and clinical parameters at 1-year. However, the efficacy of lamivudine and telbivudine is limited by drug resistance, and adefovir is limited by its potency and slower onset of action. Additional studies of tenofovir and entecavir are needed to determine the optimal agent(s) for treatment naïve patients and in those with drug-resistant decompensated HBV cirrhosis.

What factors determine the severity of hepatitis A-related acute liver failure?

The reason(s) that hepatitis A virus (HAV) infection may progress infrequently to acute liver failure are poorly understood. We examined host and viral factors in 29 consecutive adult patients with HAV-associated acute liver failure enrolled at 10 sites participating in the US ALF Study Group. Eighteen of twenty-four acute liver failure sera were PCR positive while six had no detectable virus. HAV genotype was determined using phylogenetic analysis and the full-length genome sequences of the HAV from a cute liver failure sera were compared to those from self-limited acute HAV cases selected from the CDC database. We found that rates of nucleotide substitution did not vary significantly between the liver failure and non-liver failure cases and there was no significant variation in amino acid sequences between the two groups. Four of 18 HAV isolates were sub-genotype IB, acquired from the same study site over a 3.5-year period. Sub-genotype IB was found more frequently among acute liver failure cases compared to the non-liver failure cases (chi-square test, P < 0.01). At another centre, a mother and her son presented with HAV and liver failure within 1 month of each other. Predictors of spontaneous survival included detectable serum HAV RNA, while age, gender, HAV genotype and nucleotide substitutions were not associated with outcome. The more frequent appearance of rapid viral clearance and its association with poor outcomes in acute liver failure as well as the finding of familial cases imply a possible host genetic predisposition that contributes to a fulminant course. Recurrent cases of the rare sub-genotype IB over several years at a single centre imply a community reservoir of infection and possible increased pathogenicity of certain infrequent viral genotypes.

An update on drug induced liver injury

Drug induced liver injury (DILI) is an uncommon cause of acute and chronic liver injury of increasing importance to patients, clinicians, and regulators. The incidence of DILI due to an individual agent is not well defined but population-based studies suggest that the overall incidence of DILI may be as high as 10 to 15 cases per 100000 patient years. Bona fide risk factors for DILI are also not well established, but ongoing multicenter registry studies such as the Drug Induced Liver Injury Network are attempting to identify the role of genetic, environmental, and immunological factors in DILI pathogenesis and outcomes. Acute hepatocellular injury (~50%) is more common than mixed or cholestatic liver injury but jaundiced DILI subjects with either type of liver injury have a ~10% risk of short-term mortality. Antibiotics are the most commonly implicated agents associated with DILI, but there are emerging reports of liver injury associated with the use of a multitude of herbal and dietary supplements. Despite their widespread use, the HMG-CoA reductase inhibitors or statins are an uncommon cause of idiosyncratic DILI. Furthermore, recent studies have shown that statins are actually safe and efficacious to use in hyperlipidemic patients with chronic liver disease. Acetaminophen hepatotoxicity remains a leading cause of severe acute liver injury. Limiting the amount of acetaminophen in prescription narcotic products may help reduce the incidence of future non-intentional overdoses but educating patients and providers of the multitude of over the counter products that contain acetaminophen is also recommended.

The clinical presentation and prognostic factors for intrahepatic and extrahepatic cholangiocarcinoma in a tertiary care centre

BACKGROUND

The incidence of cholangiocarcinoma is rising. Accurate predictors of survival at diagnosis are not well defined.

AIM

To clarify the clinical presentation and prognostic factors of intrahepatic cholangiocarcinoma and extrahepatic cholangiocarcinoma in a contemporary cohort of patients.

METHODS

Records for consecutive patients at the University of Michigan hospital diagnosed with cholangiocarcinoma between January 2003 and April 2008 were reviewed.

RESULTS

In all, 136 patients had cholangiocarcinoma (79 intra- and 57 extrahepatic cholangiocarcinoma). Median survival was 27.3 months-25.8 months for intrahepatic cholangiocarcinoma and 30.3 months for extrahepatic cholangiocarcinoma. Independent predictors of mortality at presentation on multivariate analysis were elevated bilirubin level (HR 1.04, 95%CI 1.01-1.07), CA 19-9 levels >100 U/mL (HR 1.90, 95%CI 1.17-3.08) and stage of disease (HR 1.51, 95%CI 1.16-1.96). After adjusting for baseline prognostic factors, surgical therapy was associated with improved survival (HR 0.48; 95% CI 0.26-0.88). There were no significant differences regarding clinical presentation, disease stage (P = 0.98), and survival (P = 0.51) between intra- and extrahepatic cholangiocarcinoma.

CONCLUSIONS

Survival for cholangiocarcinoma remains poor with no significant difference in outcomes between intra- and extrahepatic cholangiocarcinoma. Stage of disease, bilirubin level and CA 19-9 level are important prognostic factors at presentation. Surgical therapy provides similar efficacy for both tumours when adjusted for other prognostic variables.

Intravenous N-acetylcysteine improves transplant-free survival in early stage non-acetaminophen acute liver failure

BACKGROUND & AIMS

N-acetylcysteine (NAC), an antidote for acetaminophen poisoning, might benefit patients with non-acetaminophen-related acute liver failure.

METHODS

In a prospective, double-blind trial, acute liver failure patients without clinical or historical evidence of acetaminophen overdose were stratified by site and coma grade and assigned randomly to groups that were given NAC or placebo (dextrose) infusion for 72 hours. The primary outcome was overall survival at 3 weeks. Secondary outcomes included transplant-free survival and rate of transplantation.

RESULTS

A total of 173 patients received NAC (n = 81) or placebo (n = 92). Overall survival at 3 weeks was 70% for patients given NAC and 66% for patients given placebo (1-sided P = .283). Transplant-free survival was significantly better for NAC patients (40%) than for those given placebo (27%; 1-sided P = .043). The benefits of transplant-free survival were confined to the 114 patients with coma grades I-II who received NAC (52% compared with 30% for placebo; 1-sided P = .010); transplant-free survival for the 59 patients with coma grades III-IV was 9% in those given NAC and 22% in those given placebo (1-sided P = .912). The transplantation rate was lower in the NAC group but was not significantly different between groups (32% vs 45%; P = .093). Intravenous NAC generally was well tolerated; only nausea and vomiting occurred significantly more frequently in the NAC group (14% vs 4%; P = .031).

CONCLUSIONS

Intravenous NAC improves transplant-free survival in patients with early stage non-acetaminophen-related acute liver failure. Patients with advanced coma grades do not benefit from NAC and typically require emergency liver transplantation.

Preliminary analysis of early outcomes of a prospective, randomized trial of complete steroid avoidance in liver transplantation

Steroids are a mainstay in liver transplantation for induction and maintenance immunosuppression but are associated with significant adverse effects. While prior studies have successfully limited the use of steroids, whether complete steroid avoidance will improve outcomes remains unclear. To further evaluate the need for steroids, consenting patients who underwent liver transplantation between June 2002 and May 2004 were entered into a prospective, randomized trial to receive either standard therapy (tacrolimus, mycophenolate mofetil, steroid induction/maintenance) or complete steroid avoidance (standard therapy without steroid induction/maintenance). Clinically suspected rejection was confirmed by biopsy and treated with pulse steroid therapy. Outcomes were compared on an intention to treat basis. Of the 72 patients enrolled, 36 (50%) were randomized to the steroid avoidance group with a mean follow up of 412 +/- 41 days. Donor and recipient characteristics were similar between groups. The steroid avoidance group was more likely to have significant infections (52% vs 28%, P = .03). There was a trend toward an increased rate of acute rejection (25% vs 14%, P = .23). Twelve of 36 recipients (33%) enrolled in the steroid avoidance group later received steroids. The incidence of recurrent hepatitis C was similar between groups. The 1-year patient (90% vs 83%, P = .44) and graft survivals (90% vs 81%, P = .27) were similar between groups. These data suggest complete steroid avoidance in liver transplantation results in acceptable patient and graft survival. However, the potential long-term benefits of steroid avoidance, including a decrease in severity of recurrent hepatitis C, remain under investigation.

Clinical outcome and virological characteristics of hepatitis B-related acute liver failure in the United States

The role of hepatitis B virus (HBV) genotypes in the outcome of acute HBV infection is unclear. In this study, we aimed to evaluate the clinical and virological features of patients with hepatitis B-related acute liver failure (HBV-ALF) in the US. Clinical and laboratory features of consecutive patients with HBV-ALF from the US ALF Study Group were analysed. Prevalence of HBV genotypes, precore stop (G1896A) and core promoter dual (T1762A, A1764T) variants among patients with HBV-ALF were compared with a cohort of 530 patients with chronic HBV infection. Thirty-four HBV-ALF patients were studied: mean age 41 years, 56% men, 25 had detectable HBV-DNA. HBV genotypes A, B, C and D were found in 36, 24, 8 and 32% patients, respectively. Precore stop and core promoter dual variants were detected in 32 and 44% of patients, respectively. Twenty-three (68%) patients survived: 14 after liver transplant, nine without transplant. Older age was the only independent factor associated with poor outcome. Compared with patients with chronic HBV infection, patients with ALF were more likely to be non-Asians (88% vs 44%, P = 0.005) and to have genotype D (32% vs 10%, P < 0.01). A higher prevalence of HBV genotype D persisted even after matching for race and HBeAg status (32% vs 16%, P = 0.007). We concluded that HBV genotype D was more frequently found in patients with HBV-ALF than those with chronic HBV infection in the US. Further studies are needed to determine if HBV genotypes play a role in the outcome of acute HBV infection.

Liver transplantation in acute liver failure

Acetaminophen and idiosyncratic drug induced hepatotoxicity are the most commonly identified etiologies of acute liver failure in Western countries. Infectious complications and cerebral edema remain the leading causes of death. Moderate hypothermia and other medical interventions may improve cerebral edema in selected patients with acute liver failure. In addition, pilot studies suggest that recombinant factor VIIa infusions may allow for the safe placement of intracranial pressure monitoring devices in patients with cerebral edema and severe coagulopathy. Auxiliary liver transplantation and bioartificial liver devices offer the hope of temporary liver support for selected patients with a high likelihood of native liver regeneration. Prognostic survival models that include arterial lactate levels may improve our ability to identify acetaminophen overdose patients in urgent need of liver transplantation. The lower 1-year patient survival following liver transplantation for acute liver failure compared to chronic liver failure (60 vs 80%) is in part due to the emergent nature of surgery, concomitant vital organ failure, and the higher incidence of immunologically mediated graft dysfunction. Vaccination against hepatotrophic viruses and other public health measures designed to minimize the incidence of both intentional and non-intentional acetaminophen overdose may help reduce the future incidence of acute liver failure. In the meanwhile, it is recommended that acute liver failure patients be managed in experienced centers with ready access to liver transplantation to optimize outcomes in this rare but frequently fatal illness.

Comorbid illness is an important determinant of health-related quality of life in patients with chronic hepatitis C

OBJECTIVES

Chronic hepatitis C (CHC) patients selected for entry into treatment trials have been reported to have impaired health-related quality of life (HRQOL). However, these trials have an inherent selection bias, and HRQOL in CHC patients may have been underestimated because of the exclusion of patients with comorbid illness. The aim of this study was to assess HRQOL in an unselected group of CHC patients and to identify factors associated with impairment in HRQOL.

METHODS

A total of 220 consecutive eligible CHC patients were enrolled from a hepatology clinic. HRQOL was assessed by the short form 36 (SF-36) and comorbid illnesses were assessed by an interview.

RESULTS

CHC patients had significantly lower SF-36 scores in all subscales and in the summary scales when compared to those of the healthy general population in the United States (p < 0.001). Compared to CHC patients entering treatment trials, our patients had lower SF-36 scores on five subscales (p < 0.001). The presence of comorbid illness was the most important predictor of HRQOL in CHC patients. However, CHC alone resulted in significantly lower SF-36 scores in all subscales and summary scales (p < or = 0.003) compared to those of the healthy U.S. population. There was no correlation between SF-36 scores and history of i.v. drug use or dependence. alcohol dependence. and serum aminotransferase levels.

CONCLUSIONS

We conclude that unselected CHC patients presenting for medical evaluation have a reduced HRQOL, which is lower than that reported for CHC patients entering treatment trials. CHC alone is associated with significant impairment in HRQOL, but the presence of comorbid illness leads to further diminution in HRQOL.

Outcome of liver transplantation for hepatitis B: report of a single center's experience

Results of liver transplantation (LT) for hepatitis B have improved significantly with the use of hepatitis B immune globulin (HBIG) and/or lamivudine. The aim of this study is to review the long-term outcome of patients who underwent LT for hepatitis B. Records of 41 patients who underwent LT for hepatitis B and survived 3 months or longer post-LT were reviewed. Twenty patients were administered no immunoprophylaxis or short-term intramuscular HBIG, whereas 21 patients were administered high-dose intravenous (IV) HBIG. Median post-LT follow-up in these 2 groups was 76 months (range, 4 to 155 months) and 25 months (range, 4 to 68 months), respectively. Hepatitis B recurred in 15 (75%) and 4 patients (19%) who underwent LT in the pre-HBIG and post-HBIG eras, respectively. Cumulative rates of recurrent hepatitis B at 1 and 3 years post-LT in these 2 groups were 66% and 77% and 20% and 20%, respectively (P <.001). Recurrent hepatitis B in the post-HBIG era correlated with antibody to hepatitis B surface antigen titer less than 100 IU/L. Nine patients with recurrent hepatitis B were administered lamivudine for 13 to 49 months (median, 28 months); 6 patients continued to have stable or improved liver disease, whereas 3 patients developed virological breakthrough with slow deterioration of liver disease. Long-term IV HBIG is effective in preventing recurrent hepatitis B. The risk for recurrent hepatitis B is negligible after the first year post-LT. Among patients with no virological breakthrough, lamivudine can stabilize or improve liver disease for up to 4 years in patients with recurrent hepatitis B post-LT.

Helicobacter pylori-associated gastric MALT lymphoma in liver transplant recipients

BACKGROUND

Immunosuppressed transplant recipients are at increased risk of developing several forms of malignancy. The aim of this study is to report the clinical presentation, treatment, and outcome of four liver transplant recipients with Helicobacter pylori-associated gastric mucosae-associated lymphoid tissue (MALT) lymphoma.

METHODS

The medical records of four liver transplant recipients with gastric MALT lymphoma were reviewed. In situ hybridization for Epstein-Barr-encoded ribonucleic acid was performed on formalin-fixed tissues.

RESULTS

All four subjects presented with abdominal symptoms at a mean of 6.1 years posttransplant. Ulcerative lesions biopsied at endoscopy demonstrated early-stage gastric MALT lymphoma with associated Helicobacter pylori gastritis. In situ hybridization revealed no evidence of Epstein-Barr virus infection in examined tissues. Antibiotic eradication of Helicobacter pylori lead to disease remission in three subjects with a mean follow-up of 21 months, and one subject failed to respond to antibiotics and radiation therapy and died from metastatic gastric adenocarcinoma.

CONCLUSIONS

Early-stage, low-grade gastric MALT lymphoma that was associated with Helicobacter pylori gastritis responded to antibiotic therapy with a sustained clinical remission in three of four treated subjects. If other studies confirm a higher than expected incidence of gastric MALT lymphoma in immunosuppressed transplant recipients with Helicobacter pylori infection, screening and treating Helicobacter pylori infection in selected transplant patients may prove beneficial.

A multicenter study of lamivudine treatment in 33 patients with hepatitis B after liver transplantation

Hepatitis B virus (HBV) infection after liver transplantation (LT) may lead to severe and rapidly progressive graft failure. Antiviral treatment may be of benefit in selected patients with recurrent hepatitis B post-LT. The aim of this prospective open-label study is to determine the safety and efficacy of lamivudine in 33 liver transplant recipients with active HBV infection. The median time from LT to study enrollment was 51 months, all patients were hepatitis B surface antigen positive, and 75% and 94% of subjects had detectable hepatitis B e antigen (HBeAg) and HBV DNA at entry, respectively. The median duration of lamivudine treatment on study was 85 weeks, during which time median HBV DNA levels became undetectable by 16 weeks and 9% of patients lost previously detectable HBeAg. Serum alanine aminotransferase (ALT) levels improved in most patients and normalized in 27% of patients with elevated values pretreatment. Serum bilirubin and albumin levels significantly improved in patients with abnormal values at entry (P <.05). Virological breakthrough was detected in 13 subjects after a median of 61 weeks of lamivudine treatment and was confirmed to be caused by YMDD mutants in all patients tested. None of the patients with virological breakthrough showed a complete loss of clinical response to lamivudine. Serum ALT and bilirubin levels in patients with and without virological breakthrough were not significantly different at last study follow-up. Study results show that lamivudine is safe and effective in liver transplant recipients with recurrent hepatitis B. However, the high rate of virological breakthrough with prolonged therapy indicates the need for further studies of combination antiviral therapy in this patient population. Our results and others further establish the improving long-term outcomes with LT for patients with hepatitis B through advances in prevention of reinfection, as well as the availability of safe and effective antiviral therapies to treat patients with HBV recurrence.

Neuropsychiatric toxicity of antiviral treatment in chronic hepatitis C

Dose-dependent, reversible neuropsychiatric toxicity is reported in up to 30-40% of chronic hepatitis C patients treated with 6-12 months of interferon-alpha or interferon-alpha plus ribavirin combination therapy. Although risk factors remain poorly defined, neuropsychiatric side effects may be severe and dose-limiting in as many as 10-20% of treated patients. Diagnosis relies upon the detection of clinically apparent neuropsychiatric symptoms and the emerging use of self-administered mood inventories and questionnaires. The current stepwise approach to management includes evaluation and treatment of systemic side effects, early use of adjuvant medications, and interferon-alpha and ribavirin dose reduction or cessation with psychiatric referral in selected cases. Although the cellular basis of the neuropsychiatric toxicity of interferon-alpha remains unknown, several hypothesis involving changes in central adrenergic, seratonergic, opioid and neuroendocrine pathways have been proposed. Recognition and management of the neuropsychiatric side effects of antiviral therapy will be of growing clinical importance as additional patients with chronic hepatitis C are treated and longer durations of therapy are utilized.

Acute liver failure

Worldwide, viral hepatitis is the leading cause of acute liver failure, whereas acetaminophen hepatotoxicity is the most commonly identified cause in Western countries. Restricting the quantity of acetaminophen tablets dispensed has been shown to reduce morbidity and mortality in countries with a high incidence of acetaminophen overdose. Troglitazone and bromfenac are two recently approved medications that were withdrawn from the market due to an unacceptably high incidence of severe hepatotoxicity. In addition, trovafloxacin, nefazodone, and ritonavir were reported to be associated with severe hepatitis and acute liver failure. Moderate hypothermia is a simple and potentially effective means of reducing intracranial pressure in patients with acute liver failure and cerebral edema. However, controlled clinical trials are needed to determine proper patient selection and optimize treatment. Extracorporeal bioartificial liver support devices remain an exciting but as yet unproven means of supporting acute liver failure patients with advanced encephalopathy. Living donor liver transplantation has recently been reported for adults and children with acute liver failure. However, ethical concerns regarding donor safety and the ability to obtain informed consent without coercion have been raised. Lastly, advances in the identification and isolation of pluripotent liver stem cells in human bone marrow provides hope for a simple and effective means of enhancing native liver regeneration.

Hepatitis B infection in patients with acute liver failure in the United States

Occult hepatitis B virus (HBV) infection has been reported in 30% to 50% of patients with acute liver failure (ALF) in small case series. The aim of this study was to determine the prevalence of occult HBV infection in a large series of ALF patients in the United States and the prevalence of precore and core promoter variants in patients with ALF caused by hepatitis B. Sera from patients in the US ALF study and liver, when available, were tested using nested polymerase chain reaction (PCR) with primers in the HBV S and precore regions. PCR-positive samples were sequenced. Sera and/or liver from 139 patients (39 males, 100 females; mean age, 42 years) enrolled between January 1998 and December 1999 were studied. Twelve patients were diagnosed with hepatitis B, 1 with hepatitis B+C+D coinfection, and 22 had indeterminate etiology. HBV DNA was detected in the sera of 9 (6%) patients; all 9 had ALF caused by hepatitis B. HBV genotypes A, B, C, and D were present in 4, 3, 1, and 1 patients, respectively. Seven of these 9 patients had precore and/or core promoter variants. Liver from 19 patients were examined. HBV DNA was detected in the liver of 3 patients with ALF caused by hepatitis B, but in none of the remaining 16 patients with non-B ALF. Contrary to earlier reports, occult HBV infection was not present in this large series of ALF patients in the United States. HBV precore and/or core promoter variants were common among US patients with ALF caused by hepatitis B.

Comorbidities and quality of life in patients with interferon-refractory chronic hepatitis C

OBJECTIVES

Patients with chronic hepatitis C (HCV) consistently report a reduction in multiple domains of health-related quality of life (HRQOL) that does not correlate with liver disease severity. This may in part be due to the use of insensitive HRQOL instruments or extrahepatic factors that independently influence HRQOL. We hypothesized that a past history of substance abuse or active medical and psychiatric comorbidities would correlate with HRQOL scores.

METHODS

In 107 patients who had failed previous interferon therapy, HRQOL was measured by using the modified SF-36, a disease-specific instrument, and the Health Utilities Index (HUI) Mark III, a generic instrument.

RESULTS

Multiple SF-36 subscale and summary scores as well as the HUI Mark III attributes of emotion and pain were significantly reduced in the study population compared with healthy controls (p < 0.001). Serum alanine aminotransferase and HCV RNA levels, HCV genotype, liver histology, and HCV risk factors as well as demographic variables did not correlate with modified SF-36 and HUI scores. In addition, a history of alcohol abuse or dependency and intravenous drug use or dependency, identified in 52 and 51% of participants, respectively, did not correlate with HRQOL scores. However, the presence of one or more active medical comorbidities, defined as a chronic medical condition requiring treatment and monitoring, was significantly associated with both the modified SF-36 scores and HUI attribute deficits (p < 0.001). In particular, painful medical comorbidities or depressed mood requiring treatment were significantly associated with modified SF-36 scores and with HUI attribute deficits and utility scores (p < 0.001).

CONCLUSIONS

Active medical and psychiatric comorbidities may account for some of the reduction and variability in HRQOL scores in patients with chronic HCV who have failed previous interferon therapy. Future studies that control for the presence of active comorbidities in large groups of treatment naive patients with varying severity of chronic HCV are needed to confirm these findings.

Iron reduction before and during interferon therapy of chronic hepatitis C: results of a multicenter, randomized, controlled trial

Patients with chronic hepatitis C and low serum and hepatic iron stores may have an improved response to interferon (IFN). We tested whether iron reduction before and during IFN therapy would lead to an improved sustained biochemical and virological response compared with IFN alone. Eighty-two previously untreated patients with chronic hepatitis C were randomized to either: group A IFN-alpha2b 3 MU 3 times per week for 6 months, or group B iron reduction before and during IFN-alpha2b 3 MU 3 times per week for 6 months. Group B patients had lower mean serum alanine transaminase (ALT) levels than group A patients during treatment and follow-up. Group B patients had significantly lower mean hepatitis C virus (HCV)-RNA levels at treatment weeks 4 and 12 (P <.05). Serum HCV RNA was undetectable at the end of treatment in 15 group B patients compared with 7 group A patients (P =.03); 7 group B patients and 3 group A patients had persistently undetectable serum HCV RNA 24 weeks after the end of therapy (P =.20). Paired pre- and posttreatment liver biopsies in 18 group B patients demonstrated significant improvements in 2 of the 3 inflammation scores of the Knodell histological activity index (P <. 05). No changes occurred in the paired biopsies from 15 group A patients. We conclude that iron reduction via therapeutic phlebotomy improves the end-of-treatment virological and histological response to short-term IFN therapy. Additional studies are needed to determine if iron reduction in combination with higher doses or longer duration of IFN may be of benefit.

Acute liver failure associated with prolonged use of bromfenac leading to liver transplantation. The Acute Liver Failure Study Group

Bromfenac, a nonnarcotic analgesic nonsteroidal anti-inflammatory drug, was associated with reversible, minor elevations in serum aminotransferase levels during clinical trials. The aim of this study is to describe the clinical, laboratory, and histological features of 4 patients with severe bromfenac hepatotoxicity identified at 3 tertiary care centers participating in the US Acute Liver Failure Study Group. Bromfenac was administered for chronic musculoskeletal disorders to 4 women in therapeutic doses of 25 to 100 mg/d for a minimum of 90 days. All patients reported a prodrome of malaise and fatigue and presented with severe, symptomatic hepatocellular injury with associated hypoprothrombinemia. None of the subjects had underlying liver or kidney disease, and there was no evidence of a hypersensitivity reaction. Other identifiable causes of acute liver failure were uniformly excluded. Despite supportive measures, all the subjects developed progressive liver failure over 5 to 37 days, leading to emergency liver transplantation in 3 patients and death in 1 patient while awaiting transplantation. Extensive confluent parenchymal necrosis that appeared to begin in the central zones and was accompanied by a predominantly lymphocytic infiltrate was noted in all the livers examined. Nodular regeneration was seen in the 2 patients with a more protracted clinical course. Administration of therapeutic doses of bromfenac for greater than 90 days was associated with the development of acute liver failure leading to liver transplantation or death in 4 adult women. The poor outcomes observed in this series, coupled with the inability to identify individuals at risk for severe, idiosyncratic bromfenac hepatotoxicity, preclude further use of bromfenac in the medical community.

Unsuspected infection is infrequent in asymptomatic outpatients with refractory ascites undergoing therapeutic paracentesis

OBJECTIVE

Large-volume paracentesis is a safe and effective means of treating patients with refractory ascites. However, there is limited information regarding the need for ascitic fluid studies in asymptomatic outpatients presenting for therapeutic paracentesis. The aim of this prospective study was to define the incidence and natural history of peritoneal fluid infection in asymptomatic outpatients undergoing therapeutic paracentesis.

METHODS

Over a 13-month period, 118 therapeutic paracenteses were performed in 29 outpatients with decompensated cirrhosis (Child-Pugh class B = 38%, C = 62%). After a brief medical history and physical examination, ascitic fluid cell count with differential and culture were obtained from all participating subjects. Seven (24%) of the subjects were receiving norfloxacin prophylaxis, accounting for antibiotic coverage during 40% of the procedures performed. The clinical course and outcome of study subjects during a mean follow-up of 137 days was reviewed.

RESULTS

All 118 (100%) of the ascitic fluid samples demonstrated absolute neutrophil counts of <250/mm3 (mean = 6.5 +/- 22.5 pmn/mm3). Asymptomatic bacterascites was identified from three of the 118 (2.5%) fluid samples, but all of these subjects spontaneously recovered without treatment or sequelae. During follow-up, six episodes of symptomatic or hospital-associated peritoneal fluid infection were identified in study participants, emphasizing the importance of fluid studies in other clinical settings.

CONCLUSIONS

Although further studies are needed, the routine culture of ascitic fluid in asymptomatic outpatients with refractory ascites requiring therapeutic paracentesis may not be necessary when there is a low index of suspicion for occult infection. In circumstances of clinical uncertainty, however, obtaining ascitic fluid cell counts with differential is recommended to insure patient safety.

Effects of a chargrilled meat diet on expression of CYP3A, CYP1A, and P-glycoprotein levels in healthy volunteers

BACKGROUND & AIMS

Carcinogenic heterocyclic amines and polycyclic aromatic hydrocarbons present in chargrilled meat are substrates for inducible CYP1A and CYP3A enzymes and for P-glycoprotein. We examined whether consumption of a chargrilled meat diet results in induction of these proteins.

METHODS

Ten healthy adults were fed a diet enriched with chargrilled meat for 7 days. Duodenal biopsy specimens were obtained on days 1, 5, and 12 and analyzed for CYP1A, CYP3A, and P-glycoprotein messenger RNA (mRNA) and protein. On days 5 and 12, hepatic CYP3A4 and CYP1A2 activities were measured and colon biopsies were performed. The levels of polycyclic aromatic hydrocarbon DNA adducts in peripheral blood mononuclear cells were measured on days 1, 4, 11, and 26.

RESULTS

There was no detectable induction of CYP3A4, CYP3A5, or P-glycoprotein mRNAs or protein in small intestine or colon and no induction of hepatic CYP3A4 enzyme activity. In contrast, the chargrilled meat diet resulted in unequivocal induction of CYP1A enzymes in the liver and small intestine of each subject. There was an inverse correlation between the level of peripheral polycyclic aromatic hydrocarbon DNA adducts measured on day 11 and both liver CYP1A2 activity (P = 0.027) and enterocyte CYP1A1 protein concentration (P = 0.046).

CONCLUSIONS

Ingestion of chargrilled meat results in induction of CYP1A enzymes but not CYP3A4 or P-glycoprotein. This observation, combined with the correlation between adduct levels and CYP1A expression, supports an adaptive role for CYP1A but not CYP3A4 or P-glycoprotein.

Acute liver failure

Severe hepatitis A infection is an infrequent but well-recognized cause of acute liver failure that can now be effectively prevented with vaccination against hepatitis A virus. Bromfenac and troglitazone hepatotoxicity as well as various herbal remedies are some of the newly identified causes of acute liver failure. The recently identified transfusion-transmitted virus has been implicated in some cases of idiopathic acute liver failure whereas hepatitis G virus does not appear to be a causative agent. Recognizing, monitoring, and treating patients with life-threatening cerebral edema remain critically important but difficult aspects of the clinical care of acute liver failure. Hypothermia and N-acetylcysteine are promising experimental approaches to cerebral edema but emergency liver transplantation is the only proven means of improving patient survival. Although recent changes in organ allocation may reduce waiting time to transplantation, more reliable and validated markers of liver regeneration and prognosis are needed to triage patients. The potential application and limitations of novel technologies including bioartificial liver devices and auxiliary liver transplantation continue to evolve from pioneering work in animal models and human subjects.

Molecular and physical mechanisms of first-pass extraction

This is a report of a symposium held at the March 1997 meeting of the American Society for Pharmacology and Therapeutics in San Diego. Our understanding of the events that control first-pass drug elimination in humans has increased tremendously by two sequential discoveries. First, cytochrome P-450s 3A4 and 5 are expressed at high concentrations in both hepatocytes and upper intestinal enterocytes, and therefore limit the systemic availability of many drugs. Second, P-glycoprotein is expressed at the lumenal surface of the intestinal epithelium and therefore also acts to oppose the absorption of unchanged drug. The following discussion brings together our current understandings of these interrelated phenomena to aid a more complete picture of how they may contribute both qualitatively and quantitatively to first-pass elimination.

Caffeine based measures of CYP1A2 activity correlate with oral clearance of tacrine in patients with Alzheimer's disease

AIMS

To study the potential utility of caffeine based probes of CYP1A2 enzyme activity in predicting the pharmokinetics of tacrine in patients with Alzheimer's disease.

METHODS

The pharmokinetics of a single 40 mg oral dose of tacrine were measured in 19 patients with Alzheimer's disease. Each patient also received 2 mg kg(-1) [13C-3-methyl] caffeine orally and had breath and urine samples collected.

RESULTS

Tacrine oral clearance (CL F(-1) kg(-1)), which varied 15-fold among the patients, correlated significantly with the 2 h total production of 13CO2 in breath (r=0.56, P=0.01), and with each of two commonly used urinary caffeine metabolite ratios: the 'paraxanthine/caffeine ratio' (1,7X + 1, 7U)/1,3,7X) (r=0.76, P=0.0002) and the 'caffeine metabolic ratio' (AFMU + 1X + 1U)/1, 7U)(r=0.76, P=0.0001).

CONCLUSIONS

These observations support a central role for CYP1A2 in the in vivo disposition of tacrine and the potential for drug interactions when tacrine treated patients receive known inducers or inhibitors of this enzyme. The magnitude of the correlations we observed, however, are probably not sufficient to be clinically useful in individualizing tacrine therapy.

Transjugular intrahepatic portosystemic shunts and liver transplantation in patients with refractory hepatic hydrothorax

Hepatic hydrothorax is a relatively infrequent but potentially serious complication of cirrhosis resulting from the accumulation of ascitic fluid in the chest cavity. Medical management is initially directed at controlling ascites formation, but invasive therapeutic procedures may be required if symptoms persist. The aim of this study was to report on the long-term efficacy and safety of transjugular intrahepatic portosystemic shunt (TIPS) placement to reduce portal hypertension in 12 consecutive subjects with refractory hepatic hydrothorax. Most subjects had evidence of advanced cirrhosis of varying causes (Child-Pugh class A, 1; B, 5; C, 6). Mean subject age was 54 years, and subjects were followed up for a mean of 173 days (range, 7-926 days). The portosystemic pressure gradient after TIPS was reduced to <12 mmHg in all cases. Periprocedural morbidity was noted in 2 subjects, and 30-day survival after TIPS placement was 75%. Overall, 58% of subjects experienced either a complete or partial response following TIPS placement. Subject response did not correlate with age, baseline creatinine clearance, or Child-Pugh score. Cumulative subject survival was 42%, and 4 of the 5 long-term survivors required eventual liver transplantation. Subject age >65 years was associated with early mortality after TIPS placement, but this trend was not statistically significant. All 4 subjects undergoing liver transplantation required perioperative pleural fluid drainage, but only 1 subject has experienced recurrent effusion. We conclude that TIPS may be a safe and effective temporizing treatment for carefully selected patients with refractory hepatic hydrothorax. However, patient survival is limited after TIPS and is primarily determined by availability of liver transplantation.

Vascular complications of liver transplantation: evaluation with gadolinium-enhanced MR angiography

PURPOSE

To evaluate use of gadolinium-enhanced magnetic resonance (MR) angiography in detection of vascular complications of liver transplantation.

MATERIALS AND METHODS

Thirteen liver transplant recipients suspected to have vascular complications were evaluated with gadolinium-enhanced MR angiography by using a three-dimensional spoiled gradient-echo breath-hold technique during the arterial and venous phases of a high-dose (42 mL) bolus injection of gadolinium contrast material. Conventional angiography (n = 11) and surgery (n = 3) were used as the standard of reference. The transplant hepatic artery, celiac trunk, superior mesenteric artery, portal vein, superior mesenteric vein, splenic vein, hepatic veins, and inferior vena cava (IVC) were evaluated for thrombosis or stenosis by two radiologists.

RESULTS

Ten vascular complications were identified with conventional angiography or surgery: transplant hepatic artery thrombosis (n = 3) or stenosis (n = 3), portal vein stenosis (n = 1) or occlusion (n = 2), and suprahepatic IVC stenosis (n = 1). All 10 complications were correctly diagnosed with MR angiography. There was agreement between results of MR angiography and conventional angiography or surgery in 58 of 62 vessels evaluated (94%). There was minor disagreement in four vessels (6%).

CONCLUSION

Three-dimensional gadolinium-enhanced MR angiography may have the potential to enable accurate diagnosis of vascular complications of liver transplantation.

Grapefruit juice increases felodipine oral availability in humans by decreasing intestinal CYP3A protein expression

The increase in oral availability of felodipine and other commonly used medications when taken with grapefruit juice has been assumed to be due to inhibition of CYP3A4, a cytochrome P450 that is present in liver and intestine. To evaluate the effect of repeated grapefruit juice ingestion on CYP3A4 expression, 10 healthy men were given 8 oz of grapefruit juice three times a day for 6 d. Before and after receiving grapefruit juice, small bowel and colon mucosal biopsies were obtained endoscopically, oral felodipine kinetics were determined, and liver CYP3A4 activity was measured with the [14C N-methyl] erythromycin breath test in each subject. Grapefruit juice did not alter liver CYP3A4 activity, colon levels of CYP3A5, or small bowel concentrations of P-glycoprotein, villin, CYP1A1, and CYP2D6. In contrast, the concentration of CYP3A4 in small bowel epithelia (enterocytes) fell 62% (P = 0.0006) with no corresponding change in CYP3A4 mRNA levels. In addition, enterocyte concentrations of CYP3A4 measured before grapefruit juice consumption correlated with the increase in Cmax when felodipine was taken with either the 1st or the 16th glass of grapefruit juice relative to water (r = 0. 67, P = 0.043, and r = 0.71, P = 0.022, respectively). We conclude that a mechanism for the effect of grapefruit juice on oral felodipine kinetics is its selective downregulation of CYP3A4 in the small intestine.

Jejunostomy tube placement in refractory diabetic gastroparesis: a retrospective review

OBJECTIVES

Severe diabetic gastroparesis leading to recurrent episodes of diabetic ketoacidosis and frequent hospitalizations can be among the most disabling of all diabetic complications. Surgical placement of a jejunostomy tube (J-tube) beyond the affected stomach to deliver fluid, nutrients, and medication is one of the few therapeutic options remaining in the cohort of patients who have failed standard medical therapy. This study attempts to define the natural history of refractory diabetic gastroparesis and the risks and benefits of J-tube placement.

METHODS

A total of 26 patients with diabetic gastroparesis requiring J-tube placement were identified between 1980 and 1994. Medical chart review and telephone follow-up were performed using standardized questionnaires.

RESULTS

All patients had documented delayed gastric emptying, had failed medical therapy, and had been hospitalized on multiple occasions. Neuropathy, retinopathy, and nephropathy were observed in 88%, 81%, and 65% of patients, respectively. The mean duration of study follow-up was 47 months (1-130 months). The mean age of subjects at the time of J-tube placement was 31 yr, and a preponderance of female patients (73%) was noted. There were 23 major complications in 14 patients requiring surgery or hospitalization and 47 minor complications in 21 patients managed on an outpatient basis. The mean duration of J-tube use was 20 months. There were 10 deaths during follow-up, one related to J-tube placement. Retrospectively, 39% reported improved symptoms of nausea/vomiting (4% worsened), 52% reported fewer hospitalizations (4%, more frequent), 56% reported improved nutritional status (4% worsened), and 83% reported improved overall health (4% worsened) after J-tube placement. The improvement in overall health status was the only symptom that reached statistical significance.

CONCLUSION

Severe refractory gastroparesis is associated with multiple hospitalizations, a high incidence of concomitant diabetic complications, and a mortality rate of 38% at 4 yr. There is a high incidence of complications following J-tube placement in this population. Despite this, most patients retrospectively reported improved overall health after J-tube placement. Therefore, placement of a J-tube may be a workable option with acceptable perioperative morbidity and mortality rates in selected patients with severe diabetic gastroparesis who have failed medical therapy. A prospective study of J-tube placement and other available means of nutritional support is needed to demonstrate further the efficacy of this intervention in patients with severe diabetic gastroparesis.

The caffeine breath test does not identify patients susceptible to tacrine hepatotoxicity

Therapy with tacrine, a promising new treatment for Alzheimer's disease, must be discontinued in up to 15% of patients because of hepatocellular toxicity. Recent studies using human liver microsomes have suggested that a single liver enzyme, cytochrome P450 1A2 (CYP1A2), catalyzes the major route of metabolism and elimination of tacrine, and also catalyzes the pathway(s) involved in the generation of reactive metabolites capable of covalent protein binding and cytotoxicity. Because CYP1A2 activity has been shown to vary up to 60-fold among patients, we proposed that a convenient measure of CYP1A2 activity, the [(13)C 3-methyl] caffeine breath test (CBT), might be clinically useful in identifying patients most susceptible to tacrine liver toxicity. To test this hypothesis, we administered the CBT to 37 patients with Alzheimer's disease before they began treatment with tacrine. Twenty patients received 2 mg/kg of [(13)C 3-methyl] caffeine. The remaining 17 patients received the commercially available CBT kit, which employs a constant 200-mg dose. The activities of two other major drug-metabolizing enzymes (cytochrome P450 3A4 and 2D6 [CYP3A4 and CYP2D6]) were also measured in these 17 patients. We found that the results obtained from the CBT protocol did not predict the peak serum alanine transaminase (ALT) observed in the patients. The measured CYP3A4 and CYP2D6 activities also failed to predict the susceptible patients. However, the result of the standardized-dose CBT correlated well with the logarithm of the steady-state plasma tacrine level obtained in 10 patients (R(2) = .69, P = .003). We conclude that the CBT will not be clinically useful in determining the subset of patients most susceptible to tacrine hepatotoxicity. However, the correlation we observed between CBT results and tacrine blood levels is the first evidence supporting a critical role for CYP1A2 activity in the disposition of the drug in vivo.

Update of the Adult and Pediatric Liver Transplant Program at the University of Michigan

Significant technical innovations and improvements in immunosuppression have been introduced into our liver transplant program since its inception in 1985. The indications for transplantation have been extended to younger and older patients, and simultaneously more patients with comorbidities have been accepted for transplant. The net impact of these changes has been a continuing trend toward improved survival. Overall, patients with hepatitis B or malignancy have had poor survival rates. The introduction of prophylactic anti-hepatitis B immunoglobulin and lamivudine, and better selection of patients with malignancy may improve results for these patients in the future. As in other programs, our most vexing problem is the continuing scarcity of donor organs which has led to an ever-expanding waiting list, more deaths while awaiting transplant, and more suffering before transplantation. The introduction of living donor hepatic transplantation will be of some help in alleviating this shortage. We are confident that the evolution of our program into a joint multidisciplinary structure will provide more efficient, convenient and cost-effective care to our patients.

Genetic predisposition to drug-induced liver disease

Rarely do otherwise safe drugs administered at recommended doses produce liver damage that may progress to liver failure and death. Because we are generally unable to identify the patients most susceptible to this "idiosyncratic" form of toxicity, many potentially useful medications are not made available to patients. The most promising developments in identifying susceptible patients have stemmed from recent advances in characterization of bioactivation and detoxification enzyme systems, and the discovery of marked variation in the activities of these enzymes among patients. Tests capable of quantitating the activities of specific relevant enzymes have been recently developed and are now being applied in clinical trials to assess risk factors for drug-induced liver disease. These tests hold promise of identifying subsets of patients who may need close monitoring or who may be best served with an alternate treatment.