Hepatic encephalopathy--definition, nomenclature, diagnosis, and quantification: final report of the working party at the 11th World Congresses of Gastroenterology, Vienna, 1998

Research on hepatic encephalopathy is hampered by the imprecise definition of this disabling complication of liver disease. Under this light, the Organisation Mondiale de Gastroentérologie commissioned a Working Party to reach a consensus in this area and to present it at the 11th World Congress of Gastroenterology in Vienna (1998). The Working Party continued its work thereafter and now present their final report. In summary, the Working Party has suggested a modification of current nomenclature for clinical diagnosis of hepatic encephalopathy; proposed guidelines for the performance of future clinical trials in hepatic encephalopathy; and felt the need for a large study to redefine neuropsychiatric abnormalities in liver disease, which would allow the diagnosis of minimal (subclinical) encephalopathy to be made on firm statistical grounds. In the interim, it proposes the use of a psychometric hepatic encephalopathy score, based on the result of 5 neuropsychologic tests. Finally, the need for a careful evaluation of the newer neuroimaging modalities for the diagnosis of hepatic encephalopathy was stressed.

Diagnosis and phenotypic classification of Wilson disease

Wilson disease is an inherited autosomal recessive disorder of hepatic copper metabolism leading to copper accumulation in hepatocytes and in extrahepatic organs such as the brain and the cornea. Originally Wilson disease was described as a neurodegerative disorder associated with cirrhosis of the liver. Later, Wilson disease was observed in children and adolescents presenting with acute or chronic liver disease without any neurologic symptoms. While diagnosis of neurologic Wilson disease is straightforward, it may be quite difficult in non-neurologic cases. Up to now, no single diagnostic test can exclude or confirm Wilson disease with 100% certainty. In 1993, the gene responsible for Wilson disease was cloned and localized on chromosome 13q14.3 (MIM277900) (1, 2). The Wilson disease gene ATP7B encodes a P-type ATPase. More than 200 disease causing mutations of this gene have been described so far (3). Most of these mutations occur in single families, only a few are more frequent (like H1069Q, 3400delC and 2299insC in Caucasian (4-6) or R778L in Japanese (7), Chinese and Korean patients). Studies of phenotype-genotype relations are hampered by the lack of standard diagnostic criteria and phenotypic classifications. To overcome this problem, a working party discussed these problems in depth at the 8th International Meeting on Wilson disease and Menkes disease in Leipzig/Germany (April 16-18, 2001). After the meeting, a preliminary draft of a consensus report was mailed to all active participants and their comments were incorporated in the final text.

ABT-450/r-ombitasvir and dasabuvir with or without ribavirin for HCV

BACKGROUND

The interferon-free regimen of ABT-450 with ritonavir (ABT-450/r), ombitasvir, and dasabuvir with or without ribavirin has shown efficacy in inducing a sustained virologic response in a phase 2 study involving patients with hepatitis C virus (HCV) genotype 1 infection. We conducted two phase 3 trials to examine the efficacy and safety of this regimen in previously untreated patients with HCV genotype 1 infection and no cirrhosis.

METHODS

We randomly assigned 419 patients with HCV genotype 1b infection (PEARL-III study) and 305 patients with genotype 1a infection (PEARL-IV study) to 12 weeks of ABT-450/r-ombitasvir (at a once-daily dose of 150 mg of ABT-450, 100 mg of ritonavir, and 25 mg of ombitasvir), dasabuvir (250 mg twice daily), and ribavirin administered according to body weight or to matching placebo for ribavirin. The primary efficacy end point was a sustained virologic response (an HCV RNA level of <25 IU per milliliter) 12 weeks after the end of treatment.

RESULTS

The study regimen resulted in high rates of sustained virologic response among patients with HCV genotype 1b infection (99.5% with ribavirin and 99.0% without ribavirin) and among those with genotype 1a infection (97.0% and 90.2%, respectively). Of patients with genotype 1b infection, 1 had virologic failure, and 2 did not have data available at post-treatment week 12. Among patients with genotype 1a infection, the rate of virologic failure was higher in the ribavirin-free group than in the ribavirin group (7.8% vs. 2.0%). In both studies, decreases in the hemoglobin level were significantly more common in patients receiving ribavirin. Two patients (0.3%) discontinued the study drugs owing to adverse events. The most common adverse events were fatigue, headache, and nausea.

CONCLUSIONS

Twelve weeks of treatment with ABT-450/r-ombitasvir and dasabuvir without ribavirin was associated with high rates of sustained virologic response among previously untreated patients with HCV genotype 1 infection. Rates of virologic failure were higher without ribavirin than with ribavirin among patients with genotype 1a infection but not among those with genotype 1b infection. (Funded by AbbVie; PEARL-III and PEARL-IV ClinicalTrials.gov numbers, NCT01767116 and NCT01833533.).

Predicting sustained virological responses in chronic hepatitis C patients treated with peginterferon alfa-2a (40 KD)/ribavirin

BACKGROUND/AIMS

Prediction of sustained virological response (SVR) during treatment would allow clinicians to identify patients most likely to benefit from therapy.

METHODS

Retrospective analysis of data from 1121 adults with chronic hepatitis C treated for 48 weeks with peginterferon alfa-2a (40 KD) 180 microg/week plus placebo or ribavirin (1000/1200 mg/day), or interferon alfa-2b 3 MIU three times/week plus ribavirin in a randomized, multinational, study.

RESULTS

67% of patients treated with peginterferon alfa-2a (40 KD)/ribavirin with early virological responses (HCV RNA negative or > or = 2 log10 decrease) at week 12 had SVRs at week 72 (HCV RNA < 50 IU/mL). The negative predictive value (NPV) was 97%. The probability of an SVR increased with the rapidity of HCV RNA suppression. The highest SVR rates were achieved in patients with rapid virological responses at week 4, but the corresponding NPV (74%) is too low for a decision criterion. In patients with early virological responses by week 12, the SVR rate was approximately 20% lower in those who received <80% compared with patients who received > or = 80% of the planned ribavirin dose.

CONCLUSIONS

Early, sustained suppression of HCV replication portends an SVR. Cessation of treatment may be contemplated in patients without a > or = 2 log10 reduction in HCV RNA after 12 weeks.

Randomized controlled trial of silymarin treatment in patients with cirrhosis of the liver

Silymarin, the active principle of the milk thistle Silybum marianum, protects experimental animals against various hepatotoxic substances. To determine the effect of silymarin on the outcome of patients with cirrhosis, a double blind, prospective, randomized study was performed in 170 patients with cirrhosis. 87 patients (alcoholic 46, non-alcoholic 41; 61 male, 26 female; Child A, 47; B, 37; C, 3; mean age 57) received 140 mg silymarin three times daily. 83 patients (alcoholic 45, non-alcoholic 38; 62 male, 21 female; Child A, 42; B, 32; C, 9: mean age 58) received a placebo. Non-compliant patients and patients who failed to come to a control were considered as 'drop outs' and were withdrawn from the study. All patients received the same treatment until the last patient entered had finished 2-years of treatment. The mean observation period was 41 months. There were 10 drop outs in the placebo group and 14 in the treatment group. In the placebo group, 37 (+2 drop outs) patients had died, and in 31 of these, death was related to liver disease. In the treatment group, 24 (+4 drop outs) had died, and in 18 of these, death was related to liver disease. The 4-year survival rate was 58 +/- 9% (S.E.) in silymarin-treated patients and 39 +/- 9% in the placebo group (P = 0.036). Analysis of subgroups indicated that treatment was effective in patients with alcoholic cirrhosis (P = 0.01) and in patients initially rated 'Child A' (P = 0.03). No side effects of drug treatment were observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Peginterferon alfa-2a and ribavirin for 24 weeks in hepatitis C type 1 and 4 patients with rapid virological response

BACKGROUND & AIMS

This analysis reports the rate of sustained virological response (SVR) in patients infected with hepatitis C virus (HCV) genotype 1 or 4 who were assigned to 24 weeks of treatment with pegylated interferon (peginterferon) alfa-2a 180 mug/wk plus ribavirin 1000/1200 mg/day after achieving a rapid virological response (RVR; HCV RNA level <50 IU/mL) at week 4 in a prospective trial investigating response-guided therapy.

METHODS

Non-RVR patients with an early virological response were randomized to 48 or 72 weeks of therapy (this is a still-ongoing trial).

RESULTS

A total of 150 of 516 patients (29%) had an RVR, 143 of whom completed 24 weeks of treatment. Younger patients, leaner patients, and those with an HCV RNA level

CONCLUSIONS

This prospective study confirms that a 24-week regimen of peginterferon alfa-2a plus ribavirin 1000/1200 mg/day is appropriate in genotype 1 and 4 patients with a low baseline HCV RNA level who achieve an RVR by week 4 of therapy.

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MESH Headings

• Adult
• Antiviral Agents/administration & dosage
• Antiviral Agents/adverse effects
• Drug Administration Schedule
• Drug Therapy, Combination
• Female
• Genotype
• Hepacivirus/genetics
• Hepacivirus/immunology
• Hepatitis C/diagnosis
• Hepatitis C/drug therapy
• Hepatitis C Antibodies/blood
• Humans
• Interferon alpha-2
• Interferon-alpha/administration & dosage
• Interferon-alpha/adverse effects
• Male
• Middle Aged
• Polyethylene Glycols/administration & dosage
• Polyethylene Glycols/adverse effects
• Prospective Studies
• RNA, Viral/blood
• Recombinant Proteins
• Ribavirin/administration & dosage
• Ribavirin/adverse effects
• Treatment Outcome
• Viral Load

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Diagnostic value of quantitative hepatic copper determination in patients with Wilson's Disease

BACKGROUND & AIMS

A 5-fold increase of hepatic copper concentration is considered as the best available test for diagnosis of hepatic Wilson's disease (WD). However, the sensitivity and specificity of this test have never been fully investigated.

METHODS

Copper content was measured by flame atomic absorption spectroscopy in 114 liver biopsies obtained at diagnosis of WD, in 219 patients with noncholestatic liver diseases (including 144 with chronic hepatitis C and 44 with nonalcoholic fatty liver disease), and in 26 without evidence of liver disease.

RESULTS

Liver copper content was >250 microg/g in 95 WD patients (83.3%), between 50 and 250 microg/g in 15, and below 50 microg/g in 4. It did not correlate with age (r(2) = .003), the grade of fibrosis, or the presence of stainable copper. Liver copper content was >250 or between 50 and 250 microg/g in 3 (1.4%) and 20 (9.1%) of 219 patients with noncholestatic liver diseases, respectively. By lowering the cutoff from 250 to 75 microg/g, the sensitivity of liver copper content to diagnose WD increased from 83.3% (95% confidence interval, 75.2%-89.6%) to 96.5% (91.3%-99.1%), but the specificity decreased from 98.6% (96.0%-99.7%) to 95.4% (91.8%-97.8%).

CONCLUSIONS

There is no gold standard for the diagnosis of WD. Liver copper content is a useful parameter, but a value below 250 microg/g does not exclude WD. Diagnosis requires the combination of a variety of clinical and biochemical tests.

Regional distribution of mutations of the ATP7B gene in patients with Wilson disease: impact on genetic testing

Wilson disease is an autosomal recessive inherited disorder of copper metabolism. The Wilson disease gene codes for a copper transporting P-type ATPase (ATP7B). Molecular genetic analysis reveals at least 300 distinct mutations. While most reported mutations occur in single families, a few are more common. The most common mutation in patients from Central, Eastern, and Northern Europe is the point mutation H1069Q (exon 14). About 50-80% of Wilson disease (WD) patients from these countries carry at least one allele with this mutation with an allele frequency ranging between 30 and 70%. Other common mutations in Central and Eastern Europe are located on exon 8 (2299insC, G710S), exon 15 (3400delC) and exon 13 (R969Q). The allele frequency of these mutations is lower than 10%. In Mediterranean countries there is a wide range of mutations, the frequency of each of them varies considerably from country to country. In Sardinia, a unique deletion in the 5' UTR (-441/-427 del) is very frequent. In mainland Spain the missense mutation M645R in exon 6 is particularly common. Data from non-European countries are scarce. Most data from Asia are from Far Eastern areas (China, South Korea and Japan) where the R778L missense mutation in exon 8 is found with an allele frequency of 14-49%. In summary, given the constant improvement of analytic tools genetic testing will become an integral part for the diagnosis of WD. Knowledge of the differences in the worldwide distribution of particular mutations will help to design shortcuts for genetic diagnosis of WD.

Silibinin is a potent antiviral agent in patients with chronic hepatitis C not responding to pegylated interferon/ribavirin therapy

BACKGROUND & AIMS

Oral Silibinin (SIL) is widely used for treatment of hepatitis C, but its efficacy is unclear. Substantially higher doses can be administered intravenously (IV).

METHODS

Pedigreed nonresponders to full-dose pegylated (Peg)-interferon/ribavirin (PegIFN/RBV) were studied. First, 16 patients received 10 mg/kg/day SIL IV (Legalon Sil; Madaus, Köln, Germany) for 7 days. In a subsequent dose-finding study, 20 patients received 5, 10, 15, or 20 mg/kg/day SIL for 14 days. In both protocols, PegIFN alpha-2a/RBV were started on day 8. Viral load was determined daily.

RESULTS

Unexpectedly, in the first study, HCV-RNA declined on IV SIL by 1.32 +/- 0.55 log (mean +/- SD), P < .001 but increased again in spite of PegIFN/RBV after the infusion period. The viral load decrease was dose dependent (log drop after 7 days SIL: 0.55 +/- 0.5 [5 mg/kg, n = 3], 1.41 +/- 0.59 [10 mg/kg, n = 19], 2.11 +/- 1.34 [15 mg/kg, n = 5], and 3.02 +/- 1.01 [20 mg/kg, n = 9]; P < .001), decreased further after 7 days combined SIL/PegIFN/RBV (1.63 +/- 0.78 [5 mg/kg, n = 3], 4.16 +/- 1.28 [10 mg/kg, n = 3], 3.69 +/- 1.29 [15 mg/kg, n = 5], and 4.85 +/- 0.89 [20 mg/kg, n = 9]; P < .001), and became undetectable in 7 patients on 15 or 20 mg/kg SIL, at week 12. Beside mild gastrointestinal symptoms, IV SIL monotherapy was well tolerated.

CONCLUSIONS

IV SIL is well tolerated and shows a substantial antiviral effect against HCV in nonresponders.

Late-onset Wilson's disease

BACKGROUND & AIMS

The clinical symptoms and age at onset of Wilson's disease (WD) are highly variable. This study investigated patients who became symptomatic at >40 years of age.

METHODS

Clinical features, laboratory data, and mutation analysis were evaluated in 46 (3.8%) of 1223 patients who were investigated in a multinational study on genotype-phenotype correlations (1053 index patients, 170 siblings) who were >40 years of age at onset of symptoms and, in 2 asymptomatic siblings, diagnosed at >40 years of age.

RESULTS

Thirty-one patients presented with neurologic symptoms (mean age, 44.5 years; range, 40-52; male/female, 14/17), 15 presented with liver disease (mean age, 47.1 years; range, 40-58; male/female, 6/9), and 2 were asymptomatic siblings. Hepatic copper content was measured in 17 patients and was above 250 microg/g dry weight in 13. One patient with hepatic presentation had "fulminant" WD, the remaining 14 abnormal liver function tests and/or hepatomegaly. Liver biopsy specimens were available in 13 patients presenting with liver disease (cirrhosis, 10; chronic hepatitis, 2; steatosis, 1; no abnormalities, 1) and in 14 neurologic patients (cirrhosis, 9; advanced fibrosis, 1; chronic hepatitis, 2; no abnormalities, 2). Twenty-seven of the 46 index cases had mutations on both chromosomes (including 13 H1069Q/H1069Q), 13 on just 1 chromosome.

CONCLUSIONS

Late-onset WD is a frequently overlooked condition. The diagnostic features and the frequency of late-onset WD gene mutations were not different than in patients with an earlier onset of disease. Factors other than ATP7B mutations may modify the phenotypic presentation of WD.

Age and Sex but Not ATP7B Genotype Effectively Influence the Clinical Phenotype of Wilson Disease

Wilson disease (WD) is an inherited disorder of hepatic copper metabolism with considerable variation in clinical presentations, the most common ones being liver disease and neuropsychiatric disturbances. This study investigated the clinical presentation in relation to mutations in a large cohort of patients with WD. A total of 1,357 patients (702 children, 655 adults; 1,172 index patients, 185 siblings, all with a Leipzig score ≥4, male/female: 679/678) were studied. The age and the symptoms at presentation were used as key phenotypic markers. Index patients were clinically classified as having either hepatic (n = 711) or neurologic disease (n = 461). Seven hundred fifteen (52.7%) patients had a liver biopsy at diagnosis. DNA was sequenced by the Genetic Analyzers ABI Prism 310 (Perkin Elmer) or 3500 (Applied Biosystems). Three hundred ninety-four different mutation combinations were detected. The most frequent mutation was H1069Q (c.3207C>A; allele frequency: 46.9%), followed by P767P-fs (c.2304dupC; 2.85%), P1134P-fs (c.3402delC; 2.8%), and R969Q (c.2755C>T; 2.18%). There was no correlation between mutations and individual clinical manifestation. There was a gender effect in index patients: Hepatic presentation was more common in females (male/female: 328/383) and neurologic presentation in males (259/202; P < 0.001). At diagnosis, 39.5% of children/adolescents (≤18 years) and 58% of adults already had cirrhosis. The presence of cirrhosis did not correlate with the genotype. Conclusion: These findings refine and extend our understanding of the natural history and individual spectrum/manifestations of WD. Initially, there is asymptomatic hepatic involvement, which may progress and become symptomatic. Neurologic symptoms present many years later.

Successful long-term treatment of portal-systemic encephalopathy by the benzodiazepine antagonist flumazenil

A patient with portal-systemic encephalopathy refractory to standard therapy (40-g protein diet, oral neomycin and lactulose, supplementation of diet with branched chain amino acids) following extensive liver resection and construction of a portacaval shunt was treated with 25 mg of flumazenil twice daily by mouth. Before treatment with flumazenil she was encephalopathic and experienced 12 attacks of coma within 2 yr. When treated with flumazenil all signs of encephalopathy abated in spite of an unrestricted dietary intake of protein. Two days after discontinuation of flumazenil treatment she became comatose again. She remained chronically encephalopathic and had four further episodes of coma during the subsequent 3 mo. Since reinstitution of flumazenil treatment she has been well for 14 mo during follow-up without any signs of encephalopathy while on an unrestricted protein diet. Furthermore, flumazenil therapy reversed abnormalities of recordings of multimodality evoked potentials that were associated with hepatic encephalopathy. The striking remission of encephalopathy by treatment with flumazenil suggests that this benzodiazepine antagonist may be valuable in the long-term management of portal-systemic encephalopathy.

Combination of interferon induction therapy and ribavirin in chronic hepatitis C

The initial clearance of hepatitis C virus (HCV) during interferon-alfa therapy is dose-dependent. Therefore, higher initial interferon doses (induction therapy) may improve treatment results. This concept was tested in a prospective, randomized controlled trial. Previously untreated patients with chronic hepatitis C were randomized to receive 3 different interferon doses during the first 14 weeks of therapy (Group A, n = 130: 10 MU IntronA [AESCA-Schering Plough, Traiskirchen, Austria]/day for 2 weeks, followed by 10 MU/2 days for 12 weeks; Group B, n = 124: 5 MU/day for 14 weeks; Group C, n = 119; 5 MU/2 days for 14 weeks) followed in all by 5 MU/2 days for 24 weeks. Throughout the whole study all patients received 1 to 1.2 g ribavirin/day. On treatment, no differences in viral clearance rates were observed. Sustained response rates were also not different among the groups (A: 48.5%, B and C: 41.3%, intent to treat). When data were analyzed according to genotypes, sustained response was almost twice as high in patients with genotype 1 receiving high-dose interferon induction therapy (A: 44.2%, B: 28.6%, C: 27%, P <.05). In contrast, results were not different in genotype 3a patients (A: 61.3%, B: 75.9%, C: 56.3%; P >.1). These data indicate that high-dose interferon induction therapy may improve the outcome of interferon/ribavirin combination therapy in genotype 1 patients.

Review article: diagnosis and current therapy of Wilson's disease

Wilson's disease is an autosomal recessive inherited disorder of hepatic copper metabolism resulting in liver disease and/or neuropsychiatric disease. The diagnosis of neurological disease is straightforward if the following symptoms are present: Kayser-Fleischer rings, typical neurological symptoms and low serum ceruloplasmin levels. The diagnosis is more complex in patients presenting with liver diseases. None of the commonly used parameters alone allows a diagnosis with certainty. A combination of various laboratory parameters is necessary to firmly establish the diagnosis. In the future, limited mutation analysis may play an important diagnostic role. Recently, a group of international experts has proposed a score based on a variety of tests and clinical symptoms. The validity of this score needs to be assessed prospectively. Treatment requires life-long administration of copper chelators (d-penicillamine, trientine). A frequently used alternative is zinc. None of these treatments has been tested by prospective randomized controlled studies. Liver transplantation is reserved for severe or treatment-resistant cases with advanced liver disease, whilst experience with refractory neuropsychiatric disease is limited.

Peginterferon alfa-2a/ribavirin for 48 or 72 weeks in hepatitis C genotypes 1 and 4 patients with slow virologic response

BACKGROUND & AIMS

This randomized multicenter trial evaluated individualization of treatment duration with peginterferon alfa-2a 180 microg/wk plus ribavirin 1000/1200 mg/day in patients with chronic hepatitis C genotype 1/4 based on the rapidity of virologic response (VR).

METHODS

Patients with a rapid VR (RVR; undetectable hepatitis C virus [HCV]-RNA level (<50 IU/mL at week 4) were treated for 24 weeks, those with an early VR (EVR; no RVR but undetectable HCV-RNA level or >or=2-log(10) decrease at week 12) were randomized to 48 (group A) or 72 weeks of treatment (group B; peginterferon alfa-2a was reduced to 135 microg/wk after week 48). Patients without an EVR continued treatment until week 72 if they had undetectable HCV-RNA levels at week 24. The primary end point was relapse; sustained VR (SVR; undetectable HCV-RNA level after 24 weeks of follow-up evaluation) was a secondary end point.

RESULTS

Of 551 genotype 1/4 patients starting treatment, 289 were randomized to group A (N = 139) or group B (N = 150). The relapse rate was 33.6% in group A (95% confidence interval [CI], 24.8%-43.4%) and 18.5% in group B (95% CI, 11.9%-27.6%; P = .0115 vs group A) and the SVR rate was 51.1% (95% CI, 42.5%-59.6%) and 58.6% (95% CI, 50.3%-66.6%; P > .1), respectively. The overall SVR rate was 50.4% (278 of 551; 95% CI, 46.2%-54.7%), including 115 of 150 patients with an RVR treated for 24 weeks and 4 of 78 patients without an EVR.

CONCLUSIONS

Extending therapy with peginterferon alfa-2a/ribavirin to 72 weeks decreases the probability of relapse in patients with an EVR. If they can be maintained on extended-duration therapy, SVR rates also may improve.

Hepatic encephalopathy

Hepatic encephalopathy (HE) is a reversible syndrome of impaired brain function occurring in patients with advanced liver diseases. The precise pathophysiology of HE is still under discussion; the leading hypothesis focus on the role of neurotoxins, impaired neurotransmission due to metabolic changes in liver failure, changes in brain energy metabolism, systemic inflammatory response and alterations of the blood brain barrier. HE produces a wide spectrum of nonspecific neurological and psychiatric manifestations. Minimal HE is diagnosed by abnormal psychometric tests. Clinically overt HE includes personality changes, alterations in consciousness progressive disorientation in time and space, somnolence, stupor and, finally, coma. Except for clinical studies, no specific tests are required for diagnosis. HE is classified according to the underlying disease, the severity of manifestations, its time course and the existence of precipitating factors. Treatment of overt HE includes supportive therapies, treatment of precipitating factors, lactulose and/or rifaximin. Routine treatment for minimal HE is only recommended for selected patients.

Wilson's Disease

Wilson's disease (WD) is an autosomal recessive inherited disorder leading to impaired intrahepatic trafficking and biliary excretion of copper, resulting in the accumulation of copper in various organs including the liver, cornea, and brain. The WD gene (OMIM 277900) codes for a copper transporting P-type ATPase (ATP7B). Although the finding of the gene resulted in a major breakthrough for understanding the pathophysiology of WD, the role of genetic testing in the clinical management of WD patients is not yet established. There is no gold standard for diagnosis of WD. Diagnosis requires a combination of clinical and biochemical tests. None of these parameters alone allows a certain diagnosis of WD. To facilitate diagnosis, a scoring system was developed at the 8th International Meeting on Wilson Disease in Leipzig, Germany in 2001. For clinical purposes, the use of mutation analysis is limited by the occurrence of many mutations (more than 200) causing WD. In contrast to direct DNA sequencing, direct mutation detection by using allele-specific probes is rapid and clinically very helpful, if a mutation occurs with a reasonable frequency in the population (ie, H1069Q in European WD patients or R778L in WD patients from the Far East). To date, mutation analysis is the only reliable tool for screening the family of an index case with known causative mutation. Alternatively, haplotype analysis can be used to address diagnostic dilemmas in differentiating heterozygote gene carriers and affected asymptomatic siblings.

Pathophysiology and clinical features of Wilson disease

Wilson disease is an autosomal recessive inherited disorder of copper metabolism resulting in pathological accumulation of copper in many organs and tissues. ATP7B is the gene product of the Wilson disease gene located on chromosome 13 and resides in hepatocytes in the trans-Golgi network, transporting copper into the secretory pathway for incorporation into apoceruloplasmin and excretion into the bile. Mutations of the gene result in impaired trafficking of copper in and through the hepatocytes. More than 200 mutations of Wilson disease gene were found, the most common ones being H1069Q (in Europe) and R778L (in Asia). Wilson disease may present under a variety of clinical conditions, commonly as liver and/or neuropsychiatric disease. The pathogenesis of hepatic and neurologic Wilson disease is a direct consequence of copper accumulation. Presence of copper causes oxidative stress resulting in cell destruction. The diagnosis of Wilson disease requires a combination of a variety of clinical symptoms, biochemical tests, and detection of gene mutations, which are the basis of a score proposed by a group of international experts. Initial treatment for symptomatic patients should include a chelating agent (penicillamine or trientine). Treatment of presymptomatic patients or maintenance therapy can also be accomplished with zinc.

Serum levels of gamma-aminobutyric-acid-like activity in acute and chronic hepatocellular disease

Serum levels of GABA (gamma-aminobutyric acid)-like activity were measured by a radioreceptor assay in 22 healthy subjects and 170 patients with liver diseases. Levels were within normal limits (mean +/- SEM in healthy controls 0.52 +/- 0.04 mumol/l; range 0.2-0.8 mumol/l GABA equivalents) in most patients with uncomplicated acute viral hepatitis, compensated chronic hepatitis, and primary biliary cirrhosis (PBC). In 96% of patients with compensated (non-PBC) cirrhosis levels were slightly high (1.5 +/- 0.06 mumol/l). In 4 patients with decompensated cirrhosis but without hepatic encephalopathy (range 3.0-6.4 mumol/l) and in most of 26 patients with overt hepatic encephalopathy due to acute or chronic hepatocellular failure (range 2.3-18.0 mumol/l) levels were very high. Levels did not correlate closely with the clinical stage of hepatic encephalopathy or with arterial plasma ammonia concentrations. particularly high levels were detected in patients with cirrhosis 12-16 h after gastrointestinal haemorrhages. These findings are compatible with the hypothesis that the GABA neurotransmitter system is involved in the pathogenesis of hepatic encephalopathy in man.

Predicting the therapeutic response in patients with chronic hepatitis C: the role of viral kinetic studies

A substantial proportion of patients infected with hepatitis C virus (HCV) genotype 1 still does not respond to pegylated interferon-alfa/ribavirin (IFN/RBV) therapy. Factors which identify potential non-responders are needed to limit exposure to drugs in patients unlikely to benefit from treatment and to save health care resources. Host predictive factors have a low negative predictive value. In contrast, viral factors have a high precision in predicting outcome of therapy. Viral kinetics are the basis for the study of response of therapy. The decrease in viral load within 24 h after administration of a single test dose of conventional IFN reflects the IFN-sensitivity of the virus strain and predicts the outcome of conventional IFN/RBV therapy even before treatment with a specificity of 100% and a sensitivity of 83%. In contrast to conventional IFN, the two available PEG-IFN preparations differ considerably in how they suppress viral replication, and cut-off values have to be prospectively established separately for each drug. Patients without an early virological response (HCV-RNA either undetectable or decrease by >or=2 log10 after 12 weeks) (EVR), do not achieve a sustained virological response (SVR; negative predictive value: 97-98%). Thus, in the absence of an EVR, treatment should be stopped. The outcome of PEG-IFN alfa-2a/RBV combination therapy is dependent on the rapidity of the virological response. Patients who become HCV-RNA negative after 4 weeks have the best chance of achieving an SVR. The rapidity of viral elimination may be a useful guide to tailoring the length of treatment in patients with an EVR.

Changes in glutamate receptors on synaptic membranes associated with hepatic encephalopathy or hyperammonemia in the rabbit

The status of the excitatory glutamatergic neurotransmitter system in hepatic encephalopathy has been studied. Synaptic membranes (SM) were prepared from the brains of normal rabbits, hyperammonemic normal rabbits, and rabbits with fulminant hepatic failure. Data on the specific binding of glutamate to SM indicated that fulminant hepatic failure was associated with a decrease in the number of glutamate receptors on SM from cerebral cortex, cerebellum, and particularly the hippocampus, without any associated change in the affinity of these receptors. In contrast, hyperammonemia was associated with an increase in the affinity and no decrease in the number of glutamate receptors on SM from the hippocampus. These findings indicate that the effects of hyperammonemia and fulminant hepatic failure on cerebral glutamate receptors are fundamentally different. The decreased number of glutamate receptors in hepatic encephalopathy might reflect a decreased sensitivity of glutamatergic neurons to glutamate-mediated neural excitation, a phenomenon that could contribute to the neural inhibition of hepatic encephalopathy.

A randomized, prospective trial of ribavirin 400 mg/day versus 800 mg/day in combination with peginterferon alfa-2a in hepatitis C virus genotypes 2 and 3

We compared the efficacy and tolerability of 24 weeks of treatment with ribavirin 800 mg/day (group A) or 400 mg/day (group B) plus peginterferon alfa-2a 180 mug/week in treatment-naive patients infected with hepatitis C virus (HCV) genotype 2 or 3. A total of 97 of 141 patients randomized to group A (68.8%, 95% confidence interval [CI] 60.5%-76.3%) and 90 of 141 patients randomized to group B (63.8; 95% CI 55.3%-71.7%) achieved a sustained virological response, defined as undetectable serum HCV RNA at the end of untreated follow-up (week 48). Among patients infected with genotype 3, the rate of sustained virological response was 67.5% (95% CI 58.4%-75.6%) in group A and 63.9% (95% CI 54.7%-72.4%) in group B, and among patients infected with genotype 2, the rate of sustained virological response was 77.8% (95% CI 54.2%-93.6%) in group A and 55.6% (95% CI 38.4%-83.7%) in group B. Relapse rates in the 2 treatment groups were similar (17% in group A and 20% in group B). The incidence of adverse events, laboratory abnormalities, and dose reductions was similar in the 2 treatment groups.

CONCLUSION

The results suggest that when administered for 24 weeks with peginterferon alfa-2a, ribavirin doses of 400 and 800 mg/day produce equivalent outcomes in patients infected with HCV genotype 3.

Predictors of response to therapy for chronic hepatitis C

Pretreatment prediction of successful interferon-based therapy is less accurate than is prediction based on serum hepatitis C virus (HCV) RNA measurements taken during the first few weeks of therapy. Virological response, defined as loss of detectable virus RNA during the first weeks of treatment, identifies interferon-sensitive virus strains. Studies on viral decline kinetics have shown that interferon-based therapies produce a two-phase reduction in viral RNA levels. Sustained virological response is associated with rapid biphasic viral decline kinetics, resulting in elimination of virus from the blood within 4 to 12 weeks. Rapid viral elimination correlates positively with low incidence of relapse in end-of-treatment virological responders and is, therefore, an important parameter for determining duration or type of therapy. This article reviews the various patient and viral factors that help predict response to various interferon-based therapies, ranging from interferon alone to the new pegylated interferons.

Changes in the status of neurotransmitter receptors in a rabbit model of hepatic encephalopathy

It has previously been shown in an animal model of hepatic encephalopathy (HE) that the number of receptors for the inhibitory neurotransmitter, gamma-aminobutyric acid (GABA), increases and that the number of receptors for the excitatory neurotransmitter, glutamate, decreases. To determine the functional status of other neurotransmitter systems in HE, measurements were made of the specific binding of other neurotransmitters to synaptic membranes prepared from the brains of normal rabbits and rabbits in HE due to galactosamine-induced acute liver failure. The development of HE was associated with: (i) a decrease in the density (Bmax) of receptors for the two excitatory amino acid neurotransmitters, aspartate and kainic acid; (ii) an increase in the Bmax of both the low and high affinity binding site for strychnine, a marker for the inhibitory neurotransmitter glycine; (iii) a decrease in the affinity (Kd) of receptors for dopamine, and (iv) no appreciable change in either the specific binding of [3H]D-ala2-methionine enkephalinamide or [3H]naloxone, markers for opiate receptors, or in the Bmax or the Kd of receptors for acetylcholine. If it is assumed that the sensitivity of the brain to neurotransmitters varies directly with the density of neurotransmitter receptors, HE may be associated with increased sensitivity to inhibitory amino acid neurotransmitters and decreased sensitivity to excitatory amino acid neurotransmitters. Thus, the observed changes in neurotransmitter receptors in HE afford a feasible pathophysiological basis for the mediation of the neural inhibition of HE.