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Biomedical subjects

Peter Ferenci

Publications and source records attributed to Peter Ferenci.

At least 37 records · Page 2Linked to original sources
PubMed2005

Wilson disease.

Wilson disease (WD) is an autosomal recessive inherited disorder of copper metabolism, resulting in pathological accumulation of copper in many organs and tissues. The hallmarks of the disease are the presence of liver disease, neurologic symptoms, and Kayser-Fleischer corneal rings. The leading neurologic symptoms in WD are dysathria, dyspraxia, ataxia, and Parkinsonian-like extrapyramidal signs. Changes in the basal ganglia in brain magnetic resonance imaging (MRI) are characteristic features of the disease. In presence of liver cirrhosis, some features may resemble hepatic encephalopathy. Symptoms and MRI abnormalities may be fully reversible on treatment with zinc or copper chelators. Improvement can be monitored by serial recording of brain-stem-evoked responses. The basic defect is an impaired trafficking of copper in hepatocytes. ATP7B is the gene product of the WD 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. While about 40% of patients preset with neurologic symptoms, little is known about the role of copper and ATP7B in the central nervous system. In some brain areas, like in the pineal gland, ATP7B is expressed and functionally active. Increasing evidence supports an important role for metals in neurobiology. Two proteins related to neurodegeneration are copper-binding proteins (1) the amyloid precursor protein (APP), a protein related to Alzheimer's disease, and (2) the Prion protein, related to Creutzfeldt-Jakob disease. A major source of free-radical production in the brain derives from copper. To prevent metal-mediated oxidative stress, cells have evolved complex metal transport systems. APP is a major regulator of neuronal copper homeostasis and has a copper-binding domain (CuBD). The surface location of this site, structural homology of CuBD to copper chaperones, and the role of APP in neuronal copper homeostasis are consistent with the CuBD acting as a neuronal metallotransporter. There are several copper-containing enzymes in the brain, like dopamine beta hydroxylase or Cu/Zn superoxide dismutase (SOD1). Their function may be altered because of copper overload. WD appears to be associated with a dopaminergic deficit. Mutations in the SOD1gene cause familial amyotrophic lateral sclerosis. Survival of transgenic mice with a mutant SOD1 which fails to incorporate Cu((2+)) in its active site was improved by copper depletion. Wilson disease (WD) is an autosomal recessive inherited disorder in which copper pathologically accumulates primarily within the liver and subsequently in the neurologic system and many other organs and tissues. Presence of liver disease, neurologic symptoms, and Kayser-Fleischer corneal rings are the hallmarks of the disease.

Animals↗
PubMed2005

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.

Antiviral Agents↗
PubMed2005

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.

Adenosine Triphosphatases↗
PubMed2005

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.

Adenosine Triphosphatases↗
PubMed2005

Sonographic diagnosis of coeliac disease in a case with suspected acute liver failure.

Mild liver dysfunction occurs in patients with coeliac disease frequently, but severe liver diseases in combination with coeliac disease are rare. A 19-year-old woman was referred for evaluation for emergency liver transplantation with progressive jaundice and prolongation of prothrombin time. She had a history of non-bloody diarrhoea for 3 months and weight loss of 12 kg. At admission, abdominal ultrasound revealed liver enlargement with increased echogenicity and marked thickening of the circular folds of the small intestine, suggestive of coeliac disease. The diagnosis was confirmed by endoscopic biopsy from the second part of the duodenum. On a gluten-free diet the patient recovered within 1 week and remained in excellent health up to the present date. Liver tests normalized within 5 months and a repeat abdominal ultrasound after 20 months revealed a normal liver and small intestine. This case report suggests that coeliac disease should also be considered in patients with unexplained severe acute liver disease and that abdominal ultrasound may be a helpful step to obtain to the correct diagnosis.

Adult↗
PubMed2005

Relative impact of fatigue and subclinical cognitive brain dysfunction on health-related quality of life in chronic hepatitis C infection.

OBJECTIVES: To assess the relative impact of fatigue and subclinical cognitive brain dysfunction on the impairment of health-related quality of life (HRQL) in hepatitis C virus (HCV) infection. DESIGN AND METHODS: We performed a cross-sectional study in 120 patients with untreated chronic HCV infection to test the hypothesis that the severity of fatigue had an independent effect on HCV-associated impairment of HRQL. Patients were investigated using the short-form-36 questionnaire, the fatigue impact scale, the brief fatigue inventory, and P300 event-related potentials, as an objective correlate of neurocognitive function. Patients with decompensated cirrhosis or clinical depression were excluded. RESULTS: Relative to healthy controls, HCV-infected patients showed significant levels of fatigue (Fatigue Impact Scale, 49 versus 26 points, brief fatigue inventory, 3.0 versus 1.6 points, P < 0.001). Fatigue impact scale and brief fatigue inventory scores were highly correlated (r = 0.77, P < 0.001), demonstrating concurrent validity. Severity of fatigue and age were the only factors independently associated with the impairment of HRQL (P < 0.001). Fatigue was not related to the severity of hepatitis or the degree of subclinical brain dysfunction. CONCLUSION: In untreated patients with chronic HCV infection, fatigue severity and age but not neurocognitive dysfunction or hepatic function are independently associated with impaired HRQL. Both the fatigue impact scale and the brief fatigue inventory are suitable tools to assess the subjective burden of fatigue. Our findings stress the need for effective therapeutic interventions to reduce the burden of fatigue in patients with HCV infection.

Adult↗
PubMed2004

Early prediction of hepatitis C virus (HCV) infection relapse in nonresponders to primary interferon therapy by means of HCV RNA whole-blood analysis.

BACKGROUND: Routine analysis of serum and/or plasma specimens for hepatitis C virus (HCV) RNA does not always correctly reflect the response to antiviral therapy. Analysis of whole-blood specimens for detection of viral RNA should provide more-accurate prognostic information. METHODS: Whole-blood, serum, and plasma specimens (268 sample sets) were obtained from 56 patients who did not respond to initial interferon (IFN)- alpha 2b monotherapy (5 MU every 2 days for 3 months). Specimens were analyzed for HCV RNA by 4 different types of reverse-transcriptase polymerase chain reaction (RT-PCR) (Cobas Amplicor HCV-2.0 [Roche], LightCycler real-time PCR [Roche], and 2 in-house RT-PCRs) to determine whether specimen type can predict the rate of virologic response to high-dose treatment with IFN (10 MU every 2 days) and ribavirin (1-1.2 g/day). RESULTS: Of the 56 patients who provided specimens, serum and plasma obtained from 18 tested negative for HCV RNA at the end of treatment, indicating a complete virologic response. In contrast, analysis of whole-blood specimens obtained at the same time revealed the presence of viral RNA in 12 of these 18 patients. All 12 subjects had relapse of HCV in serum and plasma: 11 relapsed a median of 4 weeks after the end of treatment, and 1 relapsed 20 weeks after the end of treatment. None of these 12 patients--all of whom consistently had whole-blood specimens that tested positive and plasma and serum specimens that tested negative for HCV RNA up to 20 weeks before the end of treatment--showed a sustained virologic response (P=.0002). CONCLUSIONS: Results of whole-blood tests for detection of HCV RNA were highly predictive of viral relapse (positive predictive value, 100%) and thus may be useful tools for monitoring and tailoring IFN/ribavirin therapy. Testing of only serum or plasma specimens underestimates the true circulating HCV load and leads to an overestimation of antiviral response rates.

Adult↗
PubMed2004

Transjugular intrahepatic portosystemic shunt in Vienna--a decade later.

Implantation of a transjugular intrahepatic portosystemic shunt (TIPS) for therapy of portal hypertension has been available in Vienna, Austria, since 1991. Ten years of experience with this technique led the Vienna TIPS Study Group to retrospectively analyse characteristics and outcome of all patients undergoing TIPS in Vienna between 1991 and 2001. Survival and subgroup analyses were performed using Mann Whitney U-tests, log-rank tests, Spearman's correlation and Kaplan-Meier analyses. A total of 523 patients underwent TIPS; 23 for acute variceal bleeding, 350 for prevention of variceal bleeding, and 109 for therapy of refractory ascites. Portal hypertension was caused by cirrhosis in 503 patients; 20 presented with other diseases. 253 patients died within the study period, median follow-up was 5.07 years, median survival 4.51 years. The 3-month, 1-year, 3-year, and 5-year survival rates were 83%, 71%, 57%, and 49%, respectively. Etiology of cirrhosis had no effect on survival; patients with TIPS for refractory ascites had poorer survival rates than those undergoing TIPS for prevention of rebleeding. TIPS is a safe and effective therapy for patients with portal hypertension. The first decade of TIPS in Vienna has shown, in line with other publications, that good criteria for patient selection, effective post-interventional management, and close cooperation between internists, interventional radiologists and liver-transplant centers are the key for a good outcome.

Adolescent↗
PubMed2004

Current Treatment for Chronic Hepatitis C.

The number one choice for treatment of chronic hepatitis C is the combination of once weekly subcutaneous pegylated interferon plus daily oral ribavirin. The duration of treatment and dose of ribavirin must be tailored to the hepatitis C virus (HCV) genotype. Patients infected with HCV genotype 1 should be treated for 48 weeks with a standard dosage of ribavirin (1000 or 1200 mg/d). This ribavirin dosage regimen is 'off-label' when used in conjunction with pegylated interferon alfa-2b (12 kD). The approved dosage for use in combination with this agent is 800 mg daily. The appropriate duration of treatment and dosage of ribavirin for patients infected with HCV genotype 2 or 3 differs depending on the pegylated interferon that is chosen. It is important to note that the treatment paradigm for these individuals is quickly evolving. When using peginterferon alfa-2a (40 kD) in patients with HCV genotype 2 or 3, the duration of treatment should be 24 weeks in combination with a low dose of ribavirin (800 mg/d). When using pegylated interferon alfa-2b (12 kD) in patients infected with HCV genotype 2 or in patients infected with genotype 3 and hepatitis C virus RNA less than 600,000 IU/mL, the duration of treatment should be 24 weeks. However, recent data suggest such treatment may not be optimal for patients infected with HCV genotype 3 and hepatitis C virus RNA at levels greater than or equal to 600,000 IU/mL; treatment duration may need to be greater than 24 weeks. When using pegylated interferon alfa-2b (12 kD) in patients infected with HCV genotype 3 and high viral load, the optimal dosage of ribavirin appears to be 800 to 1400 mg/d based on bodyweight.

Journal Article↗
PubMed2004

Treatment of chronic viral hepatitis.

Current strategies for treating hepatitis B focus on clearance of active HBV infection through suppression of viral replication by interferon-alpha (IFN-alpha) and the nucleoside analogs (lamivudine and adefovir). Lamivudine therapy for 1 year leads to HBeAg seroconversion in 16-18% of patients compared to 4-6% of untreated controls, to histological improvement in 49-56% treated patients and in 23-25% controls. HBeAg seroconversion rates increase with the duration of lamivudine therapy from 17% at 1 year to 27, 40, 47 and 50% at 2, 3, 4 and 5 years, respectively. When prescribing lamivudine, drug resistance due to the emergence of tyrosine-methionine-aspartate-aspartate (YMDD) mutations that increases with duration of therapy and the potential risk of a severe flare of hepatitis with sudden cessation of therapy, probably greatest in patients with cirrhosis, are realistic concerns. After 48 weeks of treatment with 10 or 30 mg of adefovir dipivoxil per day, significantly more patients with HBeAg-positive chronic hepatitis B than those on placebo had histologic improvement (53, 59 and 25%, respectively), a reduction in serum HBV DNA levels (by a median of 3.52, 4.76 and 0.55 log copies/ml), undetectable levels of serum HBV DNA (21, 39 and 0%), normalisation of ALT levels (48, 55 and 16%) and HBeAg seroconversion (12, 14 and 6%). In HBeAg negative patients treated with adefovir dipivoxil (10mg/day) for 48 weeks, ALT levels had normalised in 72% (29% in the placebo group), serum HBV DNA levels were reduced to fewer than 400 copies/ml in 51% (none in the placebo group), liver histology improved in 64% (33% in the placebo group). No adefovir-associated resistance mutations of viral DNA were detected. Ongoing studies investigate combination therapy with lamivudine or IFN.

Adenine↗
PubMed2004

Hepatic iron concentration does not predict response to standard and pegylated-IFN/ribavirin therapy in patients with chronic hepatitis C.

BACKGROUND/AIMS: Iron overload is common among patients with chronic hepatitis C (CHC). In this study the role of hepatic iron concentration (HIC) and serum iron parameters was assessed to determine response to standard and pegylated interferon (IFN)/ribavirin combination therapy in patients with CHC. METHODS: Liver biopsies were obtained from 169 IFN-naïve patients (m=115, f=54, age: 40.8+/-10.7) with CHC. 140 patients were treated with standard IFN/ribavirin, 29 patients with pegylated-IFN/ribavirin. Biopsy specimens were evaluated according to the DiBisceglie scoring system and iron grading. HIC was determined by atomic absorption spectroscopy. Ferritin and transferrin saturation and presence of HFE-C282Y and H63D gene mutations were determined at baseline. RESULTS: Nonresponders to combination therapy had higher serum ferritin levels at baseline (p<0.01). There was no difference of HIC, transferrin saturation levels, and the HFE-mutation status between responders and nonresponders. Logistic regression analysis revealed serum ferritin as an independent predictor of response. HIC correlated with the DiBisceglie score (r=0.352, p<0.001), iron grading (r=0.352, p<0.001) and serum ferritin (r=0.335, P<0.001). CONCLUSIONS: Pretreatment liver iron concentration does not predict response to combination therapy in patients with CHC. In contrast, high baseline serum ferritin levels are predictors of poor response to antiviral therapy.

Adult↗
PubMed2004

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.

Adenosine Triphosphatases↗
PubMed2004

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.

Antiviral Agents↗
PubMed2004

Infliximab: lack of efficacy on perforating complications in Crohn's disease.

BACKGROUND: Infliximab (Remicade), a chimeric monoclonal antibody against tumor necrosis factor alpha (TNF-alpha), has emerged as promising therapeutic option in perianal fistulizing Crohn's disease (CD). However, little knowledge exists about its use for the treatment of internal fistulas in CD. We present our experience with infliximab in this situation. METHODS: Four patients with CD who had internal fistulas (Case 1: entero-enteral and entero-abdominal; Case 2: entero-enteral; Case 3: entero-enteral and parastomal; Case 4: entero-vesical) were treated with 3 infusions of infliximab (5 mg/kg body weight) with intervals of 2 and 4 weeks. In addition, 3 patients had strictures and 2 patients had perianal fistulas. RESULTS: After the three infusions of infliximab (5 mg/kg body weight), internal fistulas remained unchanged in all patients. The perianal fistulas present in 2 cases were healed. Administration of infliximab was safe and well tolerated in all cases. CONCLUSION: Treatment with 3 infusions of infliximab (5 mg/kg body weight) led to healing of only the perianal fistulas, whereas the internal fistulas were not influenced. We conclude that in these 4 cases, infliximab was well tolerated but not effective for the management of internal fistulas and was no alternative for surgery.

Adult↗
PubMed2004

Sudden hearing loss in patients with chronic hepatitis C treated with pegylated interferon/ribavirin.

BACKGROUND: Sudden hearing loss has been reported on standard interferon (IFN)-alpha2 therapy. This is the first report on the occurrence of sudden hearing loss in six cases of chronic hepatitis C in temporal relation to treatment with pegylated (PEG)-IFN alfa2a or b/ribavirin combination therapy. Three patients were treated in an ongoing randomized placebo-controlled trial comparing the addition of 200 mg amantadine or placebo to the combination of 180 microg PEG-IFN alpha2a (PEGASYS, Roche, Basel, CH)/wk and 1-1.2 g ribavirin/d (COPEGUS, Roche, Nutley, USA) in de novo patients infected with HCV genotype 1. Sudden hearing loss and tinnitus developed on day 1 and after 4, 23, 25, 36, and 40 wk of treatment, respectively. CONCLUSIONS: Sudden hearing loss may occur in about 1% of patients on PEG-IFN/ribavirin combination therapy. This rate was not different to that observed in an untreated population. Possible mechanisms involved include direct ototoxicity of IFN, autoimmunity, and hematological changes. In contrast to published cases on auditory disability due to standard IFN, hearing loss did not fully resolve after discontinuation of therapy with PEG-IFN. On the other hand, symptoms did not worsen on continued treatment. Therefore, the decision whether to continue or to stop the treatment when signs of ototoxicity appear is based on the clinical judgment of the treating physician.

Adult↗