Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023890 (cirrhosis)
 42,195 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hepatitis B virus (HBV) is a small enveloped virus containing partially double-stranded DNA. The DNA and HBV-specific DNA polymerase are surrounded by the HBV core antigen (HBcAg), which in turn is surrounded by a lipoprotein envelope containing the HBV surface antigen (HBsAg). Serum of HBV-infected patients contains complete virus particles, as well as non-infectious spherical or filamentous HBsAg particles. Acute hepatitis is characterized by the appearance of serum HBV markers, including HBsAg and IgM anti-HBc, which then disappear during convalescence. Persistence of HBsAg for more than 6 months indicates a carrier state. Chronic hepatitis develops in 90% of newborns who become infected, compared with 29-40% of children infected and 5-10% of adults infected. The immune status of the infected person also influences the development of chronic hepatitis. Chronic HBV infection can be diagnosed by serology (identification of HBsAg and HBV DNA), biochemistry (elevated aminotransferase levels) and liver biopsy. The last is important to assess the severity of disease, its stage and prognosis, and to exclude other hepatic diseases. The outcome of chronic HBV infection varies between individuals, with estimated 5-year survivals of 97% for chronic persistent hepatitis, 86% for chronic active hepatitis, and 55% for chronic active hepatitis with cirrhosis. Treatment with interferon alpha is effective in up to 40% of cases, but in view of the very large number of infected people worldwide, vaccination to prevent spread of the disease is a more cost-effective option.
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PMID:Clinical course and consequences of hepatitis B infection. 1068 39

Chronic hepatitis B virus (HBV) infection is a leading cause of cirrhosis and hepatocellular carcinoma worldwide. Its prevalence approaches 10% in hyperendemic areas, such as southeast Asia, China, and Africa. Although chronic HBV infection is seen less frequently in North America and Europe, an estimated 1.25 million persons in the United States are infected. In the past decade, revolutionary strides have been made toward the treatment of chronic HBV infection. Interferon-alpha was once the only available therapy but has recently been joined by the nucleoside analogues, the most extensively studied of which is lamivudine. Interferon therapy continues to have a role in the treatment of a carefully selected group of patients. Lamivudine therapy, which has less stringent selection criteria, suppresses HBV DNA in almost all treated patients: Seventeen percent to 33% experience loss of hepatitis B e antigen, and 53% to 56% have a histologic response. Extended lamivudine treatment leads to the development of a specific lamivudine-resistant virus with base-pair substitutions at the YMDD locus of the DNA polymerase. Newer nucleoside analogues and other immunomodulator therapies are being investigated. In the future, combination therapy with different classes of agents may yield improved response rates and delay the development of resistance.
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PMID:Chronic hepatitis B virus infection: treatment strategies for the next millennium. 1078 66

Lamivudine has been shown to be an effective therapy for chronic hepatitis B, but resistance to this nucleoside agent is common after prolonged use. Five patients with chronic hepatitis B virus (HBV) infection developed resistance to lamivudine after 9 to 19 months of treatment. In 4 patients this occurred after liver transplantation and the remaining individual had stable cirrhosis. In each case, resistance was confirmed to be caused by one or more mutations in the HBV-DNA polymerase gene and was associated with active underlying liver disease. The patients were treated with adefovir dipivoxil in a dose of 5 to 30 mg daily. Two to 4 log(10) reductions in HBV-DNA levels were observed in 4 cases, and the fifth patient became negative by quantitative polymerase chain reaction (PCR) after retransplantation in conjunction with hepatitis B immunoglobulin (HBIg). Virologic improvement was associated with stable or declining serum alanine transaminase levels in 4 patients. HBV-DNA suppression has been sustained during a mean treatment period of 13 months (range 11 to 15 months), including 1 patient in whom lamivudine has been discontinued. Mild changes in renal function were observed during treatment in most cases but did not require early discontinuation of the drug. This study provides evidence that adefovir dipivoxil can be an effective treatment for lamivudine-resistant HBV mutants as well as wild-type HBV.
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PMID:Adefovir dipivoxil for the treatment of lamivudine-resistant hepatitis B mutants. 1086

Hepatitis B virus (HBV) infection is a major cause of chronic liver disease worldwide. Famciclovir is a nucleoside analogue with potent antiviral activity that appears promising in the management of patients with HBV infection. No data exist regarding the safety of nucleoside analogue withdrawal in patients treated for HBV cirrhosis. The authors describe a 41-year-old man with compensated HBV cirrhosis who developed fatal hepatic decompensation due to a rebound in viral replication within six weeks of discontinuing famciclovir therapy. Although several mutations in the HBV DNA polymerase gene have been documented, none has been associated with famciclovir resistance or adverse clinical outcomes. Clinicians should consider the risk of inducing serious flares in hepatic inflammation as a result of abrupt nucleoside analogue withdrawal. Until further data are available regarding the safety of withdrawal of these agents, indefinite treatment may be required in patients with established cirrhosis.
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PMID:Fatal hepatic decompensation in a patient with hepatitis B cirrhosis following famciclovir withdrawal. 1118 39

Breakthroughs during lamivudine therapy were assessed according to hepatitis flares and mutational polymorphism of hepatitis B virus (HBV) infecting patients. Of 42 patients with chronic hepatitis B and positive for hepatitis B e antigen in serum, 13 (30%) harbored HBV mutants with lamivudine resistance after a mean duration of 29 months on lamivudine. The virological breakthrough occurred 14.5 months after the start of lamivudine treatment, and all the patients with it developed breakthrough hepatitis 3 months later. The clinical course of breakthrough hepatitis was self-limited except in one patient who had already developed cirrhosis at the baseline. One year after breakthrough hepatitis, serum ALT, albumin, prothrombin time and platelet counts were maintained well on conventional treatments without resorting to interferon. Major HBV mutants during breakthrough hepatitis were those with M552I in the YMDD motif of viral DNA polymerase/reverse transcriptase in 7 patients (54%), M552I/L528M in 4 patients (31%) and M552V/L528M in 2 patients (15%). There were no patients in whom mutations at nucleotide 529 occurred including the 2 who later developed hepatocellular carcinoma. There was no clear relationship between distinct mutational patterns and clinical courses. Further studies are needed for making out the effects of lamivudine-resistant mutants on clinical outcomes, taking into considerations genotypes of HBV.
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PMID:Subclones of drug-resistant hepatitis B virus mutants and the outcome of breakthrough hepatitis in patients treated with lamivudine. 1468 51

We report a case of fatal liver failure due to reactivation of lamivudine-resistant HBV. A 53-year-old man was followed since 1998 for HBV-related chronic hepatitis. Serum HBV-DNA was 150 MEq/mL (branched DNA signal amplification assay) and ALT levels fluctuated between 50-200 IU/L with no clinical signs of liver cirrhosis. Lamivudine (100 mg/d) was started in May 2001 and serum HBV-DNA subsequently decreased below undetectable levels. In May 2002, serum HBV-DNA had increased to 410 MEq/mL, along with ALT flare (226 IU/L). The YMDD motif in the DNA polymerase gene had been replaced by YIDD. Lamivudine was continued and ALT spontaneously decreased to the former levels. On Oct 3 the patient presenting with general fatigue, nausea and jaundice was admitted to our hospital. The laboratory data revealed HBV reactivation and liver failure (ALT: 1828 IU/L, total bilirubin: 10 mg/dL, and prothrombin INR: 3.24). For religious reasons, the patient and his family refused blood transfusion, plasma exchange and liver transplantation. The patient died 10 d after admission. The autopsy revealed remarkable liver atrophy.
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PMID:Fatal liver failure due to reactivation of lamivudine-resistant HBV mutant. 1516 53

Adefovir dipivoxil is an up-to-date drug for the treatment of chronic hepatitis B. Adefovir dipivoxil is a lipophilic prodrug of adefovir, an analogue of adenosine monophosphate (AMP). It suppresses efficaciously the replication of the hepatitis B virus and of other viruses. After conversion to its active metabolite, it can inhibit both DNA polymerase and reverse transcriptase. It is well absorbed by the intestinal mucosa, its bio-availability is approx. 59%, it is distributed to most tissues and eliminated by the kidneys. There are no known clinically significant drug interactions. The recommended dose is 10 mg/day; in patients with renal impairment the dose must be adjusted. Treatment has to continue for at least one year. Compared with lamivudine, adefovir resistance develops more slowly. Virus resistant to lamivudine is sensitive to adefovir and vice versa. The efficacy and safety of this treatment have been verified in four published clinical trials with more than one thousand patients, including patients with decompensated cirrhosis prior to and after liver transplantation. In these patients there was an improvement of several virological, biochemical and clinical markers. The drug is well tolerated. Seen adverse side-effects were gastrointestinal disorders, headache and a mild to moderate increase in serum creatinine. There are no specific contraindications to the therapy, with the exception of hypersensitivity. However, there are only insufficient data on the administration of the drug to pregnant women and to children. Adefovir dipivoxil offers a new treatment possibility for patients presenting a chronic infection with the hepatitis B virus, especially those infected with a lamivudine-resistant virus. Key words: adefovir dipivoxil-chronic hepatitis B-hepatitis B virus-lamivudine.
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PMID:[Adefovir dipivoxil-a new effective treatment for chronic infection with hepatitits B virus.]. 1613 74

Hepatitis B virus (HBV) is one of the major causes of liver disease worldwide, and chronic HBV infection may progress to cirrhosis and hepatocellular carcinoma. Mutations at the active site of DNA polymerase of HBV, tyrosine-methionine-aspartate-aspartate (YMDD) motif, render infected patients resistant to antiviral drug (Lamivudine) therapy. Hence, sensitive and specific methods aimed at detecting the mutants are essential. The purpose of this study was to develop methods for detecting the mutations at YMDD by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and real-time PCR using locked nucleic acid (LNA)-mediated TaqMan probes. The results obtained by these methods were compared with those examined by conventional direct sequencing on serum samples of 77 patients treated with lamivudine. Our results show that both PCR-RFLP and real-time PCR could detect wild type, YMDD, and its mutants, tyrosine-isoleucine-aspartate-aspartate and tyrosine-valine-aspartate-aspartate. In addition, the mixtures of the wild-type virus and its mutants in the serum sample were detected. Importantly, real-time PCR is less time-consuming, and more sensitive for the detection of mixed populations than PCR-RFLP. The real-time PCR with LNA-mediated TaqMan probes is a sensitive, specific and rapid detection method for mutations at the YMDD motif, which will be essential for monitoring patients undergoing lamivudine antiviral therapy.
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PMID:Rapid detection of lamivudine-resistant hepatitis B virus mutations by PCR-based methods. 1696 Mar 47

Infection with hepatitis B virus (HBV) is extremely widespread - it infects two billion people out of the six billion world population. It is estimated that between 350 and 400 million people are chronically infected with HBV. Chronic HBV infection leads to development of complications, such as cirrhosis and hepatocellular carcinoma (HCC), which arise in 15-40% of patients. HBV-related liver disease and its complications result in approximately one million deaths each year. The ultimate goals of chronic hepatitis B (CHB) therapy are decreases in the incidence of cirrhosis, end-stage liver disease and HCC. The following six medications are currently approved by the U.S. Food and Drug Administration for the treatment of CHB: interferon (INF)-alpha2b, pegylated INF-alpha2a, lamivudine, adefovir dipivoxil, entecavir and, recently, telbivudine. Interferon therapy has many contraindications and commonly causes multiple intolerable adverse effects. Lamivudine therapy leads to increased development of resistant mutations with each year of use. Entecavir, a new guanosine nucleoside analogue with specific activity against HBV DNA polymerase, represents a third agent within the nucleoside/nucleotide HBV polymerase inhibitor class. It has distinct advantages over lamivudine and adefovir dipivoxil: it has a three-step mechanism of action, is the most potent inhibitor of HBV DNA polymerase, is not associated with any major adverse effects and has a limited potential for resistance. In clinical trials, entecavir was superior to lamivudine in all primary endpoints in both nucleoside-naive and lamivudine-refractory hepatitis B e antigen (HBeAg)-positive and HBeAg-negative patients. Preliminary data support entecavir efficacy in patients with cirrhosis and HIV/HBV coinfected patients. No resistance occurred after two years of entecavir therapy in nucleoside-naive patients. Up to 9% resistance developed in patients with documented prior lamivudine resistance during 96 weeks of entecavir therapy. Currently, entecavir should be considered a first- or second-line treatment option for the management of HBeAg-positive or -negative nucleoside-naive or lamivudine-refractory CHB patients.
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PMID:Entecavir: a new nucleoside analogue for the treatment of chronic hepatitis B. 1746 Jul 84

Three hundred and fifty million people worldwide are estimated to be chronically infected with hepatitis B virus. 15%-40% of these subjects will develop cirrhosis, liver failure or hepatocellular carcinoma during their life. The treatment of chronic hepatitis B has improved dramatically over the last decade merits to the advent of nucleoside/nucleotide analogues and the use of pegylated interferons. Approved drugs for chronic hepatitis B treatment include: standard interferon-alpha 2b, pegylated interferon-alpha 2a, lamivudine, adefovir dipivoxil, and entecavir. Unfortunately, these agents are not effective in all patients and are associated with distinct side effects. Interferons have numerous side effects and nucleoside or nucleotide analogues, which are well tolerated, need to be used for prolonged periods, even indefinitely. However, prolonged treatment with nucleoside or nucleotide analogues is associated with a high rate of resistance. Telbivudine is a novel, orally administered nucleoside analogue for use in the treatment of chronic hepatitis B. In contrast to other nucleoside analogues, Telbivudine has not been associated with inhibition of mammalian DNA polymerase with mitochondrial toxicity. Telbivudine has demonstrated potent activity against hepatitis B with a significantly higher rate of response and superior viral suppression compared with lamivudine, the standard treatment. Telbivudine has been generally well tolerated, with a low adverse effect profile, and at its effective dose, no dose-limiting toxicity has been observed. Telbivudine is one of the most potent antiviral agents for chronic hepatitis B virus and was approved by the FDA in late 2006.
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PMID:Telbivudine: a new treatment for chronic hepatitis B. 1806 53


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