Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.6.1.2 (alanine aminotransferase)
26,722 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

When assessing patients with chronic hepatitis B virus (HBV) infection, consider the state of viral replication, the immune response and whether viral mutations could be present, as well as evidence for liver disease or extrahepatic manifestations. In wild-type infections, loss of hepatitis B e antigen (HBeAg), gain of anti-HBe and disappearance of HBV DNA from serum indicate immunosuppression of viral replication, or 'nonreplicative chronic HBV infection'. This 'healthy carrier' state must be distinguished from HBeAg-negative chronic hepatitis B (CHB) resulting from precore and core promoter mutations. HBeAg-negative CHB is common with genotypes D (Mediterranean region, south Asia) and C (north Asia) infections. Age, disease activity (alanine aminotransferase level) and severity (fibrosis stage, cirrhosis) influence treatment decisions. Following the marginal effectiveness of interferon and often temporary effectiveness of lamivudine due to drug resistance, treatment of CHB is entering a new era. Adefovir, entecavir, tenofovir, telbivudine and clevudine have equal or superior antiviral efficacy to lamivudine, whereas several agents are effective against lamivudine-resistant HBV. Pegylated-interferon (peginterferon) is superior to conventional interferon for obtaining sustained immunosuppression of HBV without drug resistance. Antiviral suppression of HBV replication for 2-5 years reverses hepatic fibrosis, prevents cirrhosis and, when cirrhosis is established, improves liver function, prevents hepatic decompensation and lowers the risk of liver cancer. Before embarking on immunosuppressive chemotherapy or organ transplantation in patients with chronic HBV infection, it is important to start antiviral therapy to prevent hepatitis flares. Antiviral therapy can be effective against membranous glomerulonephritis and polyarteritis nodosa caused by HBV. Further improvements in treatment of CHB are needed to prevent drug resistance and permanently suppress viral replication by eradicating viral templates or stimulating host immune responsiveness to HBV.
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PMID:Management of chronic hepatitis B virus infection: a new era of disease control. 1647 64

Chronic hepatitis B is a common disease and approximately 20% of infected patients with compensated cirrhosis will decompensate over 5 years. If untreated, the survival of decompensated cirrhosis is poor (15% at 5 years). The extent of hepatitis B virus (HBV) replication, as assessed by serum HBV-DNA level, is a strong predictor of the risk of disease progression and hepatocellular carcinoma. This provides a rationale for antiviral therapy to arrest progression of liver disease. Lamivudine is a pyrimidine analogue that inhibits HBV-DNA reverse transcriptase. It decreases HBV replication, normalises alanine aminotransferase levels and reduces hepatic inflammation and fibrosis in patients with chronic hepatitis B. This article will focus on the use of lamivudine in patients with HBV-cirrhosis. In patients with compensated HBV-cirrhosis, a randomised, placebo-controlled trial has shown that lamivudine significantly reduced the rate of disease progression and hepatocellular carcinoma development over a 3-year period. In patients with decompensated cirrhosis, treatment with lamivudine can produce spectacular improvements of liver function, but the improvement is slow and a clinical benefit is usually not observed until after at least 3-6 months of treatment. A major drawback of lamivudine treatment is the development of resistance, observed in 15-20% of patients after 1 year and up to 70% after 5 years of continued treatment. Thus, patients with HBV-cirrhosis treated with lamivudine should have regular monitoring of serum HBV-DNA levels and prompt institution of additional antiviral therapy if viral breakthrough is observed. Adefovir, tenofovir and entecavir have demonstrated efficacy in patients with lamivudine resistance. In patients with decompensated cirrhosis, in whom the development of resistance can be fatal, combination therapy (such as lamivudine plus adefovir) may prove more effective than monotherapy and this issue needs further study.
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PMID:Lamivudine treatment in patients with chronic hepatitis B and cirrhosis. 1692 9

We report a patient whose cryoglobulinemic vasculitis recurred due to reactivation of lamivudine-resistant HBV. Our patient with hepatitis B-related cryoglobulinemic vasculitis was administered lamivudine. Her vasculitis regressed, ALT normalized, HBV-DNA became negative. Under lamivudine therapy, her cryoglobulinemic cutaneous vasculitis recurred. ALT increased significantly; it was found that tyrosine-methionine-aspartate-aspartate (YMDD) motif in the DNA polymerase gene had been replaced by YIDD. Adefovir was added to lamivudine. During follow-up, her purpura disappeared, ALT normalized, HBV-DNA became negative. Our patient is the first whose cryoglobulinemic vasculitis recurred under lamivudine, who had a HBV virologic breakthrough with YMDD mutation, and was successfully treated with adefovir.
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PMID:Successful treatment with adefovir of one patient whose cryoglobulinemic vasculitis relapsed under lamivudine therapy and who was diagnosed to have HBV virologic breakthrough with YMDD mutations. 1713 20

We studied clinical and laboratory effects of 3 months of lamivudine with adefovir combination and adefovir dipivoxil (AD) alone in the treatment of patients with lamivudine-resistant hepatitis B virus (HBV) infection. Eligible patients were hepatitis B surface antigen-positive men and women with compensated liver disease who were given lamivudine at least more than 6 months and had HBV polymerase gene mutation. Patients were assigned to receive adefovir 10 mg/day (Group 1) or adefovir 10 mg once daily and lamivudine 100 mg once daily combination during first 3 months, and then stopped lamivudine and continued adefovir (Group 2). Median age was 48 years (34 males and 20 females, and 35 were HBeAg-negative). Baseline median ALT, AST, and HBV DNA levels were 66 IU/l, 49 IU/l, and 6.7 log(10) copy/ml, respectively. Median adefovir therapy time and ALT normalization time were 9 and 3.5 months, respectively. There was no significant difference between groups according to the baseline HBV DNA, ALT, HBe Ag status, age, gender, and lamivudine resistance time. Virological and biochemical responses were similar in both groups during therapy. Two patients (8%) had ALT flare more than five times upper limit of normal without any clinical decompensation in Group 1. Mild ALT elevation according to baseline levels were found in 8 (27.6%) and 4 (17.4%) patients, respectively, in Group 2 and Group 1, and no statistically significance between two groups. In conclusion, this study showed that it is not necessary to continue lamivudine therapy while switching to AD therapy. Adefovir alone is effective in the treatment of patients with lamivudine resistant HBV infection and compensated liver disease, without significant clinical and laboratory flares. However, it is not easy to say that switching to AD with cessation of lamivudine is safe, because the study population is not enough for precise conclusion and resistance may be a considerable problem against AD in patients using long-term treatment.
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PMID:Adefovir dipivoxil alone or in combination with lamivudine for three months in patients with lamivudine resistant compensated chronic hepatitis B. 1743 77

Lamivudine has a high rate of antiviral resistance. Sequential treatment of anti-hepatitis B virus (HBV) is commonly used for lamivudine resistance. We report 4 cases of patients with rapid redetection of HBV mutants during the lamivudine retreatment. The four patients received lamivudine as an initial treatment of HBV and adefovir and lamivudine as a rescue therapy consecutively. HBV-DNA level, YMDD mutations and adefovir -resistant mutations (RFMP) were tested every 3 mo during the sequential treatment. All the patients showed YMDD mutations during the initial lamivudine therapy. After adefovir therapy for lamivudine resistance, they showed viral breakthrough. Adefovir was switched to lamivudine, however, it did not induce viral suppression at all, rather increased HBV-DNA with rapid reemergence of the YMDD mutations. All the patients had ALT flares, and hepatic decompensation occurred in two patients. After switching to adefovir combined with entecavir or lamivudine for a rescue therapy, the patients had reduction in HBV-DNA and ALT improvement. These cases demonstrated that lamivudine retreatment of patients with preexposed lamivudine resistance leads to rapid reemergence of YMDD mutation with significant viral rebounds and subsequent hepatic decompensation. Sequential administration of lamivudine in patients with a prior history of YMDD mutation should be abandoned.
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PMID:Rapid re-emergence of YMDD mutation of hepatitis B virus with hepatic decompensation after lamivudine retreatment. 1866 38

Adefovir has a potent antiviral activity as a rescue treatment against lamivudine-resistant strains. The aim of this study was to assess the patterns of lamivudine-resistant mutations and their influence on the virologic response to adefovir rescue therapy in patients with lamivudine-resistant chronic hepatitis B. Sixty-seven patients with lamivudine-resistant chronic hepatitis B were treated with adefovir monotherapy. Baseline blood samples were analyzed for lamivudine-resistant mutations via restriction fragment mass polymorphism. Virologic responses, ALT normalization and loss of HBeAg were assessed. Serum HBV DNA levels were measured using real-time PCR at baseline and 24 weeks of adefovir therapy. Of the 67 patients with chronic hepatitis B, 65 patients (97%) had lamivudine-resistant mutations in the YMDD motif [27 (41%) rtM204I, 22 (34%) rtM204V, and 16 (25%) rtM204I/V]. In addition to the YMDD mutations, the rtL180M, rtL80I, and rtV173L mutations were also present in 78%, 43%, and 11% of patients, respectively. The rtM204V mutation always accompanied rtL180M, and rtL80I was always observed in conjunction with rtM204I. Decrease in mean serum HBV did not differ between patients carrying the rtM204I versus rtM204V mutant at week 24 (-3.3 vs. -3.3 log(10) copies/ml, respectively; P = 0.303). The presence of the rtL180M, rtL80I, and rtV173L did not significantly affect viral load reduction during adefovir administration. These results demonstrate that the rtL80I mutant is co-selected with rtM204I as a compensatory mutation in the same manner as rtL180M with rtM204V, and that adefovir shows similar antiviral efficacy against all of the evaluated patterns of lamivudine-resistant HBV mutations.
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PMID:Association of lamivudine-resistant mutational patterns with the antiviral effect of adefovir in patients with chronic hepatitis B. 1915 9

Chronic hepatitis B virus (HBV) infection is a major cause of liver disease throughout the world, leading to cirrhosis and hepatocellular carcinoma in many individuals. Children are more likely to develop chronic HBV infection as they demonstrate greater immunotolerance to the virus, and response to therapy in children remains disappointing. Three therapeutic agents for chronic HBV infection in children have been approved in the USA, including standard IFN-alpha, lamivudine and adefovir. IFN-alpha has been the most effective ( approximately 30% hepatitis B e antigen [HBeAg] seroconversion; 10% hepatitis B surface antigen [HBsAg] seroconversion), although benefits are primarily observed in children with alanine aminotransferase levels over two-times the upper limit of normal and must be weighed against significant side effects. Studies comparing the long-term outcome of chronic hepatitis B in children treated with IFN-alpha and in untreated controls show that the rate of anti-HBeAb seroconversion tends to overlap in treated and untreated patients within a few years of follow-up, suggesting that IFN-alpha simply accelerates a spontaneous event. Lamivudine's virologic response rates mirror those of IFN-alpha (23-31% HBeAg seroconversion) with easier administration and a better safety profile but lower HBsAg seroconversion (2-3%) and high rates of drug resistance. Adefovir data show low rates of resistance and a good safety profile, but virologic response was limited to adolescent patients and was lower than that of lamivudine (16% HBeAg seroconversion; <1% HBsAg seroconversion). Entecavir and tenofovir, both approved therapies for adults with chronic HBV infection, are in trials for use in children. Future therapies will probably include these agents as well as combined therapies. Finally, watchful waiting of children is an option since current therapies are only 30% effective at best, although the long-term impact of therapy in childhood on rates of cirrhosis and hepatocellular carcinoma remains unknown.
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PMID:Hepatitis B therapy in children. 1921 Jan 12

To compare the efficacy and safety of Lamivudine (LAM) plus Adefovir dipivoxil (ADV) combination therapy and Entecavir (ETV) monotherapy for chronic hepatitis B patients. 120 patients with chronic hepatitis B managed in a single-centre clinical practice (median 96 weeks) were split into 2 cohorts, one was treated with de-novo combination Lamivudine (100 mg/day) plus Adefovir (10 mg/day) (LAM+ADV), the other with Entecavir (0.5 mg/day) monotherapy. Serum levels of ALT, creatinine, HBsAg, HBeAg and HBV viral load, together with genotypic resistence were analyzed at 0, 12, 24, 48, 96 weeks, respectively. HBV DNA was determined by real-time PCR. HBsAg and HBeAg were assessed by chemiluminescence. Serum levels of ALT and creatinine were detected by automatic biochemical analyzer. HBV genotypic resistence was tested by direct sequencing. (1) At the time point of 96 weeks, a total of 99 patients (51 cases in combination therapy cohort and 48 case in monotherapy cohort) were compared. The baseline characteristics as for HBV viral load, median age, serum levels of ALT and creatinine were compatible between combination therapy cohort and monotherapy cohort. (2) The rates of HBV DNA values is less than 300 copies/ml and HBV DNA values is less than 1000 copies/ml had no significant difference between LAM + ADV and ETV cohorts by the 12 and 24 weeks (P more than 0.05). (3) At the time point of 48 weeks, the rates of HBV DNA is less than 1000 copies/ml, HBeAg seroconversion, and ALT normalization were similar in both cohorts, though the rate of HBV DNA values is less than 300 copies/ml was obviously higher in combination therapy cohort than that of monotherapy cohort (90.7% vs 76%, P values is less than 0.05). (4) At the time point of 96 weeks, the rates of HBV DNA values is less than 300 copies/ml (96.1% vs 79.2%), HBV DNA values is less than 1000 copies/ml (98% vs 87.5%) and the HBeAg seroconversion (41.7% vs 16.7%) were markedly higher in combination therapy cohort than those of monotherapy cohort statistically (P values is less than 0.05 for all). The mean values of decreases for HBV viral loads and HBsAg levels were smilar in both cohorts at 48 and 96 weeks. (5) Elevated serum creatinine not be found in both cohorts at the end of treatment. (6) No virological breakthrough occurred in combination therapy cohort at the end of treatment. Four patients in monotherapy cohort were found with virological breakthrough at 96 weeks and three cases among were confirmed to be of variants associated with ETV resistance (rtL180M + T184L + M204V). Present study suggests that Lamivudine plus Adefovir dipivoxil de-novo combination therapy was more efficacious than Entecavir monotherapy for CHB patients and the tolerance is compatible.
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PMID:[Efficacy and safety of lamivudine plus adefovir combination therapy and entecavir monotherapy for chronic hepatitis B patients]. 2149 8

Substantial progress has been achieved in antiviral therapy for chronic hepatitis B; however, options for women of child-bearing age with HBeAg-positive chronic hepatitis B remain a challenge. In this study, we sought to determine whether de novo combination therapy of Adefovir plus Lamivudine was a super treatment for women of child-bearing age with HBeAg-positive chronic hepatitis B prior to conception. A total of 122 women patients of child-bearing age with HBeAg-positive chronic hepatitis B were randomly assigned to receive (i) 10 mg Adefovir plus 100 mg Lamivudine (64 patients) or (ii) 10 mg Adefovir monotherapy (58 patients), administrated orally once daily for 96 weeks. The therapeutic efficacy within each group was compared at weeks 48 and 96. The results showed that de novo combination therapy of Adefovir plus Lamivudine significantly reduced HBV-DNA detectability, and enhanced ALT normalization and HBeAg seroconversion in women of child-bearing age with HBeAg-positive chronic hepatitis B. No virological breakthrough and genotypic resistance were observed in the combination therapy group. Additionally, the combination therapy with Adefovir plus Lamivudine was well tolerated. This study suggests that de novo combination therapy of Adefovir plus Lamivudine offers a therapeutic advantage for women of child-bearing age with HBeAg-positive chronic hepatitis B when taken before conception.
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PMID:De novo combination therapy adefovir plus lamivudine as a treatment for women of child-bearing age with HBeAg-positive chronic hepatitis B before pregnancy. 2416 86

Hepatitis B virus (HBV) infection is a major public health problem in the world. About 30% of world population has serological evidence of HBV infection. The prevalence of chronic hepatitis B in Bangladesh is reported to be 7.8%. Several potentially effective agents with different mechanisms of action have entered clinical practice and adefovir dipivoxil is one of them. Studies on the efficacy of adefovir dipivoxil in Bangladeshi patients are lacking. This was a prospective study to find out the effect of one year adefovir therapy in patients with chronic hepatitis B virus infection who were HBeAg positive. Total number of patients included in this study was 68. Among them 53(77.94%) patients continued the therapy and completed follow up. At the end of one year of therapy, intention to treat analysis showed that the rate of response (HBeAg seroconversion and HBV DNA negative) was 37.73% which was comparable to the results obtained in other studies. There was major difference in the pre treatment serum ALT level between the responders and non-responders. Comparison of reduction of serum ALT level before treatment and after treatment showed that ALT level to be lower in both responder group and non responder group. Adefovir was effective in replicative HBV infection in Bangladeshi population. So we suggest that treatment can be started and subsequent follow up can be done in chronic HBV patients who are HBeAg positive without liver biopsy.
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PMID:Efficacy of adefovir dipivoxil therapy in patients with chronic hepatitis B viral infection. 2548 90


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