Is it possible to predict the development of an entecavir resistance mutation in patients with chronic hepatitis B in clinical practice? (original) (raw)
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Antiviral Research, 2012
Entecavir is one of the therapeutic options currently available for the management of chronic hepatitis B. In this study, we aimed to analyse the virological response and antiviral resistance mutations in chronic hepatitis B subjects experiencing entecavir therapy from the Indian subcontinent. A total of 45 chronic hepatitis B subjects were studied at baseline and were followed up on entecavir treatment. Among these subjects, 25 (56%) were HBeAg-positive at baseline. Virological response was measured by hepatitis B virus (HBV) DNA levels. HBV reverse transcriptase (rt) domains were sequenced for the identification of resistance mutations. Three-Dimensional (3D) model of HBV polymerase/rt protein, docking and molecular dynamics simulation (MDS) studies were performed for characterization of antiviral resistance mutations. At the median treatment duration of 6 (IQR 6-11) months, 38 (84%) showed virological response. Subjects who showed anti-HBe response demonstrated significant association with virological response (p=0.034). On sequence analysis, none of the subjects were identified with signature entecavir resistance mutations. However, one subject was exclusively detected with rtV173L mutation. Molecular modeling, docking and MDS studies revealed that the rtV173L mutation cannot confer resistance to entecavir independently. Our findings also showed that the prevailing HBV genotypes, subgenotypes and subtypes in this population does not influence treatment outcome to entecavir therapy. In conclusion, entecavir is a potent drug in terms of viral DNA suppression. In addition, none of the subjects developed antiviral resistance mutations to entecavir. Therefore entecavir is a suitable drug of choice in the management of chronic HBV
Medical Research Archives
Mutations of genotypic resistance to nucleotide analogues Entecavirand Tenofovirhave been described in patients undergoing treatment and virgins for hepatitis B virus. The present study demonstrated in a sample of 263 patients with chronic HBV from the North and Northeast of Brazil, a mutation rate of resistance to nucleotide analogues of 3.8% (10). Of the 10 patients who had genotypic resistance mutations, only 1 had no genotypic resistance mutation for the first line treatment for hepatitis B, entecavir and tenofovir.Due to the emergence of vaccine escape mutations and resistance mutations to antiviral treatment, and the severity of liver disease caused by HBV, screening for genetic mutations is important due to the impact on therapeutic management.
[Entecavir resistance in entecavir naive lamivudine treated chronic hepatitis B patients]
Mikrobiyoloji bülteni, 2009
Approved hepatitis B virus (HBV) therapies include interferon-alpha and nucleos(t)ide analogues. Lamivudine (LVD) is a nucleoside analogue and following long term LVD therapy, resistance emerges in a significant number of patients. Entecavir (ETV) is a novel deoxyguanosine analogue with potent activity against HBV in chronically infected patients. ETV is highly efficacious in treating nucleoside naive and LVD refractory patients. The aim of the present study was to determine the prevalence of ETV drug resistance in LVD treated/ETV naive (study group) and in untreated naive (control group) patients with chronic B hepatitis. DNA sequencing was applied to 80.-250. amino acid positions on HBV polymerase gene to investigate the ETV resistance and also HBV genotype and HBV polymerase gene overlapped S-gene segment mutations. Primary LVD and ETV drug resistance were detected in 37 (42.6%) and 4 (4.5%) of 87 patients, respectively in the study group. rtT184A, rtT1841 and rtT1845 mutations w...
Journal of medical virology, 2017
The Brazilian public health system (SUS) has provided antiviral drugs for chronic hepatitis B treatment for over 10 years, but a system for monitoring for drug-related resistance mutations is not available. Determine the presence of HBV mutations associated with resistance to nucleos(t)ide analogs among 81 patients with chronic HBV infection in Salvador - BA - Brazil. HBV-DNA was PCR amplified with primers deduced from the rt domain at the HBV P gene, the sequence extended 1032 bp (from amino acid 1 to 344 - rt domain). Those sequences were submitted to the HBV drug resistance database to retrieve each mutation according to the genotype. HBV genotype A1 (85.2%) was the most prevalent, followed by genotype A2 (4.9%), F (6.2%), and C1, D2 and D4 (1.2% each). Six patients (7%) exhibited resistance mutations to LAM, ETV and TDF: two with patterns L180M + M204V and four with other different patterns: L80I + L180M + M204I; L80V + L180M + M204V; M204I; A194T. All of these mutations were pr...
Accuracy of Risk Scores for Patients With Chronic Hepatitis B Receiving Entecavir Treatment
Gastroenterology, 2013
BACKGROUND & AIMS: Little is known about the validity of hepatocellular carcinoma (HCC) risk scores derived from treatment-naïve patients with chronic hepatitis B for patients treated with entecavir. METHODS: We performed a retrospective-prospective cohort study of 1531 patients with chronic hepatitis B (age, 51 Ϯ 12 years; 1099 male; 332 with clinical cirrhosis) who were treated with entecavir 0.5 mg daily for at least 12 months at Prince of Wales Hospital in Hong Kong from December 2005 to August 2012. The patients were assessed once every 3 to 6 months for symptoms, drug history, and adherence; blood samples were collected for biochemical analyses. We validated 3 HCC risk scores (CU-HCC, GAG-HCC, and REACH-B scores) based on data collected when patients began treatment with entecavir and 2 years later. RESULTS: After 42 Ϯ 13 months of follow-up, 47 patients (2.9%) developed HCC. The 5-year cumulative incidence of HCC was 4.3% (95% confidence interval [CI], 3.6%-5.0%). Older age, presence of cirrhosis, and virologic remission after 24 months or more of therapy were independently associated with HCC in the entire cohort; advanced age and hypoalbuminemia were associated with HCC in patients without cirrhosis. The area under the receiver operating characteristic curves (AUCs) for baseline CU-HCC, GAG-HCC, and REACH-B scores for HCC were 0.80 (95% CI, 0.75-0.86), 0.76 (95% CI, 0.70-0.82), and 0.71 (95% CI, 0.62-0.81), respectively; the time-dependent AUCs 1 to 4 years after patients started treatment were comparable to those at baseline. The cutoff value of the baseline CU-HCC score identified patients who would develop HCC with 93.6% sensitivity and 47.8% specificity, the baseline GAG-HCC score with 55.3% sensitivity and 78.9% specificity, and the baseline REACH-B score with 95.2% sensitivity and 16.5% specificity. Compared with patients with CU-HCC scores Ͻ5 at baseline, those with CU-HCC scores that either decreased from Ն5 to Ͻ5 or remained Ն5 had a higher risk of HCC (5-year cumulative incidences, 0% vs 3.9% and 7.3%; P ϭ .002 and P Ͻ .001, respectively). CONCLUSIONS: The CU-HCC, GAG-HCC, and REACH-B HCC risk scores accurately predict which patients with chronic hepatitis B treated with entecavir will develop HCC.
Hepatology international, 2009
Entecavir (ETV) is a potent nucleoside analogue against hepatitis B virus (HBV), and emergence of drug resistance is rare in nucleoside-naive patients because development of ETV resistance (ETVr) requires at least three amino acid substitutions in HBV reverse transcriptase. We observed two cases of genotypic ETVr with viral rebound and biochemical breakthrough during ETV treatment of nucleoside-naive patients with chronic hepatitis B (CHB). Case 1: A 44-year-old HBeAg-positive man received ETV 0.1 mg/day for 52 weeks and 0.5 mg/day for 96 weeks consecutively. HBV DNA was 10.0 log(10) copies/ml at baseline, declined to a nadir of 3.1 at week 100, and rebounded to 4.5 at week 124 and 6.7 at week 148. Alanine aminotransferase (ALT) level increased to 112 IU/l at week 148. Switching to a lamivudine (LVD)/adefovir-dipivoxil combination was effective in decreasing HBV DNA. Case 2: A 47-year-old HBeAg-positive man received ETV 0.5 mg/day for 188 weeks. HBV DNA was 8.2 log(10) copies/ml at ...
Infection and drug resistance, 2017
Resistance mutation analogs to nucleos(t)ides have been described in treatment-naïve patients with chronic hepatitis B (CHB), with clinical implications. The aim of this study was to investigate primary resistance mutations and genotypes circulating in patients naïve to chronic hepatitis B, in the Northern and Northeastern regions of Brazil. We conducted a study of resistance mutations and genotypic characterization of hepatitis B virus (HBV) in 189 treatment-naïve patients chronically infected with HBV. Drug resistance-associated mutations located in the RT domain of the P gene (rtHBV) were found in 6% of the treatment-naïve patients from the Northeastern Region. The mutations were rtA194T, rtL180M + rtM204V, rtS202I, rtM204I, and rtA181S. No patient in the Northern Region had the resistance mutation. In the gene S region, the frequency of vaccine escape mutations was 2.4% in the Northeastern Region and 8.6% in the Northern Region. This information before the start of treatment may...
Journal of Hepatology, 2013
Background & Aims: Reported HBV drug resistance mutations among previously untreated patients with chronic hepatitis B are variable. Whether resistant HBV strains are transmitted in the acute setting is uncertain. We sought to document the presence of antiviral resistance (AVR) mutations in patients with acute HBV (AHB) infection. Methods: AHB infection was defined by HBsAg/IgM anti-HBc positivity, ALT>10X ULN and compatible clinical history. The TRUGENE HBV kit was used to perform genotyping and direct sequencing of the viral polymerase. INNO-LiPA HBV DRv2 and DRv3 were used to detect AVR mutations. Clonal sequencing was conducted on selected specimens. Results: Twenty-three patients were evaluated (mean age, 43 years; 54% male; 39% African American, 39% Caucasian, 13% Hispanic and 4% Asian). The mean peak ALT was 1554.2 IU/L and mean peak total serum bilirubin was 12 mg/dl. The HBV DNA median viral load (N = 15) was 5.14 log 10 IU/ml. Nineteen patients were genotype A, and 1 each were genotype C, D, E and G. HBV drug resistance mutations were not detected by direct sequencing or INNO-LiPA. Clonal sequencing was conducted on 192 clones isolated from three patients and showed rtA181T, rtM250V and rtS202G mutations at an overall frequency of 1.54%, 1.39%, and 1.67% respectively. Conclusions: We detected adefovir/lamivudine and entecavir relevant mutations in a minor population (<2%) of viral clones by clonal sequencing only. The clinical significance of these mutations is uncertain and may represent small populations of quasi-species vs. transmission of drug resistant strains.