Genotyping of HBV and tracking of resistance mutations in treatment-naïve patients with chronic hepatitis B (original) (raw)
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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...
Viral Hepatit Dergisi, 2016
Objective: The prevalence of hepatitis B virus (HBV) is highly variable throughout the world. Geographical regions are classified according to the prevalence of hepatitis B surface antigen in the general population as high (>8%), moderate (2-7%), and low endemicity (<2%). Turkey has a moderate endemicity level of HBV infection which is a serious health problem. Currently, there are various nucleos(t)ide analogues with anti-HBV activity and they are mostly used in the treatment of chronic hepatitis B (CHB) and cirrhosis. The risk of drug resistance increases because these drugs are still being used as monotherapy. It has been reported that HBV drug resistance-related mutations can occur also in patients who are classified as treatment-naive and who have not received any oral anti-HBV treatment. Materials and Methods: This prospective and descriptive epidemiological study aimed to determine the genotype/subgenotypes of HBV and to investigate the drug resistance mutations in treatment-naive CHB patients. The study included 149 CHB patients who had no chronic coinfections, and have not received treatment for CHB infection. In 53 of the samples collected from the patients, the amount of viral DNA was enough for sequence analysis to search for drug resistance. BigDyeTM Terminator Cycle Sequencing Kit (Applied Biosystems, Foster City, Calif., USA) was used for sequencing of the serum samples from these patients and drug resistance mutations were determined and genotype/ subgenotype detection was performed. Results: The mean viral load value was calculated as 9.84x10 6 , and there was no primary drug resistance in any of these 53 samples which were sequenced. There were compensatory resistance-related amino acid changes in 19 samples. Genotype D was determined as HBV in all cases. Conclusion: The early detection of drug resistance-related mutations can be important in determination of treatment protocol, and prevention of unnecessary drug use, complications, and economic loses.
Hepatitis Monthly, 2018
Background: Hepatitis B virus (HBV) has a high mutation rate due to its unusual replication strategy leading to the production of a large number of virions with single and double mutations. The mutations, in turn, are associated with the development of drug resistance to nucleos(t)ide analogs (NUCs) in patients before and during NUCs therapy. Objectives: The current study aimed at investigating the molecular characterization of HBV in Turkish patients with chronic hepatitis B (CHB) infection. Methods: Polymerase chain reaction (PCR) amplification and direct sequencing procedures were used to analyze mutations. The detected drug resistance mutations were divided into the nucleos(t)ide analogs primary, partial, and compensatory resistance groups. The amino acid substitutions of hepatitis B surface antigen (HBsAg) were categorized into antiviral drug-associated potential vaccine-escape mutations (ADAPVEMs) and typical HBsAg amino acid substitutions, which included hepatitis B hyperimmunoglobulin (HBIg)-selected escape mutation, vaccine escape mutation, hepatitis B misdiagnosis, and immune-selected amino acid substitutions. Results: The number of patients included in the study was 528 out of which 271 (51.3%) were treatment-naive and 351 (66.3%) were hepatitis B e antigen (HBeAg)-negative. Moreover, 325 (61.6%) were males with a mean age of 38 years (range: 18-69). Primary, partial, and compensatory resistance to NUCs was reported in 174 (32.9%) patients. Six different ADAPVEM motifs were determined in both treatment-naive and treatment-experienced patients, namely, sF161L/rtI169X, sE164D/rtV173L, sL172L/rtA181T, sL173F/rtA181V, sS195M/rtM204V, and sS196L/rtM204I. The prevalence of ADAPVEMs and typical HBsAg escape mutations was 5.3% (n = 28) and 34.8% (n = 184), respectively. Conclusions: The analysis of drug resistance should constitute a fundamental part of the follow-up period of patients with CHB undergone treatment with NUCs. The surveillance of development of drug resistance mutations, while receiving treatment for hepatitis B is of paramount importance to monitor and control the emerging resistance.
Hepatitis monthly, 2011
Treatment for chronic hepatitis B (CHB) has improved over the last 10 years mainly due to the development of effective oral antiviral agents [nucleoside/nucleotide analogs (NUCs)]. The aim of the present study is to identify the frequency and major patterns of resistance to the hepatitis B virus (HBV) in a Turkish population of CHB patients treated with NUCs using add-on and switch therapy strategies. The investigation involved a total of 194 patients (88 were treated using add-on therapy, and 106 were treated using switch therapy). We analyzed the HBV polymerase gene by amplification and direct sequencing procedures. Primary drug-resistance mutations were detected in 84 patients (43%; 42 in add-on therapy, and 42 in switch therapy) taking lamivudine (LAM), 10 patients (5%; 6 in add-on therapy, and 4 in switch therapy) taking entecavir (ETV), and 16 patients (8%; 8 in add-on therapy, and 8 in switch therapy) taking adefovir (ADV). The most common LAM and ETV resistance mutations wer...
Absence of Hepatitis B Resistance Mutants before Introduction of Oral Antiviral Therapy
ISRN Hepatology, 2013
Introduction. The aim of this study was to assess whether hepatitis B virus drug resistant mutations antedated the widespread use of nucleos(t)ide analogues in treatment naïve patients. A number of reports have suggested that drug resistant mutants can be detected in apparently treatment naïve patients. Study. Fifty deidentified serum samples collected from 1986 to 1992 from patients with replicative chronic HBV infection at the University of Miami were genotyped and tested for resistance mutations using a line probe assay InnoLiPA HBV DR v2/v3. Serum HBV DNA was measured. All patients had documented chronic HBV infection with a detectable viral load, HBeAg seropositivity, and absence of HIV infection. Results. Of the 50 individuals included, 86% were male, mean age was 40 ± 12 years, and mostly genotype A. The mean HBV DNA was 126 pg/mL (range 6.4 to 557.0). No mutations were identified. Conclusions. The absence of drug induced mutations in these sera collected several years prior ...
2020
Background: For detection of the nucleus(t)ide analog resistance (NAr) mutants among Hepatitis B virus (HBV) quasispecies, the selection of appropriate methodologies is necessary. Here, we aimed to investigate the role of different methods for the detection of NAr mutations among treatment-naïve patients with chronic HBV (CHB) infection. Methods: In this systematic review and meta-analysis study, ve databases were searched. Desired data were extracted from the selected studies. The I 2 was used as an indicator of heterogeneity. The NAr mutations rate was investigated with a 95% con dence interval (CI). Results: The overall ratio of occurrence of NAr within treatment-naïve CHB patients (14653) from 128 studies was 0.085 (95% CI, 0.069-0.103, p-value < 0.0001). Direct sequencing was the most prevalent method of DNA sequencing (56.25%). The rates of NAr mutations in the different methodologies, including the direct sequencing, InnoLipa, NGS, and PASS, were 0.079 (0.037-0.160, p < 0.0001), 0.058 (0.021-0.152, p < 0.0001), 0.729 (0.441-0.902, p = 0.114), and 0.448 (0.281-0.628, p = 0.001), respectively. Conclusions: Drug-resistant quasispecies of HBV exist in treatment-naïve patients in relatively high abundance. More sensitive methodologies like NGS should be used for detecting NAr fractions of the viral population. Replacement of current therapy with novel anti-HBV candidates also should be considered.
International Journal of Infectious Diseases, 2010
The hepatitis B virus (HBV) genome is one of the smallest viral genomes (approximately 3200 base pairs) and encodes only one viral enzyme, namely the HBV reverse transcriptase (RT). Like the HIV RT, the HBV RT is an error-prone enzyme lacking proofreading activity. In combination with a high virus production, this results in HBV quasi-species. The use of antiviral agents licensed for the treatment of chronic HBV infection, namely nucleos(t)ide analogs (NUCs), can lead to the development of resistance. Additional, compensatory mutations then accumulate that help to restore full replicative capacity. It is important to keep in mind that the HBV polymerase gene completely overlaps the envelope gene. 2 Mutations in and around the major neutralization domain of HBV, known as the 'a' determinant, may (1) result in HBV reactivation by escape mutants in previously antibody to hepatitis B surface antigen (anti-HBs) immune persons, (2) cause diagnostic problems, and (3) result in failure of infection prevention with vaccination or hepatitis B immunoglobulin (HBIg). Background: The hepatitis B virus (HBV) polymerase gene completely overlaps with the envelope gene. In the present study we aimed to monitor the prevalence and pattern of the typical mutations for hepatitis B surface antigen (HBsAg) escape, and concomitantly nucleos(t)ide analog (NUC) resistance mutations, in Turkish patients undergoing different antiviral therapies and in treatment-naïve patients with chronic hepatitis B (CHB). Methods: The investigation was undertaken between March 2007 and August 2009 and involved a total of 142 patients under NUC therapy (88 males; mean age 42 years (range 13-68); hepatitis B e antigen (HBeAg) negativity in 94 patients; HBV DNA median log 4.3 log 10 IU/ml (range 2.0->6.0); alanine aminotransferase (ALT) median level 76.1 IU/ml (range 12-1082)) and 185 treatment-naïve CHB patients (120 males; mean age 39 years (range 1-76 years); HBeAg negativity in 132 patients; HBV DNA median log 3.5 log 10 IU/ml (range 2.0-6.0); ALT median level 60.7 IU/l (range 8-874)). Results: The overall prevalence of typical HBsAg escape mutations found in the CHB patients was 8.3% (27/327). In the NUC therapy group the prevalence was 8.5% (12/142), with the following patterns: sY100C + sI110V, sL109I, sP120T, sP127T, sG130R + sG145X, sS132A + sY134N, sY134N + sG145R, sC137G, sD144E, sG145R. In the treatment-naïve group the prevalence was 8.1% (15/185), with the following patterns: sL109I, sI110V, sS117INST, sP120T, sP127T, sM133I, sC137L + sG145R, sS143L. However, NUC resistance mutations were found in 7.7% (11/142) of the patients on NUC therapy and 3.8% (7/185) of the treatment-naïve group patients. Interestingly, the treatment-naïve patients had preexisting drug resistance mutations related to lamivudine (rtL180M + rtM204I), adefovir (rtA181V, rtQ215S, rtI233V), entecavir (intermediate susceptibility with rtL180M + rtM204IHBV variant), telbivudine (rtL180M + rtM204I), and tenofovir (rtA194T). Conclusions: The findings of this study show preexisting typical HBsAg escape and NUC resistance mutations are possible. The genetic arrangement of the HBV genome with polymerase and surface genes overlapping has substantial public health and diagnostic implications and relevance. ß
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.
HBV carrying drug-resistance mutations in chronically infected treatment-naive patients
Antiviral Therapy, 2015
Background: Nucleos(t)ide analogue (NA) treatment causes selection pressure for hepatitis B virus strains carrying mutations conferring NA resistance. Drug-resistance mutations occur in the reverse transcriptase (RT) region of the HBV polymerase gene and spontaneously arise during viral replication. These mutations can also alter the HBs protein and in some cases reduce binding to HBs antibodies. The spread of NAresistant HBV may impact the efficacy of antiviral treatment and hepatitis B immunization programs. In this study, we used direct sequencing to assess the occurrence of HBV carrying known mutations that confer NA resistance in the largest cohort of treatment-naïve patients with chronic hepatitis B (CHB) to date.
Journal of Medical Virology, 2013
While the selection of complex HBV drugresistance patterns on therapeutic failure can compromise the efficacy of anti-HBV therapies, recent data show that patients failing treatment without drug-resistance have a rate of virological success close to drug-naive patients. The goal of this study is defining, in clinical practice, the burden of drug-resistance mutations in a cohort of patients treated with anti-HBV drugs. Prevalence and patterns of drug-resistance were analyzed by RT-sequencing in 204 patients infected chronically: 148 experiencing virological rebound (defined as an increase in serum HBV-DNA > 20 IU/ml after achieving virological success [HBV-DNA < 20 IU/ml]), and 56 null/partial responders (always detectable serum HBV-DNA [>20 IU/ml] within 48 weeks of therapy). The highest rate of drug-resistance was observed in patients experiencing virological rebound (prevalence, 79.1%). Conversely, almost half (46.4%) null/partial responders have no evidence of drug-resistance. The rate of drug-resistance was higher in patients treated with lamivudine (76.8% [109/142]) and telbivudine (83.3% [5/6]), followed by adefovir (62.5% [15/24]), and entecavir (52.2% [12/23]). Complex mutational patterns characterized by the copresence of rtM204V/I-rtA181T/V (impairing the efficacy of all anti-HBV drugs) were detected in four patients (2.7%) with virological rebound. Drug-resistance is the main cause of failure to therapy in patients experiencing virological rebound, supporting the need of rapid switch to anti-HBV drugs with higher genetic barrier and potency (entecavir/tenofovir). Conversely, nearly half of null/partial responders shows no evidence of drug-resistance mutations, maintaining high chance of achieving therapeutic success with the same class of drug. In this setting, genotypic resistance may help in selecting patients still carrying wild-type viruses, that may take major benefits from antiviral treatment.