Resistant Hepatitis Research Articles

Treatment of lamivudine-resistant chronic hepatitis B infection: a multicenter retrospective study

Objectives.To compare the efficacy of rescue therapies in lamivudine (LAM)-resistant chronic hepatitis B (CHB) infections including: (1) adefovir dipivoxil (ADV) monotherapy, (2) ADV plus LAM combination therapy and (3) entecavir (ETV) 1.0 mg monotherapy. Materials and methods.The authors designed a multicenter-retrospective study. Eight institutions participated in the study from Korea. Results. A total of 343 LAM-resistant CHB patients were enrolled. The proportion of patients with undetectable serum hepatitis B virus (HBV) DNA levels at month 24 after the initiation of rescue therapy was higher in the ADV plus LAM combination therapy group (39/64, 60.9%) than in the ADV monotherapy (50/126, 39.7%) and ETV 1.0 mg monotherapy (19/48, 39.6%) groups (p = 0.014). Mean serum HBV DNA levels at 24 months were 2.07 ± 1.21 log10 IU/ml in the ADV plus LAM combination therapy group, 2.74 ± 1.74 log10 IU/ml in the ADV monotherapy group and 3.08 ± 1.97 log10 IU/ml in the ETV 1.0 mg monotherapy group (p = 0.014). In multivariate analysis, a finding of undetectable serum HBV DNA level at 6 months and ADV plus LAM combination therapy (vs. ADV) was an independent factor for predicting undetectable serum HBV DNA at month 24 (odds ratio, 1.003; 95% confidence interval, 1.000–1.006; p = 0.026). Conclusions.ADV plus LAM combination therapy is more effective in reducing viral load than switching to ADV or ETV 1.0 mg in patients with LAM-resistant CHB.

Cost-effectiveness analysis of different rescue therapies in patients with lamivudine-resistant chronic hepatitis B in China

BackgroundSeveral rescue therapies have been used in patients with lamivudine (LAM)-resistant chronic hepatitis B (CHB); however, the economic outcome of these therapies is unclear. The object of the current analysis was to evaluate the lifetime cost-effectiveness of rescue therapies among patients with LAM-resistant CHB.MethodsA Markov model was developed to simulate the clinical course of patients with LAM-resistant CHB. From the perspective of Chinese health care, a lifetime cost-utility analysis was performedfor 4 rescue strategies: adefovir (ADV), entecavir (ETV) or tenofovir (TDF) monotherapy and combination therapy using LAM and ADV. A hypothetical cohort of 45-year-old patients with genotypic or clinical LAM-resistant CHB entered the model, and the beginning health state was LAM-resistant CHB without other complications. The transition probabilities, efficacy and resistance data for each rescue therapy as well as the costs and utility data were estimated from the literature. The discount rate (3%) utilized for costs and benefits. Sensitivity analyses were used to explore the impact of uncertainty on the results.ResultsIn LAM-resistant HBeAg-positive and HBeAg-negative CHB cohorts, TDF monotherapy and combination therapy were on the efficiency frontier for both positive and negative populations. Compared with no treatment, the use of combination therapy cost an additional $6,531.7 to gain 1 additional quality-adjusted life year (QALY) for HBeAg-positive patients and $4,571.7 to gain 1 additional QALY for HBeAg-negative patients. TDF monotherapy for HBeAg-positive patients, shows greater increase in QALYs but higher incremental cost-effectiveness ratio (ICER) in comparison with combination therapy. In probabilistic sensitivity analyses, combination therapy was the preferred option for health care systems with limited health resources, such as Chinese health care system.ConclusionIn Chinese patients with LAM-resistant CHB, combination therapy is a more cost-effective option than the competing rescue therapies.

Prevention and management of drug resistant hepatitis B virus infections

In the past decade, broadened therapeutic options of oral direct antiviral agents for the treatment of chronic hepatitis B infection include: Lamivudine, Adefovir Dipivoxil, Telbivudine, Entecavir and Tenofovir Disoproxil Fumarate. These direct oral antiviral agents effectively suppress the replication of the virus and reduce the risk of potential liver-related complications. However, prolonged use of these nucleos(t)ide analogues has been associated with drug resistance that compromises the initial clinical benefits. Moreover, the oncogenic risk of mutations due to prolonged nucleos(t)ide analogue therapy needs to be further investigated by in vitro and in vivo studies. In the current era of potent nucleotide analogues, new data are emerging, we are still facing the pool of patients who have developed resistance to the prior generation of nucleos(t)ide analogues. This paper aims to focus on incidence of antiviral drug resistance and virological breakthrough, prudent selection of initial therapy, on-treatment monitoring for drug resistance and revise treatment strategies for patients with resistant virus.

Clinical characteristics and chronicity of acute hepatitis B induced by lamivudine‐resistant strains

Whether resistant hepatitis B virus (HBV) strains are transmissible and can lead to chronic infection remains to be studied. The aim of this study was to investigate the clinical characteristics of patients with acute hepatitis B caused by lamivudine (LAM)-resistant strains. Sera were collected from 234 Chinese patients with acute hepatitis B. LAM-resistance mutations were identified by direct polymerase chain reaction (PCR) sequencing. LAM-resistant HBV variants were detected in 11 of the 234 (4.7%) patients. Among these patients, six harbored the rtM204I mutation, two harbored the rtL180M + rtM204I mutations, one harbored the rtM204I + rtM204V mutations, one harbored the rtL80I + rtM204I mutations, and one harbored the rtV173L + rtL180M + rtM204V mutations. Three patients were infected with genotype B HBV and eight patients were infected with genotype C HBV. Two patients infected with viruses with LAM-resistance mutations developed severe acute hepatitis. One patient developed chronic hepatitis B. This patient was infected with genotype C HBV that had LAM-resistance mutations (rtL180M + rtM204I). The patient was diagnosed with an occult hepatitis B virus infection based on the presence of HBV DNA in the liver and the absence of detectable hepatitis B surface antigen (HBsAg) in the serum. LAM-resistant HBV strains in China are transmissible, can cause acute hepatitis B, and can even progress to chronic infection in China.

Emergence of lamivudine resistance hepatitis B virus mutations in pregnant women infected with HBV and HIV receiving antiretroviral prophylaxis for the prevention of mother‐to‐infant transmission in Malawi

HIV/HBV co-infection is highly prevalent in sub-Saharan Africa. The aim of this study was to determine if the use of triple combination lamivudine-containing prophylaxis for the prevention of mother-to-infant HIV transmission was associated with the emergence of lamivudine HBV mutations. The study included 21 pregnant co-infected women in Malawi who received either zidovudine or stavudine plus lamivudine and nevirapine from week 25 of gestation until 6 months after delivery or indefinitely if they met the criteria for treatment (CD4+ <350/mm(3)). HBV-DNA was determined using the Roche COBAS assay. Resistance mutations were assessed by the Trugene assay (Siemens Diagnostics). At baseline 33% of the women were HBeAg positive and had HBV-DNA > 10(4) IU/ml. Median CD4 count was 237 cells/mm(3) and median HIV-RNA was 3.8 log(10) copies/ml. After a median of 259 days of treatment, HBV-DNA was detectable in 9 out of 21 patients (42.8%). In three cases the HBV-DNA level was >10(4) IU/ml. Resistance mutations (M204I in five cases and L180M + M204I/V in one case) were present in 6 (28.6%) patients. Women with a resistant virus had significantly higher baseline HBV-DNA levels than those not developing resistance (1.1 × 10(7) IU/ml vs. 20.8 IU/ml, P = 0.022). Levels of ALT and AST were higher in women with resistant viruses compared to those retaining a wild-type virus. A high rate of lamivudine resistance was seen in this cohort of pregnant women. Follow-up of these patients will clarify if the presence of resistance has a significant impact on liver disease.

Correlation between pretreatment viral sequences and the emergence of lamivudine resistance in hepatitis B virus infection

The emergence of amino acid or nucleotide substitutions leads to lamivudine resistance in hepatitis B virus (HBV) infected patients. The aim of this study was to investigate whether viral sequences help predict the emergence of lamivudine resistance. The study subjects comprised 59 consecutive patients infected with HBV treated with daily therapy of 100 mg lamivudine. Among those, 32 patients with adequate pretreatment serum preservation were investigated for the correlation between viral amino acid substitutions and the appearance of lamivudine resistance with consideration of clinical background by determining dominant HBV full open reading frames. Viral resistance to lamivudine emerged in 28 of 59 patients (47%) in a median period of 2.45 years. Sequence comparisons of HBV genomes between patients who later developed lamivudine resistance and patients who did not revealed the existence of significant differences between the two groups in the pre-S1 84 (P = 0.042), pre-S2 1 (P = 0.017) and 22 (P = 0.015), and polymerase tp 95 (P = 0.046), judged by a log-rank test. Viral sequence analyses revealed the presence of amino acid substitutions in HBV pre-S1 and pre-S2 that may be associated with the emergence of lamivudine resistance during chronic HBV infection.

Impact of Drug-Resistance Polymerase Mutations on the Replication of HBeAg-Positive and HBeAg-Negative Hepatitis B Virus Strains in Vitro

Impact of Drug-Resistance Polymerase Mutations on the Replication of HBeAg-Positive and HBeAg-Negative Hepatitis B Virus Strains in Vitro

Modeling Quasispecies and Drug Resistance in Hepatitis C Patients Treated with a Protease Inhibitor

Telaprevir, a novel hepatitis C virus (HCV) NS3-4A serine protease inhibitor, has demonstrated substantial antiviral activity in patients infected with HCV. However, drug-resistant HCV variants were detected in vivo at relatively high frequency a few days after drug administration. Here we use a two-strain mathematical model to explain the rapid emergence of drug resistance in HCV patients treated with telaprevir monotherapy. We examine the effects of backward mutation and liver cell proliferation on the preexistence of the mutant virus and the competition between wild-type and drug-resistant virus during therapy. We also extend the two-strain model to a general model with multiple viral strains. Mutations during therapy only have a minor effect on the dynamics of various viral strains, although they are capable of generating low levels of HCV variants that would otherwise be completely suppressed because of fitness disadvantages. Liver cell proliferation may not affect the pretreatment frequency of mutant variants, but is able to influence the quasispecies dynamics during therapy. It is the relative fitness of each mutant strain compared with wild-type that determines which strain(s) will dominate the virus population. This study provides a theoretical framework for exploring the prevalence of preexisting mutant variants and the evolution of drug resistance during treatment with other HCV protease inhibitors or polymerase inhibitors.

Long‐term outcomes of add‐on adefovir dipivoxil therapy to ongoing lamivudine in patients with lamivudine‐resistant chronic hepatitis B

Add-on adefovir dipivoxil (ADV) therapy has been a standard rescue treatment for patients with lamivudine (LAM)-resistant chronic hepatitis B, but the overall benefits of long-term add-on ADV therapy are still limited. The aim of this study was to evaluate the long-term efficiency of add-on ADV treatment and to explore predictive factors associated with it. A total of 158 patients with LAM-resistant chronic hepatitis B were included in this retrospective, multicenter, nationwide study in Japan. After confirming LAM resistance, ADV was added to LAM treatment. Three types of events were considered as outcomes: virological response, hepatitis B e antigen (HBeAg) clearance and alanine aminotransferase (ALT) normalization. Virological response was defined as serum hepatitis B virus (HBV) DNA levels of less than 3 log copies/mL. Baseline factors contributing to these outcomes were examined by univariate and multivariate analyses. The median total duration of ADV treatment was 41 months (range, 6-84). The rate of virological response was 90.8% at 4 years of treatment; HBeAg clearance and ALT normalization were achieved by 34.0% and 82.7%, respectively, at the end of follow up. Each outcome had different predictive factors: baseline HBV DNA and albumin level were predictive factors for virological response, history of interferon therapy and ALT level for HBeAg clearance, and sex and baseline albumin level for ALT normalization. Long-term add-on ADV treatment was highly effective in LAM-resistant chronic hepatitis B patients in terms of virological and biochemical responses. Lower HBV replication and lower albumin level at baseline led to better outcomes.

Impact of Peginterferon Alpha and Ribavirin Treatment on Lipid Profiles and Insulin Resistance in Hepatitis C Virus/HIV-Coinfected Persons: The AIDS Clinical Trials Group A5178 Study

The effect of peginterferon alpha/ribavirin (PEG-IFN/RBV) and hepatitis C virus (HCV) clearance on lipid and insulin resistance (IR) profiles in HCV/human immunodeficiency virus (HIV) coinfection is unknown. We measured fasting total cholesterol (TC), low-density lipoprotein (LDL-C), high-density lipoproteins (HDL-C), triglycerides (TG), glucose, and insulin at defined intervals in the A5178 study (N = 329), a prospective treatment trial in HCV/HIV coinfection. Changes from baseline and the relation between baseline values of these variables to sustained virologic response (SVR) were determined. Of 182 subjects with metabolic data, 98 achieved early virologic response (EVR) and continued PEG-IFN/RBV. Among those, median pretreatment HCV RNA was 6.6 log(10 )IU/mL; 73% had HCV genotype 1. Median pretreatment TC was 176 mg/dL (interquartile range [IQR],150-205]; median LDL-C was 99 mg/dL (IQR, 79-123); median HDL-C was 40 mg/dL (IQR, 31-47); and median TG was 147 mg/dL (IQR, 101-221). Median homeostasis model assessment of IR (HOMA-IR) was 3.3 (IQR, 1.7-5.3). The EVRs demonstrated a decline in TC, LDL-C, and HDL-C, whereas TG increased on treatment but returned to near baseline 24 weeks after end of treatment (EOT). The HOMA-IR decline from entry to 24 weeks after EOT was significant among non-sustained virologic responders and nonsignificant among sustained virologic responders; this difference was offset after adjusting for higher HOMA-IR at baseline among the former. Among all 182 subjects, entry LDL-C was associated with SVR in a joint logistic model adjusted for HCV genotype, race, and prior IFN (odds ratio, 1.17 per 10 mg/dL increase; 95% confidence interval, 1.03-1.32), but TC, HDL, TG, and IR were not. Peginterferon alpha and RBV can significantly affect lipid profile and IR in HCV/HIV-coinfected persons. Although the lipid profile returns to near pretreatment levels after completion of treatment, our data suggest persistent modest improvement in IR with treatment. Clinical Trials Registration. NCT00078403.

Investigation of interleukin-6 in hepatitis B patients with high blood glucose levels

Hepatitis B virus plays an important role in persistent inflammation with necrosis of the liver tissue, with the result that some patients with hepatitis develop diabetes. The present study aims to understand the correlation between pro-inflammatory interleukin-6 (IL-6) expression and insulin resistance in hepatitis B patients. Forty-three patients with diabetes, 68 patients with hepatitis, and 68 controls without diabetes and hepatitis were included in this study. The concentrations of glycated hemoglobin, glucose, and insulin antibodies in patients with hepatitis B and diabetes were significantly higher than those in controls without hepatitis and diabetes (p < 0.001). The IL-6 concentrations in the patients with hepatitis B were significantly higher than those in the group with diabetes and the control group. The results suggest that an increase in IL-6 level in hepatitis B patients may lead to the occurrence of high blood glucose levels.

Simple Scoring System Predicting Genotypic Resistance During Rescue Therapy for Lamivudine-Resistant Chronic Hepatitis B

In this study, we aimed to devise a simple scoring system predicting the risk of genotypic resistance (GR) to current rescue therapies for patients with lamivudine (LAM)-resistant chronic hepatitis B. LAM and adefovir (ADV) combination therapy should be recommended for an initial rescue therapy against LAM-resistant hepatitis B virus (HBV). However, there still are many LAM-resistant patients being treated with entecavir (ETV) or ADV monotherapy. This retrospective cohort study included consecutive patients treated for LAM-resistant chronic hepatitis B with ETV or ADV monotherapy, or LAM/ADV combination therapy. The cumulative probabilities of GR and virological responses and breakthrough according to clinical variables were analyzed by survival analyses and derived an index for future GR. A total of 224 patients were included (median treatment duration=117.9 wk). Using risk factors indentified on multivariable analyses, a simple index for future GR (Antiviral Resistance Prediction Index, ARPI) was developed with 3 clinical variables: the rescue therapy regimens (+0, ADV; +1, ETV; +2, LAM/ADV), HBV DNA reduction at 12 weeks (+0, <3 log10 copies/mL; +1, >3 log10 copies/mL), and the initial HBV DNA level (+0, >10 copies/mL; +1, <10 copies/mL). No patient with ARPI ≥2 exhibited GR, whereas 47% of the patients with an ARPI <2 developed GR by week 144 (P=0.005). The results of this study suggest that the ARPI is a simple and early index that can be used to determine the risk for subsequent GR during rescue therapy for LAM-resistant chronic hepatitis B.

RtL180M mutation of hepatitis B virus is closely associated with frequent virological resistance to adefovir dipivoxil therapy

We intended to investigate the effects of pre-existing mutations at reverse transcriptase region of hepatitis B virus (HBV) on the occurrence of virological breakthrough (VB) to adefovir dipivoxil (ADV) in patients with lamivudine (LAM)-resistant chronic hepatitis B (CHB). Ninety-seven patients with LAM-resistant CHB were treated with ADV at a dose of 10 mg daily, and were followed for a median period of 13 months. Just before the initiation of ADV therapy, the whole length of reverse transcriptase region of serum HBV-DNA was sequenced using direct sequencing. All patients had genotype C HBV and mutations in the YMDD motif, specifically, YIDD (65%), YVDD (28%), or both (7%). The rtL180M and rtL80V/I mutations were identified in 68% and 69%, respectively. The cumulative probability of VB was 19% and 27% at 1 and 2 years, respectively. There was no difference in the occurrence of VB with regard to types of YMDD mutation or rtL80V/I. However, interestingly, patients carrying rtL180M experienced VB during ADV monotherapy more frequently than those not carrying rtL180M (2-year cumulative probability of VB: 37% vs 3% at 2 years, P < 0.01). On multivariate Cox proportional hazards analysis, rtL180M (hazard ratio [HR]: 8.62, 95% confidence interval: 1.08-69.09, P = 0.042) and decrease in HBV-DNA for 1 year of treatment (HR: 0.69, 95% CI: 0.51-0.95, P = 0.024) are independently associated with VB. The rtL180M mutation of HBV, as well as a small decrease in HBV-DNA after 1 year of treatment might be closely associated with frequent occurrence of virological resistance to ADV in patients with LAM-resistant CHB.

Entecavir Therapy for Patients with Hepatitis B Virus-related Decompensated Cirrhosis

Entecavie (ETV) has a potent antiviral effect and low rates of resistance in hepatitis B virus (HBV) and is the first-line monotherapy in patients with HBV-related decompensated cirrhosis. We evaluated the efficacy of 12 months treatment with ETV and tried to determine predictive factors of response. Forty-five consecutive decompensated cirrhotic patients who received ETV (0.5 mg/day) for more than six months were included. All patients were positive for HBV DNA, and the Child-Turcotte-Pugh (CTP) scores were over 8 point. Seventeen patients were HBeAg-positive. CTP score, model for end-stage liver disease (MELD) score, serum markers of liver function and HBV DNA were assessed every 3 months. ETV treatment for 12 months resulted in improvement of CTP and MELD scores. Pre-treatment mean CTP and MELD score were decreased from 10.1 (±2.0) and 13.48 (±4.05) to 7.24 (±2.0) and 9.68 (±4.85) at 12 months, respectively. The 1-year cumulative rates of HBV DNA negativity and HBeAg loss were 88.9% and 52.9%, respectively, by intention-to-treat analysis. Thirty-two (71.1%) showed improvement in CTP score. Eleven patients did not show change, and 2 patients got worse. The AST/ALT, albumin, bilrubin, prothrombin time were significantly normalized within six months. The good responder group had high level of prothrombin time than the poor responder group (p=0.004). Our result shows that entecavir can improve liver function in about 70% of patients with HBV related decompensated liver cirrhosis. INR may be a predictive factor of good response with entecavir in these patients.

New developments in HCV therapy

About half of the patients with chronic hepatitis C are still not cured by treatment with the current standard of care, peginterferon α/ribavirin. Direct antiviral drugs may overcome the limitations of standard antiviral therapy. The most promising new agents are inhibitors of the NS3/4A protease, the NS5B polymerase and the NS5A protein. Several compounds against these targets have entered clinical evaluation. Early clinical trials have emphasized the high potential for selecting resistant Hepatitis C virus variants. Furthermore, development of several new direct antivirals was stopped because of concerns over tolerability and safety. Then, in 2010, two phase III trials with the NS3/4A protease inhibitors boceprevir (SPRINT-2) and telaprevir (ADVANCE) showed that the combination of these compounds with standard care increases sustained virologic response rates in treatment-naïve genotype 1 patients from 38-44% to 66-75%. Future goals of therapy with direct antiviral agents are to improve tolerability, shorten the duration of therapy and overcome the issue of resistance. Several studies have been initiated that combine different novel therapies, with and without interferon α/ribavirin.

Stability of lyophilized siRNA nanosome formulations

The goal of this study is to evaluate the stability of lyophilized siRNA formulations. The gene silencing efficiency of a stored lyophilized siRNA formulation (i.e. siRNA nanosomes) was evaluated in interferon-α (IFN-α) resistant hepatitis C virus (HCV) at different time points up to three months in an in vitro cell culture model and compared with freshly prepared siRNA formulations. Novel siRNA sequences were encapsulated within nanosize liposomes following condensation with protamine sulfate. The siRNA encapsulated nanosomes were lyophilized and stored at 4°C for 3 months, along with liquid liposomes (L) and lyophilized liposome powder (P) which were subsequently used to prepare siRNA nanosomes (L) and siRNA nanosomes (P), respectively at different time points. Physiochemical and biological properties of all three formulations were compared at different time points up to 3 months. The particle size of the stored siRNA nanosomes (642±25nm) was considerably larger initially in comparison with the liquid liposomes (134±5nm) and lyophilized liposomes (118±3). However, the particle size gradually became smaller over time (413±128nm by the third month). The zeta potential of all three formulations was initially very high (> +40mV), followed by a gradual decrease over time. The amount of siRNA in the stored siRNA nanosomes decreased ∼18% during the 3 month storage period (1.16±0.03nmol initially on day 1 vs. 0.95±0.04nmol after 3 months). With respect to biological potency, all three formulations were significantly effective to knock-down HCV throughout the storage time. The cell viability was well-maintained throughout this period. Thus, this study indicates that the stored lyophilized siRNA formulation is as effective as the fresh preparation and that long-term storage could be a viable option to treat deadly diseases such as cancer and viral infection.

Insulin resistance and chronic hepatitis C in non-diabetic patients

he recent publication on Insulin resistance and chronic hepatitis C in non-dia-betic patients was very interesting (1). Souza and cols. concluded that “Insulin resistance is often present in patients with chronic hepatitis C, and this parameter is associated with more advanced HCV-related hepatic fibrosis (1).” The finding in this study is concordant with the recent report by Itoh and cols. (2). It is believed that direct damage caused by the virus with proinflammatory cytokines will interfere with normal insulin signaling, and this further disturbs glucose metabolism (3). However, some issues on the present study (1) should be mentioned. First, the protocol in the present study cannot exclude the interference of other possible confounding diseases in the patients (such as HIV and other uncommon hepatitis virus infection). Second, this is only an observational study, hence, it is not reasonable to draw conclusions on any association (which would require an analytical study).

Reply to: insulin resistance and chronic hepatitis C in non-diabetic patients

We appreciate the interest of Dr. Wiwanitkit in our article recently published in Journal of the Brazilian Society of Endocrinology and Metabology. According to the study results, chronic hepatitis C patients with insulin resistance (HOMA IR> 2.5) had more advanced HCV – related liver fibrosis (1). One of the issues considered by Dr. Wiwanitkit is that our results may have been influenced by the other liver diseases. However, as described in the methods section, previous antiviral treatment, co-infection with HBV or HIV, chronic renal disease, DM2, decompensated liver cirrhosis, hepatocellular carcinoma, and alcohol intake above 20 g ethanol/d were exclusion criteria. The second question issue raised by him, is that although theon the fact that it was an observational study, data were submitted to statistical analysis (univariate analysis) and results were considered statistically significant when p < 0.05. Therefore, we found possible to conclude that there was an association between IR and HCV-induced liver fibrosis. We did not analyze in our study whether insulin resistance was independently associated with HCV-induced liver fibrosis.

A Combination anti-HBV regimen using lamivudine and other agents in treatment of resistant chronic hepatitis B

Background: Several difficulties remain in formulating treatment for chronic hepatitis B (CHB), 350 million people are chronically infected with HBV, Chronic infection with hepatitis B virus accounts for an enormous burden of disease worldwide, including up to half of all cases of cirrhosis, end stage liver disease , and hepatocellular carcinoma. Aim of the work: To maximize the elimination of the viral infection while minimizing or preventing damage to the liver cells and tissues and development of viral resistance to more antivirals. Patients and Methods: Eighty eight patients of chronic hepatitis B virus infection with resistance to lamivudine treatment as proved by quantitative PCR (more than 200 IU/ ml). Their age between (20-60) years, (85 males, and 3 females) were selected from the National Hepatology and Tropical Medicine Research Institute and were included in this study. The included patients were two groups, the first group 42 patients , were receiving Lamivudine, plus (Baraclude) Entecavir (tablet 0.5mg / day) treatment at the time of assessment. The second group 46 patients were receiving ( Hepsera tablet 10 mg / day ) Adefovir dipivoxil plus lamivudine (tablet). All the patients were subjected to the following : thorough history and clinical examination, abdominal ultrasonography and collection of blood samples for routine liver and kidney function investigations and serological assay for HBsAg, HBsAb, HBeAg, HBeAb, HBcAb quantitative HBV DNA (PCR). Results: Our results revealed significant differences between the two groups of patients of CHBV infection, resistant to Lamivudine drug, the first group were higher in response to a combination between Lamivudine + (Baraclude) Entecavir, than the second group who were receiving Lamivudine + (Hepsera) Adefovir dipivoxil combination therapy. Conclusion: Our study concluded that the clinical benefit is apparent with high percentage after a combination regimen using Lamivudine + Entecavir than a combination regimen using Lamivudine + Adefovir dipivoxil for the treatment of resistant chronic hepatitis B virus who were treated with Lamivudine only before. Recommendations: Optimal management of chronic hepatitis B,that may require long-term and sometimes lifelong treatment to maintain its clinical benefit is challenging. It is important to initiate treatment with a drug that has the least potential for induction of drug resistance as sequential monotherapy which may result in selection of multidrug resistant HBV mutatants.

Characterization of naturally occurring protease inhibitor-resistance mutations in genotype 1b hepatitis C virus patients

Protease inhibitor (PI)-resistant hepatitis C virus (HCV) variants may be present in substantial numbers in PI-untreated patients according to recent reports. However, influence of these viruses in the clinical course of chronic hepatitis C has not been well characterized. The dominant HCV nonstructural 3 (NS3) amino acid sequences were determined in 261 HCV genotype 1b-infected Japanese patients before pegylated interferon plus ribavirin (PEG-IFN/RBV) therapy, and investigated the patients' clinical characteristics as well as treatment responses including sustained virological response (SVR) rate. HCV-NS3 sequences were also determined in 39 non-SVR patients after completion of the therapy. Four single mutations (T54S, Q80K, I153V, and D168E) known to confer PI resistance were found in 35 of 261 patients (13.4%), and double mutations (I153V plus T54S/D168E) were found in 6 patients (2.3%). Responses to PEG-IFN/RBV therapy did not differ between patients with and without PI-resistance mutations (mutation group, SVR 48%; wild-type group, SVR 40%; P=0.38). On the other hand, two mutations appeared in two non-SVR patients after PEG-IFN/RBV therapy (I153V and E168D, 5.1%). PI-resistance-associated NS3 mutations exist in a substantial proportion of untreated HCV-1b-infected patients. The impact of these mutations in the treatment of PIs is unclear, but clinicians should pay attention to avoid further development of PI resistance.