Tenofovir disoproxil fumarate has a substantial efficacy against multidrug-resistant strains of hepatitis B virus.

BACKGROUND & AIMS: To evaluate the efficacy of tenofovir in chronic hepatitis B (CHB) patients with adefovir resistance (ADF-R) and suboptimal response to adefovir (ADF-S). METHODS: Nucleos(t)ide analogue (NA)-naïve patients and patients with previous adefovir failure receiving tenofovir therapy for at least 6 months were included in the study. Biochemical and virological tests were obtained at baseline and 3-month intervals in the first year and every 6 months thereafter. The primary outcome measure was complete virological response (CVR) (HBVDNA < 20 IU/ml). CVR rates were calculated by Kaplan-Meier analysis, and a multivariate Cox proportional hazard model was generated to find out factors independently associated with CVR. RESULTS: A total of 165 patients (118 men, mean age 42 ± 12, 64 HBeAg(+) ) were included in the study. There were 105 patients in NA-naïve, 32 patients in ADF-S and 28 patients in ADF-R groups. All patients in the ADF-R group had multidrug resistance patterns. Mean duration of tenofovir treatment was 29 ± 14 months. CVR rates in NA-naïve, ADF-S and ADF-R groups were 65% vs. 75% vs. 58% at 12th month, 77% vs. 87% vs. 79% at 24th month and 83% vs. 94% vs. 79% at 36th month respectively. According to multivariate Cox regression model, HBeAg positivity (HR = 0.56, 95%CI 0.36-0.86, P = 0.008), high baseline HBVDNA level (HR = 0.64, 95%CI 0.55-0.74, P < 0.001) and ADF-R (HR = 0.47, 95%CI 0.28-0.81, P = 0.006) were independent predictors for CVR. Seven patients encountered mild renal dysfunction and were managed by dose adjustments. CONCLUSION: CVR rates during the follow-up show that tenofovir has a decreased, yet still potent in vivo efficacy against multidrug-resistant strains of HBV.

Effects of polymorphisms in interferon λ 3 (interleukin 28B) on sustained virologic response to therapy in patients with chronic hepatitis D virus infection.

BACKGROUND & AIMS: We investigated the association between interferon λ 3 (IFNL3) genotype (also known as interleukin 28B) and response to IFNα therapy in patients with chronic hepatitis D virus (HDV) infection. METHODS: We studied IFNL3 genotypes of 32 patients (19 men; median age, 42.5 y) with chronic HDV infection. Nineteen patients (59%) were treated with pegylated IFNα and 13 patients (41%) were treated with standard IFNα, for at least 12 months. Levels of HDV RNA were measured before the initiation of treatment and every 6 months thereafter; patients were followed up for a median time of 16 months (range, 6-164 mo) after treatment ended. We used real-time polymerase chain reaction to classify the IFNL3 polymorphism rs12979860 as CC, CT, or TT, and rs8099917 as TT, GT, or GG. A virologic response was defined as undetectable HDV RNA in serum, and a sustained virologic response (SVR) was defined as undetectable HDV RNA after cessation of treatment until the end of the follow-up period. We evaluated the association between IFNL3 polymorphism and treatment response using univariate and multivariate analyses. RESULTS: After treatment, a response was achieved in 16 patients (50%) and an SVR was achieved in 9 (28%). The percentages of patients with CC, CT, and TT at rs12979860 were 47%, 47%, and 6%, respectively; the percentages of patients with TT, GT, and GG at rs8099917 were 69%, 28%, and 3%, respectively. Rates of SVR were 27%, 27%, and 50% in patients with CC, CT, TT at rs12979860 (P = .78 for CC vs CT vs TT) and 36%, 11%, and 0% in patients with TT, GT, and GG at rs8099917 (P = .30 for TT vs GT vs GG). CONCLUSIONS: The IFNL3 polymorphisms rs12979860 and rs8099917 do not significantly affect responses of patients with chronic HDV infection to treatment with IFNα.

Efficacy of tenofovir in patients with Lamivudine failure is not different from that in nucleoside/nucleotide analogue-naive patients with chronic hepatitis B.

We evaluated the efficacy of tenofovir disoproxil fumarate (TDF) in patients with lamivudine failure (LAM-F) in comparison with that in nucleoside/nucleotide analogue (NA)-naïve patients with chronic hepatitis B (CHB). The criteria for inclusion were being NA naïve or having previous LAM-F and receiving TDF therapy for at least 6 months. Biochemical and virological tests were performed at the baseline, at 3-month intervals in the first year, and every 6 months thereafter. The primary outcome measure for efficacy was a complete virological response (CVR), defined as an HBV DNA level of <20 IU/ml. CVR rates were calculated by Kaplan-Meier analysis, and a multivariate Cox proportional-hazard model was generated in order to find predictive factors independently associated with the time to a CVR. We included 197 patients in the study (136 males; mean age, 43 ± 12 years; 105 patients were NA naïve). Sixty-five patients had hepatitis B e antigen (HBeAg)-positive CHB. The median duration of TDF treatment was 29 (range, 6 to 52) months. Seventy-one patients (77%) in the LAM-F group were treated with TDF add-on therapy. The CVR rates of the NA-naïve and LAM-F groups were comparable in HBeAg-negative (94% versus 96% at month 36, P = 0.10) and HBeAg-positive patients (67% versus 83% at month 36, P = 0.48). According to the multivariate Cox regression model, only HBeAg positivity (hazard ratio [HR], 0.39; 95% confidence interval [CI], 0.26 to 0.59; P < 0.001) and a high baseline HBV DNA level (HR, 0.44; 95% CI, 0.29 to 0.67; P < 0.001) had a significant influence on the time to a CVR. The similar cumulative CVR rates during the follow-up show that TDF has comparable efficacy in lamivudine-experienced and NA-naïve patients, and the presence of resistance mutations did not alter the response rates.

Role of the line probe assay INNO-LiPA HBV DR and ultradeep pyrosequencing in detecting resistance mutations to nucleoside/nucleotide analogues in viral samples isolated from chronic hepatitis B patients.

Despite the effectiveness of nucleoside/nucleotide analogues in the treatment of chronic hepatitis B (CHB), their long-term administration is associated with the emergence of resistant hepatitis B virus (HBV) mutants. In this study, mutations resulting in antiviral resistance in HBV DNA samples isolated from 23 CHB patients (nine treatment naïve and 14 treated previously) were studied using a line probe assay (INNO-LiPA HBV DR; Innogenetics) and ultradeep pyrosequencing (UDPS) methods. Whilst the INNO-LiPA HBV DR showed no resistance mutations in HBV DNA samples from treatment-naive patients, mutations mediating lamivudine resistance were detected in three samples by UDPS. Among patients who were treated previously, 19 mutations were detected in eight samples using the INNO-LiPA HBV DR and 29 mutations were detected in 12 samples using UDPS. All mutations detected by the INNO-LiPA HBV DR were also detected by UDPS. There were no mutations that could be detected by INNO-LiPA HBV DR but not by UDPS. A total of ten mutations were detected by UDPS but not by INNO-LiPA HBV DR, and the mean frequency of these mutations was 14.7 %. It was concluded that, although INNO-LiPA HBV DR is a sensitive and practical method commonly used for the detection of resistance mutations in HBV infection, UDPS may significantly increase the detection rate of genotypic resistance in HBV at an early stage.

Prevalence and virological features of occult hepatitis B virus infection in female sex workers who work uncontrolled in Turkey.

BACKGROUND: There is little information about the prevalence of occult hepatitis B virus infection (OHBVI). We have investigated the prevalence and virological features of OHBVI among female sex workers (FSWs) in Istanbul. METHODS: Hepatitis B surface antigen (HBsAg) was tested in FSWs who work uncontrolled and were admitted to Venereal Diseases Hospital. HBV DNA and anti-HBs were investigated in all the HBsAg-negative cases. Hepatitis B envelope (HBe) antigen, anti-HBe, anti-hepatitis B core (HBc) antigen, HBV genotype, S gene and precore (PC)/basic core promoter (BCP) mutations were determined in HBV DNA-positive sera. RESULTS: Two hundred and eighty-six volunteers were enrolled and 32.5% (n=93) of them had anti-HBs positivity. HBV DNA (range 30-209 copy/ml) was positive in 11 anti-HBs-negative and two anti-HBs-positive cases. The prevalence of OHBVI was 4.5% (13/286). Anti-HBc was positive in 77% (10/13) of those with OHBVI and anti-HBe positivity was 53.8% (7/13). Only genotype D was present in all occult HBV-infected cases. One PC (G1896A) and one BCP (T1762/A1764) mutation was found, but S gene mutation was not detected in any of the samples. CONCLUSION: In this population, OHBVI may have a negligible role in the horizontal transmission because of a very low viral load, and PC and core promoter mutations are very rare.

Mutations in influenza A virus (H5N1) and possible limited spread, Turkey, 2006.

We report mutations in influenza A virus (H5N1) strains associated with 2 outbreaks in Turkey. Four novel amino acid changes (Q447L, N556K, and R46K in RNA polymerase and S133A in hemagglutinin) were detected in virus isolates from 2 siblings who died.

Comparison of the efficacy of 12 months and longer courses of interferon therapy for the treatment of chronic delta hepatitis: a retrospective cohort study.

OBJECTIVES: Interferon (IFN) therapy is associated with low rates of treatment success and high rates of recurrence in hepatitis D virus (HDV) infection. Several strategies to increase efficacy, including extending the treatment duration, have been tested. This study aimed to compare treatment outcomes between patients receiving 12 months vs. longer courses of interferon therapy for chronic delta hepatitis (CDH). METHODS: Data from CDH patients receiving standard or pegylated IFN therapy were retrospectively evaluated. Patients were divided into two groups: group I received ≤12 months of therapy and group II received >12 months (maximum: 24 months) of therapy. Viral response at the end of treatment (EOT-VR), post-treatment week 24 viral response (PTW24- VR) and viral response after long-term follow-up (LTFU-VR) were compared. Parameters affecting virologic response were investigated. RESULTS: Sixty-five patients, 14 in group I and 51 in group II, were included. The EOT-VRs were 21% and 45% (p > 0.05), and the PTW24-VRs were 7% and 41% (p = 0.02), respectively. Recurrence rates were 66% and 17% in Groups I and II, respectively. The LTFU-VRs were 7% and 37%, respectively (p = 0.04). The HDV RNA at week 24 of treatment was the only parameter significantly affecting the PTW24-VR (odds ratio: 71.2; 95% CI: 3.7-1353, p = 0.005). PTW24-VR was achieved in 68% and 5% of patients with negative and positive HDV RNA, respectively, at week 24 of treatment (p < 0.01). CONCLUSION: IFN treatment for up to 24 months may increase the virologic response rate for CDH. HDV RNA negativity at week 24 of treatment was a significant predictor of virologic response.

Predictors of treatment requirement in HBeAg-negative chronic hepatitis B patients with persistently normal alanine aminotransferase and high serum HBV DNA levels.

OBJECTIVES: Serum alanine aminotransferase (ALT) is a controversial marker for disease monitoring in hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (CHB) patients. The aim of this study was to determine the fibrosis stage and histological activity index (HAI) in HBeAg-negative CHB patients with persistently normal ALT (PNALT) and high serum HBV DNA (≥2000 IU/ml) and to investigate clinical risk factors for the requirement of treatment through the examination of liver biopsy specimens. METHODS: HBeAg-negative CHB patients with PNALT (≤40 IU/l) and high serum HBV DNA (≥2000 IU/ml) were included. HBV fibrosis stage and HAI were scored according to the Ishak system. Multivariate logistic regression analysis was used to estimate the independent risk factors for fibrosis stage ≥2 and/or HAI ≥6. Receiver operating characteristic curve analysis was used to determine an optimal age cut-off for liver biopsy. RESULTS: A total 120 patients were enrolled. These patients had a mean HBV DNA level of 123680±494500 IU/ml; the HBV DNA load was 2000-20000 IU/ml in 68 patients (56.6%) and ≥20000 IU/ml in 52 (43.4%). Eighteen patients (15%) had moderate-to-severe histological activity (HAI ≥6). Forty-three patients (35.9%) had a fibrosis stage ≥2. Forty-eight patients (40%) had a fibrosis stage ≥2 and/or HAI ≥6. On multivariate logistic regression analysis, independent variables associated with fibrosis stage ≥2 and/or HAI ≥6 included age and HBV DNA viral load. Patients with HBV DNA 2000-20000 IU/ml were more likely to require treatment compared to those with a viral load ≥20000 IU/ml. The optimal age cut-off to predict fibrosis stage ≥2 and/or HAI ≥6 was 46 years. CONCLUSIONS: Significant liver damage was detected in 40% of CHB patients with PNALT and high HBV DNA upon biopsy. Age and HBV DNA viral load were independent predictors of significant liver damage. A biopsy to determine the degree of liver damage is advisable for CHB patients older than 46 years.

Acute hepatitis B due to immune-escape mutations in a naturally immune patient.

Incidence of hepatitis B virus infection (HBV) has been greatly reduced globally after the introduction of universal vaccination programs. However, another potential threat was noticed almost 2 decades ago, which is the selection of antibody escape HBV strains. Antibody or immune escape strains of HBV carry mutations in the S gene which encodes "a" determinant region located at amino acid positions 124 to 149. Certain mutations in this region, which promotes antibody response, might lead to an alteration in the antigenicity of hepatitis B surface antigen (HBsAg). Anti-HBs might fail to neutralize the mutant virus and transmission or reappearance of infection in previously immunized individuals can be possible. Herein, we report a patient with known HBV seropositivity (HBsAg negative, anti-HBs positive, anti-HBc IgG positive) for more than 10 years who developed a symptomatic acute hepatitis due to occurrence of immune escape mutants in the absence of any immunosuppression or cytotoxic chemotherapy. To the best of our knowledge, this is the first reported case of acute hepatitis B due to escape mutations in a naturally immune patient.

Efficacy of tenofovir in adefovir-experienced patients compared with treatment-naive patients with chronic hepatitis B.

BACKGROUND: Tenofovir (TDF) has similar antiviral efficacy in both treatment-naive and lamivudine-resistant chronic hepatitis B (CHB) patients. Data on TDF use in patients with adefovir (ADV) resistance is inconsistent. The aim of our study was to assess antiviral efficacy of TDF against nucleoside analogue-naive (NN) and ADV-resistant (ADV-R) CHB and suboptimal responders to ADV (ADV-S). METHODS: A database of 135 CHB patients treated with TDF was analysed. A total of 37 patients with incomplete data were excluded and analysis was performed in 98 (44 NN, 30 ADV-R and 24 ADV-S). Patients with primary ADV-R mutations had either A181T/V or N236T mutations or both. HBV DNA was measured at 3-month intervals until month 24. Primary outcome measures were comparison of the decline of HBV DNA between the three treatment groups. RESULTS: NN patients had higher baseline HBV DNA compared with ADV-R and ADV-S patients (6.08 log10 IU/ml versus 5.53 and 4.88, respectively; P=0.002). By exponential regression analysis, HBV DNA decline kinetics differed between the three groups. HBV DNA decline was faster in NN patients compared to ADV-R and ADV-S CHB patients (P=0.002 and P=0.004, respectively). Undetectable HBV DNA was achieved in 77.2%, 60% and 75% of NN, ADV-R and ADV-S CHB patients, respectively, at month 12 (P= not significant). CONCLUSIONS: HBV DNA decline is slower in ADV-experienced patients compared with treatment-naive patients. The clinical significance of this slow response may be important in patients with critical liver reserve and high viral load. Optimal combination treatment (TDF+ entecavir) could be considered in these patients.

Acute hepatitis A virus infection in Turkey.

Anti-HAV IgM positive serum samples from acute phase hepatitis A patients from various areas in Turkey were tested for viral RNA by RT-PCR (reverse transcriptase polymerase chain reaction), using primer pairs from two different regions of the HAV genome. The PCR products amplified from both genomic regions underwent phylogenetic analyses. A comparison of the regions showed the same genotyping results, and the RT-PCR-2 in the 5'NCR demonstrated greater sensitivity compared to RT-PCR-1 in the VP1-P2A region. The majority of the isolates belonged to genotype IB and are related closely to each other; however, two isolates related even more strongly to the HAV HM175 strain. Two (n = 37) RT-PCR positive sera were classified under genotype IA. A surprising finding emerged for the mean levels of serum transaminases AST and ALT: higher levels were found in patients under 10 years of age compared to older patients. Anti-HAV IgM levels were determined quantitatively and, in addition, the HAV-RNA genome equivalents were ascertained by real time RT-PCR. No evidence was found for an association between viral load and the higher transaminase levels in the younger group.

Lamivudine monotherapy and lamivudine plus interferon alpha combination therapy in HBeAg negative chronic hepatitis B not responding to previous interferon alpha monotherapy.

BACKGROUND AND STUDY AIMS: To investigate the efficacy of the combined therapy of lamivudine (LAM) plus alpha interferon (IFN) and LAM monotherapy in HBeAg negative chronic hepatitis B (CHB) patients who were unresponsive to previous IFN monotherapy, and the incidence of YMDD mutations. PATIENTS-METHODS: Forty-five HBeAg negative patients were enrolled in this study. 24 of these were treated with LAM (100 mg/day, PO, for 24 months) alone (group 1) and 21 with combined therapy (IFN-alpha-2b, 10 MU, tiw, SC, for 6 months plus LAM 100 mg/day, PO, for 24 months) (group 2). Normal alanine aminotransferase values and negativity of HBV DNA (molecular hybridization; Digene, USA) were accepted as treatment response. YMDD variants were analyzed at the end of treatment or when clinical breakthrough was observed (Inno-Lipa Innogenetic kit, Belgium). RESULTS: End of follow-up response rate was 29.2%, by ITT in group 1, 19% in group 2 (p > 0.05). Histological activity index was statistically decreased by LAM monotherapy as compared to combination therapy. YMDD mutation rates were 59% in group 1, 62.5% in group 2 (p > 0.05). CONCLUSIONS: Additional IFN-alpha therapy to LAM in HBeAg negative CHB not responding to previous IFN-alpha monotherapy does not increase the response rate compared to LAM monotherapy and does not also decrease the incidence of YMDD mutations.

Long-term results of interferon alpha monotherapy in patients with HBeAg-negative chronic hepatitis B.

We sought to evaluate the long-term results of interferon-alpha (IFN-alpha) therapy in patients with hepatitis B e antigen (HBeAg)-negative chronic hepatitis B. Eighty HBeAg-negative naive patients (62 men; mean age, 39.9 years) who received IFN-alpha for 6 months were studied. Alanine aminotransferase normalization with undetectable HBV-DNA by molecular hybridization was accepted as response. All patients but 1 were precirrhotic stage. At the end of treatment, 44 (55%) patients responded, and they were followed for a mean of 59.5 months (range, 18-132). Twenty-seven patients (61.4%) showed recurrence (63% in first year). Responses at 6 months and at the end of the follow-up period 42.5% and 30% (including 7 patients without end treatment response), respectively. Recurrence of HBV replication was not detected after the 2-years follow-up period. Histologic improvement was observed in 83.3% patients with end-of-follow-up response. HBsAg became negative in 4 patients (5%). On multivariate analysis, younger age (P = .04) and lower GGT level (P = .037) were independent factors for prediction of end-of-follow-up response. Nearly half of the patients with HBeAg-negative chronic hepatitis B responds to IFN-alpha at the end of therapy. Despite the high recurrence rates, response continues in about one third of patients after a mean of 59.5 months.

Occult HBV infection and YMDD variants in hemodialysis patients with chronic HCV infection.

BACKGROUND/AIMS: End-stage renal disease patients on chronic hemodialysis are at risk for both hepatitis B virus (HBV) and hepatitis C virus (HCV) infection. Although the prevalence is unknown in hemodialysis patients, occult HBV infection is frequent in subjects with chronic HCV infection. We aimed to investigate (1) the prevalence and clinical impact of occult HBV infection in hemodialysis patients with chronic HCV infection, and (2) the frequency of YMDD variants (tyrosine-methionine-aspartate-aspartate amino acid motif of HBV polymerase) in this setting. METHODS: Thirty-three anti-HCV and HCV-RNA-positive, HBsAg-negative hemodialysis patients (mean age 36.9+/-10.4 years, 22 male) were admitted to this study. HBV-DNA (Innogenetics kit) and HCV-RNA (Cobas Amplicor HCV kit) were investigated by polymerase chain reaction technique (PCR). YMDD mutation was studied in all HBV-DNA-positive patients by the BOOM method. RESULTS: HBV-DNA was detected in 12 of 33 patients (36.4%) by PCR. Their mean age was 33.0+/-9.0 years. Age, dialysis period (years) and biochemical parameters were not significantly different in patients with and without occult HBV infection. YMDD variants were identified in six of 12 (50%) patients with occult HBV infection. CONCLUSIONS: Occult HBV infection is frequent in hemodialysis patients with chronic HCV infection. YMDD variants are common in this setting.