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1.
Liver Int ; 39(4): 628-632, 2019 04.
Article in English | MEDLINE | ID: mdl-30690862

ABSTRACT

BACKGROUND & AIMS: Hepatitis C virus (HCV)-related mixed cryoglobulinaemia vasculitis (MCV) is characterized by the expansion of rheumatoid factor-producing B-cell clones. The aim of this study was to assess whether B-cell clones may persist in these patients after the clearance of the virus with antiviral therapy, and whether their persistence influences clinical outcomes. METHODS: Forty-five HCV-cured MCV patients were followed up for a median of 18.5 (range 9-38) months after the clearance of HCV. Circulating B-cell clones were detected using flow cytometry either by the skewing of kappa/lambda ratio or by the expression of a VH 1-69-encoded idiotype. RESULTS: The clinical response of vasculitis was 78% complete, 18% partial and 4% null. However, cryoglobulins remained detectable in 42% of patients for more than 12 months. Circulating B-cell clones were detected in 18 of 45 patients, and in 17 of them persisted through the follow-up; nine of the latter patients cleared cryoglobulins and had complete response of vasculitis. Several months later, two of these patients had relapse of MCV. CONCLUSIONS: B-cell clones persist in MCV patients long after HCV infection has been cleared but halt the production of pathogenic antibody. These 'dormant' cells may be reactivated by events that perturb B-cell homeostasis and can give rise to the relapse of cryoglobulinaemic vasculitis.


Subject(s)
B-Lymphocytes/immunology , Cryoglobulinemia/immunology , Hepatitis C/complications , Vasculitis/immunology , Adult , Aged , Aged, 80 and over , Antiviral Agents/therapeutic use , Clone Cells/immunology , Cryoglobulinemia/virology , Female , Flow Cytometry , Hepatitis C/drug therapy , Humans , Male , Middle Aged , Vasculitis/virology
2.
Int J Infect Dis ; 138: 1-9, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37944585

ABSTRACT

OBJECTIVES: Here we investigate Hepatitis D virus (HDV)-prevalence in Italy and its fluctuations over time and we provide an extensive characterization of HDV-infected patients. METHODS: The rate of HDV seroprevalence and HDV chronicity was assessed in 1579 hepatitis B surface antigen (HBsAg)+ patients collected from 2005 to 2022 in Central Italy. RESULTS: In total, 45.3% of HBsAg+ patients received HDV screening with an increasing temporal trend: 15.6% (2005-2010), 45.0% (2011-2014), 49.4% (2015-2018), 71.8% (2019-2022). By multivariable model, factors correlated with the lack of HDV screening were alanine-aminotransferase (ALT) less than two times of upper limit of normality (<2ULN) and previous time windows (P <0.002). Furthermore, 13.4% of HDV-screened patients resulted anti-HDV+ with a stable temporal trend. Among them, 80.8% had detectable HDV-ribonucleic acid (RNA) (median [IQR]:4.6 [3.6-5.6] log copies/ml) with altered ALT in 89.3% (median [IQR]:92 [62-177] U/L). Anti-HDV+ patients from Eastern/South-eastern Europe were younger than Italians (44 [37-54] vs 53 [47-62] years, P <0.0001), less frequently nucleos(t)ide analogs (NUC)-treated (58.5% vs 80%, P = 0.026) with higher HDV-RNA (4.8 [3.6-5.8] vs 3.9 [1.4-4.9] log copies/ml, P = 0.016) and HBsAg (9461 [4159-24,532] vs 4447 [737-13,336] IU/ml, P = 0.032). Phylogenetic analysis revealed the circulation of HDV subgenotype 1e (47.4%) and -1c (52.6%). Notably, subgenotype 1e correlated with higher ALT than 1c (168 [89-190] vs 58 [54-88] U/l, P = 0.015) despite comparable HDV-RNA. CONCLUSIONS: HDV-screening awareness is increasing over time even if some gaps persist to achieve HDV screening in all HBsAg+ patients. HDV prevalence in tertiary care centers tend to scarcely decline in native/non-native patients. Detection of subgenotypes, triggering variable inflammatory stimuli, supports the need to expand HDV molecular characterization.


Subject(s)
Hepatitis D , Hepatitis Delta Virus , Humans , Hepatitis B Surface Antigens/genetics , Hepatitis B virus , Hepatitis D/diagnosis , Hepatitis D/epidemiology , Hepatitis Delta Virus/genetics , Italy/epidemiology , Phylogeny , Prevalence , RNA , Seroepidemiologic Studies , Virus Replication , Adult , Middle Aged
3.
J Gen Virol ; 94(Pt 1): 143-149, 2013 Jan.
Article in English | MEDLINE | ID: mdl-23052389

ABSTRACT

How the overlap between the hepatitis B virus (HBV) reverse transcriptase (RT) and HBV S antigen (HBsAg) genes modulates the extent of HBV genetic variability is still an open question, and was investigated here. The rate of nucleotide conservation (≤1% variability) followed an atypical pattern in the RT gene, due to an overlap between RT and HBsAg (69.9% nucleotide conservation in the overlapping region vs 41.2% in the non-overlapping region; P<0.001), with a consequently lower rate of synonymous substitution within the overlapping region [median(interquartile range)dS=3.1(1.5-7.4) vs 20.1(10.6-30.0); P=3.249×10(-22)]. The most conserved RT regions were located within the YMDD motif and the N-terminal parts of the palm and finger domains, critical for RT functionality. These regions also corresponded to highly conserved HBsAg domains that are critical for HBsAg secretion. Conversely, the genomic region encoding the HBsAg antigenic loop (where immune-escape mutations are localized) showed a sharp decrease in the extent of conservation (40.6%), which was less pronounced in the setting of human immunodeficiency virus (HIV)-driven immune suppression (48.8% in HIV-HBV co-infection vs 21.5% in mono-infected patients; P=0.020). In conclusion, the overlapping reading frame and the immune system appear to have shaped the patterns of RT and HBsAg genetic variability. Highly conserved regions in RT and HBsAg may deserve further attention as novel therapeutic targets.


Subject(s)
Genome, Viral , Hepatitis B virus/genetics , Hepatitis B virus/immunology , Hepatitis B, Chronic/genetics , Hepatitis B, Chronic/immunology , Amino Acid Sequence , Base Sequence , Coinfection/genetics , Coinfection/immunology , Evolution, Molecular , Genetic Variation , HIV/genetics , HIV/immunology , HIV Infections/genetics , HIV Infections/immunology , HIV Infections/virology , Hepatitis B Surface Antigens/genetics , Hepatitis B Surface Antigens/immunology , Hepatitis B, Chronic/virology , Humans , Molecular Sequence Data , Mutation/immunology , RNA-Directed DNA Polymerase/genetics , RNA-Directed DNA Polymerase/immunology
4.
Cancers (Basel) ; 14(18)2022 Sep 12.
Article in English | MEDLINE | ID: mdl-36139581

ABSTRACT

Hepatocellular carcinoma (HCC) usually develops in cirrhotic liver, with high recurrence rates. However, considering its increasing detection in non-cirrhotic liver, the choice of treatment assumes particular relevance. This study aimed to investigate outcomes of patients among BCLC stages and enrolled for surgical resection (SR) according to a more complex evaluation, to establish its safety and efficacy. A total of 186 selected HCC patients (median age 73.2 yrs), submitted to SR between January 2005 and January 2021, were retrospectively analyzed. Of which, 166 were staged 0, A, B according to the BCLC system, while 20 with a single large tumor (>5 cm) were classified as stage AB. No perioperative mortality was recorded; complications occurred in 48 (25.80%) patients, and all but two were Clavien−Dindo grade I−II. Median follow-up was 9.2 years. Subsequently, 162 recurrent patients (87,1%) were selected for new treatments. Comparable overall survival rates (OS) were observed at 1, 3, 5, and 10 years in 0, A, B and AB stages (p = 0.2). Eventually, the BCLC-B group was matched to 40 BCLC-B patients treated (2015-2021) with TACE. Significant differences in baseline characteristics (p <0.0001) and in OS were observed at 1 and 3 years (p <0.0001); a significant difference was also observed in oncological outcomes, in terms of the absence, residual, or relapse of disease (p <0.05). Surgery might be a valid treatment in HCC for patients affected by chronic liver disease in a condition of compensation, up to BCLC-B stage. Surgical indication for liver resection in case of HCC should be extensively revised.

5.
Cancers (Basel) ; 13(12)2021 Jun 17.
Article in English | MEDLINE | ID: mdl-34204186

ABSTRACT

Hepatocellular carcinoma (HCC) accounts for 75-85% of primary liver malignancies, and elderlies have the highest incidence rates. Direct-acting antiviral agents (DAAs) have shown satisfying results in terms of HCV sustained viral response (SVR). However, data regarding HCC risk post-DAA-SVR is still conflicting. This study aims to consider HCC onset in moderate underlying liver disease. We conducted a retrospective study on 227 chronically infected patients (cHCV), treated with DAAs. Patients were divided into three groups: "de novo occurrent HCC", "recurrent HCC", and "without HCC". Fifty-six patients aged <65 years (yDAA) were studied separately. HCC patients aged ≥65 years (DAA-HCC) were compared to a historical group of 100 elderly HCC patients, treated with peginterferon (Peg-IFN) ± ribavirin antiviral agents, non-SVR (hHCC). The HCC prevalence in DAA patients was 32.75%: "de novo occurrent'' 18.13% and "recurrent'' 14.62%, despite 42.85% of them having no fibrosis to mild or moderate fibrosis (F0-F1-F2). yDAA showed 5.36% "de novo occurrent" HCC. Curative procedure rates were compared between DAA-HCC and hHCC at the first and at recurrent presentation (22 (39.29%) vs. 72 (72%); 17 (30.36%) vs. 70 (70%), respectively (p < 0.001)). No significant difference was found in 3-year OS (p = 0.6). However, in cause-specific mortality analysis, HCC-related death was higher in the DAA-treated group, whereas cirrhosis-related death was more common in the historical group (p = 0.0288), considering together the two causes of death. A more accurate patient stratification according to multifactorial and new diagnostic investigations identifying HCC risk might allow an improvement in management and access to curative therapies.

6.
Emerg Microbes Infect ; 9(1): 928-939, 2020 Dec.
Article in English | MEDLINE | ID: mdl-32312174

ABSTRACT

Increasing evidences suggest that HBsAg-production varies across HBV-genotypes. HBsAg C-terminus plays a crucial role for HBsAg-secretion. Here, we evaluate HBsAg-levels in different HBV-genotypes in HBeAg-negative chronic infection, the correlation of specific mutations in HBsAg C-terminus with HBsAg-levels in-vivo, their impact on HBsAg-secretion in-vitro and on structural stability in-silico.HBsAg-levels were investigated in 323 drug-naïve HBeAg-negative patients chronically infected with HBV genotype-D(N = 228), -A(N = 65) and -E(N = 30). Genotype-D was characterized by HBsAg-levels lower than genotype-A and -E (3.3[2.7-3.8]IU/ml; 3.8[3.5-4.2]IU/ml and 3.9[3.7-4.2]IU/ml, P < 0.001). Results confirmed by multivariable analysis correcting for patients'demographics, HBV-DNA, ALT and infection-status.In genotype-D, specific C-terminus mutations (V190A-S204N-Y206C-Y206F-S210N) significantly correlate with HBsAg<1000IU/ml(P-value from <0.001 to 0.04). These mutations lie in divergent pathways involving other HBsAg C-terminus mutations: V190A + F220L (Phi = 0.41, P = 0.003), S204N + L205P (Phi = 0.36, P = 0.005), Y206F + S210R (Phi = 0.47, P < 0.001) and S210N + F220L (Phi = 0.40, P = 0.006). Notably, patients with these mutational pairs present HBsAg-levels 1log lower than patients without them(P-value from 0.003 to 0.02). In-vitro, the above-mentioned mutational pairs determined a significant decrease in HBsAg secretion-efficiency compared to wt(P-value from <0.001 to 0.02). Structurally, these mutational pairs reduced HBsAg C-terminus stability and determined a rearrangement of this domain.In conclusion, HBsAg-levels in genotype-D are significantly lower than in genotype-A and -E in HBeAg-negative patients. In genotype-D, specific mutational clusters in HBsAg C-terminus correlate with lower HBsAg-levels in-vivo, hamper HBsAg-release in-vitro and affect its structural stability, supporting their detrimental role on HBsAg-secretion. In this light, genotypic-testing can be a valuable tool to optimize the clinical interpretation of HBsAg in genotype-D and to provide information on HBV-pathogenicity and disease-progression.


Subject(s)
Hepatitis B Surface Antigens/analysis , Hepatitis B virus , Hepatitis B, Chronic/diagnosis , Adult , Female , Genotype , Hepatitis B Surface Antigens/genetics , Hepatitis B virus/genetics , Hepatitis B virus/pathogenicity , Humans , Male , Middle Aged , Mutation
7.
J Hepatol ; 50(3): 461-70, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19041149

ABSTRACT

BACKGROUND/AIMS: To investigate the different clusters of mutations associated with lamivudine resistance in HBV genotypes D and A. METHODS: HBV reverse transcriptase sequences of 89 HBV-infected patients failing lamivudine treatment were analyzed. The association of mutations with HBV genotypes was assessed by Chi-Squared test and multivariate logistic regression analysis. Covariate analysis was based on hierarchical clustering. RESULTS: In genotype A, the rtM204V (prevalence: 68.2%) was the main sign of lamivudine failure. Multivariate analysis confirmed that genotype A is the only predictor for rtM204V emergence (OR: 14.5 [95% CI: 1.3-158], P=0.02). Covariate analysis showed that rtM204V clusters with rtL180M, rtL229V (corresponding to sF220L in the HBsAg), and, interestingly, with HBsAg mutation sS207N (bootstrap=0.95). Both sF220L and sS207N co-localized in the fourth transmembrane HBsAg domain. In contrast, in genotype D the primary mutations rtM204V and rtM204I occurred with similar prevalence (39.1% versus 45.3%, P=0.47), and showed a distinct pattern of compensatory mutations. rtM204V clusters with mutations localized in the RT-B domain (rtV173L, rtL180M, and rtT184A/S) (bootstrap=0.94), while rtM204I clusters with mutations localized in the RT-A domain (rtS53N, rtT54Y, and rtL80I/V) (bootstrap=0.96) (without associations with HBsAg specific mutations). CONCLUSIONS: HBV genotype plays an important role in driving RT evolution under lamivudine treatment, and thus can be relevant for therapeutic sequencing, immunological response and disease progression.


Subject(s)
Hepatitis B virus/genetics , Hepatitis B, Chronic/drug therapy , Lamivudine/therapeutic use , Adult , Alanine Transaminase/blood , Amino Acid Substitution , Antiviral Agents/therapeutic use , Aspartate Aminotransferases/blood , Cluster Analysis , DNA Primers , DNA, Viral/genetics , DNA, Viral/isolation & purification , Drug Resistance, Viral/drug effects , Drug Resistance, Viral/genetics , Genotype , HIV Infections/complications , Hepatitis B virus/drug effects , Hepatitis B virus/enzymology , Hepatitis B, Chronic/complications , Hepatitis B, Chronic/genetics , Humans , Middle Aged , Polymerase Chain Reaction , RNA-Directed DNA Polymerase/genetics
8.
Viruses ; 10(7)2018 07 09.
Article in English | MEDLINE | ID: mdl-29987240

ABSTRACT

Chronic HBV + HDV infection is associated with greater risk of liver fibrosis, earlier hepatic decompensation, and liver cirrhosis hepatocellular carcinoma compared to HBV mono-infection. However, to-date no direct anti-HDV drugs are available in clinical practice. Here, we identified conserved and variable regions in HBsAg and HDAg domains in HBV + HDV infection, a critical finding for the design of innovative therapeutic agents. The extent of amino-acid variability was measured by Shannon-Entropy (Sn) in HBsAg genotype-d sequences from 31 HBV + HDV infected and 62 HBV mono-infected patients (comparable for demographics and virological-parameters), and in 47 HDAg genotype-1 sequences. Positions with Sn = 0 were defined as conserved. The percentage of conserved HBsAg-positions was significantly higher in HBV + HDV infection than HBV mono-infection (p = 0.001). Results were confirmed after stratification for HBeAg-status and patients' age. A Sn = 0 at specific positions in the C-terminus HBsAg were correlated with higher HDV-RNA, suggesting that conservation of these positions can preserve HDV-fitness. Conversely, HDAg was characterized by a lower percentage of conserved-residues than HBsAg (p < 0.001), indicating higher functional plasticity. Furthermore, specific HDAg-mutations were significantly correlated with higher HDV-RNA, suggesting a role in conferring HDV replicative-advantage. Among HDAg-domains, only the virus-assembly signal exhibited a high genetic conservation (75% of conserved-residues). In conclusion, HDV can constrain HBsAg genetic evolution to preserve its fitness. The identification of conserved regions in HDAg poses the basis for designing innovative targets against HDV-infection.


Subject(s)
Evolution, Molecular , Hepatitis B Surface Antigens/genetics , Hepatitis B virus/genetics , Hepatitis B/virology , Hepatitis Delta Virus/physiology , Microbial Interactions , Adult , Antiviral Agents/pharmacology , Coinfection , Female , Genetic Variation , Genotype , Hepatitis B/diagnosis , Hepatitis B Surface Antigens/chemistry , Hepatitis B virus/drug effects , Humans , Male , Middle Aged , Models, Molecular , Mutation , Phylogeny , Protein Conformation , RNA, Viral , Viral Proteins/chemistry , Viral Proteins/genetics , Viral Proteins/metabolism
9.
Clin Rheumatol ; 36(3): 617-623, 2017 Mar.
Article in English | MEDLINE | ID: mdl-28111716

ABSTRACT

This study aims to evaluate the efficacy and safety of repeated treatments with low-dose rituximab for relapsing mixed cryoglobulinemia vasculitis. Thirty-seven patients with mixed cryoglobulinemia vasculitis refractory to standard of care treatment, 34 of which were HCV-positive, were treated with rituximab at the reduced dosage of 250 mg/m2 given twice 1 week apart per cycle. Thirty patients (81%) achieved a clinical response; 5 of them remain in remission, 3 were lost to follow-up or died, and 22 relapsed after a mean of 15.7 months. Eleven relapsers were retreated with one (6 patients), 2 (3 patients), or 3 (2 patients) additional rituximab cycles given at each relapse. Clinical and laboratory efficacy and side effects of long-term treatment were evaluated. Clinical response to retreatment was 91% (10/11) at the first relapse, 80% (4/5) at the second relapse, and 100% (2/2) at the third relapse. The mean (±SD) time to relapse was 17.1 ± 14.1 months in 30 patients who were treated with only one cycle (from first cycle to the first relapse) and 45.7 ± 30.6 months (from first cycle to the last observed relapse) in 11 patients treated with 2 or more cycles (p = 0.0037). Severe adverse reactions occurred in 3 patients, in 2 of whom at the first cycle. Our results suggest that repeated treatment of relapsing mixed cryoglobulinemia with a low-dose rituximab regimen is efficacious, safe, and cost-effective for the long-term management of this disorder.


Subject(s)
Cryoglobulinemia/drug therapy , Immunologic Factors/therapeutic use , Rituximab/therapeutic use , Vasculitis/drug therapy , Adult , Aged , Aged, 80 and over , Female , Follow-Up Studies , Humans , Immunologic Factors/adverse effects , Male , Middle Aged , Recurrence , Retreatment , Rituximab/adverse effects , Treatment Outcome
10.
J Infect ; 70(3): 288-98, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25452041

ABSTRACT

BACKGROUND: To define HBsAg-mutations correlated with different serum HBV-DNA levels in HBV chronically-infected drug-naive patients. METHODS: This study included 187 patients stratified into the following ranges of serum HBV-DNA:12-2000 IU/ml, 2000-100,000 IU/ml, and >100,000 IU/ml. HBsAg-mutations were associated with HBV-DNA levels by applying a Bayesian-Partitional-Model and Fisher-exact test. Mutant and wild-type HBV genotype-D genomes were expressed in Huh7 cells and HBsAg-production was determined in cell-supernatants at 3 days-post-transfection. RESULTS: Specific HBsAg-mutations (M197T,-S204N-Y206C/H-F220L) were significantly correlated with serum HBV-DNA <2000 IU/ml (posterior-probability>90%, P < 0.05). The presence of Y206C/H and/or F220L was also associated with lower median (IQR) HBsAg-levels and lower median (IQR) transaminases (for HBsAg:250[115-840] IU/ml for Y206C/H and/or F220L versus 4300[640-11,838] IU/ml for wild-type, P = 0.023; for ALT:28[21-40] IU/ml versus 53[34-90] IU/ml, P < 0.001). These mutations were localized in the HBsAg C-terminus, known to be involved in virion and/or HBsAg secretion. The co-occurrence of Y206C + F220L was found significant by cluster-analysis, (P = 0.02). In addition, in an in-vitro model Y206C + F220L determined a 2.8-3.3 fold-reduction of HBsAg-amount released in supernatants compared to single mutants and wt (Y206C + F220L = 5,679 IU/ml; Y206H = 16,305 IU/ml; F220L = 18,368 IU/ml; Y206C = 18,680 IU/ml; wt = 14,280 IU/ml, P < 0.05). CONCLUSIONS: Specific HBsAg-mutations (compartmentalized in the HBsAg C-terminus) correlated with low-serum HBV-DNA and HBsAg-levels. These findings can be important to understand mechanisms underlying low HBV replicative potential including the inactive-carrier state.


Subject(s)
DNA, Viral/blood , Hepatitis B Surface Antigens/genetics , Hepatitis B virus/genetics , Hepatitis B, Chronic/virology , Adult , Bayes Theorem , Carrier State/virology , Female , Genotype , Hepatitis B Surface Antigens/blood , Hepatitis B Surface Antigens/chemistry , Humans , Male , Middle Aged , Models, Molecular , Molecular Sequence Data , Mutagenesis, Site-Directed , Mutation , Transaminases/blood
11.
Ann Ital Chir ; 85(2): 120-8, 2014.
Article in English | MEDLINE | ID: mdl-23603490

ABSTRACT

AIM: Health-status of elderly patients with hepatocellular carcinoma (HCC) may limit surgical approach; other options are thus auspicable. METHODS: The authors reviewed 98 selected patients, aged 65 to 90 years, with 149 HCC treated between 2002 and 2011. According to the extent of malignancy, health status and treatment, patients were divided into 3 groups. Sixty-one, submitted to major and minor curative resections, were in group A and B while group C included 37 patients, unsuitable for high-risk procedures and percutaneous ablation, submitted to intraoperative-radiofrequency ablation (IRFA) alone or combined with minor resections. Assessment of safety and therapeutic efficacy of this managment was evaluated. RESULTS: A postoperative mortality rate of 1,02% and an overall survival rate at 5 years of 62.3% were observed. Indeeed matched post-operative morbidity and mortality rates of A, B, C groups were 45%, 8%, 16.21% (p < 0.004) and 9 %, 0%, 0% (p= 0.112 ) respectively. 3 years overall-survival was not statistically different (p= 0.585). However 5 years survival rate and disease-free-survival rate were significantly higher in patients of group A and B (p= 0.003; p< 0.001). CONCLUSION: Treatment strategies to minimize treatment-related morbidity and mortality have resulted satisfactory for early and late outcomes of an heterogeneous group of elderly patients with HCC.


Subject(s)
Carcinoma, Hepatocellular/surgery , Hepatectomy/methods , Liver Neoplasms/surgery , Aftercare , Aged , Aged, 80 and over , Carcinoma, Hepatocellular/mortality , Comorbidity , Diagnostic Imaging , Disease Management , Disease-Free Survival , Humans , Kaplan-Meier Estimate , Liver Neoplasms/mortality , Male , Neoplasm Recurrence, Local/diagnosis , Neoplasm Recurrence, Local/epidemiology , Patient Selection , Postoperative Complications/epidemiology , Postoperative Complications/prevention & control , Retrospective Studies , Survival Rate , Treatment Outcome
12.
J Infect ; 67(4): 303-12, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23796863

ABSTRACT

INTRODUCTION: The identification of novel reverse-transcriptase (RT) drug-resistance mutations is critical in predicting the probability of success to anti-HBV treatment. Furthermore, due to HBV-RT/HBsAg gene-overlap, they can have an impact on HBsAg-detection and quantification. METHODS: 356 full-length HBV-RT sequences from 197 drug-naive patients and 159 patients experiencing virological-breakthrough to nucleoside/nucleotide-analogs (NUCs) were analyzed. Mutants and wild-type HBs-antigens were expressed in HuH7-hepatocytes and quantified in cell-supernatants and cell-lysates by Architect HBsAg-assay. RESULTS: Ten novel RT-mutations (rtN53T-rtS78T-rtS85F-rtS135T-rtA181I-rtA200V-rtK212Q-rtL229V/F-rtM309K) correlated with specific NUC-treatments and classical drug-resistance mutations on divergent evolutionary pathways. Some of them reduced RT-binding affinity for anti-HBV drugs and altered S-antigen structure. Indeed, rtS78T (prevalence: 1.1% in drug-naïve and 12.2% in adefovir-failing patients) decreased the RT-affinity for adefovir more than the classical adefovir-resistance mutations rtA181 T/V (WT:-9.63 kcal/mol, rtA181T:-9.30 kcal/mol, rtA181V:-7.96 kcal/mol, rtS78T:-7.37 kcal/mol). Moreover, rtS78T introduced a stop-codon at HBsAg-position 69, and completely abrogated HBsAg-quantification in both supernatants and cell-lysates, indicating an impaired HBsAg-secretion/production. Furthermore, the HBsAg-mutation sP217L, silent in RT, significantly correlated with M204V/I-related virological-breakthrough and increased HBsAg-quantification in cell-lysate. CONCLUSIONS: Mutations beyond those classically known can affect drug-binding affinity of mutated HBV-RT, and may have potential effects on HBsAg. Their cumulative effect on resistance and HBV-pathogenicity indicates the importance of preventing therapeutic failures.


Subject(s)
Hepatitis B Surface Antigens/analysis , Hepatitis B virus/drug effects , Hepatitis B/drug therapy , Mutation , RNA-Directed DNA Polymerase/genetics , Reverse Transcriptase Inhibitors/administration & dosage , Adenine/administration & dosage , Adenine/analogs & derivatives , Adenine/pharmacology , Adult , Cell Line , Codon, Nonsense , Drug Resistance, Viral , Female , Gene Expression , Hepatitis B Surface Antigens/genetics , Hepatocytes/virology , Humans , Male , Middle Aged , Organophosphonates/administration & dosage , Organophosphonates/pharmacology , Protein Binding , RNA-Directed DNA Polymerase/metabolism , Reverse Transcriptase Inhibitors/metabolism , Reverse Transcriptase Inhibitors/pharmacology , Selection, Genetic , Treatment Failure
13.
Dig Liver Dis ; 43(12): 975-83, 2011 Dec.
Article in English | MEDLINE | ID: mdl-21831732

ABSTRACT

BACKGROUND: Impact of hepatitis B virus genetic barrier, defined as the number and type of nucleotide substitutions required to overcome drug/immune selective pressure, on drug-resistance/immune-escape development is unknown. METHODS: Genetic barrier was calculated according to Van de Vijver (2006) in 3482 hepatitis B virus-reverse transcriptase/HBV surface antigen sequences from 555 drug-naïve patients and 2927 antiviral-treated patients infected with hepatitis B virus genotypes A-G. RESULTS: Despite high natural variability, genetic barrier for drug-resistance development is identical amongst hepatitis B virus genotypes, but varies according to drug-resistance mutation type. Highest genetic barrier is found for secondary/compensatory mutations (e.g. rtL80I/V-rtL180M-rtV173L), whilst most primary mutations (including rtM204V-rtA181T/V-rtI169T-rtA194T) are associated with low genetic barrier. An exception is rtM204I, which can derive from a transition or a transversion. Genotypes A and G are more prone to develop immune/diagnostic-escape mutations sT114R and sG130N. Vaccine-escape associated sT131N-mutation is a natural polymorphism in both A and G genotypes. CONCLUSION: Genetic barrier and reverse transcriptase/HBV surface antigen overlapping can synergistically influence hepatitis B virus drug-resistance/immune-escape development. The different immune-escape potential of specific hepatitis B virus genotypes could have important clinical consequences in terms of disease progression, vaccine strategies and correct HBV surface antigen detection.


Subject(s)
Drug Resistance, Viral/genetics , Genotype , Hepatitis B Surface Antigens/genetics , Hepatitis B virus/genetics , Hepatitis B virus/immunology , RNA-Directed DNA Polymerase/genetics , Amino Acids/genetics , Codon/genetics , Hepatitis B/drug therapy , Hepatitis B/immunology , Humans , Mutation , Polymorphism, Genetic , Statistics, Nonparametric , Treatment Failure
14.
Dig Liver Dis ; 42(12): 902-7, 2010 Dec.
Article in English | MEDLINE | ID: mdl-20621632

ABSTRACT

OBJECTIVE: To investigate lamivudine (LAM)-resistance profiles of hepatitis B virus (HBV) at the early stages of virological breakthrough (serum HBV-DNA 12-345IU/ml) or when HBV-DNA is undetectable. METHODS: Sixty-four HBV-mono-infected patients were enrolled: 25 had virological breakthrough with serum HBV-DNA ranging from 12 to 345IU/ml during first-line LAM-monotherapy; 24 were on LAM-monotherapy, and 15 were on LAM+adefovir dipivoxil (ADV) with undetectable serum HBV-DNA (<12IU/ml). RESULTS: HBV-reverse transcriptase was successfully sequenced in 22 (88.0%) LAM-treated patients with HBV-DNA between 12 and 345IU/ml, and in 12 (30.8%) patients receiving LAM (±ADV) with HBV-DNA<12IU/ml. Drug-resistance mutations were observed in 17 (77.2%) LAM-treated patients with virological breakthrough: 8 M204V, 7 M204I, 1 M204I/V, and 1 A181T. One or ≥2 compensatory mutations were found in 10 (58.8%) and in 4 (23.5%) patients. Drug-resistance mutations were present also in patients with undetectable serum HBV-DNA: M204I was detected in 2 patients receiving LAM-monotherapy, and V84M in 1 patient receiving LAM+ADV. CONCLUSION: Overall findings support the existence of drug-resistance mutations even at very low levels of viral replication. The persistence of low-level HBV replication and consequent drug-resistance emergence should be considered when choosing therapeutic strategies.


Subject(s)
Antiviral Agents/pharmacology , Drug Resistance, Viral/genetics , Hepatitis B virus/genetics , Hepatitis B, Chronic/drug therapy , Lamivudine/pharmacology , Adenine/analogs & derivatives , Adenine/pharmacology , Adult , Aged , DNA, Viral , Female , Humans , Male , Middle Aged , Mutation , Organophosphonates/pharmacology , Viral Load , Viremia
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