- Email: [email protected]
556 ROLE OF IL-10-PRODUCING REGULATORY B CELLS IN THE PATHOGENESIS OF CHRONIC HBV INFECTION
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POSTERS
Conclusions: The distribution of SOCS-1 in the liver tissue of CHB is variable. This expression was correlated with the inflammation grade and fibrosis stage. 554 EX-VIVO RECOMBINANT INTERLEUKIN-2 (IL-2) IMPROVES MATURATION AND FUNCTION OF HBVSPECIFIC EFFECTOR T CELLS IN PATIENTS WITH CHRONIC HEPATITIS B C. Lawlor, M.S. Longhi, S. Bansal, F. Meda, M. Mytilinaiou, G. MieliVergani, D. Vergani, I. Carey. King’s College London School of Medicine at King’s College Hospital, Institute of Liver Studies, Denmark Hill Campus, London, UK E-mail: [email protected] Inefficient viral control in chronic hepatitis B (CH-B) may derive from impaired memory/effector CD8 T-cell maturation caused by inadequate release of pro-inflammatory cytokines by HBV-specific T helper-1 cells. High expression of programmed cell death (PD-1) receptor characterises a CD8 T-cell immature and suppressive phenotype. Aims: To determine the effect of recombinant IL-2 on the maturation and function of HBV-specific CD8 T-cells in different stages of CH-B. Patients: 21 HLA-A2+ve children (9 males, median age 13.4 years) were divided into 3 groups according to HBeAg/HBsAg status and aminotransferase activity. Group A: HBeAg+/HBsAg+/ALT normal, n = 7; Group B: HBeAg+/HBsAg+/ALT elevated, n = 7; Group C: HBeAg-/HBsAg+/ALT normal, n = 7. Three HCV infected children (2 males, median age 12.8 years) and 3 healthy individuals (1 male, median age 31.5years) served as controls. Methods: Peripheral blood mononuclear cells (PBMC) were incubated in the presence/absence of recombinant HLA-A2 restricted immunodominant HBV-core18−27 peptide, IL-2 (15 IU and 90 IU) and antibody against IL-2. Phenotype of pentamer positive HLA-A2 HBV-core18−27 CD8 T-cells was determined by flow-cytometry using anti-CD62L, -CD127 (maturation phenotype) and anti-CD107a, -PD-1 (functional phenotype) antibodies. HBV-specific CD8 T-cell effector function was evaluated by Elispot and intracellular IFN-gamma/granzyme B staining. Results: Compared to unstimulated PBMC, IL-2 stimulation in groups A, B and C induced: (1) increase of mature/effector (= lower CD62L and higher CD127 expression) HBV-core18−27-specific CD8 T cells, CD62L being 57%, 45% and 46% vs 68%, 73% and 66% (p = 0.049, 0.012 and 0.025) and CD127 being 56%, 62% and 70% vs 47%, 53% and 55% (p = 0.12, 0.11 and 0.06); (2) increased HBV-core18−27-specific production of IFN-gamma (50%, 56% and 48% vs 36%, 40% and 38%, p = 0.02, 0.04 and 0.06); (3) no increased granzyme B expression; (4) decreased PD-1 expression on HBV-core18−27-specific CTL (51%, 57% and 58% vs 73%, 69% and 69%, p = 0.024, 0.045 and 0.06). Conclusions: In patients with CH-B, IL-2 stimulation drives HBV-specific CD8 T-cells from an “exhausted” to a mature/effector phenotype, with increased anti-viral cytokine production (IFN-g), but unchanged granzyme B expression. IL-2 stimulation may be considered in the treatment of immunotolerant CH-B patients. 555 EFFICIENT CONTROL OF HEPATITIS B VIRUS REPLICATION IS LINKED WITH STRONG HBV-SPECIFIC IMMUNE REACTIVITY AND LOW NUMBER OF MUTATIONS IN HBV CORE GENE IMMUNODOMINANT EPITOPES I. Carey, M. Mytilinaiou, S. Bansal, F. Meda, M.S. Longhi, D. Cebecauerova, G. Mieli-Vergani, D. Vergani. King’s College London School of Medicine at King’s College Hospital, Institute of Liver Studies, Denmark Hill Campus, London, UK E-mail: [email protected] Background: The outcome of hepatitis B virus (HBV) infection depends on the interaction between virus and host immune response. While ef-
fective immune recognition controls viral replication, escape mutations may arise from the immune system selective pressure, with consequent persistent infection. Aim: To investigate whether there is a relationship between presence of mutations within HBV core gene immunodominant epitopes and HBVspecific immune responses in five different HBV infection settings. Patients: 100 paediatric patients (median age 13.1 years, 54 males) were divided into 5 groups according to their HBeAg/HBsAg status and aminotransferase activity: immunotolerant = HBeAg+/HBsAg+/normal ALT (n = 46); immunoactive = HBeAg+/HBsAg+/elevated ALT (n = 24); low replication = HBeAg-/HBsAg+/normal ALT (n = 22); HBeAg neg. hepatitis = HBeAg-/HBsAg+/elevated ALT (n = 2); self-limited = HBeAg/HBsAg+/normal ALT (n = 6). Five HCV-infected children (median age 13.4 years, 3 males) and 3 healthy individuals (median age 31.1 years, 1 male) served as negative controls. Methods: The presence of point mutations in serum within HBV precore and core promoter regions and amino acid substitutions within immunodominant epitopes of HBV core gene was analysed by direct sequencing (mutations/patient). HBV-specific T-cell immune responses were determined by interferon (IFN)-gamma Elispot assay after stimulation of peripheral blood mononuclear cells (PBMC) with HBV antigens (HBcAg, HBeAg and HBsAg) (specific spot forming cells/106 PBMC). Results: A higher number of mutations within the HBV pre-core region and HBV core gene were detected in HBeAg negative patients than in those HBeAg positive (pre-core: 4.5±0.2 vs 2.6±0.2, p = 0.001 and core: 5.5±0.4 vs 4.1±0.3, p = 0.04). Patients with self-limited infection had lower number of core gene mutations (2.5±0.6) then chronically infected patients (4.8±0.6) (p = 0.007). HBV-core specific T-cell reactivity was higher in self-limited group (198±8) then in chronically infected patients: immunotolerant (13.4±2.3), immunoactive (46.1±11.9), low replication (23.9±7.2) and HBeAg neg hepatitis (16.7±8.3) groups (p = 0.006). There was an inverse correlation between number of HBV core gene mutations and HBV-core specific reactivity (r = −0.428, p = 0.028). Conclusions: Efficient control of HBV infection is associated with strong HBV-specific T-cell reactivity and low number of HBV core gene mutations. Failure to control HBV replication may be linked to the development of mutations within the immunodominant epitopes of HBV core.
556 ROLE OF IL-10-PRODUCING REGULATORY B CELLS IN THE PATHOGENESIS OF CHRONIC HBV INFECTION A. Das1 , G. Ellis1 , D. Peppa1,2 , M. Brunetta3 , P. Blair4 , C. Mauri4 , M.K. Maini1,2 . 1 Division of Infection and Immunity, UCL, London, 2 Centre for Sexual Health and HIV Research, UCL, London, UK; 3 U.O. Gastroenterologia ed Epatologia, Spediali Reuniti de Santa Chiara, Pisa, Italy; 4 Division of Medicine, UCL, London, UK E-mail: [email protected] Background and Aims: Chronic HBV infection (CHB) is associated with an impaired CD8+ T cell response, both within the virus specific CD8+ and the non-antigen specific compartment. This generalised T cell hyporesponsiveness points to a global suppressive effect by a regulatory factor/population. Recent work in murine chronic viral infections has highlighted the role of Il-10 in preventing disease resolution through its suppressive effects on T cells. Our aim was therefore to investigate whether Il-10 plays a role in suppressing CD8 T cell responses in CHB. Methods: We correlated HBV disease status with serum IL-10 levels measured by ELISA directly ex vivo in cross-sectional and longitudinal cohorts. Intracellular cytokine staining and supernatant ELISAs were used to investigate the cellular source of IL-10. IL-10 blocking mAb were used to investigate the suppression of virus-specific CD8 responses. Results: We found a significant increase in levels of circulating IL-10 in patients with high level HBV infection and liver inflammation compared to healthy HBV carriers and controls (p < 0.0001). Levels of IL-10 also showed a close temporal correlation with fluctuations of viral load and
05A. VIRAL HEPATITIS – A) HEPATITIS B – EXPERIMENTAL ALT during spontaneous flares of CHB. The amount of IL-10 detectable by supernatant ELISA after direct ex vivo stimulation of PBMC was increased in CHB patients with high viral load (p < 0.02) and the majority of this IL-10 was found to come from B cells. IL-10 producing B cells, detectable by intracellular cytokine staining after 4 days CPC expansion of PBMC, were increased in CHB patients with high viral load (p < 0.0001). Transitional B cells (CD24hiCD38hi), the putative regulatory subset, were also increased in patients with high-level CHB (p < 0.0001). Preferential IL-10-mediated suppression of HBV-specific CD8 compared to responses specific for other viruses was demonstrated by IL-10 blocking experiments. Conclusion: Regulatory B cell production of IL-10, induced by active CHB, may suppress T cell function and contribute to viral persistence. 557 PREVALENCE AND MUTATIONAL PATTERN OF OCCULT HEPATITIS B VIRUS ISOLATED FROM LIVER TISSUE OF HIV INFECTED PATIENTS M.S. De Mitri1 , R. Cassini1 , L. Urbinati2 , M. Pavoni2 , C. Biagetti2 , D. Pocaterra2 , L. Calza2 , E. Ferlini1 , M. Bernardi1 , F. Chiodo2 , G. Verucchi2 . 1 Department of Internal Medicine, Cardioangiology, Hepatology; 2 Department of Clinical and Experimental Medicine – Infectious Disease Section; University of Bologna, Bologna, Italy E-mail: [email protected] Background and Aim: The persistence of HBVDNA without detectable serum HBsAg is defined as occult HBV infection. We investigated the true prevalence, the genomic heterogeneity and the mutational pattern of occult HBV in the liver tissue of patients with HIV infection. Methods: The HBV genomes were analysed in the liver of 29 HIV+ patients with chronic hepatitis: 24 were HBsAg−, twenty-two HCVRNA+ and 5 patients were HBsAg+//HCVRNA+. Twenty-one HBsAg− patients were under antiretroviral therapy with Lamivudine in eighteen. The genomic pattern and HBV genotyping of both occult and evident HBV infection was defined by direct sequence analysis of the S, X and PreC/C regions, encompassing the basal core promoter (BCP A1762-G1764) and the unpaired sites within the pregenome encapsidation signal (T1858G1896, T1855-G1899, T1850-G1904), a functional structure involved in HBV replication activity. A comparison of the molecular profiles between occult and evident HBV strains were performed. Results: Ten HBsAg-/HIV+ patients (42%) showed HBVDNA genomes in the liver tissue. HBV genotypes D (60%) and A (40%) were the viral strains prevalent in occult HBV. No significant difference was observed among the patients with or without occult hepatitis and with evident hepatitis in terms of HIV viral load, CD4+ count, ALT/AST values, HCV viremia and genotype, histologic diagnosis, antiretroviral therapy. The HBV genomic analysis showed a low variability in the S, X, and Pre-C/C regions in both occult and evident HBV infection. In particular, in the S and X regions emerged only point mutations, and the Pre-C/C sequence analysis revealed a decreased emergence of the pre-C stop mutant (G1896A) detected in only two cases and a trend to maintain the unpaired sites within the encapsidation structure. The emergence of BCP variant not evolved in any patients. Conclusions: Occult HBV infection occurred often in HIV infected patients and genotypes D and A were the most common infecting strains. The long-term persistence in the liver of HBV DNA strain, characterized by low heterogeneity and absence of genomic divergences between the occult and the evident HBV strains suggests that the occult HBV constitutes a genetically stable virus that silently retain its pathogenic potential.
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558 COST-EFFECTIVENESS SIMULATION ANALYSIS OF TENOFOVIR DISOPROXIL FUMARATE (TENOFOVIR), LAMIVUDINE, ADEFOVIR DIPIVOXIL (ADEFOVIR) AND ENTECAVIR OF HBEAG NEGATIVE (−) PATIENTS WITH CHRONIC HEPATITIS-B (CHB) IN SPAIN B. Deniz1 , M. Buti2 , M. Brosa3 , M.A. Casado5 , M. Rueda4 , F. Everhard4 , R. Esteban2 . 1 United BioSource Corporation, Concord, MA, USA; 2 Department of Hepatology, Hospital Vall D Hebron, Barcelona, Spain; 3 Oblikue Consulting, Barcelona, Spain, 4 Gilead Sciences Incorporated, Foster City, CA, USA; 5 Pharmacoeconomics & Outcomes Research Iberia, Madrid, Spain E-mail: [email protected] Background and Aim: To predict long-term cost and health outcomes of treating CHB in treatment naive, HBeAg(−) patients comparing tenofovir, lamivudine, adefovir and entecavir as 1st line treatments in Spain. Methods: A simulation model was developed to predict disease progression, incidence and cost of CHB-related complications according to HBV-DNA viral suppression achieved with different treatments over time. Patients were assigned levels of viral suppression and risk of developing viral resistance specific to their 1st line treatment. Patients who became resistant to treatment could switch or add-on another treatment. Patients who developed resistance to 1st and 2nd line treatments were assumed to discontinue treatment and disease progression rates assumed no further viral suppression. Three categories of HBV-DNA suppression were considered to predict incidence of complications: full response <300 copies/ml; partial response 300–105 copies/ml; and non-response >105 copies/ml. Complications included compensated cirrhosis (CC), decompensated cirrhosis (DCC) or hepatocellular carcinoma (HCC). Patients who developed DCC or HCC were eligible for liver transplant. Patients remained within simulation model until HBsAg seroconversion or death from either CHBrelated complications or natural causes. Costs of managing CHB and complications reflect clinical practice in Spain. All clinical, epidemiologic inputs were obtained from published literature. Analysis was conducted in 1,000 simulated patients over a 30 year time horizon reflecting the chronicity of CHB. Results: In 1st line, tenofovir is predicted to be more effective and less expensive compared to lamivudine and adefovir. Tenofovir is predicted to provide similar health outcome at lesser medical costs compared to entecavir. Conclusions: When considering a 1st line treatment option in Spain, tenofovir is predicted to be one of the most cost-effective treatments compared to lamivudine, adefovir and entecavir. Outcomes (Discounted at 3%)
Tenofovir
Lamivudine
Adefovir
Entecavir
Quality Adjusted Life Years Life Years Average cost per patient Undetectable HBV DNA at year 1 (<300 copies/mL)
13.65 16.07 €70,589 92%
11.68 14.30 €87,394 59%
12.95 15.42 €95,859 72%
13.58 15.99 €90,549 91%
POSTERS
Conclusions: The distribution of SOCS-1 in the liver tissue of CHB is variable. This expression was correlated with the inflammation grade and fibrosis stage. 554 EX-VIVO RECOMBINANT INTERLEUKIN-2 (IL-2) IMPROVES MATURATION AND FUNCTION OF HBVSPECIFIC EFFECTOR T CELLS IN PATIENTS WITH CHRONIC HEPATITIS B C. Lawlor, M.S. Longhi, S. Bansal, F. Meda, M. Mytilinaiou, G. MieliVergani, D. Vergani, I. Carey. King’s College London School of Medicine at King’s College Hospital, Institute of Liver Studies, Denmark Hill Campus, London, UK E-mail: [email protected] Inefficient viral control in chronic hepatitis B (CH-B) may derive from impaired memory/effector CD8 T-cell maturation caused by inadequate release of pro-inflammatory cytokines by HBV-specific T helper-1 cells. High expression of programmed cell death (PD-1) receptor characterises a CD8 T-cell immature and suppressive phenotype. Aims: To determine the effect of recombinant IL-2 on the maturation and function of HBV-specific CD8 T-cells in different stages of CH-B. Patients: 21 HLA-A2+ve children (9 males, median age 13.4 years) were divided into 3 groups according to HBeAg/HBsAg status and aminotransferase activity. Group A: HBeAg+/HBsAg+/ALT normal, n = 7; Group B: HBeAg+/HBsAg+/ALT elevated, n = 7; Group C: HBeAg-/HBsAg+/ALT normal, n = 7. Three HCV infected children (2 males, median age 12.8 years) and 3 healthy individuals (1 male, median age 31.5years) served as controls. Methods: Peripheral blood mononuclear cells (PBMC) were incubated in the presence/absence of recombinant HLA-A2 restricted immunodominant HBV-core18−27 peptide, IL-2 (15 IU and 90 IU) and antibody against IL-2. Phenotype of pentamer positive HLA-A2 HBV-core18−27 CD8 T-cells was determined by flow-cytometry using anti-CD62L, -CD127 (maturation phenotype) and anti-CD107a, -PD-1 (functional phenotype) antibodies. HBV-specific CD8 T-cell effector function was evaluated by Elispot and intracellular IFN-gamma/granzyme B staining. Results: Compared to unstimulated PBMC, IL-2 stimulation in groups A, B and C induced: (1) increase of mature/effector (= lower CD62L and higher CD127 expression) HBV-core18−27-specific CD8 T cells, CD62L being 57%, 45% and 46% vs 68%, 73% and 66% (p = 0.049, 0.012 and 0.025) and CD127 being 56%, 62% and 70% vs 47%, 53% and 55% (p = 0.12, 0.11 and 0.06); (2) increased HBV-core18−27-specific production of IFN-gamma (50%, 56% and 48% vs 36%, 40% and 38%, p = 0.02, 0.04 and 0.06); (3) no increased granzyme B expression; (4) decreased PD-1 expression on HBV-core18−27-specific CTL (51%, 57% and 58% vs 73%, 69% and 69%, p = 0.024, 0.045 and 0.06). Conclusions: In patients with CH-B, IL-2 stimulation drives HBV-specific CD8 T-cells from an “exhausted” to a mature/effector phenotype, with increased anti-viral cytokine production (IFN-g), but unchanged granzyme B expression. IL-2 stimulation may be considered in the treatment of immunotolerant CH-B patients. 555 EFFICIENT CONTROL OF HEPATITIS B VIRUS REPLICATION IS LINKED WITH STRONG HBV-SPECIFIC IMMUNE REACTIVITY AND LOW NUMBER OF MUTATIONS IN HBV CORE GENE IMMUNODOMINANT EPITOPES I. Carey, M. Mytilinaiou, S. Bansal, F. Meda, M.S. Longhi, D. Cebecauerova, G. Mieli-Vergani, D. Vergani. King’s College London School of Medicine at King’s College Hospital, Institute of Liver Studies, Denmark Hill Campus, London, UK E-mail: [email protected] Background: The outcome of hepatitis B virus (HBV) infection depends on the interaction between virus and host immune response. While ef-
fective immune recognition controls viral replication, escape mutations may arise from the immune system selective pressure, with consequent persistent infection. Aim: To investigate whether there is a relationship between presence of mutations within HBV core gene immunodominant epitopes and HBVspecific immune responses in five different HBV infection settings. Patients: 100 paediatric patients (median age 13.1 years, 54 males) were divided into 5 groups according to their HBeAg/HBsAg status and aminotransferase activity: immunotolerant = HBeAg+/HBsAg+/normal ALT (n = 46); immunoactive = HBeAg+/HBsAg+/elevated ALT (n = 24); low replication = HBeAg-/HBsAg+/normal ALT (n = 22); HBeAg neg. hepatitis = HBeAg-/HBsAg+/elevated ALT (n = 2); self-limited = HBeAg/HBsAg+/normal ALT (n = 6). Five HCV-infected children (median age 13.4 years, 3 males) and 3 healthy individuals (median age 31.1 years, 1 male) served as negative controls. Methods: The presence of point mutations in serum within HBV precore and core promoter regions and amino acid substitutions within immunodominant epitopes of HBV core gene was analysed by direct sequencing (mutations/patient). HBV-specific T-cell immune responses were determined by interferon (IFN)-gamma Elispot assay after stimulation of peripheral blood mononuclear cells (PBMC) with HBV antigens (HBcAg, HBeAg and HBsAg) (specific spot forming cells/106 PBMC). Results: A higher number of mutations within the HBV pre-core region and HBV core gene were detected in HBeAg negative patients than in those HBeAg positive (pre-core: 4.5±0.2 vs 2.6±0.2, p = 0.001 and core: 5.5±0.4 vs 4.1±0.3, p = 0.04). Patients with self-limited infection had lower number of core gene mutations (2.5±0.6) then chronically infected patients (4.8±0.6) (p = 0.007). HBV-core specific T-cell reactivity was higher in self-limited group (198±8) then in chronically infected patients: immunotolerant (13.4±2.3), immunoactive (46.1±11.9), low replication (23.9±7.2) and HBeAg neg hepatitis (16.7±8.3) groups (p = 0.006). There was an inverse correlation between number of HBV core gene mutations and HBV-core specific reactivity (r = −0.428, p = 0.028). Conclusions: Efficient control of HBV infection is associated with strong HBV-specific T-cell reactivity and low number of HBV core gene mutations. Failure to control HBV replication may be linked to the development of mutations within the immunodominant epitopes of HBV core.
556 ROLE OF IL-10-PRODUCING REGULATORY B CELLS IN THE PATHOGENESIS OF CHRONIC HBV INFECTION A. Das1 , G. Ellis1 , D. Peppa1,2 , M. Brunetta3 , P. Blair4 , C. Mauri4 , M.K. Maini1,2 . 1 Division of Infection and Immunity, UCL, London, 2 Centre for Sexual Health and HIV Research, UCL, London, UK; 3 U.O. Gastroenterologia ed Epatologia, Spediali Reuniti de Santa Chiara, Pisa, Italy; 4 Division of Medicine, UCL, London, UK E-mail: [email protected] Background and Aims: Chronic HBV infection (CHB) is associated with an impaired CD8+ T cell response, both within the virus specific CD8+ and the non-antigen specific compartment. This generalised T cell hyporesponsiveness points to a global suppressive effect by a regulatory factor/population. Recent work in murine chronic viral infections has highlighted the role of Il-10 in preventing disease resolution through its suppressive effects on T cells. Our aim was therefore to investigate whether Il-10 plays a role in suppressing CD8 T cell responses in CHB. Methods: We correlated HBV disease status with serum IL-10 levels measured by ELISA directly ex vivo in cross-sectional and longitudinal cohorts. Intracellular cytokine staining and supernatant ELISAs were used to investigate the cellular source of IL-10. IL-10 blocking mAb were used to investigate the suppression of virus-specific CD8 responses. Results: We found a significant increase in levels of circulating IL-10 in patients with high level HBV infection and liver inflammation compared to healthy HBV carriers and controls (p < 0.0001). Levels of IL-10 also showed a close temporal correlation with fluctuations of viral load and
05A. VIRAL HEPATITIS – A) HEPATITIS B – EXPERIMENTAL ALT during spontaneous flares of CHB. The amount of IL-10 detectable by supernatant ELISA after direct ex vivo stimulation of PBMC was increased in CHB patients with high viral load (p < 0.02) and the majority of this IL-10 was found to come from B cells. IL-10 producing B cells, detectable by intracellular cytokine staining after 4 days CPC expansion of PBMC, were increased in CHB patients with high viral load (p < 0.0001). Transitional B cells (CD24hiCD38hi), the putative regulatory subset, were also increased in patients with high-level CHB (p < 0.0001). Preferential IL-10-mediated suppression of HBV-specific CD8 compared to responses specific for other viruses was demonstrated by IL-10 blocking experiments. Conclusion: Regulatory B cell production of IL-10, induced by active CHB, may suppress T cell function and contribute to viral persistence. 557 PREVALENCE AND MUTATIONAL PATTERN OF OCCULT HEPATITIS B VIRUS ISOLATED FROM LIVER TISSUE OF HIV INFECTED PATIENTS M.S. De Mitri1 , R. Cassini1 , L. Urbinati2 , M. Pavoni2 , C. Biagetti2 , D. Pocaterra2 , L. Calza2 , E. Ferlini1 , M. Bernardi1 , F. Chiodo2 , G. Verucchi2 . 1 Department of Internal Medicine, Cardioangiology, Hepatology; 2 Department of Clinical and Experimental Medicine – Infectious Disease Section; University of Bologna, Bologna, Italy E-mail: [email protected] Background and Aim: The persistence of HBVDNA without detectable serum HBsAg is defined as occult HBV infection. We investigated the true prevalence, the genomic heterogeneity and the mutational pattern of occult HBV in the liver tissue of patients with HIV infection. Methods: The HBV genomes were analysed in the liver of 29 HIV+ patients with chronic hepatitis: 24 were HBsAg−, twenty-two HCVRNA+ and 5 patients were HBsAg+//HCVRNA+. Twenty-one HBsAg− patients were under antiretroviral therapy with Lamivudine in eighteen. The genomic pattern and HBV genotyping of both occult and evident HBV infection was defined by direct sequence analysis of the S, X and PreC/C regions, encompassing the basal core promoter (BCP A1762-G1764) and the unpaired sites within the pregenome encapsidation signal (T1858G1896, T1855-G1899, T1850-G1904), a functional structure involved in HBV replication activity. A comparison of the molecular profiles between occult and evident HBV strains were performed. Results: Ten HBsAg-/HIV+ patients (42%) showed HBVDNA genomes in the liver tissue. HBV genotypes D (60%) and A (40%) were the viral strains prevalent in occult HBV. No significant difference was observed among the patients with or without occult hepatitis and with evident hepatitis in terms of HIV viral load, CD4+ count, ALT/AST values, HCV viremia and genotype, histologic diagnosis, antiretroviral therapy. The HBV genomic analysis showed a low variability in the S, X, and Pre-C/C regions in both occult and evident HBV infection. In particular, in the S and X regions emerged only point mutations, and the Pre-C/C sequence analysis revealed a decreased emergence of the pre-C stop mutant (G1896A) detected in only two cases and a trend to maintain the unpaired sites within the encapsidation structure. The emergence of BCP variant not evolved in any patients. Conclusions: Occult HBV infection occurred often in HIV infected patients and genotypes D and A were the most common infecting strains. The long-term persistence in the liver of HBV DNA strain, characterized by low heterogeneity and absence of genomic divergences between the occult and the evident HBV strains suggests that the occult HBV constitutes a genetically stable virus that silently retain its pathogenic potential.
S209
558 COST-EFFECTIVENESS SIMULATION ANALYSIS OF TENOFOVIR DISOPROXIL FUMARATE (TENOFOVIR), LAMIVUDINE, ADEFOVIR DIPIVOXIL (ADEFOVIR) AND ENTECAVIR OF HBEAG NEGATIVE (−) PATIENTS WITH CHRONIC HEPATITIS-B (CHB) IN SPAIN B. Deniz1 , M. Buti2 , M. Brosa3 , M.A. Casado5 , M. Rueda4 , F. Everhard4 , R. Esteban2 . 1 United BioSource Corporation, Concord, MA, USA; 2 Department of Hepatology, Hospital Vall D Hebron, Barcelona, Spain; 3 Oblikue Consulting, Barcelona, Spain, 4 Gilead Sciences Incorporated, Foster City, CA, USA; 5 Pharmacoeconomics & Outcomes Research Iberia, Madrid, Spain E-mail: [email protected] Background and Aim: To predict long-term cost and health outcomes of treating CHB in treatment naive, HBeAg(−) patients comparing tenofovir, lamivudine, adefovir and entecavir as 1st line treatments in Spain. Methods: A simulation model was developed to predict disease progression, incidence and cost of CHB-related complications according to HBV-DNA viral suppression achieved with different treatments over time. Patients were assigned levels of viral suppression and risk of developing viral resistance specific to their 1st line treatment. Patients who became resistant to treatment could switch or add-on another treatment. Patients who developed resistance to 1st and 2nd line treatments were assumed to discontinue treatment and disease progression rates assumed no further viral suppression. Three categories of HBV-DNA suppression were considered to predict incidence of complications: full response <300 copies/ml; partial response 300–105 copies/ml; and non-response >105 copies/ml. Complications included compensated cirrhosis (CC), decompensated cirrhosis (DCC) or hepatocellular carcinoma (HCC). Patients who developed DCC or HCC were eligible for liver transplant. Patients remained within simulation model until HBsAg seroconversion or death from either CHBrelated complications or natural causes. Costs of managing CHB and complications reflect clinical practice in Spain. All clinical, epidemiologic inputs were obtained from published literature. Analysis was conducted in 1,000 simulated patients over a 30 year time horizon reflecting the chronicity of CHB. Results: In 1st line, tenofovir is predicted to be more effective and less expensive compared to lamivudine and adefovir. Tenofovir is predicted to provide similar health outcome at lesser medical costs compared to entecavir. Conclusions: When considering a 1st line treatment option in Spain, tenofovir is predicted to be one of the most cost-effective treatments compared to lamivudine, adefovir and entecavir. Outcomes (Discounted at 3%)
Tenofovir
Lamivudine
Adefovir
Entecavir
Quality Adjusted Life Years Life Years Average cost per patient Undetectable HBV DNA at year 1 (<300 copies/mL)
13.65 16.07 €70,589 92%
11.68 14.30 €87,394 59%
12.95 15.42 €95,859 72%
13.58 15.99 €90,549 91%