Il Virus: categorie virologiche e stadiazione

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1 Il Virus: categorie virologiche e stadiazione Maurizia Rossana Brunetto UO Epatologia Azienda Ospedaliero Universitaria Pisana - Centro Riferimento Regionale Diagnosi e trattamento delle epatopatie croniche e del tumore di fegato

2 Non è possibile visualizzare l'immagine. To optimize the management of HBV carriers HBcAg DNA MHBsAg Immune system Virus DNA Polymerase LHBsAg SHBsAg

3 HBV replication and life Cycle HBV receptor modulation of cccdna activity Adapted from Wands JR, NEJM 2004

4 Sodium taurocholate cotransporting polypeptide is a functional receptor for human hepatitis B and D virus By using near zero distance photo-cross-linking and tandem affinity purification, the receptor-binding region of pre-s1 was shown to specifically interacts with sodium taurocholate cotransporting polypeptide (NTCP), a multiple transmembrane transporter predominantly expressed in the liver. Silenging NTCP inhibits HBV and HDV infections, while exogenous NTCP expression rendered nonsusceptible hepatocarcinoma cells susceptible to these viral infections Myrcludex B HBV entry inhibitor (lipopeptide representing part of the pre-s1 domain of L-HBsAg) blocks NTCP-mediated bile salt transport Cyclosporin A and Ezetimibe interfere with HBV infection by inhibiting NTCP New tools to study in vitro HBV infection New target for antiviral therapy Boettler T et al J Hep 2014; Yan H, elife 2012; Ni Y et al, Gastro. 2014; Lucifora J Antivir. Res 2013; Watashi K et al, Int J Mol Sci 2014

5 HBV replicative cycle HBV-DNA integration an early The event longer after the hepatocytes replication phase the infection higher the integration rate cccdna Cell cure by IFN gamma and TNF alpha cccdna dilution by hepatocyte turnover once new infection of liver cells is stopped However, the long half life of both cccdna and hepatocytes explains the persistence of occult HBV infection even after a resolved acute hepatitis B

6 From RC-HBV-DNA to cccdna formation and modulation Host DNA repair mechanisms (tyrosil-dna-phosphodiesterase 2 and additional components of the host DNA repair machinery) are though to be exploited by HBV to convert RC-DNA into cccdna. HBV cccdna is organized as a minichromosome in the nucleus of infected cells by histone and non-histone proteins long half-life (not established) HBV replication is regulated by the acetylation status of cccdna-bound H3/H4 histones Viral (HBx, HBc) and cellular regulatory proteins bind to and modulate cccdna functions Low Replication Phenotype Quiescent or active Medium to Low Viraemia High Replication Phenotype Transcriptionally Active High Viraemia Boettler T et al J Hep 2014; Newbold 1995, Bock 2001; Pollicino 2006; Newbold, 1995; Levrero 2009

7 cccdna epigenetic control in HBV carriers High Replication Low Replication Occult HBV PCA F p300 PCA F p300 HDAC 1 Ezh HDAC2 1 Sirt1 Sirt1 HP 1 MeCP 2 HDAC 1 Suv3 9 HDAC Sirt1 1 Sirt1 Histones Histones Histones ChI P Input IgG the epigenetic control of cccdna activity foster the transition from low-replicative to occult HBV infection PCAF p300 + IFNa HDAC1 YY1 PCAF p300 Sir t1 acetylated histones deacetylated histones Ez h2 IFNa treatment is accompanied by a decrease in the acetylation of cccdna bound H4 histones in vitro IFN-α inhibits HBV transcription and replication in cell culture and in humanized mice by targeting the epigenetic regulation of the nuclear cccdna minichromosome Active IFN-α repression of HBV transcription associated with 60-70% reduction of 3.5 kb pgrna, mrna (pres/s RNA), without affecting levels of cccdna copies per cell Pollicino T, 2006; Belloni et al., J Clin Invest 2012 ; Palumbo AASLD 2014

8 IFN- ELISpot ASSAY EX-VIVO 60,0 60,0 40,0 OCCULT HBV INFECTION Anti-HBc NEG 11 PATIENTS OCCULT HBV INFECTION 7 PATIENTS Anti-HBc POS 40,0 20,0 20,0 0,0 mix Pre s1 Pre s2 s P25 0,0 mix Pre s1 Pre s2 s P25 X CORE ENV POL X CORE ENV POL 60,0 60,0 40,0 HBs Ag POS Inactive Carriers 6 PATIENTS Anti-HBe positive CH-B 6 PATIENTS 40,0 20,0 20,0 sfu/10 6 cells 0,0 60,0 40,0 20,0 mix X CORE ENV POL 8 9 CH-C CONTROLS Intrahepatic HBV-DNA NEG Pre s1 9 PATIENTS Pre s2 s P25 0,0 mix X CORE ENV POL Pre s1 Pre s2 pres1-s2 S A multispecific T cell response directed to different HBV proteins is detectable exvivo in subjects with occult HBV Infection indipendently from the serological status s P25 0,0 mix Pre s1 Pre s2 s P25 X CORE ENV POL pres1-s2 S Missale G, EASL 2006

9 Non è possibile visualizzare l'immagine. Outcome of HBV infection and liver damage Disease Drugs Immune system Virus Drugs direct or indirect

10 cccdna epigenetic control in HBV carriers High Replication Low Replication Occult HBV PCA F p300 PCA F p300 HDAC 1 Ezh HDAC2 1 Sirt1 Sirt1 HP 1 MeCP 2 HDAC 1 Suv3 9 HDAC Sirt1 1 Sirt1 Histones spontaneously iatrogenic immunosuppression Histones iatrogenic immunosuppression Histones ChI P Input IgG the epigenetic control of cccdna activity foster the transition from low-replicative to occult HBV infection treatment with drugs able to modify histones acetylation may modulate cccdna activity, inducing HBV reactivation (i.e.. Romidepsin, histone deacetylase inhibitor, HDAC) or silencing cccdna (Histone Acetyl Transferase Inhibitor, Sirt1/2 or Ezh2 histone methyltransferase activity activators) Pollicino T, 2006; Belloni et al., J Clin Invest 2012 ; Palumbo AASLD 2014

11 Immune response to hepatitis B Innate immunity Adaptive immunity DC CD8+ lysis Hepatocyte IFN activation Viral replication Hepatocyte Viral replication CD4+ neutralization NK(T) B Anti-HBe, HBc, HBs Rehermann et al, Nature Rev Immunol 2005; Bertoletti et al, J Gen Virol 2006, Wotman Gut 2010

12 HBV Immune response Acute/Resolved infection Chronic infection Presence of an integrated activation of both cellular and humoral arms of adaptive immunity. Impaired T and B cell response Functional defects Ability to mount an efficient T and B cell response is the main mechanism responsible for HBV control.

13 Natural history of Chronic Hepatitis B Virus Infection Immune tolerance Immune clearance Immune control HBsAg positive HBsAg neg HBeAg HBeAg or anti-hbe Anti-HBe HBV DNA (log 10 IU/ml) IgM anti-hbc (PEI Units) ALT (U/L) HBeAg Immune tolerant carriers Patients with CHB HBeAg positive or negative Inactive carriers OBI carriers

14 The Virus: HBV-DNA HBsAg qt HBeAg HBcrAg HBV-RNA The host s immune response: T cell response anti-hbc qt NK phenotype The virus/host interplay: mirna profile MiR-B-Index R. Magritte, The masterpiece or the mysteries of the horizon 1955

15 Serum HBV-DNA HBsAg Virions Virions + defective particles (exceeding virions by a factor of ) replication replication cccdna transcription/ mrnas translation Serum HBV-DNA decline: reduction of replication Serum HBsAg decline: reduction of the cccdna amount or of the cccdna transcription /mrnas translation Brunetto et al, J Hepatol 2010

16 HBV-DNA and HBsAg quantification in clinical practice HBsAg production follows cellular pathways distinct from viral replication HBsAg production depends, at least in part, on constitutive viral features, such as genotype and quasispecies. - In-vitro HBsAg production differs among HBV genotypes and in vivo HBsAg serum levels are higher in genotype A than genotype B, C and D infected individuals. - Pre-S/S mutants may impact on HBsAg production as they are negatively correlated with HBsAg serum levels (r=-0.431; P <0.005). Both HBV-DNA and HBsAg production are modulated by the interplay between virus and host's immune response Only the combined quantification of HBsAg and HBV-DNA can contribute to pinpoint accurately the single HBV carrier within the highly dynamic phases of chronic HBV infection, provided that all variables interfering with HBsAg production are carefully considered.

17 Natural history of Chronic Hepatitis B Virus Infection Immune tolerance Immune clearance Immune control HBsAg positive HBsAg neg HBeAg HBeAg or anti-hbe Anti-HBe HBV DNA (log 10 IU/ml) IgM anti-hbc (PEI Units) ALT (U/L) High and stable HBsAg (4.5-5 log 10 IU/ml) and HBV-DNA (8 log 10 IU/ml) serum levels are the virologic hallmark of Immune tolerant phase Low HBsAg serum levels (3.85 log 10 IU/ml) in genotype B and C infected HBeAg positive patients are associated with significant fibrosis ( F2) HBeAg Immune tolerant carriers Patients with CHB HBeAg positive or negative Inactive carriers OBI carriers Chan HL et al, Hepatology 2010; Martinot-Peignoux M et al, J Hep 2013; Xun Y-H et al, J. Gastro and Hepat. 2013

18 Natural history of Chronic Hepatitis B Virus Infection Immune tolerance Immune clearance Immune control HBsAg positive HBsAg neg HBV DNA (log 10 IU/ml) IgM anti-hbc (PEI Units) ALT (U/L) HBeAg HBsAg serum levels <1000 IU/ml in low viremic HBeAg negative carriers are associated with better outcomes Combined HBsAg (<1000 IU/ml) and HBV-DNA (<2000 IU/ml) serum levels in genotype D show high diagnostic accuracy (94.3%) in the identification of Inactive Carriers HBeAg or anti-hbe Anti-HBe HBeAg Immune tolerant carriers Patients with CHB HBeAg positive or negative Inactive carriers OBI carriers Brunetto MR et al, Gastroenterology 2010; Lee M-H et al Hepatology 2013; Tseng T-C et al, Hepatology 2013

19 Long term outcome of Inactive and Active, Low Viremic HBeAg negative carriers: benign one direction course towards spontaneous HBsAg clearance In 89 Inactive Carriers (84% genotype D) 31% had HBsAg levels >1,000 IU/mL as compared to 9% of a previous study (56 IC Inactive Carrier, all genotype D) Surace L & Oliveri F.et al, submitted

20 HBsAg (log 10 IU/mL) IU/mL 883 IU/mL 5412 IU/mL 2740 IU/mL 0.05 percentile First Quart Median Third Quart 0.95 Percentile Subjects (N) HBV DNA (IU/mL) 2,000 2,001-19,999 20,000 20,000 Liver disease Absent Absent Chr Hep Cirrhosis Carriers Inactive Active Active Active Brunetto MR et al.gastroenterology 2010

21 Liver biopsy in 10 patients: Grading 3/18 (6 pts); 4/18 (4 pts) // Staging 0/6 (8 pts); 1/6 (2 pts) Brunetto MR et al.gastroenterology 2010

22 Long term outcome of Inactive and Active, Low Viremic HBeAg negative carriers: benign one direction course towards spontaneous HBsAg clearance. Initial follow-up (12 months) Additional follow-up [57.2 ( ) months] 153 HBsAg carriers HBeAg-/anti-HBe+ with HBV-DNA 20,000 IU/mL and normal ALT 133 (86.9%) carriers with HBV-DNA 20,000 IU/ml 20 (13.1%) carriers with HBV-DNA >20,000 IU/mL and elevated ALT 87 IC (HBV-DNA 2000 IU/mL and normal ALT) 46 LV-AC (HBV-DNA ,000 IU/mL) and normal ALT 84 IC (96.6%) 3 IC (3.4%) transition to LV-AC 20 IC (43.5%) 25 LV-AC (54.3%) 1 Hepatitis Reactivation (2.2%) 19 HBsAg loss (21.8%) 2 HBsAg loss (4.3%) Surace L & Oliveri F.et al, submitted

23 Natural history of Chronic Hepatitis B Virus Infection Immune tolerance Immune clearance Immune control HBsAg positive HBsAg neg HBeAg HBeAg or anti-hbe Anti-HBe HBV DNA (log 10 IU/ml) IgM anti-hbc 10 (PEI Units) ALT (U/L) HBeAg Immune tolerant carriers CHB Low viremic Active Carriers Inactive Carriers OBI Surace L & Oliveri F.et al, submitted

24 HBsAg (log 10 IU/mL) IU/mL 883 IU/mL 5412 IU/mL 2740 IU/mL 0.05 percentile First Quart Median Third Quart 0.95 Percentile Subjects (N) HBV DNA (IU/mL) 2,000 2,001-19,999 20,000 20,000 Liver disease Absent Absent Chr Hep Cirrhosis Carriers Inactive Active Active Active Brunetto MR et al.gastroenterology 2010

25 HBsAg serum levels according to the prevalence of pre-s mutants during the natural history of chronic HBV infection HBsAg IU/ml 10 6 Early effective immune control Inactive carriers Long lasting ineffective immune response Cirrhotic patients Stabile A et al, EASL 2011 Low High Prevalence of Pre-s mutants

26 HBV Diagnostic categories anti-hbs immunity anti-hbc exposure HBsAg, HBV-DNA infection HBeAg, HBV-DNA replication IgM anti-hbc, HBV-DNA disease

27 Identification of virus induced liver disease Viral infection Liver disease HEPATITIS Other factors causing liver damage dismetabolisms, drugs, other hepatotropic viruses

28 Management of chronic HBV carriers Laboratory ethiology (viral markers, autoantibodies, Fe and Cu metabolism, glucose and lipids metabolism) liver injury (AST/ALT; Aph GGT) liver function (albumin, bilirubin, PT, PCHE) serum globulins complete blood count Morfology Liver biopsy Instrumental evaluation liver elastometry ultrasound

29 Liver stiffness in the hepatitis B virus carrier: A non-invasive marker of liver disease influenced by the pattern of transaminases Study Population: 268 CHB carriers Oliveri F et al, World J Gastroenterol 2008

30 Liver stiffness in the hepatitis B virus carrier: A non-invasive marker of liver disease influenced by the pattern of transaminases Study Population: 268 CHB carriers Cut- off levels for identification of: S3 Fibrosis Cirrhosis 7.5 KPa 11.8 KPa CHB with S2 fibrosis stage Cirrhotic pt on NA Oliveri F et al, World J Gastroenterol 2008

31 HBV infection: virologic characterization staging of liver disease Magritte R,

32 Hepatology Unit University Hospital of Pisa, Italy Antonella Cristofani Simonetta Ferretti (part-time) Simona Giannetti Teresa Crisponi Isabella Rossi (Chief) Nurses Medical Doctors Pietro Ciccorossi Barbara Coco Piero Colombatto Filippo Oliveri Veronica Romagnoli Beatrice Cherubini Administrative Personel Arianna Del Chicca Biologists Daniela Cavallone Francesco Moriconi Bio-Physics Luigi Civitano Ranieri Bizzarri Ferruccio Bonino Gatroenterology Chair Pisa University