Hepatitis B and D Viruses

Hepatitis B and D Viruses

Zhenghong YuanKey Lab of Medical Molecular Virology

Shanghai Medical College, Fudan University

2014.12.08

HEPATITISHepatitis---“INFLAMMATION OF THE LIVER”

resulting in a clinical illness characterized by fever, gastrointestinal symptoms such as nausea and vomiting, and jaundice.

CAUSED BY:

• VIRUSES - HEPATITIS A, B, C, D, E, G etc.

• OTHER INFECTIONS (yellow fever virus, CMV,HSV, rubella virus, and enteroviruses )

• CHEMICALS

– ALCOHOL

– ACETAMINOPHEN

Definitions for Hepatitis

• Acute: Acute hepatitis is where the disease develops quickly,

has symptoms and lasts less than 6 months. Short term and/or

severe.

• Chronic: Lingering or lasting where the symptoms and disease

last longer than 6 months. May or may not be severe

• Fulminant: Developing quickly and lasting a short time, high

mortality rate.

• Hepatocellular carcinoma：closely associated with hepatitis B,

and at least in some regions of the world with hepatitis C virus.

Viral hepatitis needs detail discussion as

It is responsible for more than 90% cases of both acute and chronic hepatitis

Very important from public health point of view – as preventable

Types A and E cause only acute hepatitis and spread by feaco-oral route

Types B,C,D and G cause both acute & chronic hepatitis and are transmitted by blood and blood products and body fluids

Overview of Hepatitis Virus

Virus Virus group Nucleic acid

Mode of infection

Severity

(chronicity)

HAV Enterovirus 72(heptovirus)

RNA Fecal-oral +(acute)

HBV hepadnavirus

DNA Percutaneous; Permucosal

++(chronic)

HCV Flavivirus RNA Blood(transfusion-associated)

+ (chronic)

HDV B-dependent small virus

RNA blood + (chronic)

HEV Calicivirus RNA Fecal-oral +(acute)

HGV ? RNA Blood ?

Hepatitis B Virus

> 8% - High

2-7% - Intermediate

< 2% - Low

Hepatitis B virus (HBV）prevalence

BackgroundBackground

Infected: 2 billion

Chronically infected:

350-400 million

Outcome of Hepatitis B and C Virus Infection

HBV HCV

Horizontal transmission(adults)

Vertical transmission

Clearance Chronic infection

Protectiveantibodies

Chronic hepatitis

Liver cirrhosis

Hepatocellular carcinoma

Horizontal transmission

No protective Antibodies

95% 5% 95-100% 85-100%

70%

Hepatitis B In the World

• 2 billion people have been infected (1 out of 3 people).

• 400 million people are chronically infected.

• 10-30 million will become infected each year.

• An estimated 1 million people die each year from hepatitis B and its complications.

• Approximately 2 people die each minute from hepatitis B.

Hepatitis B in China

• 1.3 billion people

• the world's largest population of hepatitis B patients, with nearly half a million people dieing of the liver disease every year

• 120 million Chinese have tested positive for hepatitis B, which has become a severe public health problem in the country

HBV

• Properties of HBV

• HBV: Replication

• Pathogenesis & Immunity

• Epidemiology

• Clinical Features and outcomes

• Diagnosis

• Treatmet

• Prevention

1、Properties of HBV

• a member of the hepadnavirus group

• Circular partially double-stranded DNAviruses

• Replication involves a reverse transcriptase.

• a number of variants

• It has not yet been possible to propogate the virus in cell culture

Particles and Structures

Spheres

Dane Particle

Filaments

HBV : Structure

• Virion also referred to as Dane particle (ds-tranded DNA)

• 42nm enveloped virus

• Core antigens located in the center (nucleocapsid)

* Core antigen (HBcAg)

* e antigen (HBeAg)- an indicator of transmissibility (minor component of the core- antigenically distinct from HBcAg)

• 22nm spheres and filaments other forms- no DNA in these forms so they are not infectious (composed of surface antigen)- these forms outnumber the actual virions

Dane particle

Complete particle, infective HBV

spherical，double capsid,双层衣壳。outer capsid=envelope外壳（包膜） =脂质双层+蛋白质，厚7nm

含有HBsAg、PreS1Ag和PreS2Ag蛋白质等

病毒核心颗粒：直径为28nm

颗粒表面:Nuclear capsid核衣壳，27nm ,HBcAg、HBeAg

颗粒内部Internal core：

DNA--- circular, double- stranded环状双链

DNA polymerase 多聚酶

GE

NO

ME

There are 4 open reading frames derived from the same strand (the incomplete + strand)

• S - the 3 polypeptides of the surface antigen (preS1, preS2 and S - produced from alternative translation start sites.

• C - the core protein

• P - the polymerase

• X - a transactivator of viral transcription (and cellular genes?). HBx is conserved in all mammalian (but not avian) hepadnaviruses. Though not essential in transfected cells, it is required for infection in vivo.

Open Reading Frames

AAAA

AA

AAAA

AAAA

AAAA

AAAA

AA

2.1kb RNA2.1kb RNA

2.4kb RNA2.4kb RNA

3.5kb RNA3.5kb RNA

0.7kb RNA0.7kb RNA

Pre-S1Pre-S1 Pre-S2Pre-S2

ORF-SORF-S

ORF-PORF-P

ORF-XORF-X

ORF-CORF-C DR1DR1

5’5’

5’5’

+strand+strand

-strand-strand

Pre-CPre-C

DR2DR2

ＨＢＶGenome

19

• The S gene has three start codons and iscapable of producing three different sizes ofHBsAg (small, medium, and large S).

•

• The C gene has two start codons and canproduce two antigenically distinct products:

• the HBcAg retained in hepatocytes untilassembled as core particles.

• HBeAg secreted into the serum as a smallsoluble protein.

Viral envelope proteins esp. LHBs

play a pivotal role in HBV entry;

PreS1(21-47) is the putative viral

attachment site to hepatocytes.

PreS1 PreS2 S

ATG ATG ATG TAGSP1 SP2

LHBsMYR

1 119 174 400

SHBs

MHBs

226AA 281AA400AA

55AA

119AA

HBeAg is the product of Pre and C gene

HBV C genePre-C region C region

Pre C / C Protein

HBeAg HBcAg

Expression

Secreted outside of the cells

HBeAg present in the serum

29AA 181AA

--19AA ---34AA

PreC

C

区HBcAg

HBeAgMutation in the Pre C region

result in no synthesis of HBeAg，

and HBV patients without HBeAg

（-），thus appears---HBeAg(-)

patients

TP SPACER RT

preC C S1 S2 S X

RNaseH

1 178 347 691 843

421~436 505~528 546~556 576~589 592~600 652

A B D EC

XS1 S2 SpreC C

RNaseHSPACER

Functional domains of

HBV polymeraseJ Virol. 2001 Dec;75(23):11827-33. 1

Hepatitis B Virus Mutants

Variations in nucleotide sequence in one of the HBV genes can result in change in the virological and, in some cases, clinical features of the infection.

S gene: vaccine or HBIG escape mutants

C gene: can affect disease severity or serological and clinical manifestations

P gene: can effect replicative efficiency and resistance to antiviral therapy

2、HBV: Replication

• Reverse transcription: one of the mRNAs is replicated with a reverse transcriptase making the DNA that will eventually be the core of the progeny virion

• RNA intermediate: HBV replicates through an RNA intermediate and produces and release antigenic decoy particles.

• Integration: Some DNA integrates into host genome causing carrier state

HBV Replication Cycle

1. A structure component of HBV virion.2. Encapsidate viral pol/pgRNA complex and host subsequent DNA replication

and rcDNA deproteination.3. Deliver rcDNA/DP-rcDNA into nucleus for cccDNA formation.4. A putative nucleosome-interacting protein in cccDNA minichromosome.

Hepatitis B Virus life cycle

Image courtesy of The New England Journal of Medicine

• Approved antiviral drugs only inhibit replication

HBV replication

Uncoating

Nuclear import

Repair

cccDNA

rcDNA

TranscriptionTranslation

Encapsidation

Viral proteins

Budding into ER

Exocytosis

Entry

CYTOPLASM

NUCLEUS

Viral RNAs

RTi

Reverse Transcription

Targeted Endonuclease

HBcAg/Polymerase

HBsAgRecycling

pgRNA

• cccDNA degradation or inactivation could eliminate HBV persistence

Linearization anddegradation

• cccDNA persists in hepatocyte nuclei even during drug therapy

Mutation/inactivation

Weber, et al, Mol Ther 2013

Hepatitis B Virus - ReplicationHepatitis B Virus - Replication

Viral entryViral entry

NucleusNucleus

Uncoating

Uncoating

Nuclear import

Nuclear import

RepairRepair Transcription

Transcription

cccDNAcccDNA

5’5’

5’5’

3’3’

3’3’

3.5 kb RNA3.5 kb RNA


2.4/2.1 kb RNA2.4/2.1 kb RNA



Uncoating

Uncoating

Nuclear import

Nuclear import


Transcription

TranslationTranslation

Positive strand synthesis


Removal of pregenome


Negative strand synthesis


Encapsidation

Encapsidation

cccDNAcccDNA

5’5’

5’5’

3’3’

3’3’



2.4/2.1 kb RNA2.4/2.1 kb RNA


Uncoating

Uncoating

Nuclear import

Nuclear import


Transcription

TranslationTranslation

HBsAgHBsAg



Assembly &

budding

Assembly &

budding

ERER





Encapsidation

Encapsidation

cccDNAcccDNA

5’5’

5’5’

3’3’

3’3’



2.4/2.1 kb RNA2.4/2.1 kb RNA

ExportExport

3.Immunity and Pathogenesis

Non antigen specific-INNATE

IMMUNITY

NK/T

Phagocytes

NK

pDC

Plasmacytoid DC

调节性T细胞

Antigen specific-ADAPTIVEIMMUNITY

CD8

CD4

B

Tregs CD4+CD25+Treg cell

LINK

CytokinesType I interferon

IL-12Granzyme B

mDCMyeloid DC

Antigenpresentation

Th17

0 1 2 3 4 5 6 7 8 9 10 11 12

Days after infection

PMNTNF-aIL12

IFN-a/b

NKKilling

CTL Antiviralantibody

Rela

tive

act

ivity

Host immune response to virus infection

INNATE ADAPTIVE

Chemokine Secretion

INF-g, INF a/b

Viral purge

Release of ALT

Virions

Hepatocytelysis

CTL

Mf

Inflammatory cells

Neutrophil

Necro-inflammatory

foci

Cytokine secretion(eg. IL-12, IL-18, TNF-a,

INF-a/b)

INF a/b

Innate Immunity

Virions Immature DC

INF a/b

IL-12

phagocytes

NK / NKT cells

Cytokine secretion(eg. IL12, INF-g)

Peripheral Compartment

Th2

Cytokine secretion(eg. IL-2, INF-g, TNF-a)

Th1

Adaptive Immunity

CTL

Cytokine secretion(eg. IL-4, IL-5, IL-10)

B cell

Ab

T cell

-ve

-ve

-ve

State of The Art

CD8+

Perforin / Granzyme

IFNγ / TNF

Cytolytic Mechanisms

Non-Cytolytic Mechanisms

Hepatocyte

Hepatocyte

Antiviral Efficacy

Ando et al. J. Immunol. 1994Thimme et al. J. Virol. 2003

Guidotti et al. Immunity 1996Guidotti et al. Science 1999Phillips et al. J. Immunol. 2010

CD8+ T cells are of major importance in the resolution of HBV infection

Immune Responses to HBV Infection

Acute, Self-Limiting HBV infection• Vigorous, heterogeneous CD4+ TH response to HBe-HBc antigens

• Weaker response to viral envelope proteins

• Vigorous CTL response to envelope, polymerase, HBcAg and HBeAg

• TH1 response is dominant:

APC

+

+

Lysis of Infected Hepatocytes

Virus Neutralization

Inhibitors

TH1 CTL

TH2 B

IL-10IL-4Inhibition of HBV

Viral Targets: Core 18-27

Env 183-191335-343

Pol 455-463

575-583

Immune Responses to HBV InfectionChronic HBV Infection

Predominant but weak CD4+ response to HBe-HBc antigens

Relatively weak and narrowly focused weak CTL response; chronic hepatocyte destruction

Maintenance of carrier state caused by an imbalance in the HBeAg/HBcAg specific TH cytokine responses (Milich, 1997)

TH2 response is dominant:

Seroclearance (HBeAg/HBsAg) associated with major immunological changes in TH1/TH2 balance

+

APC

+ Antibody

Inhibitors

TH1 CTL

TH2 B

IL-10IL-4

No Lysis of Infected Hepatocytes

CD8+ CTLMacrophage

NK cells

Cytolytic

Pathogenesis of HBV infectionsPathogenesis of HBV infections

Apotosis

Non-cytolytic

HBV infected Hepatocytes

Pathogenesis(1)

• Hypoimmune response.

IFN↓,HLA-I↓→CTL↓(An insufficient T-cell

response )

• Cell mediated immunopathogenic damage.

CTL →acute hepatitis/chronic hepatitis

Pathogenesis (2)

• Immune complexes formed between HBsAg

and anti-HBs contribute to the development

of hypersensitivity reactions, leading to

problems such as vasculitis血管炎, arthralgia

关节痛, rash, and renal damage.

Pathogenesis(3)

• Pathogenic damage caused by

autoimmunity

liver specific protein(LSP)

• Viral variation

HBeAg

Pathogenesis & Immunity• Virus enters hepatocytes via blood

• Immune response (cytotoxic T cell) to viral antigens expressed on hepatocyte cell surface responsible for clinical syndrome

• 5 % become chronic carriers (HBsAg> 6 months)

• Higher rate of hepatocellular cancer in chronic carriers, especially those who are “e” antigen positive

• Hepatitis B surface antibody likely confers lifelong immunity (IgG anti-HBs)

• Hepatitis B e Ab indicates low transmissibility

4.Epidemiology

• 350,000,000 carriers worldwide

• 120,000,000 carriers in China

- the carrier rate can exceed 10%

-15 to 25% of chronically infected patients will die

from chronic liver disease

• 500,000 deaths/year in China

• 982,297 liver disease in China 2005

• 50% of children born to mothers with chronic HBV in

the US are Asian American

Parenteral - IV drug abusers, health workers areat increased risk.

Sexual - sex workers and homosexuals areparticular at risk.

Perinatal(Vertical) - mother(HBeAg+) →infant.

HBV: Modes of Transmission

47

Sources of infection in hepatitis B

•

• The patients with acute or chronic hepatitis B andHBV carrier all can be regarded to the source ofinfection.

•

• However, chronic hepatitis B and HBV carrier areimportant as the sources of infection.

High-risk groups for HBV infection

• People from endemic regions

• Babies of mothers with chronic HBV

• Intravenous drug abusers

• People with multiple sex partners

• Hemophiliacs and other patients requiting blood and blood product treatments

• Health care personnel who have contact with blood

• Residents and staff members of institutions for the mentally retarded

49

Routes of transmission in hepatitis B

Hepatitis B is spread predominantly by the parenteral route or by intimate person contact.

Investigations of the source of hepatitis B reveal that most adult cases are due to sexual or parenteral contact.

intimate person contact

High ModerateLow/Not

Detectable

blood semen urine

serum vaginal fluid feces

wound exudates saliva sweat

tears

breastmilk

Concentration of Hepatitis B Virusin Various Body Fluids

伤口渗出液

唾液

精液

阴道分泌液

51

Blood transfusion and plasma products are now rarely infections for hepatitis B because of the institution of routine screening of blood donations for HBsAg and anti-HBc.

Transfusion

52

Maternal-infant spread of hepatitis B is another important mode of transmission not only in endemic areas of the world, but also in the country among immigrants from the endemic areas.

Routine screening of pregnant women and prophylaxis of newborns are now recommended.

Intrafamilial spread of hepatitis B also can occur, although the mode of spread in this situation is not well defined.

53

Susceptibility and Immunity in hepatitis B

Human without anti-HBs is susceptible to hepatitis Bvirus.

When the infection occurs in new neonate, theyeasily become to chronic carrier, because theirimmunity is not mature.

54

Epidemic features of hepatitis B• Low epidemic region with <2% of HBsAg

carrier rate is found in north American, western Europe and Australia.

•

• Moderate epidemic region with 2~7% of HBsAg carrier rate is reported in Eastern Europe, Mediterranean, Japan and Pre-Soviet Union.

•

• High epidemic region with 8~20% of HBsAgcarrier rate is reported in tropic Africa, Southeast

Asia and China.

What determines the development of chronic vs. acute infection

• Age (chronic infections decrease with increasing age)

• Sex: Syndrome: Males : Females

Chronic Infection: 1.5 : 1

Cirrhosis: 3 : 1

PHC: 6 : 1

• Route of infection (oral/sexual infections give rise to less chronic cases than serum infection

Symptomatic Infection

Chronic Infection

Age at Infection

Chronic Infection (%)

Sy

mp

tom

atic In

fection (%

)

Birth 1-6 months 7-12 months 1-4 years Older Childrenand Adults

0

20

40

60

80

100100

80

60

40

20

0

Outcome of Hepatitis B Virus Infectionby Age at Infection

Ch

ron

ic I

nfe

ctio

n (

%)

Nature History of HBV Infection

AcuteHBVInfection

Chronic HBVInfection

ChronicHepatitisB

Cirrhosis

Liver Failure

HCC

3-5% Adult

95% Children

5y

6-15%5y

20-23%5y

12-20%

Antiviral treatment

HBV Virons

Complete Response Partially Response Non Response

Immune as a key factor influences the outcome and progression of disease

5、Clinical Features and outcomes

Incubation period: Average 60-90 daysRange 45-180 days

Insidious onset of symptoms.Tends to cause a more severe disease than Hepatitis A.

Clinical illness (jaundice): <5 yrs, <10%≥ 5 yrs, 30%-50% 1/3 adults-no symptoms

Clinical Illness at presentation 10 - 15%

Acute case-fatality rate: 0.5%-1% Chronic infection: < 5 yrs, 30%-90%

≥ 5 yrs, 2%-10% More likely in ansymptomatic infections

Premature mortality fromchronic liver disease: 15%-25%

Age effect of HBV infection in humans

Possible Outcomes of HBV Infection

Acute hepatitis B infection

Chronic HBV infection

3-5% of adult-acquired infections

95% of infant-acquired infections

Cirrhosis

Chronic hepatitis

12-25% in 5 years

Liver failureHepatocellularcarcinoma

Liver transplant

6-15% in 5 years 20-23% in 5 years

DeathDeath

Symptoms of Acute Infection

The serological events associated with the typical course of acute HBV disease

Typical Serologic CourseAcute Hepatitis B Virus Infection with

Recovery

Typical Serologic CourseAcute Hepatitis B Virus Infection with

Recovery

Weeks after ExposureWeeks after Exposure

TiterTiter

Symptoms

HBeAg anti-HBe

Total anti-HBc

IgM anti-HBc anti-HBsHBsAg

0 4 8 12 16 20 24 28 32 36 52 100

Chronic Infection

• Chronic hepatitis occurs in 5% to 10% of people with HBV infections, usually after mild or inapparent initial disease.

• Detected by the finding of elevated liver enzyme levels

IgM anti-HBc

Total anti-HBc

HBsAg

Acute(6 months)

HBeAg

Chronic(Years)

Anti-HBe

0 4 8 12 16 20 24 28 32 36 52 Years

Weeks after Exposure

Acute HBV Infection with Progression toChronic Infection: Typical Serologic Course

Development of the chronic HBV carrier state

Primary Hepatocellular Carcinoma

• The WHO estimates that 80% of all cases of PHC can be attributed to chronic HBV infections.

• HBV may induce PHC by promoting continued liver repair and cell growth in response to tissue damage or by integrating into the host chromosome and stimulating cell growth directly.

68

6.Diagnosis

① Epidemic evidences

Evidences of exposure to infection, but not easy toobtain in sporadic cases in endemic areas.

② Clinical data

Case history, symptoms and physicalexaminations.

③ Laboratory investigations

Liver function tests

Detection of viral markers.

69

Laboratory examination

⒈) Routing blood examination

White blood cell count is normal or slightdecreased, and lymphocytes are elevated in acutehepatitis; sometimes atypical lymphocytes can beseen.

But white blood cells are increased in severeform hepatitis.

Deceases of platelet, RBC and WBC can befound in cirrhosis with hypersplenism.

70

⒉) Routing urine examination

The detection of bilirubinuria andurobilinogen can make diagnosis of hepatitisearly and help to differential diagnosis ofjaundice.

Bilirubinuria and urobilinogen are positivein hepatic cell jaundice at the same time.

Bilirubinuria and urobilinogen arepredominently increased in obstructive andhemolytic jaundice, respectively.

71

⒊)Liver functions(1)

In acute hepatitis, levels of serumaminotransferase increase during the prodromalphase, and the peak is typically heralded byintense nausea, anorexia, and vomiting, whichprecedes the onset of jaundice.

Peak aminotransferase levels are commonly morethan 500 IU/L and decrease at the rate of 75% perweek initially and the decline more slowly.

72

Liver functions(2)

Serum bilirubin levels peak after aminotransferaseactivity and usually less than 171μmol/L.

The bilirubin levels fall more slowly than theaminotransferase levels but will return to normal by2 weeks to 3 months.

73

In chronic hepatitis, mild, moderate and severechronic hepatitis can be classified according to thedifferent levels of ALT, T Bilirubin, Albumin,albumin/globulin, νGlobulin, choline esterase andprothrombin activity.

In severe form hepatitis, hyperbilirubinemia>171μmol/L, prolonged prothrombin time >26second or prothrombin activity (PTA<40%) areconsistent with liver failure.

74

4). Viral hepatitis marks of hepatitis B

①HBsAg

• HBV surface antigen can be found in serum,saliva, breast milk, semen in most patients ofacute or chronic infection.

• HBsAg contains no nucleic acid and notinfectious itself.

• HBsAg positive generally suggests HBVinfection.

75

②Anti-HBs

• Anti-HBs is an antibody to surface antigen.

• It becomes positive late in convalescence inmost acute patients.

• Anti-HBs is a protective antibody whichindicates past infection and immunity to HBVreinfection.

76

③HBeAg

• HBeAg is a core component of HBV.

• HBeAg reflects Dane particle concentration and infectivity.

• It is transiently positive during active replication, acute hepatitis and in some chronic patients.

• In some patients infected with pre-C mutant produce no this antigen.

77

④Anti-HBe

• Anti-HBe is transiently positive duringconvalescence and in some chronic patients andcarriers; not protective; reflects low infectivity.

⑤HBcAg

• HBcAg reflects HBV replication and infectivity.

• Because it is difficult to be detected inlaboratory, HBcAg do not be routinely used inclinical setting.

78

⑥Anti-HBc

• Anti-HBc is positive in all acute and chronicpatients and in carriers; Thus, marker of HBVinfection; not protective; IgM anti-HBc mayreflect active HBV replication.

⑦HBV DNA

• HBV DNA is indicative of replication of HBVand infectivity and most useful in diagnosis ofHBV and in evaluation of the anti-virustreatment.

HBV DNA

Laboratory Diagnosis

80

5). Ultrasonics

Morphology of liver and spleen can bemeasured accurately.

6) Liver biopsy

• Liver biopsy can estimate liver injury andprognosis and hepatic viral types sometimes.

• If a liver biopsy is performed, it maydemonstrate the pathologic features of acuteviral hepatitis.

Liver biopsy

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7. Treatment

• ①Interferon-α(conventional and pegylated)

• Conventional IFN-alpha has been replaced by Pegylated IFN-alpha.

• Indications of interferon in chronic hepatitis B areactive replication of HBV, active phase of hepatitis B,low concentration of HBV DNA and anti-HBc IgMpositive.

Interferon

First：RecognitionPattern Recognition Receptor Signaling

Second: Antiviral Genes ExpressionType I Interferon Signaling

82

Viruses

IFN and Innate Antiviral Responses

83

• Pegylated IFN alpha

[聚二乙醇化（长效）α－干扰素]

• Efficacy at one year:

• 1. HBV DNA suppression (<400 copies/ml):

HBeAg (+) 25%; HBeAg (-) 63%.

• 2. HBeAg seroconversion: 27% (32% at 2 year)

• 3. ALT Normalization:

HBeAg (+) 39%;HBeAg (-) 38%.

Drug resistance: No

84

• Special features of Pegylated IFN alpha

• 1. Baseline ALT levels positively correlates with the chance of HBeAg seroconversion.

• 2. Associated with mild to moderate clinical side effects including flu-like symptoms, bone marrow suppression, depression, weight loss and thyroid dysfunction.

85

②Nucleoside analogs:

• 1. Lamivudine(拉米夫定）

Dose of Lamivudine is 100mg/day, for 28 days; a98~100% reduction in circulating HBV DNA can beseen,

but HBV DNA rebound is observed in themajority of patients when treatment is stopped.

•

l Lamivudine

86

Efficacy at one year:

1. HBV DNA supression (<300copies):

HBeAg (+) 60%; HBeAg (-)72%.

2. HBeAg seroconversion: 18% (26% at year 2)

3. ALT normalization:

HBeAg (+) 60%; HBeAg (-) 71%.

Drug resistance: 23%, 40%, 55%, 68%, 71% ( f

Suggested duration:

• 1. HBeAg (+): minimum 1 year and after at least 6 months with stable HBeAg seroconversion.

• 2. HBeAg (-): long-term treatment.

87

Special features of lamivudine

1. Long term therapy is associated with improvement of virological, biochemical and liver histological parameters, but development of drug resistance may reverse the benefits.

2. Proven to be able to retard disease progression including reducing the risk of hepatocellular carcinoma in patient with chronic hepatitis B infection with long-term therapy.

88

• 2. Adefovir（阿德福韦）


1. HBV DNA suppression (<400 copies/ml):

HBeAg (+) 21%; HBeAg (-) 51%.

2. HBeAg seroconversion: 12% (29% at year 2).


HBeAg (+) 48%; HBeAg (-)72%.

Drug resistance:

HBeAg (+): 0% (year 1), 3% (year 2-3), 20% (year 5).

HBeAg(-): 0%, 3%, 11%, 18%, 29% (from year 1 to 5).

89

Suggested duration:

• same as that for lamivudine.

Side effect of adefovir:

• Renal toxicity has been reported in higher dosages and caution is needed in patients with creatinine clearance less than 50ml/min.

90

Entecavir（恩替卡韦）

• Efficacy at one year:


HBeAg (+)67%; HBeAg (-) 90%.

2. HBeAg seroconversion: 21% (31% at year 2).


• HBeAg(+)68%; HBeAg(-)78%.

Drug resistance: <1%,<1%,<1.1%,<1.1%(from year 1 to 4).

Suggested duration: same as that for lamivudine.

91

Telbivudine (替比夫定)



HBeAg(+)60%; HBeAg(-)88%.

2. HBeAg seroconversion: 22%.


HBeAg(+) 77%, HBeAg (-)74%.

Drug resistance:

HBeAg(+)4.4%(year 1), 21.6%(year 2);

HBeAg(-)2.7%(year 1), 8.6%(year 2).

Suggested duration:

same as that for lamivudine.

92

• Management of drug resistance:

• General principle:

• Adding and switching to another nucleoside/nucleotide analogue as early as possible.

93

（3)Liver transplantation

Liver transplantation has transformed themanagement of patients with decompensatedcirrhosis and liver failure.

• The decision to perform transplantation in apatient with severe form hepatitis must balance thelikelihood of spontaneous recovery with the risks ofsurgery and long-term immunosuppression.

8、Prevention

• Vaccination

- highly effective recombinant vaccines

• Hepatitis B Immunoglobulin (HBIG)

-exposed within 48 hours of the incident/ neonateswhose mothers are HBsAg and HBeAg positive.

• Other measures

-screening of blood donors, blood and body fluidprecautions.

Prevention

• HBV:• Pre-exposure prophylaxis:

Vaccine :months 0,1,6

Booster is not recommended

• Post-exposure prophylaxis:

HBIG:0.06 cc/kg and complete

course of vaccine

Hepatitis B Vaccine

• Infants: several options that depend on status of the mother – If mother HBsAg negative: birth, 1-2m,6-18m

– If mother HBsAg positive: vaccine and Hep B immune globulin within 12 hours of birth, 1-2m, <6m

• Adults

* 0,1, 6 months

• Vaccine recommended in – All those aged 0-18

– Those at high risk

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• Passive Immunization

• Passive immunoprophylaxis is used in foursituations:

• A. neonates born to HBsAg-positive mothers,

• B. after needlestick exposure,

• C. after sexual exposure,

• D. after liver transplantation in patients whowere HBsAg positive before transplantation.

• Neonates administered with hepatitis B vaccineand hepatitis B immune globulin (HBIG) canenhance protective rate up to 90%.

HEPATITIS B Virus

AGENT:HBV is hepatitis B virus, a double-stranded DNA virus. ANTIGENS AND ANTIBODIES:HBsAg

is hepatitis B surface antigen, a viral envelope antigenappears in late IP and remains for up to 6 months.In CLD it remains throughout.

Anti-HBsis the antibody to hepatitis B surface antigen that confers immunity to

HBV infection.Anti-HBs appears after 3-6 months of acute infection with HBV and

following vaccination.In past infection Anti HBsAg+Anti HBc both are presentbut in post vaccination cases only Anti HBsAg is present.

HBeAgis a secreted, viral antigen of the hepatitis B virus core that is

indicative of active viral replication and increased infectiousness.It appears for a short time at the onset of the illness.

Hepatitis B Virus (contd)

4: Anti HBe:

1. Appears late in acute illness and indicate cessation of viralreplication .

2. In CLD its presence is a good indicator and reflects either viralclearance or low replication.

5: IgM anti-HBc

1. is the antibody to hepatitis B core antigen that develops at the onsetof infection in acute HBV infection.

2. HBcAg does not appear in the blood.6: Total anti-HBc

1. total antibody response to HB core antigen (IgM anti-HBc + IgGanti-HBc)

2. detectable after acute HBV infection and convalescence.3. a useful screen for past HBV infection.4. Total anti-HBc is not detectable following hepatitis B vaccination.5. This may be the only sign of infection in the window period.

Hepatitis B Virus (contd) TRANSMISSION :

HBV is a blood borne and sexually transmitted pathogen that isspread through :

percutaneous and mucosal exposures to infected blood and bodyfluids,

injection drug use, sexual intercourse with an infected partner, perinatal transmission from mother to child, chronic hemodialysis, Tattooing with shared, contaminated needles. HBV is viable for at least 7 days on environmental surfaces and

can be transmitted by sharing contaminated household items such asrazors and toothbrushes.


Persons with chronic hepatitis B infection (HBsAg-positive)are often asymptomatic, but can still transmit their infectionto others.

Contagiousness increases significantly if persons with chronicHBV infection are also hepatitis B e antigen-positive (HBeAg-positive).

INCUBATION PERIOD : 90-120 days (range: 45-180 days).

CLINICAL FEATURES :

1. Acute hepatitis B occurs in approximately 30-50% of infectedadults and may be mild, severe, or fulminant.

2. Signs and symptoms of acute hepatitis include fever, jaundice,nausea, abdominal pain, and malaise.

3. Arthritis, serum sickness, and a nonspecific rash may also occurwith acute HBV infection and, when present, are helpfuldiagnostically.


LONG-TERM EFFECTS :

1. The majority of adults (85-90%) acutely infected with HBVeventually clear HBsAg from the blood and develop antibodies toHBsAg (anti-HBs) that confer long-term protection from re-infection.

2. A subset of persons (10-15%) acutely infected with HBV developchronic HBV infection (HBsAg-positive for 6 months or longer).

3. 5-10 % of people with Chronic HBV infection (HBsAg-positive)may get chronic hepatitis or asymptomatic chronic infection, oreventually clear the virus at a later stage.

4. 1-5% Individuals with chronic HBV infection are at increased riskof developing decompensated cirrhosis and hepatocellularcarcinoma (HCC).

Hepatitis B Virus(contd) DIAGNOSIS :

1. RAISED ALT (range in Thousands units in children to hundreds in adults)

SEROLOGY IN ACUTE HBV INFECTION:

Early illness 1: HBsAg

2:Anti HBc (IgM)

3:HBeAg

Late illness 1: Anti HBs

2:Anti HBc (IgG)

3:Anti HBe

4:HBS Ag for 6 months

2. The diagnosis of chronic HBV infection is confirmed by the detection ofhepatitis B surface antigen (HBsAg) on two separate occasions, 6 months apart;

SEROLOGY IN CHRONIC HBV INFECTION:

1:HBS Ag

2:Anti HBc of IgG type

3:HBe Ag – indicate active viral replication

4:Anti HBe- Indicate either low replication

or viral clearance


TREATMENT :

1. No effective therapies are available for acute hepatitis B, thereforetreatment efforts are largely supportive.

2. Approved antiviral therapies for chronic hepatitis B includeinterferon alfa-2b, pegylated interferon alfa-2a, adefovir dipivoxil,entecavir, and lamivudine.

3. Treatment options for cirrhosis and HCC are limited and drugtherapy mostly unrewarding. Liver transplantation is the onlyoption but most expensive and not cost effective.

Hepatitis D virus

Defective virus which requires Hepatitis B virus as a helper virus in order to replicate.

Infection only occurs in patients who are already infected with Hepatitis B.

Structure

• Virus particle 36 nm in diameterencapsulated with HBsAg, derived from HBV

• Delta antigen is associated with virus particlesssRNA genome

Hepatitis D (Delta) VirusHepatitis D (Delta) Virus

HBsAg

RNA

d antigen

Replication

• Transcription and replication of the HDV genome are unusual. Specifically, the host cell’s RNA polymerase II makes an RNA copy, replicates the genome, and makes mRNA.

HEPATITIS D (HDV)

• Transmission

– The modes of HDV transmission are similar to those for HBV, with percutaneous exposures the most efficient (blood from an infected person enters the body of a person who is not immune).Sexual transmission of HDV is less efficient than for HBV. Perinatal HDV transmission is rare.

HEPATITIS D (HDV)

• Transmission

– Risk groups include

• Injection drug users

• Men who have sex with men

• Hemodialysis patients

• Sex contacts of infected persons

• Healthcare and public safety officers

• Infants born to infected mothers (very rare)

Geographic Distribution of HDV InfectionGeographic Distribution of HDV Infection

HDV PrevalenceHigh

Intermediate

Low

Very Low

No Data

Taiwan

Pacific Islands

Pathogenesis

• Spread in blood, semen, and vaginal secretion.

• It can replicate and cause disease only in people with active HBV infections.

• Replication of the delta agent results in cytotoxicity and liver damage.

• Coinfection

–severe acute disease

–low risk of chronic infection

• Superinfection

–usually develop chronic HDV infection

–high risk of severe chronic liver disease

Hepatitis D - Clinical Features

Hepatitis D - Clinical Features

• In most persons with HBV-HDV co-infection, both IgM antibody to HDV (anti-HDV) and IgG anti-HDV are detectable during the course of infection.

• However, in about 15% of patients the only evidence of HDV infection may be the detection of either IgM anti-HDV alone during the early acute period of illness or IgG anti-HDV alone during convalescence.

• Anti-HDV generally declines to sub-detectable levels after the infection resolves and there is no serologic marker that persists to indicate that the patient was ever infected with HDV.

• Hepatitis Delta Antigen (HDAg) can be detected in serum in only about 25% of patients with HBV-HDV co-infection. When HDAg is detectable it generally disappears as HBsAg disappears and most patients do not develop chronic infection.

• Tests for IgG anti-HDV are commercially available in the United States.

• In patients with chronic HBV infection who are super-infected with HDV, several characteristic serologic features generally occur, including:– the titer of HBsAg declines at

the time HDAg appears in the serum

– HDAg and HDV RNA remain detectable in the serum because chronic HDV infection generally occurs in most patients with HDV superinfection, unlike the case with co-infection

– high titers of both IgM and IgG anti-HDV are detectable, which persist indefinitely.

Laboratory Diagnosis

• Detect the delta antigen of antibodies

• ELISA and RIA

• HBV-HDV Coinfection

Pre or postexposure prophylaxis to prevent HBV infection

• HBV-HDV Superinfection

Education to reduce risk behaviors among persons with chronic HBV infection

Hepatitis D - PreventionHepatitis D - Prevention

HEPATITIS D (HDV)

• Treatment

– Acute HDV

• Supportive care

– Chronic HDV

• Interferon – alfa

• Liver transplant

HEPATITIS D Virus

HDV is a an incomplete virus and need HBV for clinical disease.Thereforepreventive measures as discussed under HBV prevention secondarily alsoprevent HDV infection too.

Community education, Reporting, Containment, Contact investigation andother measures as discussed under HBV apply here.

It is worth mentioning here that suspected contacts should be tested forHBsAg in order to identify at-risk persons with chronic HBV infection(HBsAg- positive).

In Short steps to be taken for the prevention of HDV are:

1: Hepatitis B vaccination (FOR HBs NEGATIVE PEOPLE)o Hepatitis B vaccine should be given to prevent HBV/HDV co-infection

2:HBV-HDV co-infection (HERE HBs IS YET NEGATIVE)o pre- or post-exposure prophylaxis (hepatitis B immune globulin or

vaccine) to prevent HBV infection

3:HBV-HDV super-infection (HERE HBV IS ALREADY PRESENT)o education to reduce risk behaviors among persons with chronic HBV

infection

Comparison of Five Hepatitis Viruse

HAV HBV HCV HDV HEV

Genome +ssRNA dsDNA +ssRNA -ssRNA +ssRNA

Transmission Fecal –oral

blood、sex contact、vertical route

Fecal-oral

Clinical features

Mild symptoms

Seldom severe

Subtle, often chronic

Severe with HBV

Severe in pregnant women

Chronic or carrier state

no yes no

Lab exam Anti-HAV IgM

HBsAg-Ab HBcAb

HBeAg-Ab

Anti-HCV HCV-RNA

Anti-HDV IgM

Anti-HEV IgM

Prevention vaccine vaccine no same as HBV

being evaluated

Summary

• General concepts for hepatitis

• Types of hepatitis

• Properties: Structure\ ORF\Replication

• Transmission \Epidemiology

• Pathogenesis & Immunity

• Clinical Features

• Laboratory Diagnosis

• Treatment \Prevention

Questions

• What is hepatitis and type of hepatitis viruses?

• What are the properties of HBV ?

• How many ORFs of HBV ?

• How is HBV spread?

• How does the HBV cause the liver diseases?

• How do you interpret serological lab results for HBV?

• How to treat and prevent hepatitis B?

Review Quiz

• Following transmission of HBV from mother to infant, which of the following is the most common medical problem for the infant?

A. Liver failure.

B. Chronic HBV carrier state

C. Development of lymphoma.

D. Opportunistic infections.

E. Development of CNS disease.

What does it mean to be a "chronic carrier" of hepatitis B?

• People who are unable to get rid of the hepatitis B virus are diagnosed as being a "chronic carrier".

• The virus can stay in their blood and liver for a long time.

• They can unknowingly pass the virus on to other people.

• Chronic hepatitis B can also lead to serious liver diseases, such as cirrhosis or liver cancer. Not every chronic carrier will develop serious liver disease.

• However, they have a greater chance than someone who is not infected.

Why should HBV patients be worried about chronic hepatitis B infections?

• Because chronic hepatitis B can lead to cirrhosis or liver cancer.

• It's important to get tested because early diagnosis can lead to early treatment which can save your life.

• Also, chronic carriers can spread the virus to others. Since most chronic carriers don't know they are infected, they are unknowingly spreading it to many other people.

• If people are not tested, hepatitis B can pass through several generations in one family and throughout the community.

How can I stop the spread of hepatitis B?

• The good news is that you can break the cycle of infection in your family and in the Chinese community.

• Get tested for hepatitis B.

• Make sure everyone in your family is vaccinated against hepatitis B.

• Get the vaccine yourself.

• Look for good medical care.

• Discuss treatment options with your family doctor or a liver specialist if you already have chronic hepatitis B.

Are there any treatments if I have chronic hepatitis B?

• Currently, there are five approved drugs for people who have chronic hepatitis B infections:

• 1、Epivir-HBV or Zeffix (lamivudine) is a pill that is taken orally

• 2、Hepsera (adefovir dipivoxil) is a pill that is taken orally

• 3、Baraclude (entecavir) is a pill that is taken orally

• 4、Intron A (interferon alpha) is a drug given by injection

• 5、Pegasys (pegylated interferon) is a drug that is give by injection

Are there any treatments if I have chronic hepatitis B?

• It is important to know, not every chronic hepatitis B patient needs to be on medication.

• Some patients only need to be monitored by their doctor on a regular basis (at least once a year, or more).

• Other patients with active signs of liver disease may benefit the most from treatment.

• Be sure to talk to your doctor about whether you could benefit from treatment and discuss the treatment options.

• In addition, there are promising new drugs in clinical trials and in the research pipeline.

• However, it is vital that all people with chronic hepatitis B visit their doctor on a regular basis, whether they receive treatment or not!

Thank you

Lab of MV

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Documents

Hepatitis B and D Viruses