Transcript No Slide Title

THE CHANGING
FACE OF VIRAL
HEPATITIS
D. Robert Dufour, MD, FACB, FCAP
Consultant Pathologist
Attending, Liver Clinic
VAMC, Washington DC
Emeritus Professor
of Pathology
SIGNIFICANCE
• Acute viral hepatitis has become an
increasingly rare disease
• Reported incidences are at their lowest
recorded values for all major viruses
• Childhood immunization has led to near
universal immunity to HBV in USA
• From this standpoint, we are winning the
war against viral hepatitis
Source: CDC Viral Hepatitis Surveillance and Statistics
Source: CDC Viral Hepatitis Surveillance and Statistics
Source: CDC Viral Hepatitis Surveillance and Statistics
SIGNIFICANCE
• Chronic HBV and HCV remain common
• In US, chronic HCV affects at least 2% (2.7
million individuals), while chronic HBV
affects approximately 1 million (85% born
outside US)
• Both may lead to cirrhosis (20-30% after
20 yr), hepatocellular carcinoma (HCC) (35%/yr once cirrhosis present)
SIGNIFICANCE
• Symptoms of chronic infection minimal,
most unaware until complications develop
• Cirrhosis expected to increase 4-fold over
next 30 years
• HCC incidence doubled over past 20 years,
expected to increase further 3x; at VAMC
DC, have gone from 5-6/yr to 3-4/month
• Effective therapies available for HBV, HCV
HEPATITIS A, E
HEPATITIS A
• Peak age incidence now 20-35
• Major risk factors injection drug
use, males having sex with males
• IgM anti-HAV now largely (62%)
false positive; CDC recommends use
only in clinical setting of acute
hepatitis (MMWR 2005;54:453)
HEPATITIS E
• Recognized as an enteric virus in locations with
poor hygiene; anti-HEV < 5% in children, but
30-60% in young adults, men > women
• High mortality in pregnant women (30-50%);
low mortality rate otherwise (as with HAV)
• As with HAV, thought not to have a chronic
phase
• In developed countries, felt to not occur without
travel to endemic areas
HEPATITIS E
• HEV is endemic in pigs and rats worldwide
• Link between pork ingestion, death from
chronic liver disease in 18 countries
• Studies have shown high frequency (10-20%)
anti-HEV in blood donors in western countries
• Has raised issue of zoonotic spread of HEV, but
known cases of HEV difficult to link to pork
ingestion or pig exposure
HEPATITIS E
• In past few years, well documented case series
of HEV in Europe with the same genotype as
found in animals (J Med Virol 2008;80:646);
age range similar but mortality higher (10%),
esp. in those with chronic liver disease (70%)
• Anti-HEV more common in IV drug users;
post-transfusion cases in several countries
• Recently, reports of chronic HEV in liver
transplant recipients (Liv Transpl 2008;14:547)
HEV DIAGNOSIS
• IgM anti-HEV best test for acute infection; as
with HAV, false positive possible, may be false
negative in early stage
• IgG anti-HEV long-lasting (but probably not
life-long); rise in titer can also be used for acute
infection diagnosis
• HEV RNA viremia persists for an average of 4
weeks in acute infection; no commercial labs in
US currently offer HEV RNA, however
HEPATITIS B
HBV BIOLOGY
• Partially double-stranded DNA virus, belongs
to family hepadnaviridae
• Peculiar pattern of coding, replication unique
among viruses
• Virus is not hepatotoxic; damage occurs from
T-cell response to the virus
• Virus may be carcinogenic (? Related to HBV
X antigen)
HBV Replication
Free HBsAg
Circulating HBV
Free HBeAg
Partially
ds-DNA
HBV
particle
Partially ds-DNA
Pre-S
Rnase
DNA Polymerase
Covalently Closed
Circular (ccc) DNA
RNA-DNA Hybrid
HBV
mRNA
Replication
Infection
Reservoir
HBV
mRNA
HBV
mRNA
Reverse
Transcriptase
HBVpolymerase
HBV core Ag
HBV BIOLOGY
• RNA replication leads to high rate of
mutations (not as high as HIV, though)
• Certain sites of mutation more common - #1 is
stop codon in pre-core coding region, also
commonly affect core promoter region; both
decrease production of HBeAg (latter may
also increase risk of HCC)
• Mutations commonly induced by some reverse
transcriptase inhibitors used to treat virus
OUTCOME
• Outcome mainly dependent on age at
exposure, less affected by immune status
• In infants, 95% chronically infected; in
young children, 30-50% chronically infected
• In adults and adolescents, HBV is usually
“cleared” after exposure, < 5% chronically
infected (may be < 1%)
• In immunosuppressed adults and adolescents,
10-20% chronically infected
HBV Outcomes in Infants and Children < 5
HBV
Exposure
5%
95%
50-70%
Loss of HBsAg
30-50%
0.5-1%/yr
Immune
Tolerance
7-8%/yr
1-2%/yr
Immune
Control
7-8%/yr
1-2%/yr
Immune
Active
Outcomes of HBV exposure in Adults
HBV
Exposure
30-50%
50-70%
? 0.5%
Loss of HBsAg
1-2% (normal immune status)
10-20% (low immune status)
0.5%/yr
Immune
Control
Acute
Hepatitis
7-8%/yr
1%/yr
Immune
Active
HBV SEROLOGIC TESTS
• Complicated set of markers lead to confusing
patterns
• Even more complicated by increased
knowledge of biology of HBV
• Still most widely used tests for HBV
diagnosis, becoming less widely used for
monitoring of treatment
HBsAg
• Responsible for genotypes of HBV; common
“a” determinant in all genotypes
• Vaccine response mainly to “a” determinant
• Mutants in “a” determinant may not be
recognized by vaccine, HBsAg serologic tests
• Multiple mutants occur; none recognized by
all current HBsAg test kits
• Little data, but mutants usually occur with
wild-type virus, in low amounts, and rare as
sole infection
ISOLATED ANTI-HBc
• Early in viral clearance (“Core window” in
acute hepatitis, during recovery)
• Many years following infection; especially
common in HCV infected
• Failure to develop anti-HBs (?especially in
immune deficient)
• False positive result (post-influenza vaccine,
other states)
• HBsAg mutants (recent study – 3%)
HBeAg
• Produced along with viral particles, but not
part of virus; not needed for replication,
function uncertain (?  immune response)
• Correlates with replicating virus in untreated;
loss usually = low level (or no) viremia
• Not produced by pre-core or core promoter
mutants
• During treatment, loss indicates likelihood of
continued response after discontinuation
HBV DNA in HBeAg Pos vs Neg
HBeAg Pos
HBeAg neg
Source: VA Medical Center Washington DC
100%
80%
60%
40%
20%
0%
<2
2
3
4
5
Log HBV DNA (IU/mL)
6
>7
ANTI-HBe
• Appears with loss of HBeAg, indicating loss
of circulating virus
• Formerly used to indicate transition to carrier
state
• Also present if HBeAg lost due to
development of pre-core mutant strains
• Usually persists for life, but some lose antiHBe and re-develop HBeAg (and re-activate
HBV DNA production)
HBV DNA
• Assays have marked difference in detection
limit; reported in pg/mL, copies/mL (1 pg =
285,000 copies)
• WHO standard now used for most assays
(IU/mL), but correlation not linear
(unresolved issue)
• Most with chronic hepatitis have > 105
copies/mL (often > 109); levels < 102 thought
to have low transmission risk
Lower Detection Limits
for HBV DNA
Method
Hybrid Capture
Branched DNA 2.0
Liquid Hybridization
Branched DNA 3.0
PCR
Real Time PCR
Detection Limit
IU/mL
pg/mL
1.0 * 106
10.5
1 * 105
2.5
4.0 * 103
0.02
2.0 * 103
0.01
1-2 * 102
0.001
2-5 * 101
0.0001
HBV OUTCOMES & SEROLOGY
State
HBsAg AntiHBs
Anti- HBeAg Anti- HBV* ALT
HBc
HBe DNA
Acute hepatitis
Pos
Neg
Pos‡
Pos
Neg
> 106

Immune
tolerance
Pos
Neg
Pos
Pos
Neg
> 106
Nl
Immune active
Pos
Neg
Pos
Pos
Neg
> 106

HBeAg +
hepatitis
Pos
Neg
Pos
Neg
Pos
< 106

Immune control Pos
Neg
Pos
Neg
Pos
< 102†
Nl
Occult
Pos
Pos
Neg
Pos
< 102†
Nl
Neg
*In IU/mL; ‡ Typically IgM anti-HBc positive; †May be positive with very sensitive techniques
in serum or liver biopsy
HBV REACTIVATION
• Return of HBV replication where previously
inactive
• More common form: HBsAg positive but in
immune control phase, virus again replicative
(often with return of HBeAg)
• Less common form: HBsAg negative, antiHBc positive when viral replication returns
(sometimes termed seroreversion)
HBV REACTIVATION
• Usually occurs in setting of immune
suppression (HIV, transplant, steroids, cancer
chemotherapy); frequency higher with more
intense immune suppression
• While viral replication itself, immune
response to virus often causes severe liver
injury with recovery of immune function
• High morbidity and moratlity
HBV Reactivation
Immune
Suppression
Anti-HBc pos
HBsAg neg
Restore
Immunity
10-20%
30-50%
Acute
Hepatitis
1-2%
20%
Acute liver
failure
Immune
Control
HBV REACTIVATION
• Treatment of HBsAg positive pre-immune
suppression highly effective
• Associated with reduced overall and liverrelated mortality
• Recent guidelines suggest routine testing for
HBsAg and anti-HBc before immune
suppression, treatment if HBsAg positive; less
clear for anti-HBc positive
HEPATITIS C
HCV BIOLOGY
• Single strand RNA virus, part of flaviridae
family (WNV, yellow fever, dengue)
• Relatively new virus (? Late 1880’s)
• High rate of spontaneous mutation leads to
unique pattern of quasispecies in each
individual after initial infection
• Virus not cytopathic, destroyed by T-cell
response
ANTI-HCV
• Major screening test for HCV, detects
antibody to  1 of 4 HCV antigens
• Two basic versions (2nd, 3rd generation) in
use; 2nd sl less sensitive, not positive till avg
12 wk after exposure, 3rd sl less specific, pos.
avg 9 wk.
• EIA tests less specific than CA, MEIA
versions for same generation, but false
positive results relatively common with all
ANTI-HCV
• Most false positive are weakly positive
• Weak positive defined as  3.8 by EIA,  8 by
Ortho,  10 by Abbott, < 11 by Siemens
• Majority of weakly positive are negative on
other anti-HCV assays or on confirmatory
tests
• CDC recommends performance of RIBA on
all weakly positive before reporting
Screening test for Anti-HCV
Negative
Report
Positive
OR
Positives defined by S/C ratio
Positives with high S/C ratio
Report
All positives
Positives with low S/C ratio
RIBA for anti-HCV
OR
HCV RNA
Positive
Positive
Report
Negative
Negative
Indeterminate
Report
Report
RIBA for anti-HCV
Report
Positive
Negative Indeterminate
Report
Report
Report
HCV RIBA
Equivalent to western blot; uses purified
HCV antigens from yeast recombinants
 Positive: Ab to at least 2 Ag

Indeterminate: Ab to one Ag, or to yeast
marker (SOD) plus HCV Ags
 Most patients with high titer anti-HCV
have positive, usually used only when low
titer anti-HCV (or in blood donors)

TREATMENT OF
CHRONIC
HBV AND HCV
ACUTE HEPATITIS
• No treatment is recommended for acute HBV
(except in rare cases with acute liver failure)
• Acute HCV usually not recognized; when
diagnosed (e.g., post-needlestick) several
studies suggest that treatment with interferon
for 6 months can clear virus in 90-100% of
cases, compared to 50% with no treatment
• Treatment effective in first 6 months
CHRONIC HEPATITIS B
• Seven agents approved: interferon (std.,
pegylated), lamivudine, adefovir, telbivudine,
entecavir, tenofovir; last two most used
• Combination treatment not currently used
• Response rate to IFN low in those with normal
ALT, or viral load < 105 or > 1010 copies/mL
• “Ideal” response: nl ALT, loss of HBeAg and
HBV DNA, and development of anti-HBe
• Rarely, HBsAg is also cleared
CHRONIC HEPATITIS B
• Histologic improvement usually seen with
clearance
• Relapses after treatment can occur
• Success rate with 1 yr Rx about 30-40%
• With oral agents, increasing treatment to 3-4 yrs
increases response to  70%, but resistant
mutants also increase (28% with 5 yr treatment
for adefovir, 70% for lamivudine, < 5% for
entecavir, tenofovir [2 yr data only])
TREATMENT INDICATIONS
• In HBeAg +,  ALT (> 1.5 x nl), or advanced
biopsy findings (mod or higher inflammation,
stage II or higher fibrosis), esp if > 40 yrs old
• In HBeAg -, similar, but also based on VL
(treatment not recommended if < 2000 IU/mL,
or if < 20,000 IU/mL and biopsy shows
minimal damage), esp. if > 40 yrs old
• Patients not treated should be monitored, as
changes in status are common
Cumulative Incidence of Hepatocellular Carcinoma
by Serum HBV DNA Level at Study Entry
HBsAg
pos
>
HBeAg
neg
106
> 106
105-106
104-105
<
104
Chen, C.-J. et al. JAMA 2006;295:65-73.
Copyright restrictions may apply.
105-106
104-105
< 104
TREATMENT BENEFITS
• In those with cirrhosis, reduces likelihood of
complications (including HCC), can delay or
eliminate need for transplant
• Histologic improvement (including decreased
fibrosis) common with viral response
• Felt to have similar benefits in those with less
advanced disease, but long term data lacking
(although histologic improvement documented)
MONITORING Rx
• Loss of HBV DNA (< 100 IU/mL) is achieved
in 70-80%; measurable HBV DNA indicates
high rate of relapse
• Timing of measurements unclear; one study
suggests response highest if < 100 at 12 wk
• If < 2 log decrease by 3 mo, we generally
switch to another agent
• If viral load detectable but > 100, we usually
continue treatment, re-evaluate at 6 mo
MONITORING Rx
• In HBeAg + with loss HBV DNA, serial
monitoring of HBeAg status prognostic; if
HBeAg lost (and anti-HBe develops), treatment
can be D/C after 6-12 mo with 80% success
• In HBeAg – (or HBeAg + who do not convert),
D/C treatment leads to rapid reactivation of
HBV replication; treatment usually long-term in
these patients
CHRONIC HEPATITIS C
• Current treatment of choice is pegylated
interferon plus ribavirin
• Treatment usually for 24 wks with genotype 2
or 3, 48 wks for other genotypes
• Goal of treatment is clearance of virus that
persists after therapy stopped
• Response rate is about 40% with genotype 1,
70-80% with genotypes 2, 3, 60-70% with
genotype 4
CHRONIC HEPATITIS C
• Effectiveness monitored at 12 wk; failure to
clear virus or fall by > 2 logs (early virologic
response, EVR) indicates < 5% likelihood of
success
• Success evaluated 6 mo post-Rx as absent HCV
RNA by sensitive method (sustained virologic
response, SVR)
• In those with SVR, likelihood of recurrent
viremia < 1%; however, virus persists in
mononuclear cells in most
CHRONIC HEPATITIS C
• Intermediate time points provide additional data
and can be used to customize treatment duration
• Rapid virologic response (RVR): absent HCV
RNA after 4 weeks of treatment (~90% SVR)
• In those still positive at 4 weeks but negative at
8 weeks, 70% SVR rate
• In those with EVR but viral load measurable at
8 wk, longer treatment (72 wk G1, 48 wk G2/3)
improves response rate
RECENT ARTICLES
• HBV Guidelines:
– AASLD - Hepatology 2007;45:507
– CDC Recommentations: MMWR 2008;57(RR-08)
• HCV Guidelines:
– AASLD - Hepatology 2004;39:1147
– CDC (on lab testing) MMWR 2003;52 RR-3
• Reactivation Review
– Ann Intern Med 2008;148:519
• HEV Review
– Lancet Infect Dis 2008;8:698