Hepatitis B Infection; Diagnosis and Interpretation.pdf

Hepatitis B Infection; Diagnosis and Interpretation

1. Dr.T.V.Rao MD
HEPATITIS BINFECTION
DIAGNOSIS AND INTERPRETATION
DR.T.V.RAO MD 1

2. 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.
DR.T.V.RAO MD 2

3. PREVALENCE OF HEPATITIS BCARRIERS
.Worldwide prevalence of hepatitis B carriers and primary hepatocellular carcinoma. (Courtesy Centers for
Disease Control and Prevention, Atlanta.)
From Murray et. al., Medical Microbiology 5
th
edition, 2005, Chapter
66, published by Mosby Philadelphia,,

4. 1、PROPERTIES OF HBV
•Amember of the hepadnavirus group
•Circular partiallydouble-stranded DNA viruses
•Replication involves a reverse transcriptase.
•Endemic in the human population and hyper endemic
in many parts of the world.
Anumber of variants
•It has not yet been possible to propagate the virus in
cell culture
DR.T.V.RAO MD 4

5. HEPATITIS B
Diagrammatic
representation of the
hepatitis B virion and
the surface antigen
components
EM of Hepatitis
B viron
–Hepadnaviridae family
–DNA virus
–Double-shelled particles
–Outer lipoprotein
envelope (surface Ag)
–Inner viral nucleocapsid
(core)
–seven genotypes
–four major subtypes.
–All HBV subtypes share one
common antigenic
determinant -"a.“
–Thus, antibodies to the "a"
determinant confer protection
to all HBV subtypes

6. HEPATITIS B VIRUS A MAJOR CAUSE OF
HEPATITIS
DR.T.V.RAO MD 6

7. DNA virus –hepadnavirus
3200 bp
Compact -uses overlapping
genes
Complicated replication –
has a ssDNA
component to RNA to DNA
Difficult to grow
Liver damage may be due
to host immunity
HEPATITIS B
DR.T.V.RAO MD 7

8. STRUCTURE OF HEPATITIS B VIRUS
DR.T.V.RAO MD 8

9. HBVSTRUCTURE & ANTIGENS
Dane particle
HBsAg= surface (coat) protein (4 phenotypes : adw, adr, ayw and ayr)
HBcAg= inner core protein (a single serotype)
HBeAg = secreted protein; function unknownDR.T.V.RAO MD 9

10. SURFACE PARTICLES
•HBsAg-containing particles
are released into the serum
of infected people and
outnumber the actual
virions.
•Spherical or filamentous
•They are immunogenic and
were processed into the first
commercial vaccine against
HBV.
DR.T.V.RAO MD 10

11. HEPATITIS B
Structure and major antigens:
22 nm –most abundant –extra viral envelope protein
-spheres and tubes
42 nm double-shelled –intact virus
Both covered by HBsAg –see in blood
Disrupt 42 nm with mild detergent –get 27nm core
particle –covered by HBcAg –neversee in blood
HBeAg –soluble –binds to the smooth ER and gets
exported into the circulation –see in blood
DR.T.V.RAO MD 11

12. There are 4 open reading framesderived 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) hepadnavirus.
Though not essential in transfected cells, it is required for
infection in vivo.
Open Reading Frames
DR.T.V.RAO MD 12

13. •Acute infection
•HBsAg positive and anti-HBcAg
IGM
•Rarely, IgM anti-HBc only marker
•Usually seen in acute fulminate
Hep B
•Chronic infection
•HBsAg positive and anti-HBcAg
•Previous Infection
•HBsAg negative
•anti-HBs positive
•IgG anti-HBc positive
HBV –SEROLOGY INTERPRETATION

14. ETIOLOGY
•HBcAg—anti-HBc system
HBcAg can be found in the nuclei of liver cells, no free
HBcAg in serum
HBcAg is the marker of replication of HBV
The stage called window phase
Anti-HBc IgM is a marker of acute infection and acute
attack of chronic infection of HBV. Anti-HBc IgG is the
marker of past infection, high titer means low level
replication of HBV
DR.T.V.RAO MD 14

15. •Secretory protein that is processed from the precore
protein
•Elevated early in infection and usually coverts to antibody
early on.
•Traditionally used as a marker for viral load as viral load
was undetectable with early assays when Ag was absent.
•However, certain variants of the Hep B virus do not create the
HBeAg as it has no known function.
•When present, it does correlate with elevated viral load
and seroconversion the antibody usually correlates with a
decrease in viral load by a magnitude of 4-5.
HEPATITIS B VIRUS –E ANTIGEN

16. THREE ANTIGEN-ANTIBODY SYSTEM
Include HBsAg, anti-HBs, pre-s1,s2 antigen and
anti-pres1, s2
HBsAg appears 1-2 weeks (late to 11-12 weeks)
after exposure, persists for 1-6 weeks( even 5
months) in acute hepatitis B.
In chronic patients or carrier, HBsAg persist
many years
HBsAg antigencity but no infectivity
DR.T.V.RAO MD 16

17. .Clinical outcomes of acute hepatitis B infection. (Redrawn from White DO, Fenner F: Medical virology,ed 3, New
York, 1986, Academic Press
CLINICAL OUTCOMES OF HEPATITIS B INFECTIONS
From Murray et. al., Medical Microbiology 5
th
edition, 2005, Chapter 62, published by Mosby Philadelphia,,

18. DETERMINANTS OR ACUTE AND CHRONIC
HBV INFECTION
From Murray et. al., Medical Microbiology
5
th
edition, 2005, Chapter 66, published by
Mosby Philadelphia,, Figure 66-7

19. SCREENING –WHO?
•Who should be screened
•Persons born in hyper endemic areas
•Men who have sex with men
•Injection drug users
•Patients on dialysis
•HIV infected patients
•Pregnant women
•Family and household contacts and sexual contacts of
HBV-infected persons.
•Testing should be performed by obtaining an HBsAg and anti-
HBs.

20. SEROLOGICAL MARKERS
DR.T.V.RAO MD 20

21. HEPATITIS B MARKERS:
•HBsAg:Present in acute or chronic infection.
•HBsAb:Present in recovery or immunization.
•Anti -HB Core:May be “Total” (IgG&IgM) or IgM.
Lifelong marker of past and active infection in either
acute or chronic.
•HBeAg:Acute infection, and extremely infectious.
•Anti-Hbe:Usually prognostic for resolution.
DR.T.V.RAO MD 21

22. ETIOLOGY
•HBcAg—anti-HBc system
HBcAg can be found in the nuclei of liver cells, no free
HBcAg in serum
HBcAg is the marker of replication of HBV
The stage called window phase
Anti-HBc IgM is a marker of acute infection and acute
attack of chronic infection of HBV. Anti-HBc IgG is the
marker of past infection, high titer means low level
replication of HBV
DR.T.V.RAO MD 22

23. Symptoms
HBeAg anti-HBe
Total anti-HBc
IgM anti-HBc anti-HBs
HBsAg
04812162024283236 52 100
Acute Hepatitis B Virus Infection withRecovery
Typical Serologic Course
Weeks after Exposure
Titre
DR.T.V.RAO MD 23

24. IgM anti-HBc
Total anti-HBc
HBsAg
Acute
(6 months)
HBeAg
Chronic
(Years)
Anti-HBe
04812162024283236 52 Years
Weeks after Exposure
Acute HBV Infection with Progression to
Chronic Infection: Typical Serologic Course
DR.T.V.RAO MD 24

25. 0
10
20
30
40
50
60
1 2 3 4 5 6 7 8 910 Months after exposure
Titer
Anti-HBsAb
Anti-HBeAb
Anti-HBcAb
HBeAg
HBsAg
Elevated ALT
JaundiceIncubation Recovery IMMUNE
―Window‖
HEPATITIS B
Serologic Markers During Acute HBV Hepatitis and Recovery
DR.T.V.RAO MD 25

26. ETIOLOGY
•HBcAg—anti-HBc system
HBcAg can be found in the nuclei of liver cells, no
free HBcAg in serum
HBcAg is the marker of replication of HBV
The stage called window phase
Anti-HBc IgM is a marker of acute infection and acute
attack of chronic infection of HBV. Anti-HBc IgG is the
marker of past infection, high titer means low level
replication of HBV
DR.T.V.RAO MD 26

27. HEPATITIS B
Serology: -acute:
HBsAg+ (HBsAb-) = acute infection or chronic
carrier
HBeAg+ = highly infectious
HBsAb = immune –naturally or vaccine
Window = HBsAg-and HBsAb-
will be HBcAb+ (IgM –acute)
DR.T.V.RAO MD 27

28. ETIOLOGY
•HBeAg—anti-HBe system
HBeAg is a soluble antigen
HBeAg is a reliable indicator of active replication of
HBV
Anti-HBe is a marker of reduced infectivity. If exist
long may be a marker of integration of HBV into liver
cell
DR.T.V.RAO MD 28

29. IgM anti-HBc
Total anti-HBc
HBsAg
Acute
(6 months)
HBeAg
Chronic
(Years)
anti-HBe
04812162024283236 52
Weeks after Exposure
Progression to Chronic Hepatitis B Virus Infection
Typical Serologic Course
DR.T.V.RAO MD 29

30. ETIOLOGY
•The marker of molecular biology of HBV
•HBV-DNA
The direct indicator of HBV infection
Can integrate into the genome of hepatocytes
•HBV DNA polymerase
Possesses the ability of reverse transcriptase
and the indicator of the ability of replication of
HBV
DR.T.V.RAO MD 30

31. Possible Outcomes of HBV Infection
Acute hepatitis B infection
ChronicHBV infection
3-5% of adult-acquired
infections
95% of infant-acquired
infections
Cirrhosis
Chronic hepatitis
12-25% in 5 years
Liver failureHepatocellular
carcinoma
Liver transplant
6-15% in 5 years 20-23% in 5 years
Death
DeathDR.T.V.RAO MD 31

32. PRACTICE!!!!!!!!!!!!!!!
•HBsAg N.
•HBcAB (TOTAL) N.
•HBsAB N.
•HAV-IGM N.
•HCV N.
•NO evidence of viral hepatitis viruses.
DR.T.V.RAO MD 32

33. SOLVING THE PROBLEMS
•HBsAG N.
•HBcAB (TOTAL) P.
•HBsAB P.
•HAV-IGM N.
•HCV N.
•PAST INFECTION.
DR.T.V.RAO MD 33

34. IMMUNIZED FOR HBV INFECTION
•HBsAg N.
•HBcAB (total) N.
•HBsAB P.
•HAV-IGM N.
•HCV N.
DR.T.V.RAO MD 34

35. PRACTICE……..
DR.T.V.RAO MD 35
•HBsAg P
•HBcAB (Total) P
•HBsAB N
•HAV-IGM N
•HCV N
•MAY BE ACUTE OR CHRONIC.
•Order Hep. B Core IgM to clarify.
•The IgM will be positive , If Acute.

36. CO INFECTION WITH HBV, HAV, AND HCV
•HBsAg P
•HBcAB (TOTAL) P
•HBsAB N
•HAV-IGM P
HCV P
DR.T.V.RAO MD 36

37. PAST INFECTION WITH RECOVERY, AND THEN RE-INFECTION THAT HAS
BECOME CHRONIC, THIS IS VERY RARE BUT DOES HAPPEN.
•HBsAG P
•HBcAB (total) P
•HBsAB P
•HAV-IGM N
•HCV N
•.
DR.T.V.RAO MD 37

38. HEPATITIS B PERSISTENT INFECTION
•Persistent viral load that
declines over time
•HBeAg declines overtime,
converting eventually to
anti-HBe antibody
•Seroconversion correlates
with rise in LFTs and 5 order
of magnitude decline in viral
load.
•Classically, to Anti-HBe
antibody = no viral DNA
circulating, which is
incorrect
•0.5% clear HBsAg annually

39. •Recent diagnostic
developments
including HBV
genotyping and
precore/core
promoter assays that
could well play
important future
roles in HBV patient
management
MOLECULAR ADVANCES IN DIAGNOSIS OF
HBV INFECTION
39

40. EMERGING TOOLS IN DIAGNOSIS OF HBV
INFECTION
DR.T.V.RAO MD 40
•Current HBV DNA assays make use of differing
technologies and can generally be divided into (i) signal
amplification assays (liquid phase
hybridization, antibody capture approach, branched
DNA) and (ii) DNA amplification tests based on the
polymerase chain reaction (PCR) . Signal amplification
assays have sensitivities approaching 1 pg of DNA
(10
5
-10
6
genome copies) or even to 10
3
genome
copies. Alternatively, HBV DNA detection based on a
nested PCR approach can detect as few as 10
2
-10
3
genome copies.

41. •Programme created by Dr.T.V.Rao MD
for Health care workers in the
Developing world
•Email
•[email protected]
DR.T.V.RAO MD 41