Hepatitis B Infection Diagnosis

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Hepatitis B Infection Diagnosis

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Hepatitis B Infection Diagnosis

  1. HEPATITIS B INFECTION DIAGNOSIS AND INTERPRETATION Dr.T.V.Rao MDDR.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 B CARRIERS. Worldwide prevalence of hepatitis B carriers and primary hepatocellular carcinoma. (Courtesy Centers forDisease Control and Prevention, Atlanta.) From Murray et. al., Medical Microbiology 5th edition, 2005, Chapter 66, published by Mosby Philadelphia,,
  4. 1、PROPERTIES OF HBV• A member of the hepadnavirus group• Circular partially double-stranded DNA viruses• Replication involves a reverse transcriptase.• Endemic in the human population and hyper endemic in many parts of the world. A number of variants• It has not yet been possible to propagate the virus in cell culture DR.T.V.RAO MD 4
  5. HEPATITIS B– Hepadnaviridae family Diagrammatic – DNA virus representation of the hepatitis B virion and – Double-shelled particles the surface antigen components – Outer lipoprotein envelope (surface Ag) – Inner viral nucleocapsid (core) – seven genotypes – four major subtypes. EM of Hepatitis – All HBV subtypes share one B viron common antigenic determinant - "a.“ – Thus, antibodies to the "a" determinant confer protection to all HBV subtypes
  6. HEPATITIS B VIRUS A MAJOR CAUSE OF HEPATITISDR.T.V.RAO MD 6
  7. HEPATITIS BDNA virus – hepadnavirus 3200 bpCompact - uses overlapping genesComplicated replication – has a ssDNAcomponent to RNA to DNADifficult to growLiver damage may be dueto host immunityDR.T.V.RAO MD 7
  8. STRUCTURE OF HEPATITIS B VIRUSDR.T.V.RAO MD 8
  9. HBV STRUCTURE & ANTIGENS Dane particleHBsAg = surface (coat) protein ( 4 phenotypes : adw, adr, ayw and ayr)HBcAg = inner core protein (a single serotype)HBeAg = secreted protein; function unknown DR.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 BStructure and major antigens:22 nm – most abundant – extra viral envelope protein - spheres and tubes42 nm double-shelled – intact virus Both covered by HBsAg – see in bloodDisrupt 42 nm with mild detergent – get 27nm core particle – covered by HBcAg – never see in bloodHBeAg – soluble – binds to the smooth ER and gets exported into the circulation – see in blood DR.T.V.RAO MD 11
  12. Open Reading FramesThere are 4 open reading frames derived from the same strand (theincomplete + strand)• S - the 3 polypeptides of the surface antigen (preS1, preS2 andS - 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 forinfection in vivo. DR.T.V.RAO MD 12
  13. HBV – SEROLOGY INTERPRETATION• 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
  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 HBVDR.T.V.RAO MD 14
  15. HEPATITIS B VIRUS – E ANTIGEN• 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.
  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 infectivityDR.T.V.RAO MD 16
  17. CLINICAL OUTCOMES OF HEPATITIS B INFECTIONS . Clinical outcomes of acute hepatitis B infection. (Redrawn from White DO, Fenner F: Medical virology, ed 3, New York, 1986, Academic Press From Murray et. al., Medical Microbiology 5th edition, 2005, Chapter 62, published by Mosby Philadelphia,,
  18. DETERMINANTS OR ACUTE AND CHRONIC HBV INFECTION From Murray et. al., Medical Microbiology 5th edition, 2005, Chapter 66, published byFigure 66-7 Mosby Philadelphia,,
  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 MARKERSDR.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 HBVDR.T.V.RAO MD 22
  23. Acute Hepatitis B Virus Infection with Recovery Typical Serologic Course Symptoms HBeAg anti-HBe Total anti-HBcTitre HBsAg IgM anti-HBc anti-HBs 0 4 8 12 16 20 24 28 32 36 52 100 DR.T.V.RAO MD Weeks after Exposure 23
  24. Acute HBV Infection with Progression toChronic Infection: Typical Serologic Course Acute Chronic (6 months) (Years) HBeAg Anti-HBe HBsAg Total anti-HBc IgM anti-HBc 0 4 8 12 16 20 24 28 32 36 52 YearsDR.T.V.RAO MD Weeks after Exposure 24
  25. HEPATITIS B Serologic Markers During Acute HBV Hepatitis and Recovery 60 50 40 Anti-HBcAb Titer 30 HBsAg 20 Anti-HBsAb ―Window‖ 10 HBeAg Anti-HBeAb 0 1 2 3 4 5 6 7 8 9 10 Months after exposure Incubation Jaundice Recovery IMMUNE Elevated ALTDR.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 HBVDR.T.V.RAO MD 26
  27. HEPATITIS BSerology: - acute:HBsAg+ (HBsAb-) = acute infection or chronic carrierHBeAg+ = highly infectiousHBsAb = immune – naturally or vaccineWindow = 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 cellDR.T.V.RAO MD 28
  29. Progression to Chronic Hepatitis B Virus Infection Typical Serologic Course Acute Chronic (6 months) (Years) HBeAg anti-HBe HBsAg Total anti-HBc IgM anti-HBc 0 4 8 12 16 20 24 28 32 36 52 DR.T.V.RAO MD Weeks after Exposure 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 HBVDR.T.V.RAO MD 30
  31. Possible Outcomes of HBV Infection Acute hepatitis B infection 3-5% of adult-acquired 95% of infant-acquired infections infections Chronic HBV infection Chronic hepatitis 12-25% in 5 years Cirrhosis 6-15% in 5 years 20-23% in 5 years Hepatocellular Liver failure carcinoma Death DR.T.V.RAO MD Liver transplant Death 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……..• 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.DR.T.V.RAO MD 35
  36. CO INFECTION WITH HBV, HAV, AND HCV• HBsAg P• HBcAB (TOTAL) P• HBsAB N• HAV-IGM P HCV PDR.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. MOLECULAR ADVANCES IN DIAGNOSIS OF HBV INFECTION• Recent diagnostic developments including HBV genotyping and precore/core promoter assays that could well play important future roles in HBV patient management 39
  40. EMERGING TOOLS IN DIAGNOSIS OF HBV INFECTION• 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 (105-106 genome copies) or even to 103 genome copies. Alternatively, HBV DNA detection based on a nested PCR approach can detect as few as 10 2-103 genome copies.DR.T.V.RAO MD 40
  41. • Programme created by Dr.T.V.Rao MD for Health care workers in the Developing world • Email • doctortvrao@gmail.comDR.T.V.RAO MD 41

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