Diagnosis of Hepatitis B

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Diagnosis of Hepatitis B

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Diagnosis of Hepatitis B

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1. Dr.T.V.Rao MD Hepatitis b infection 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 B carriers

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 Diagrammatic representation of the hepatitis B virion and the surface antigen components

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. HBV Structure & Antigens 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. 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 – never see 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. 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 Hepatitis B infections

18. Determinants or acute and chronic HBV infection

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

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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. 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. Dr.T.V.Rao MD 29 [SLIDE 35] Progression to Chronic Hepatitis B Virus Infection: Typical Serologic Course In patients with chronic HBV infection, both HBsAg and IgG anti-HBc remain persistently detectable, generally for life. HBeAg is variably present in these patients. The presence of HBsAg for 6 months or more is generally indicative of chronic infection. In addition, a negative test for IgM anti-HBc together with a positive test for HBsAg in a single serum specimen usually indicates that an individual has chronic HBV infection. [SLIDE 35] Progression to Chronic Hepatitis B Virus Infection: Typical Serologic Course In patients with chronic HBV infection, both HBsAg and IgG anti-HBc remain persistently detectable, generally for life. HBeAg is variably present in these patients. The presence of HBsAg for 6 months or more is generally indicative of chronic infection. In addition, a negative test for IgM anti-HBc together with a positive test for HBsAg in a single serum specimen usually indicates that an individual has chronic HBV infection.

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. Dr.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 (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 102-103 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

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