1. THE CHANGING FACE OF VIRAL HEPATITIS
D. Robert Dufour, MD, FACB, FCAP
Consultant Pathologist
Attending, Liver Clinic
VAMC, Washington DC
Emeritus Professor
of Pathology

2. 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

3. Source: CDC Viral Hepatitis Surveillance and Statistics

4. Source: CDC Viral Hepatitis Surveillance and Statistics

5. Source: CDC Viral Hepatitis Surveillance and Statistics

6. 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) (3-5%/yr once cirrhosis present)

7. 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

8. HEPATITIS A, E

9. 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)

10. 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

11. 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

12. 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)

13. 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

14. HEPATITIS B

15. 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)

16. HBV Replication Circulating HBV Free HBsAg Free HBeAg Partially ds-DNA
Pre-S
Free HBsAg
Free HBeAg
Partially
ds-DNA
HBV
particle
Rnase
DNA Polymerase
Partially ds-DNA
Covalently Closed
Circular (ccc) DNA
HBV
mRNA
Reverse
Transcriptase
RNA-DNA Hybrid
Infection
Reservoir
Replication
HBV
mRNA
HBV core Ag
HBVpolymerase

17. 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

18. 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

19. HBV Outcomes in Infants and Children < 5
Exposure 5%
95%
50-70%
30-50%
Loss of HBsAg
Immune
Tolerance
0.5-1%/yr
7-8%/yr
1-2%/yr
Immune
Control
Immune
Active
7-8%/yr
1-2%/yr

20. Outcomes of HBV exposure in Adults
30-50%
50-70%
Loss of HBsAg
Acute
Hepatitis
? 0.5%
1-2% (normal immune status)
0.5%/yr
10-20% (low immune status)
Immune
Control
7-8%/yr
Immune
Active
1%/yr

21. 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

22. 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

23. 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%)

24. 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

25. Source: VA Medical Center Washington DC

26. 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 anti-HBe and re-develop HBeAg (and re-activate HBV DNA production)

27. 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

29. HBV OUTCOMES & SEROLOGY
State
HBsAg
Anti-HBs
Anti-HBc
HBeAg
Anti-HBe
HBV* DNA
ALT
Acute hepatitis
Pos
Neg
Pos‡
> 106 
Immune tolerance Nl
Immune active 
HBeAg + hepatitis
< 106
Immune control
< 102†
Occult
*In IU/mL; ‡ Typically IgM anti-HBc positive; †May be positive with very sensitive techniques in serum or liver biopsy

30. 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, anti-HBc positive when viral replication returns (sometimes termed seroreversion)

31. 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

32. HBV Reactivation Immune Suppression Anti-HBc pos HBsAg neg Immune
Control
Restore
Immunity
10-20%
30-50%
Acute
Hepatitis
1-2%
20%
Acute liver
failure

33. HBV REACTIVATION
Treatment of HBsAg positive pre-immune suppression highly effective
Associated with reduced overall and liver-related mortality
Recent guidelines suggest routine testing for HBsAg and anti-HBc before immune suppression, treatment if HBsAg positive; less clear for anti-HBc positive

34. HEPATITIS C

35. 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

36. 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

37. 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

38. Screening test for Anti-HCV Report
Negative
HCV RNA
All positives
RIBA for anti-HCV
Report
Negative
Positive
Indeterminate
Positives defined by S/C ratio OR
Report
Positives with high S/C ratio
Positives with low S/C ratio OR
RIBA for anti-HCV
Report
Positive
Indeterminate
Negative

39. 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)

40. TREATMENT OF CHRONIC HBV AND HCV

41. 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 % of cases, compared to 50% with no treatment
Treatment effective in first 6 months

42. 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

43. 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])

44. 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

45. Cumulative Incidence of Hepatocellular Carcinoma by Serum HBV DNA Level at Study Entry
HBsAg
pos
HBeAg
neg
> 106
> 106
< 104
< 104
Chen, C.-J. et al. JAMA 2006;295:65-73.
Copyright restrictions may apply.

46. 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)

47. 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

48. 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

49. 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

50. 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

51. 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

52. RECENT ARTICLES HBV Guidelines: HCV Guidelines: Reactivation Review
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