ASTROBIOLOGY SCIENCE CONFERENCE 2006

Washington, DC

March 25 – 31, 2006

Viral Evolution03.29.06

HEPATITIS B VIRUS: COMMENTS ON VIRAL AND HUMAN EVOLUTION

Baruch S. Blumberg

Fox Chase Cancer CenterPhiladelphia, PA, 19111, USA

1. Hepatitis B Virus is a very common virus.

2. Humans have been infected with virus for a very long time, possibly from the time of the origin of humans.

3. Viruses closely related to HBV (“Hepadna viruses”) are known in many species other than humans.

4. HBV is a major deadly infectious agent.

5. Males are more likely than females to become chronic carriers of HBV and to die as a consequence

of infection.

6. HBV related deaths are highest in older males; high

HBV prevalence decreases the male to female ratio in older age groups.

7. There are a series of polymorphisms that affect susceptibility to chronic infection.

8. Parents who are carriers of HBV have a higher ratio of males to females in their newborn offspring than do parents who have antibody against the surface antigen of HBV; high HBV incidence increases the male to female ratio at birth.

9. There may be host advantages to the carrier state.

10. The worldwide vaccination program is decreasing the prevalence of HBV.

11. Virus sequences are very common in the human genome.

12. HBV as an “engine” of human evolution.

13. Were viruses an early form of life and, possibly, the earliest form?

Primary Cancer of the Liver– Worldwide:

• Third most common cause of death from cancer in males

• Seventh most common cause of death from cancer in females

• More than a million deaths per year• Hepatitis B virus (about 85%) and hepatitis C

virus account for most of these cancers• Many other factors involved in the pathogenesis

Human Hepatitis Viruses

Genome

Virus Genome Size (Kb) Envelope Classification

HAV RNA 7.5 - Picornavirus(Hepatovirus)

HBV DNA 3.2 HBsAg Hepadnavirus

HCV RNA 9.4 + Pestivirus- orFlavivirus-like

HDV RNA 1.7 HBsAg Unclassified

HEV RNA 7.5 - Claicivirus-likeor Alpha-likesupergroup

HBV is one of the most common infections in the world.

About 600,000 to 1,000,000 deaths per year

are attributable to the diseases associated with HBV.

(H. Margolis, Center for Disease Control. Paper presented at ThirdInternational Conference on Therapies for Viral Hepatitis, Maui, 12/12/99)

VirusNumberInfected(Millions)

Low 15%

34

CaseFatality

Rate

TotalDeaths

(Millions)

High 25%

100%

371

HIV

HBV

34

92.8

55.7

PREDICTED DEATHS FROM PREVALENT CARRIERS OF HIV AND HBV

“Hepatitis B is a viral infection of the liver. More than

two thousand million (2 billion) people alive today have

been infected with the hepatitis B virus. Approximately

350 million are chronically infected and are at high risk

of serious illness and death from cirrhosis of the liver

and primary liver cancer.

Hepatitis B is preventable with a safe and effective

vaccine — the first vaccine against cancer.”

WHO website, 2004

0

500

1000

1500

2000

2500

25-34 35-44 45-54 55-64 65-74

Age group (years)

Mor

tali

ty p

er 1

00,0

00 p

y M HBV+ M HBV- F HBV+ F HBV-

MORTALITY BY AGE, GENDER AND HBV RESPONSE

HAIMEN CITY, CHINA

G. Chen, W. Lin, F. Shen, U. Iloeje, T. London and A. Evans

Inter. J. of epid. 2004, in print

HEPATITIS B VIRUS MORPHOLOGY

CharacteristicsNucleic acid: DNAClassification:hepadnavirus type 1Serotypes: multipleIn vivo replication:reverse transcription inliver and other tissuesIn vitro propagation:primary hepatocyteculture and transfectionby cloned HBV DNA

42 nm

22 nm

C

HBsAg

HBcAgHBV DNA

HEPATITIS B LIKE VIRUSES

Hepadnaviruses

Human Homo sapiens HBVGorilla Gorilla sp. HBVChimpanzee Pan troglodytes ChHBVGibbon Family Hylobatidae HBVOrangutan Pongo pygmaeus HBVWoolly monkey Lagothrix lagotricha WMHBVTree shrew Tupaia belangeri HBV(Kangaroo Family Macropodidae KHV)Woodchuck or Groundhog Marmota monax WHVBeechey ground squirrel Spermophilus beecheyi GSHVArctic squirrel S. parryi kennicotti ASHBVRichardson ground squirrel S. richardsonii RGSHV(Tree squirrel Sciurus carolinensis THBV)Pekin duck Anas domesticus DHBVGreat blue heron Ardea herodias HHBVGrey heron A. cinerea HHBV Snow goose Anser caerulescens SGHBVRoss’ goose A. rossii RGHBVWhite Stork Ciconia ciconia STHBVDemoiselle crane Anthropoides virgo CHBVGrey crowned crane Balearica regulorum CHBV (Stink snake Elaphe carinata SSHV)

(Items in parentheses have not been validated. Tree shrews were experimentally infected.)

CONTROL OF HEPATITIS B VIRUS IN CHINA

Z.Y. Xu, T.Q. Yan, S.J. Zhao, et al. Shanghai Medical University

“Infant HBV immunization has been implemented into public health service in China since 1986… the seropositivity for HBsAg was reduced from 16.3% (879/5397) of historical controls to 1.43% (70/4886) in cross-sectional study and 1.81% (210/11582) in a cohort study.”

In the United States, the number of new HBV infections per year has declined from an average of 260,000 in the 1980s to about 78,000 in 2001. The highest rate of disease occurs in the 20-49 age group. Greatest decline is the consequence of the routine HBV vaccination program among children and adolescents.  There are an estimated 1.25 million chronically infected Americans, of whom 20-30% acquired their infection in childhood.

CDC Website, 2004

HBV VACCINATION IN THE UNITED STATES

A universal childhood vaccination program was undertaken between 1981 and 1983 in Native Americans in Alaska, USA (McMahon, et al., 1996).

Acute hepatitis B infection dropped from 215 cases/100,000 before the vaccination program, to 7 to 14 cases in 1993 after the program was in place.

In 1995, no cases were reported.

HBV VACCINATION IN ALASKA, USA

As of May 2003, 151 (79%) of 192 national members of the WHO had universal childhood vaccination programs. There are 89 member states that have been designated as having a high prevalence of HBV carriers. Sixty four (72%) have universal infant vaccination programs. It is the goal of the WHO to have vaccination programs in all countries by 2007.

Hepatitis B Virus Worldwide Vaccination Program

Distribution of Australia Antigen (HBsAg) by Gender

Marshall Islands, USTTPI Male Female TotalCebu, Philippines Male Female TotalManila, Philippines Male Female TotalCashinahua, Peru Male Female Total

Total Number

243226495

430334764

13859197

454489

NumberPositive

191433

271037

639

106

16

PercentPositive

7.86.26.7

6.33.04.8

4.35.14.6

22.213.618.0

Blumberg, et al, Amer. J. Human Genetics 18, 594, 1966

Parent’s response

To HBV

Either parent HBsAg + :

anti-HBs –

Both parents HBsAg - :

anti-HBs –

Both parents HBsAg - :

either parent anti-HBs +

Couples

(No.)

33

29

154

Live births

Male Females

60 (1.8 ± 0.2)

51 (1.8 ± 0.2)

24 (1.6 ± 0.1)

24 (0.7 ± 0.1)

35 (1.2 ± 0.2)

22 (1.4 ± 0.1)

Sex ratio

250 (161,429)*

146 (96,230)*

109 (91,131)*

PLATI, GREECE. NUMBER OF MALE AND FEMALE LIVE BIRTHS ACCORDING TO THE RESPONSES TO HBV OF PARENTS

*In parentheses, the 5 percent confidence limits.Blumberg, B.S. Sex differences in response to Hepatitis B Virus, Arthritis and Rheumatism,22, 1261, 1979

Hepatitis B and Sex Ratio: Individual Level Estimates

Notes: This table shows sex ratios among the children of carrier and non-carrier parents in four regions. Data were collected by testing married women and, in all cases except for Greenland, their husbands for HBV. Detailed reproductive histories were also collected. The table represents all births to women in those samples, with generally more than one birth to each women. The last two studies (Greece 2 and France) were designed specifically to test the hypothesis that HBV affects offspring sex ratio, and were run after the original theory was expressed.

LocationGreenlandGreenlandKar Kar IslandKar Kar IslandGreece 1Greece 1PhilippinesPhilippinesGreece 2Greece 2FranceFrance

HBV StatusPositiveNegativePositiveNegativePositiveNegativePositiveNegativePositiveNegativePositiveNegative

Sons64

17463

16385

28766

30452

100620

149

60

19454

20646

25541

30130

95512

122

Sex Ratio1.070.901.170.791.851.131.611.011.731.051.661.22

Daughters

From Oster, E. 2004

Notes: Sex ratio is number of boys for each girl. Only countries with more than 15,000 people used to caclulate HBV pravalence are included. Citations for each country are in Appendix B.

Se

x R

atio

at B

irth

SEX RATIO AND HEPATITIS, WORLD

Hepatitis Rate (%)

Brazil

Belarus

Bangladesh

Iran

Malaysia

Singapore

Israel

Pakistan

China

Mexico

Turkey

France

IrelandGreece

South Korea

Spain

AustraliaItaly

PolandJapan

1.14

1.12

1.1

1.08

1.06

1.04

1.02

10 2 4 6 8 10 12 14 16

Oster, E., Hepatitis B and the Case of the Missing Women, Presentation, October 12, 2004

N. Amer &W. Europe

EFFECTS OF VACCINATION PROGRAMALASKA

• High HBV prevalence among Alaskan Native Americans; low among non-Native American

• Universal vaccination program (including catch-up) instituted in early 1980s.

Oster, E., Hepatitis B and the Case of the Missing Women, Presentation, October 12, 2004

1996-20021991-19951986-19901980-1985

CHANGES IN SEX RATIO IN ALASKA BEFORE AND DURING VACCINATION PROGRAM

1.16

1.14

1.12

1.1

1.08

1.06

1.04

1.02

1

Native American High HBVNative American Low HBVNon-Native American

Oster, E., Hepatitis B and the Case of the Missing Women, Presentation, October 12, 2004

• HBV explains about 50% of the missing women overall: over 90% in China, 11% in India

• Vaccination programs appear to decrease sex ratio

Oster, E., Hepatitis B and the Case of the Missing Women, Presentation, October 12, 2004

Microorganism Gene Affinity Clusters

Locus Allele Agent/Disease Chrom Function

MHC Class II DRB1*1302 HBV chronicity (P) Chrom 6 Immune response

HBV response to interferonMalaria, cerebral (P)Pappiloma virus

VDR tt HBV chronicity (P) Chrom 12 Vitamin D ReceptorBinds Vit. D 1,25D3

tt TB Pulmonary (P)

TT Leprosy, tuberculoid (P)

Tt Leprosy, infection (P)tt Leprosy, lepromatous (P)tt Bone mineral density,

lower Osteoporosis,increase risk Prostaticcancer (P) Inflamatory boweldisease

Microorganism Gene Affinity Clusters (cont.)

Locus Allele Agent/Disease Chrom Function

TNF G-308 HBV chronicity Chrom 6 Tumor NecrosisFactor

Malaria, cerebralMicrocutaneous leish.Lepromatous leprosyMeningococcalMeningitisTrachomaAsthma

MBP Codon 52 HBV chromicity Chrom 10 Mannose BindingProtein

SLE, HIV (?)Infections in childhood

SM-1 5q31-33 Schistosomiasis Chrom 5 Schist. Susceptibility

? HBV chronicity

IL-10 Promoter Mutat. - 108 HBV chronicity Chrom 1 Immune response

Mutat. - 059 HBV chronicity

HBV and Iron in Down’s Syndrome Patients With and Without HBsAg

Increased Hemoglobin, Hematocrit, Serum Iron and decreased Total Iron Binding Capacity (TIBC) in 20 Down’s Syndrome patients with serum HBsAg

compared to 20 without. The differences are significant.

HBsAg(+)Mean

SD

HBsAg(+)Mean

SD

Hemoglobing/100ml

15.21.4

14.91.4

Hematocrit%

44.23.8

43.53.6

Serum Irong/100ml

163.7115.1

84.133.6

TIBCg/ml

250.4108.2

356.8144.8

Sutnick, Blumberg, Lustbader. Ann. Int. Med. 81, 855, 1974

Serum Iron Levels (mg/dl)

Serum Iron levels in 1) Patients with Down’s Syndrome 2) Patients on renal dialysis and 3) Residents of a rural community in Senegal, West Africa.

Blumberg in Szentivanyi and Friedman, Editors, Viruses, Immunity and Immunodeficiency, Plenum 1986

HBsAg(+)

HBsAg(-)

Number

Downs SyndromeMale Female

164 -

84 -

40 -

Total

164

84

40

Renal Dialysis Male Female

114 214

98 100

40 117

Total

145

100

220

Senegal Male Female

77 81

75 58

81 112

Total

79

65

193

Large numbers of retroviral sequences (includingthose of HBV) are found in the human genome. These are often the “fossil” record of viruses that were incorporated into the germ line in previous generations. It is estimated that 8% of the modern human genome is made of retroviral sequences, a larger number than the coding sequences, and they are often highly conserved.

Modified from Blumberg, B. S. 2005, Hepatitis B virus. Conjectures on human interactions and the origin of life, in, “Life As We Know It”, Volume 10 of the series “Cellular Origins, Life in Extreme Habitats and Astrobiology” edited by J. Seckbach, Springer, Dordrecht, NL.; and Kilbourne, E. D. (2004). Virus paleontology, disease, and evolution: an introduction. Proc. Amer. Philosophical Society 148: 261 and following articles.

• Hepatitis B vaccination is one of the largest worldwide disease prevention programs.

• It has decreased the spread of HBV, particularly in China and East Asia. It has significantly decreased morbidity from liver disease and prevented the death of millions.

• HBV vaccination appears to prevent primary cancer of the liver; it is the first widely used preventive cancer vaccine.

SUMMARY (1)

• There are important non-pathological interactions of HBV with Humans. Parents who are carriers of HBV have a higher ratio of males to females among their offspring than parents who developed antibody against the surface antigen. This may account for the high sex ratios seen in China and in other areas with a high prevalence of HBV infection. The apparent “loss” of females in these populations may be ascribed, at least in part, to HBV infection.

• In two studied populations the HBV vaccination has decreased the ratio of males to females among newborns. If confirmed, this may have important, biological, demographic and economic effects.

SUMMARY (2)

• The response of the host to HBV infection is related to a series of polymorphic locii that are, in turn, related to other disease causing agents.

• There may be advantages to the HBV carrier state at certain periods of the hosts life, i.e. there is increased iron retention in HBV carriers compared to those with anti-HBs and uninfected people.

• HBV is integrated into the genomes of tens of millions of humans.

SUMMARY (3)