Understanding the prevalence of potential antigenic variation of the hepatitis B virus (HBV) surface antigen (HBsAg) is fundamental for assay design and to future changes in vaccine formulation. In this study, the nature and frequency of HBsAg polymorphisms occurring in France in chronic carriers and in newly diagnosed patients were determined. We focused on variations in the major hydrophilic region (MHR), the central core of HBsAg known to be exposed on the surface and involved in antibody binding.
Methods
Two patient groups were identified: 51 chronic HBV carriers followed at our institution for >1 year; and 129 newly diagnosed patients (63 of whom had a first HBsAg-positive result at our hospital laboratory and 66 a first positive result in a private laboratory).
DNA sequences of HBsAg were obtained from these 180 patients and compared with consensus sequences built with 168 full-length HBV sequences imported from GenBank. Polymorphisms of the MHR of HBsAg were analysed with the Mutation Master Software. Literature review and BLOSUM scores were used to define potentially altered antigenicity.
Results
The global frequency of MHR variants was 27.8%. Occurrence of MHR variants was independent of viral load, HBeAg status and sex, but was associated with the chronic carriers’ group, advancing age, the presence of antibodies to HBsAg, immunoprophylaxis administration, antiviral treatment and genotypic resistance to antivirals. In multivariate analysis, the independent variables associated with MHR variants were advancing age and the presence of genotypic resistance to nucleoside or nucleotide analogues.
Conclusion
Most MHR variants emerge with longer disease duration and upon indirect selective pressure. Variation of the MHR may serve to restore virus replication of resistant strains. Combined envelope and polymerase variants could impair diagnostic assays and limit treatment alternatives.
References
1.
LavanchyD.Worldwide epidemiology of HBV infection, disease burden, and vaccine prevention.J Clin Virol2005; 34Suppl 1: S1–3.
2.
ScheiblauerH., SobollH., NickS.Evaluation of 17 CE-marked HBsAg assays with respect to clinical sensitivity, analytical sensitivity, and hepatitis B virus mutant detection.J Med Virol2006; 78Suppl 1: S66–70.
3.
ChenY.C., DelbrookK., DealwisC., MimmsL., MushahwarI.K., MandeckiW.Discontinuous epitopes of hepatitis B surface antigen derived from a filamentous phage peptide library.Proc Natl Acad Sci U S A1996; 93: 1997–2001.
4.
HowardC.R.The structure of hepatitis B envelope and molecular variants of hepatitis B virus.J Viral Hepat1995; 2: 165–170.
5.
CarmanW.F., KorulaJ., WallaceL., MacPheeR., MimmsL., DeckerR.Fulminant reactivation of hepatitis B due to envelope protein mutant that escaped detection by monoclonal HBsAg ELISA.Lancet1995; 345: 1406–1407.
6.
MoermanB., MoonsV., SommerH., SchmittY., StetterM.Evaluation of sensitivity for wild type and mutant forms of hepatitis B surface antigen by four commercial HBsAg assays.Clin Lab2004; 50: 159–162.
7.
CarmanW.F., Van DeursenF.J., MimmsL.T.The prevalence of surface antigen variants of hepatitis B virus in Papua New Guinea, South Africa, and Sardinia.Hepatology1997; 26: 1658–1666.
8.
LyT.D., Servant-DelmasA., BagotS.Sensitivities of four new commercial hepatitis B virus surface antigen (HBsAg) assays in detection of HBsAg mutant forms.J Clin Microbiol2006; 44: 2321–2326.
9.
LouisirirotchanakulS., KanoksinsombatC., O'CharoenR.HBsAg diagnostic kits in the detection of hepatitis B virus mutation within ‘a’ determinant.Viral Immunol2006; 19: 108–114.
10.
HouJ., WangZ., ChengJ.Prevalence of naturally occurring surface gene variants of hepatitis B virus in nonimmunized surface antigen-negative Chinese carriers.Hepatology2001; 34: 1027–1034.
11.
WeinbergerK.M., BauerT., BohmS., JilgW.High genetic variability of the group-specific a-determinant of hepatitis B virus surface antigen (HBsAg) and the corresponding fragment of the viral polymerase in chronic virus carriers lacking detectable HBsAg in serum.J Gen Virol2000; 81: 1165–1174.
12.
CarmanW.F., ZanettiA.R., KarayiannisP.Vaccine-induced escape mutant of hepatitis B virus.Lancet1990; 336: 325–329.
13.
ChakravartyR., NeogiM., RoychowdhuryS., PandaC.K.Presence of hepatitis B surface antigen mutant G145R DNA in the peripheral blood leukocytes of the family members of an asymptomatic carrier and evidence of its horizontal transmission.Virus Res2002; 90: 133–141.
14.
TerraultN.A., ZhouS., McCoryR.W.Incidence and clinical consequences of surface and polymerase gene mutations in liver transplant recipients on hepatitis B immunoglobulin.Hepatology1998; 28: 555–561.
15.
Protzer-KnolleU., NaumannU., BartenschlagerR.Hepatitis B virus with antigenically altered hepatitis B surface antigen is selected by high-dose hepatitis B immune globulin after liver transplantation.Hepatology1998; 27: 254–263.
16.
OguraY., KurosakiM., AsahinaY., EnomotoN., MarumoF., SatoC.Prevalence and significance of naturally occurring mutations in the surface and polymerase genes of hepatitis B virus.J Infect Dis1999; 180: 1444–1451.
17.
HsuH.Y., ChangM.H., NiY.H., ChenH.L.Survey of hepatitis B surface variant infection in children 15 years after a nationwide vaccination programme in Taiwan.Gut2004; 53: 1499–1503.
18.
AvellonA., EchevarriaJ.M.Frequency of hepatitis B virus ‘a’ determinant variants in unselected Spanish chronic carriers.J Med Virol2006; 78: 24–36.
19.
SongB.C., KimS.H., KimH.Prevalence of naturally occurring surface antigen variants of hepatitis B virus in Korean patients infected chronically.J Med Virol2005; 76: 194–202.
20.
Rodriguez-FriasF., ButiM., JardiR.Genetic alterations in the S gene of hepatitis B virus in patients with acute hepatitis B, chronic hepatitis B and hepatitis B liver cirrhosis before and after liver transplantation.Liver1999; 19: 177–182.
21.
LiuC.J., KaoJ.H., ShauW.Y., ChenP.J., LaiM.Y., ChenD.S.Naturally occurring hepatitis B surface gene variants in chronic hepatitis B virus infection: correlation with viral serotypes and clinical stages of liver disease.J Med Virol2002; 68: 50–59.
22.
LadaO., BenhamouY., PoynardT., ThibaultV.Coexistence of hepatitis B surface antigen (HBs Ag) and anti-HBs antibodies in chronic hepatitis B virus carriers: influence of ‘a’ determinant variants.J Virol2006; 80: 2968–2975.
23.
KramvisA., RestorpK., NorderH., BothaJ.F., MagniusL.O., and KewM.C.Full genome analysis of hepatitis B virus genotype E strains from South-Western Africa and Madagascar reveals low genetic variability.J Med Virol2005; 77: 47–52.
HenikoffS., HenikoffJ.G.Amino acid substitution matrices from protein blocks.Proc Natl Acad Sci U S A1992; 89: 10915–10919.
26.
StuyverL.J., LocarniniS.A., LokA.Nomenclature for antiviral-resistant human hepatitis B virus mutations in the polymerase region.Hepatology2001; 33: 751–757.
27.
Seddigh-TonekaboniS., LimW.L., YoungB.Hepatitis B surface antigen variants in vaccinees, blood donors and an interferon-treated patient.J Viral Hepat2001; 8: 154–158.
28.
WallaceL.A., EchevarriaJ.E., EchevarriaJ.M., CarmanW.F.Molecular characterization of envelope antigenic variants of hepatitis B virus from Spain.J Infect Dis1994; 170: 1300–1303.
29.
TorresiJ., Earnest-SilveiraL., DeliyannisG.Reduced antigenicity of the hepatitis B virus HBsAg protein arizing as a consequence of sequence changes in the overlapping polymerase gene that are selected by lamivudine therapy.Virology2002; 293: 305–313.
30.
HannounC., HoralP., and LindhM.Long-term mutation rates in the hepatitis B virus genome.J Gen Virol2000; 81: 75–83.
31.
HsuH.Y., ChangM.H., LiawS.H., NiY.H., ChenH.L.Changes of hepatitis B surface antigen variants in carrier children before and after universal vaccination in Taiwan.Hepatology1999; 30: 1312–1317.
32.
YamamotoK., HorikitaM., TsudaF.Naturally occurring escape mutants of hepatitis B virus with various mutations in the S gene in carriers seropositive for antibody to hepatitis B surface antigen.J Virol1994; 68: 2671–2676.
33.
KohnoH., InoueT., TsudaF., OkamotoH., AkahaneY.Mutations in the envelope gene of hepatitis B virus variants co-occurring with antibody to surface antigen in sera from patients with chronic hepatitis B.J Gen Virol1996; 77 (Pt 8): 1825–1831.
34.
ZhangJ.M., XuY., WangX.Y.Coexistence of hepatitis B surface antigen (HBsAg) and heterologous subtype-specific antibodies to HBsAg among patients with chronic hepatitis B virus infection.Clin Infect Dis2007; 44: 1161–1169.
35.
TorresiJ., Earnest-SilveiraL., CiviticoG.Restoration of replication phenotype of lamivudine-resistant hepatitis B virus mutants by compensatory changes in the ‘fingers’ subdomain of the viral polymerase selected as a consequence of mutations in the overlapping S gene.Virology2002; 299: 88–99.
36.
FungS.K., ChaeH.B., FontanaR.J.Virologic response and resistance to adefovir in patients with chronic hepatitis B.J Hepatol2006; 44: 283–290.
37.
PreikschatP., MeiselH., WillH., GuntherS.Hepatitis B virus genomes from long-term immunosuppressed virus carriers are modified by specific mutations in several regions.J Gen Virol1999; 80 (Pt 10): 2685–2691.
38.
GuntherS., FischerL., PultI., SterneckM., WillH.Naturally occurring variants of hepatitis B virus.Adv Virus Res1999; 52: 25–137.
39.
MinukG.Y., SunD.F., GreenbergR.Occult hepatitis B virus infection in a North American adult hemodialysis patient population.Hepatology2004; 40: 1072–1077.
40.
WesthoffT.H., JochimsenF., SchmittelA.Fatal hepatitis B virus reactivation by an escape mutant following rituximab therapy.Blood2003; 102: 1930.
41.
AlexopoulouA., DourakisS.P., PandelidakiH., ArchimandritisA.J., KarayiannisP.Detection of a hepatitis B surface antigen variant emerging in a patient with chronic lymphocytic leukaemia treated with fludarabine.J Med Virol2006; 78: 1043–1046.
