Characterization of occult hepatitis B virus from blood donors carrying genotype A2 or genotype D strains.
J Hepatol
; 49(4): 537-47, 2008 Oct.
Article
em En
| MEDLINE
| ID: mdl-18602718
ABSTRACT
BACKGROUND/AIMS:
Nucleic acid testing (NAT) for hepatitis B virus (HBV) DNA in blood donations identified occult HBV infection (OBI) as a potential threat to blood safety.METHODS:
A collaborative study was undertaken to explore the molecular basis of OBIs prevalent in Europe in relation to clinical and serological data.RESULTS:
Ninety-one percent of 77 donor samples of European origin HBV DNA positive but HBV surface antigen (HBsAg) negative were confirmed. Viral load ranged between unquantifiable and 5640 IU/mL (median 25 IU/mL). Fifty-two strains were genotyped (14 HBV(A2) and 38 HBV(D)). Compared to HBsAg+ samples, genotype D was significantly more frequent than genotype A2 in OBIs from Poland or Italy (P<0.04). Amino acid substitutions were concentrated in the immunologically active parts of the Pre-S/S proteins (P<0.0001) affecting both cellular CD8 T-cell epitopes and B-cell neutralizing Major Hydrophilic Region epitopes. Substitutions were more frequent in OBIs than in HBsAg+ strains of both genotype D (P<0.001) and A2 (P<0.01), in OBIs of genotype D than A2 in the 'a' region (P<0.001) but not cellular epitopes, and in anti-HBs+ than anti-HBs- OBIs (P<0.001).CONCLUSIONS:
Results support the hypothesis that humoral and cellular immune pressure on the HBV envelope proteins are major mechanisms generating OBI.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Doadores de Sangue
/
DNA Viral
/
Vírus da Hepatite B
/
Hepatite B
Tipo de estudo:
Clinical_trials
/
Diagnostic_studies
/
Prevalence_studies
/
Prognostic_studies
/
Risk_factors_studies
Limite:
Adult
/
Aged
/
Female
/
Humans
/
Male
/
Middle aged
País/Região como assunto:
Europa
Idioma:
En
Ano de publicação:
2008
Tipo de documento:
Article