Hepatitis B virus genotypes and precore mutations in Scottish blood donors.
OBJECTIVE
This study was carried out to determine the frequency of hepatitis B virus (HBV) core promoter variants (nucleotide positions 1762, 1764) and precore variants (nucleotide position 1896) in hepatitis B surface antigen (HBsAg)-positive Scottish blood donors. HBV genotypes present in this population were also identified.


METHODS
A total of 85 HBsAg-positive blood donor samples were included in the study. Of these, 79 were polymerase chain reaction (PCR) positive and had sequence and mutation information. They were divided into two groups: group 1 (23 individuals) were hepatitis B e antigen (HBeAg)-positive and negative for antibody to HBe (anti-HBe); and group 2 (56 individuals) were HBeAg negative and positive for anti-HBe. A line probe assay was used to detect mutations, and a comparison was made by using direct sequence analysis. A different line probe assay was used to identify HBV genotype.


RESULTS
The frequencies of mutations in group 1 were 22% each for mutations 1762, 1764 and 1896, increasing to 26%, 35% and 55% in group 2, respectively. By contrast, direct sequence analysis failed to identify 70% of wild-type/mutant mixes. The prevalence of viral genotypes was 41% for genotype A, 12% for genotype B, 5% for genotype C, 30% for genotype D and 12% for mixed-genotype infections. Precore mutations were seen in 10%, 88%, 25% and 74% of genotypes A, B, C and D, respectively.


CONCLUSIONS
The results indicate that core promoter and/or precore mutants may be under-reported. The combination of HBV PCR and line probe assays is useful for supplementing HBV serological tests. Non-Caucasian genotypes are present in the UK blood-donating population and will therefore affect the demographics of HBV infection.
Davidson
F
F
Transfusion Transmitted Infection Group, Scottish National Blood Transfusion Service, Royal (Dick) Veterinary School, Edinburgh, UK. fiona.davidson@snbts.csa.scot.nhs.uk
Lycett
C
C
Sablon
E
E
Petrik
J
J
Dow
B C
BC
D001782:Blood Donors; D004252:DNA Mutational Analysis; D005787:Gene Frequency; D014644:Genetic Variation; D005838:Genotype; D006509:Hepatitis B / Q000175:diagnosis / Q000821:virology; D006511:Hepatitis B Antigens / Q000235:genetics*; D006514:Hepatitis B Surface Antigens / Q000235:genetics; D006513:Hepatitis B e Antigens / Q000235:genetics; D006515:Hepatitis B virus / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D009154:Mutation; D015995:Prevalence; D011401:Promoter Regions, Genetic / Q000235:genetics; D012606:Scotland; D012698:Serologic Tests
D006511:Hepatitis B Antigens; D006514:Hepatitis B Surface Antigens; D006513:Hepatitis B e Antigens