Genetic variability of the S gene of hepatitis B virus: clinical and diagnostic impact.

Prevention of transfusion-transmitted infections.

Ana Avello´n* and Jose´ M. EchevarriaHepatitis Laboratory, Diagnostic Microbiology Service, National Centre of Microbiology,Instituto de Salud Carlos III, Majadahonda, Madrid, SpainThe prevalence in the population of hepatitisB virus (HBV) surface antigen (HBsAg) variantsthat may impair diagnosis, or allow the virus toescape vaccine-induced immunity or passiveimmunoglobulin therapy is unknown. A genomefragment encoding HBsAg amino acids 112–212was ampliﬁed and sequenced from the sera of272 unselected DNA-positive, HBV-chronic car-riers from Spain. The genotype and the HBsAgsubtype were predicted from the sequences.Analysis of amino-acid positions 112–157revealed single or multiple substitutions in 39%of the carriers studied. Mutations were notdetected for residues 121, 135, 137, 139, 140,141, 142, 146, 147, 148, 149, 151, 152, 153, 155,156, and 157. Substitutions reported previouslyto be in association with failures of diagnostictests or with vaccine or immunoglobulin therapyescape were found in 12.5%, 6.6%, and 9.2%of carriers, respectively. Met133Thr (2.2%);Gln129His, Met133Ile, Phe/Tyr134Asn (1.8%);Phe/Tyr134Leu,Gly145Ala(1.5%),andPro120Thr(1.1%) were the most frequent. Other substitu-tions, including Gly145Arg (0.4%), were found ata frequency of less than 1%. Samples containingHBV mutants were tested with three commercialassays for HBsAg screening. Almost all themutants reacted to the upper cut-off values ofthe assays, but six samples with weak reactivitywithoneormoreofthemethodswerealsofound.Thus, HBV mutants with a potential impact onclinical and public health issues are moderatelyfrequent among chronic carriers from Spain,although their inﬂuence on the performance ofdiagnostic tests seems to be slight. J. Med.Virol. 78:24–36, 2006.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/jmv.20516

Frequency of hepatitis B virus 'a' determinant variants in unselected Spanish chronic carriers.

A novel diagnostic immunoassay testing procedure for hepatitis B virus core antibody (anti-HBc) using homogeneous purified full-length hepatitis B virus core antigen (HBcAg) capsids obtained from Escherichia coli was compared with Abbott Architect anti-HBc chemiluminescent microparticle immunoassay (CMIA; indirect method) against a library of specimens. A monoclonal anti-HBc neutralization confirmatory assay was then used to determine the degree of discordance between specimens. The new assay was found to be superior in both sensitivity and specificity.

Novel Double-Antigen Sandwich Immunoassay for Human Hepatitis B Core Antibody

Residual risk of transfusion-transmitted hepatitis B virus (HBV) infection caused by blood components derived from donors with occult HBV infection in Japan.

Talal A. Sallam

Papers

The significance of 'anti-HBc only' in the clinical virology laboratory.