Detection and molecular characterisation of a diagnosis escape variant associated with occult hepatitis B virus in Brazil
| Autor: | Ricardo Wagner de Almeida, Elisabeth Lampe, Francisco C. A. Mello, Lia Laura Lewis-Ximenez, Cleber F. Ginuino, Márcia Paschoal do Espírito Santo, Paulo Sergio Fonseca de Sousa, Livia Melo Villar, Isabelle Vasconcelos Menegoy |
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| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Microbiology (medical) Hepatitis B virus HBsAg occult hepatitis B infection lcsh:Arctic medicine. Tropical medicine Genotype lcsh:RC955-962 genotype lcsh:QR1-502 Real-Time Polymerase Chain Reaction medicine.disease_cause Sensitivity and Specificity lcsh:Microbiology Serology 03 medical and health sciences 0302 clinical medicine medicine Humans Mutation Hepatitis B Surface Antigens business.industry HbsAg Reproducibility of Results virus diseases Articles Hepatitis B medicine.disease Occult Virology digestive system diseases 030104 developmental biology Real-time polymerase chain reaction DNA Viral 030211 gastroenterology & hepatology mutation business Brazil |
| Zdroj: | Memórias do Instituto Oswaldo Cruz, Volume: 112, Issue: 7, Pages: 485-491, Published: JUL 2017 Memórias do Instituto Oswaldo Cruz Memórias do Instituto Oswaldo Cruz., Vol 112, Iss 7, Pp 485-491 |
| Popis: | BACKGROUND Many studies have identified mutations in the hepatitis B surface antigen (HBsAg) as important factors limiting the ability of commercial serological assays to detect this viral antigen. However, an association between mutations in the HBsAg gene and the occurrence of occult HBV infection (OBI) in patients has not been established. OBJECTIVES To detect hepatitis B virus (HBV) DNA in patients with anti-HBc as a unique serological marker, a previously published, cost-effective TaqMan-based real-time polymerase chain reaction (PCR) test with minor groove binding probes was adapted for use in this study. The current study also aimed to investigate HBsAg mutations and genotypes of HBV in OBI at the Viral Hepatitis Ambulatory Clinic in Rio de Janeiro to determine any possible association. METHODS Intra-assay and inter-assay reproducibility were determined, and the mean coefficient of variation values obtained were 2.07 and 3.5, respectively. Probit analysis indicated that the 95% detection level was 25 IU/mL. The prevalence of OBI was investigated in 35 serum samples with an ‘anti-HBc alone’ profile from individuals who attended our clinic between 2011 and 2013. FINDINGS HBV DNA was detected in only one sample, resulting in an OBI rate of 2.9%. Nucleotide sequencing of the pre-S/S region was performed to genotype and analyse mutations within the HBsAg gene of this HBV DNA. The HBV in the OBI case was classified as sub-genotype A1, and a sequence analysis of the small S gene revealed 12 mutations in the major hydrophilic region compared to the consensus A1 sequence. Most of these mutations occurred in amino acid residues that have been reported as clinically relevant because they have been implicated in vaccine escape and/or inability to detect HBsAg by commercial serological assays. MAIN CONCLUSIONS Our study suggests the importance of specific HBsAg mutations, different from those in D, B, and C genotypes, in sub-genotype A1 HBV associated with OBI. |
| Databáze: | OpenAIRE |
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