1. Hepatitis B genotypes and surface antigen mutants present in Pakistani blood donors
- Author
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Catherine A. Brennan, Saleem Ahmed Khan, Sarfaraz Jafri, Barbara J. Harris, Nuzhat Salamat, Huma Qureshi, Mohammad Ayyub Khan, and Vera Holzmayer
- Subjects
Male ,0301 basic medicine ,HBsAg ,lcsh:Medicine ,Blood Donors ,Artificial Gene Amplification and Extension ,medicine.disease_cause ,Polymerase Chain Reaction ,law.invention ,Serology ,Geographical Locations ,0302 clinical medicine ,law ,Genotype ,Pakistan ,030212 general & internal medicine ,lcsh:Science ,Pathology and laboratory medicine ,Polymerase chain reaction ,Multidisciplinary ,Geography ,Database and informatics methods ,Sequence analysis ,virus diseases ,Middle Aged ,Medical microbiology ,Hepatitis B ,Mutant Strains ,Phylogeography ,Biogeography ,Viruses ,Blood Banks ,Female ,Pathogens ,Research Article ,Adult ,Hepatitis B virus ,Asia ,Adolescent ,Bioinformatics ,Biology ,Microbiology ,Virus ,Donor Selection ,03 medical and health sciences ,Antigen ,Genetics ,medicine ,Humans ,Blood Transfusion ,Molecular Biology Techniques ,Molecular Biology ,DNA sequence analysis ,Aged ,Immune Evasion ,Medicine and health sciences ,Evolutionary Biology ,Hepatitis B Surface Antigens ,Population Biology ,lcsh:R ,Ecology and Environmental Sciences ,Viral pathogens ,Organisms ,Biology and Life Sciences ,medicine.disease ,Virology ,Hepatitis viruses ,digestive system diseases ,Microbial pathogens ,Research and analysis methods ,Health Care ,030104 developmental biology ,Health Care Facilities ,DNA, Viral ,Mutation ,People and Places ,Earth Sciences ,lcsh:Q ,Sequence Alignment ,Population Genetics - Abstract
Background The prevalence of chronic Hepatitis B Virus (HBV) infection is 2–4% in the Pakistani population, defining Pakistan as an intermediate prevalence country. In this study, hepatitis B surface antigen (HBsAg) reactive blood donations were screened using a combination of serological and molecular methods to identify immune escape HBV mutant strains and to determine the HBV genotypes and subtypes present in Pakistan. Methods Blood donations were collected at the Armed Forces Institute of Transfusion (AFIT) located in northern Pakistan and the Hussaini Blood Bank (HBB) located in the south. From 2009 to 2013 a total of 706,575 donations were screened with 2.04% (14,409) HBsAg reactive. A total of 2055 HBsAg reactive specimens, were collected and screened using a monoclonal antibody based research assay to identify immune escape mutants followed by PCR amplification and DNA sequencing to identify the mutation present. DNA sequences obtained from 192 specimens, including mutant candidates and wild type strains, were analyzed for escape mutations, genotype, and HBsAg subtype. Results Mutations were identified in approximately 14% of HBsAg reactive donations. Mutations at HBsAg amino acid positions 143–145 are the most common (46%) with the mutation serine 143 to leucine the most frequently occurring change (28%). While regional differences were observed, the most prevalent HBV strains are subgenotypes of D with subgenotype D1/subtype ayw2 accounting for the majority of infections; 90.2% at AFIT and 52.5% at HBB. Conclusions The high frequency of immune escape HBV mutants in HBV infected Pakistani blood donors highlights the need for more studies into the prevalence of escape mutants. Differences between vaccinated and unvaccinated populations, the correlation of escape mutant frequency with genotype, and impact of escape mutations in different genotype backgrounds on the performance of commercially available HBsAg assays represent avenues for further investigation.
- Published
- 2017