Impact of hepatitis B virus genotype F on in vitro diagnosis: detection efficiency of HBsAg from Amerindian subgenotypes F1b and F4.

LIMERES MJ; GOMEZ ER; NOSEDA DG; CERRUDO CS; GHIRINGHELLI PD; NUSBLAT AD; CUESTAS ML

ARCHIVES OF VIROLOGY

SPRINGER WIEN

Lugar: Viena; Año: 2019

0304-8608

The influence of the high genetic variability of hepatitis B virus (HBV) in the sensitivity of serological assays has received little attention so far. A major source of variability is related to viral genotypes and subgenotypes. Their possible influence on diagnosis and prophylaxis is poorly known and has mostly been evaluated for genotypes A, B, C and D. Robust data showing the detection efficiency of HBsAg from genotype F is lacking. This study examined the effect of viral-like particles containing HBsAg from genotypes A and F (particularly, F1b and F4) produced in Pichia pastoris in relation to the anti-HBs antibodies used in the immunoassays for in vitro diagnosis and compared it with that exerted by the G145R S-escape mutant. Results showed that HBsAg detection values of subgenotypes F1b and F4 significantly differed from those obtained for genotype A and that subgenotype F1b displayed the major impact on the sensitivity of the immunoassays tested. Prediction of the tertiary structure of subgenotypes F1b and F4 revealed changes inside and outside the major hydrophilic region (aa 101-160) of the HBsAg compared to genotype A and the G145R variant. A phosphorylation site (target for Protein Kinase C) produced in the G145R substitution might prevent the recognition by the anti-HBs antibodies. In conclusion, the use of different genotypes or variants for diagnosis could support a better detection of HBV infection. The incorporation of the genotype F-derived HBsAg vaccine in endemic areas for such genotype should be evaluated since it might also affect vaccination efficacy.