IgG antibody response demonstrates inverse correlation with viral load in Bangladeshi women with acute hepatitis E virus genotype 1 infection

Abstract

Objectives: To determine IgG immune responses and hepatitis E virus (HEV) viral load, and to explore the associations with pregnancy.

Methods: A total of 121 HEV-infected women (57 pregnant, 64 non-pregnant) were analysed. Quantitative reverse transcription PCR (RT-qPCR) was done for 78 HEV IgM-positive patients to determine viral load, and Sanger sequencing was performed for 62 HEV-RNA-positive patients to confirm genotyping. ELISA was conducted to determine HEV antibody and avidity indices.

Results: The HEV genotype was identified as variant 1. Significant negative correlations were observed between log HEV copy number and log hepatitis E virus IgG antibody index in the late acute phase of jaundice for both pregnant women (r = -0.7971, p = 0.0002) and non-pregnant women (r = -0.9117, p = 0.0002). Pregnant women had significantly higher serum log viral copy numbers and lower IgG antibody indices than non-pregnant women in the late acute phase of HEV-induced jaundice (p = 0.0196 and p = 0.0303, respectively). Moreover, pregnant women with acute HEV hepatitis had higher cross-reactive IgG antibodies compared to the non-pregnant women (p = 0.0017). Five patients with HEV hepatitis died, of whom four were pregnant.

Conclusions: Pregnancy might be associated with higher viral loads and a lower IgG response in the HEV-induced late acute phase of jaundice.

Keywords: Antibody index; Avidity index; Hepatitis E virus; IgG; Log viral copy; Pregnancy.