Course of HEV viremia and anti-HEV IgM/IgG response in asymptomatic blood donors

J Clin Virol. 2018 Aug;105:26-30. doi: 10.1016/j.jcv.2018.05.013. Epub 2018 May 29.

Abstract

Background: Globally, an estimated 20 million Hepatitis E infections occur every year. The course of viremia and antibody response has been investigated in patients with symptomatic hepatitis E. However, the majority of HEV infections in industrialized countries take a subclinical course.

Objectives: To investigate the course of HEV viremia and epitope specific anti-HEV IgM/IgG response in asymptomatic blood donors in order to understand the immune response and viral clearance in asymptomatic blood donors with HEV infections.

Methods: In this study 27 HEV viremic donors were identified by HEV-PCR during routine screening of blood donors and the course of anti-HEV IgM/IgG and HEV-RNA was retrospectively studied using RT-PCR and a commercial immunoblot (Mikrogen®) allowing classification of the antibody response according to HEV epitopes.

Results: At time of donation, serological testing failed to identify viremic donors as 70.4% had no detectable antibody response. Anti-HEV IgM could be detected in 22.2% of viremic donors while anti-HEV IgG could be found in 7.4%. At least three donors experienced prolonged viremia beyond 100 days. Spontaneous HEV-RNA clearance within a median time span of 57 days was observed in all 27 donors. In all donors anti-HEV IgG specific for the immunogenic viral epitope O2C could be detected in close temporal association with viral clearance.

Conclusion: Serological testing is inappropriate for identifying HEV-viremic blood donors. Acute HEV infection in asymptomatic blood donors can persist for more than 100 days. HEV-RNA clearance coincided with the appearance of anti-HEV IgM/IgG confirming the importance of a B-cell mediated response in clearing acute infections. Anti-HEV IgM and IgG specific for the epitope O2C are associated with the clearance of HEV-viremia.

Keywords: Bloodborne Hepatitis E virus infection; Hepatitis E virus; Hepatitis E virus blood donor screening; Serological response; Viral course.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Antibodies, Viral / blood*
  • Asymptomatic Infections*
  • Blood Donors*
  • Cohort Studies
  • Female
  • Genotype
  • Hepatitis E / blood
  • Hepatitis E / immunology*
  • Hepatitis E virus / genetics
  • Hepatitis E virus / immunology
  • Humans
  • Immunoglobulin G / blood*
  • Immunoglobulin M / blood*
  • Male
  • Middle Aged
  • Polymerase Chain Reaction
  • RNA, Viral
  • Viremia / immunology*
  • Young Adult

Substances

  • Antibodies, Viral
  • Immunoglobulin G
  • Immunoglobulin M
  • RNA, Viral