title: Ongoing subclinical infection of hepatitis E virus among blood donors with an elevated alanine aminotransferase level in Japan.
abstract: Ongoing subclinical infection of hepatitis E virus (HEV) has not been fully studied. In the present study, serum samples were collected from 6700 voluntary blood donors with an elevated alanine aminotransferase (ALT) level of 61-476 IU/l at a Japanese Red Cross Blood Center, and were tested for the presence of IgG, IgM and IgA classes of antibodies to HEV (anti-HEV) by in-house ELISA and HEV RNA by nested RT-PCR. Overall, 479 blood donors (7.1%) were positive for anti-HEV IgG, including 8 donors with anti-HEV IgM and 7 donors with anti-HEV IgA. Among the nine donors with anti-HEV IgM and/or anti-HEV IgA, six had detectable HEV RNA. The presence of HEV RNA was further tested in 10-sample minipools of sera from the remaining 6691 donors, and three donors including one without anti-HEV IgG were found to be positive for HEV RNA. When stratified by ALT level, the prevalence of HEV RNA was significantly higher among the 109 donors with ALT > or = 201 IU/l than among the 6591 donors with ALT of 61-200 IU/l (2.8% vs. 0.1%, P < 0.0001). The HEV isolates obtained from the nine viremic donors segregated into genotype 3, shared a wide range of identities of 85.6-98.5% and were 87.3-93.9% similar to the Japan-indigenous HEV strain (JRA1), in the 412-nucleotide sequence of open reading frame 2. This study suggests that approximately 3% of Japanese individuals with ALT > or = 201 IU/l have ongoing subclinical infection with various HEV strains.
authors: Japanese Red Cross Saitama Blood Center, Saitama-Ken, Japan.
authors: Yuhko
authors: Y
authors: Gotanda
authors: Akiko
authors: A
authors: Iwata
authors: Hitoshi
authors: H
authors: Ohnuma
authors: Akira
authors: A
authors: Yoshikawa
authors: Hideaki
authors: H
authors: Mizoguchi
authors: Kazunori
authors: K
authors: Endo
authors: Masaharu
authors: M
authors: Takahashi
authors: Hiroaki
authors: H
authors: Okamoto
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000410:Alanine Transaminase / Q000097:blood*; D001782:Blood Donors; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006508:Hepatitis Antibodies / Q000097:blood; D016751:Hepatitis E / Q000097:blood / Q000175:diagnosis* / Q000503:physiopathology; D016752:Hepatitis E virus / Q000145:classification / Q000235:genetics / Q000276:immunology; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D007564:Japan; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D010802:Phylogeny; D012367:RNA, Viral / Q000097:blood / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D012727:Sex Characteristics
chemical_list: D006508:Hepatitis Antibodies; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D012367:RNA, Viral; D000410:Alanine Transaminase