Evaluation of anti-hepatitis E virus (HEV) immunoglobulin A in a serological screening for HEV infection.
BACKGROUND
Several formulations of serological diagnostic kits were developed recently in Japan for detecting hepatitis E virus (HEV) infection. The present study was conducted to evaluate a novel anti-HEV serological kit based on detection of class A immunoglobulin antibody (anti-HEV IgA).


METHODS
Serum samples from 81 acute hepatitis (AH) and 112 chronic hepatitis (CH) patients were tested for anti-HEV IgG, anti-HEV IgM, and anti-HEV IgA by enzyme immunoassay, and HEV RNA was detected by reverse transcription-polymerase chain reaction.


RESULTS
Eight of 81 (9.9%) AH patients were positive for anti-HEV IgG; 6/81 (7.4%) were positive for anti-HEV IgM; and 3/81 (3.7%) were positive for anti-HEV IgA. HEV RNA was detected only in two patients, and both were positive for anti-HEV IgA and negative for hepatitis A, B, and C virus markers. Of 112 CH patients, reactivity to anti-HEV IgM and anti-HEV IgG was found in two and four patients, respectively. None of these six patients was positive for anti-HEV IgA or HEV RNA. For these six CH patients, serial serum samples stored during the clinical follow-up (1994-2003) were further subjected to anti-HEV IgG, IgM, IgA, and HEV RNA examinations. None of the examined stored samples was reactive for anti-HEV IgA or HEV RNA despite reactivity to anti-HEV IgM and IgG.


CONCLUSIONS
Serological examination for anti-HEV IgA together with IgM and IgG allows sensitive and specific determination of acute or past infection with HEV. Although its prevalence is low, HEV infection must be investigated in acute hepatitis patients even in nonendemic HEV countries.
Elkady
Abeer
A
Department of Clinical Molecular Informative Medicine, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-ku, Nagoya 467-8601, Japan.
Tanaka
Yasuhito
Y
Kurbanov
Fuat
F
Hirashima
Noboru
N
Sugiyama
Masaya
M
Khan
Anis
A
Kato
Hideaki
H
Okumura
Akihiko
A
Mizokami
Masashi
M
D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D005260:Female; D016751:Hepatitis E / Q000175:diagnosis* / Q000453:epidemiology / Q000276:immunology / Q000821:virology; D016752:Hepatitis E virus / Q000145:classification / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification; D006801:Humans; D007124:Immunoenzyme Techniques; D007070:Immunoglobulin A / Q000097:blood*; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D012367:RNA, Viral / Q000097:blood; D017422:Sequence Analysis, DNA
D007070:Immunoglobulin A; D012367:RNA, Viral