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Humoral immune response in Japanese acute hepatitis patients with hepatitis C virus infection
N Yamaguchi | K Tokushige | K Yamauchi | N Hayashi
The
humoral immune response to acute infection by hepatitis
C virus (HCV) is not yet perfectly clear in terms of
immunoglobulin (Ig) response, diversity of HCV antigen,
and the relation with hepatitis severity and antibody
response. Serum IgM and IgG anti-HCV levels in
patients with HCV and either acute hepatitis (AH) or
fulminant hepatitis (FH) were investigated; the diversity
of HCV antigen was investigated by RIBA test III. Of
22 AH patients, 12 (54.5%) were positive for IgM anti-HCV,
mainly reacting to HCV core protein. The mean interval
until the appearance of IgM anti-HCV after onset was
24.1±26.2 days. IgG anti-HCV mainly reacted to
both core and NS-3 antigen, appearing 42.6±42.1
days after onset. From a serial study of 15 AH
patients, it was considered that in seven AH patients
(46.7%), the IgM response would precede the IgG response.
In another two AH patients, IgM anti-HCV was not detected
during the acute disease phase. Of 48 chronic hepatitis
patients with HCV-RNA, 40 patients were positive for
IgM anti-HCV. Therefore, IgM anti-HCV was useful
for diagnosis in some of the AH patients, but it was
difficult to use for distinguishing between acute and
chronic infection. All four FH patients with HCV-RNA
were positive for both IgM and IgG antibody to HCV at
onset. Their antibody titres were higher than those
of AH patients. These results suggested that, as in
FH due to HBV, FH due to HCV could induce strong and
rapid humoral immunity.
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