A sensitive serodiagnosis of hepatitis C virus (HCV) infection with two non-fused peptides: comparison of antibody responses detected with a newly developed assay and a commercial second-generation test.
An enzyme-linked immunosorbent assay (ELISA) was developed for the detection of anti-HCV antibody. We assayed for antibodies against either oligopeptide (S29-1) deduced from the nucleocapsid gene or the product of nonstructural region (NS3) synthesized in a recombinant Escherichia coli (S4). To reduce false-positive results induced by non-specific binding of antibodies with a carrier protein and to increase the sensitivity of an immunoassay, non-fused S4 peptide was prepared by the recombinant DNA technique and site-specific proteolysis (by factor Xa). In 71 non-A, non-B hepatitis patients with chronic liver disease, 70 (98.5%) were positive by S29-1/S4 ELISA as well as by a second-generation test (Abbott II). On the other hand, of 40 serum samples from blood donors, in which anti-N14 (core) and C100-3 antibodies were not detected but hepatitis C virus (HCV) RNA was detectable by polymerase chain reaction (PCR), 24 (60%) were positive by S29-1/S4 ELISA, whereas only 18 (45%) were diagnosed by Abbott II. In addition, based on results in a small group of 92 blood donors, detection of anti-S29-1/S4 antibody correlated well with HCV viremia as confirmed by PCR. These results indicated that the preparation of nonfused protein (S4) by recombinant DNA technique and a combination of S29-1 and S4 as immobilized antigens in an ELISA provide a sensitive and specific diagnosis for HCV infection with good correlation with the presence of viral RNA as confirmed by PCR.
Sato
A
A
Medical Devices Laboratory, Toray Industries, Inc., Shiga, Japan.
Ida
N
N
Ishikawa
M
M
Tanahashi
K
K
Nakamura
H
H
Sho
Y
Y
Arima
T
T
Kunitomo
T
T
D000595:Amino Acid Sequence; D000956:Antigens, Viral / Q000235:genetics* / Q000276:immunology; D001483:Base Sequence; D001782:Blood Donors; D003001:Cloning, Molecular; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D000939:Epitopes / Q000276:immunology; D004926:Escherichia coli / Q000235:genetics; D006508:Hepatitis Antibodies / Q000097:blood*; D006526:Hepatitis C / Q000175:diagnosis* / Q000276:immunology; D018937:Hepatitis C Antibodies; D006525:Hepatitis, Viral, Human / Q000276:immunology; D006801:Humans; D008969:Molecular Sequence Data; D011933:Reagent Kits, Diagnostic; D011994:Recombinant Proteins / Q000276:immunology; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000379:methods*; D014758:Viral Core Proteins / Q000276:immunology; D017361:Viral Nonstructural Proteins / Q000276:immunology
D000956:Antigens, Viral; D000939:Epitopes; D006508:Hepatitis Antibodies; D018937:Hepatitis C Antibodies; D011933:Reagent Kits, Diagnostic; D011994:Recombinant Proteins; D014758:Viral Core Proteins; D017361:Viral Nonstructural Proteins