Detection of hepatitis C core antigen in the antibody negative 'window' phase of hepatitis C infection.
OBJECTIVE
Despite improvements in assays for anti-HCV, there remains a significant delay before the appearance of antibodies following infection, during which, circulating viral RNA is present. We have evaluated a prototype assay for the serological detection of hepatitis C virus (HCV) core antigen with specimens derived from the early phase of HCV infection.


METHODS
Serial specimens from 24 individuals undergoing HCV seroconversion were tested for the presence of anti-HCV, HCV RNA and HCV core antigen.


RESULTS
HCV antigen was detected at the same time as HCV RNA in 83% (20/24) cases. The mean time to the first detection of HCV antigen was approximately 1 day later than HCV RNA. Overall, 87% of HCV-RNA-positive specimens contained detectable HCV core antigen.


CONCLUSIONS
These results indicate that HCV core antigen can be identified by routine serological ELISA in specimens from the early antibody-negative phase of HCV infection. A test for HCV core antigen may be a useful test for identifying window phase blood donations from antibody negative donors infected with HCV.
Peterson
J
J
Ortho Clinical Diagnostics, Raritan, NJ 08869, USA.
Green
G
G
Iida
K
K
Caldwell
B
B
Kerrison
P
P
Bernich
S
S
Aoyagi
K
K
Lee
S R
SR
D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000592:standards; D016174:Hepacivirus / Q000235:genetics / Q000276:immunology; D006526:Hepatitis C / Q000175:diagnosis / Q000276:immunology*; D018937:Hepatitis C Antibodies / Q000097:blood*; D018936:Hepatitis C Antigens / Q000097:blood; D012367:RNA, Viral / Q000097:blood; D012680:Sensitivity and Specificity; D013997:Time Factors; D014758:Viral Core Proteins / Q000097:blood*
D018937:Hepatitis C Antibodies; D018936:Hepatitis C Antigens; D012367:RNA, Viral; D014758:Viral Core Proteins; C069130:nucleocapsid protein, Hepatitis C virus