Detection of HCV core antigen in human serum and plasma with an automated chemiluminescent immunoassay.
BACKGROUND
Currently, the detection of HCV infection in blood donors relies on the ability of immunoassays to detect circulating HCV antibodies. However, a significant delay exists between the time of infection and the development of antibodies. This delay (window period) can last up to 70 days. The introduction of NAT for the detection of HCV RNA has reduced this window period dramatically. However, NAT is labor intensive, prone to contamination, and expensive as compared with standard serologic tests.


METHODS
An automated, microparticle-based chemiluminescent assay for the detection of HCV core antigen in human serum and plasma was developed. The specificity and sensitivity of this prototype assay were evaluated by testing a population of normal blood donors and commercially available seroconversion panels.


RESULTS
The HCV core antigen assay exhibited a 99.9-percent specificity by detecting a single repeatably reactive sample out of 1004 normal donors tested. Assay sensitivity was determined by comparing the HCV core antigen detection rate with the antibody seroconversion profile and the rate of HCV RNA detection. Among 15 seroconversion panels examined, core antigen was detected in 69 of 70 antibody-negative and/or RNA-positive samples for a sensitivity relative to NAT of 98.6 percent.


CONCLUSIONS
These data indicate that the automated, microparticle-based chemiluminescent HCV core antigen assay can reduce the window period for detection of potentially infected blood donors by 32.7 days, and it represents a viable alternative to HCV RNA testing.
Muerhoff
A Scott
AS
Experimental Biology Research, Abbott Laboratories, North Chicago, Illinois 60064-6269, USA. scott.muerhoff@abbott.com
Jiang
Lily
L
Shah
Dinesh O
DO
Gutierrez
Robin A
RA
Patel
Jigisha
J
Garolis
Cynthia
C
Kyrk
Charles R
CR
Leckie
Gregor
G
Frank
Andrea
A
Stewart
James L
JL
Dawson
George J
GJ
D000911:Antibodies, Monoclonal; D001322:Autoanalysis; D001782:Blood Donors; D005838:Genotype; D016174:Hepacivirus / Q000235:genetics; D006526:Hepatitis C / Q000175:diagnosis / Q000517:prevention & control / Q000635:transmission; D018937:Hepatitis C Antibodies / Q000097:blood; D018936:Hepatitis C Antigens / Q000097:blood*; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D008163:Luminescent Measurements; D012367:RNA, Viral / Q000097:blood; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D019562:Viral Load
D000911:Antibodies, Monoclonal; D018937:Hepatitis C Antibodies; D018936:Hepatitis C Antigens; D012367:RNA, Viral