Combination HCV core antigen and antibody assay on a fully automated chemiluminescence analyzer.
BACKGROUND
HCV exposure among blood donors is serologically determined by detection of antibodies to HCV (anti-HCV); however, the recent development of an assay for the detection of HCV core antigen identifies infection before anti-HCV development. Simultaneous detection of HCV core antigen and anti-HCV would shorten the window period before seroconversion over conventional HCV antibody screening assays.


METHODS
A prototype chemiluminescent immunoassay was developed for simultaneous detection of HCV core antigen and anti-HCV in human sera and plasma. The assay was performed on a single-channel instrument representing an automated serologic analyzer (PRISM, Abbott Laboratories) system. Sensitivity and specificity were evaluated by testing 23 HCV seroconversion panels and plasma or sera from volunteer blood donors.


RESULTS
The prototype HCV core antigen and antibody combination assay detected 80 of 89 (89.9% ) HCV RNA-positive and antibody-negative specimens from 23 panels, thereby reducing the seroconversion window period by an average of 34.3 days compared to PRISM HCV antibody detection. All PRISM HCV antibody-positive specimens were detected by the combination assay for a relative sensitivity of 100 percent. The repeatedly reactive rate was 0.20 percent based on testing of 3017 screened anti-HCV-negative sera and plasma.


CONCLUSIONS
The prototype combination assay was shown to detect HCV core antigen and anti-HCV simultaneously and significantly closed the time gap between the initial detection of HCV RNA and the first appearance of detectable antibodies to HCV.
Shah
Dinesh O
DO
New Assay Development and Infectious Diseases R & D, Abbott Diagnostics Division, Abbott Laboratories, Abbott Park, Illinois, USA. dinesh.shah@abbott.com
Chang
Chi D
CD
Jiang
Lily X
LX
Cheng
Kevin Y
KY
Muerhoff
A Scott
AS
Gutierrez
Robin A
RA
Leary
Thomas P
TP
Desai
Suresh M
SM
Batac-Herman
Irenea V
IV
Salbilla
Vince A
VA
Haller
Alla S
AS
Stewart
James L
JL
Dawson
George J
GJ
D001322:Autoanalysis; D001782:Blood Donors; D016174:Hepacivirus / Q000235:genetics / Q000378:metabolism*; D006526:Hepatitis C / Q000097:blood / Q000175:diagnosis*; D018937:Hepatitis C Antibodies / Q000097:blood*; D018936:Hepatitis C Antigens / Q000097:blood*; D006801:Humans; D007118:Immunoassay; D008163:Luminescent Measurements; D012367:RNA, Viral / Q000032:analysis; 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