Comparative yield of HCV RNA testing in blood donors screened by 2.0 versus 3.0 antibody assays.
BACKGROUND
Two HCV antibody tests (EIA 2.0 [EIA2], Abbott; and the Version 3.0 ELISA [EIA3], Ortho) are currently licensed for screening of US blood donors. Testing of donors for HCV RNA allows comparison of the sensitivities of the two antibody-screening assays.


METHODS
All allogeneic blood donations at 13 US test sites were screened for HCV RNA by testing plasma minipools using an investigational assay (COBAS AmpliScreen HCV test, v2.0, Roche Molecular Systems). Some sites screened for HCV antibody by EIA2 and some used EIA3. The frequency of RNA-positive and antibody-negative (RNA-pos and Ab-neg) donations among donors screened by each antibody assay was compared. Antibody appearance was assessed in a donor follow-up study.


RESULTS
A total of 5.51 x 10(6) donations were screened for HCV RNA. Of these, 2.27 million were screened for antibody by EIA2, and 3.24 million by EIA3. Twenty-three donations were HCV RNA-pos and Ab-neg. The frequency of RNA-pos and Ab-neg donations was higher among donations screened by EIA2 (1 in 134,000), compared to those screened by EIA3 (1 in 540,000) (p = 0.001). Of the 17 RNA-pos and Ab-neg donations identified by test sites that used EIA2, 14 were retested by EIA3 and 10 (71%) were reactive. Most RNA-pos and Ab-neg donors appear to be in the process of seroconversion. Donors that were initially EIA2-negative and EIA3-reactive showed a more prolonged pattern of seroconversion compared to those that were initially nonreactive by both antibody assays. Four donors were EIA2-negative, EIA3-reactive, and RIBA-indeterminate (c33c) for at least 90 days, 1 for more than 317 days.


CONCLUSIONS
EIA3 would have detected the majority of RNA-positive donations missed by EIA2. Some RNA-positive donors are EIA2-negative and EIA3-reactive for a prolonged period of time.
Galel
Susan A
SA
Stanford Medical School Blood Center, Department of Pathology, Stanford University School of Medicine, Palo Alto, California 94304, USA. susangal@stanford.edu
Strong
D Michael
DM
Tegtmeier
Gary E
GE
Holland
Paul V
PV
Kuramoto
Isamu K
IK
Kemper
Marti
M
Pietrelli
Larry
L
Gallarda
James
J
D000328:Adult; D000410:Alanine Transaminase / Q000097:blood; D015415:Biomarkers; D001782:Blood Donors; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005500:Follow-Up Studies; D005838:Genotype; D016174:Hepacivirus / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D006526:Hepatitis C / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology / Q000821:virology; D018937:Hepatitis C Antibodies / Q000097:blood*; D006801:Humans; D015151:Immunoblotting; D007124:Immunoenzyme Techniques; D008297:Male; D008403:Mass Screening / Q000379:methods*; D011237:Predictive Value of Tests; D012367:RNA, Viral / Q000097:blood*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016036:Seroepidemiologic Studies; D013997:Time Factors; D014481:United States / Q000453:epidemiology; D014766:Viremia / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology / Q000821:virology
D015415:Biomarkers; D018937:Hepatitis C Antibodies; D012367:RNA, Viral; D000410:Alanine Transaminase