Date:  May 16, 1996 
From:  Director, Center for Biologics Evaluation and Research 
Subject:  Additional Recommendations for Testing Whole Blood, Blood 
Components, Source Plasma and Source Leukocytes for Antibody to 
Hepatitis C Virus Encoded Antigen (Anti-HCV) 
To:  All Registered Blood and Plasma Establishments 
On April 23, 1992, August 5, 1993, and August 19, 1993, FDA issued memoranda to all registered 
blood and plasma establishments, which provided recommendations for testing for antibody to Hepatitis 
C Virus Encoded Antigen (anti-HCV). This memorandum supplements those previous  memoranda by 
transmitting additional recommendations for testing for antibody to anti-HCV in blood establishments. 
(See attached recommendations.) 
In a public meeting of the Blood Products Advisory Committee (BPAC) on March 21, 1996, after 
review and discussion of the relevant information available, concern was expressed that the use of a 
supplemental test for anti-HCV that uses fewer antigens than the screening test for anti-HCV may 
cause uncertainties. In particular, the Committee discussed its concern that the use of the Chiron RIBA 
HCV 2.0 Immunoblot Assay (SIA) as a supplemental test for anti-HCV should not be used for donor 
re-entry if the OrthoTM HCV Version 3.0 ELISA Test System was used as a screening test. FDA has 
considered the BPAC concerns and sets forth in the attached rcommendations donor re-entry and 
counseling procedures that should be used in this situation. 
According to the attached recommendations, the use of either the Abbott HCV EIA 2.0 or the 
OrthoTM HCV 2.0 ELISA Test System to screen donor blood remains acceptable and no changes or 
clarifications to previous FDA HCV recommendation memoranda are needed. The Chiron RIBA 2.0 
SIA would continue to be used as a supplemental test for both donor counseling and re-entry following 
screening with the latter assays. 
Although this guidance document does not create or confer any rights, privileges or benefits for or on 
any person, and does not operate to bind FDA or the public, it does represent the agencys current 
thinking with regard to determining donor re-entry for donors who test repeatedly reactive when using 
the OrthoTM HCV Version 3.0 ELISA Test System. 
1
  Questions or comments concerning these recommendations may be directed to the Laboratory of 
Hepatitis, Division of Transfusion Transmitted Diseases, FDA/CBER, (HFM-325), 1401 Rockville 
Pike, Rockville, MD 20852; Phone: (301) 827-3011; FAX: (301) 496-0338. 
______________________________ 
Kathryn C. Zoon, Ph.D. 
Attachment: 	 Additional Recommendations for Testing Whole Blood, Blood 
Components, Source Plasma and Source Leukocytes for Antibody to 
Hepatitis C Virus Encoded Antigen (Anti-HCV) 
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  Additional Recommendations for Testing for 
Antibody to Hepatitis C Virus Encoded Antigen (Anti-HCV) 
In Blood Establishments 
May 16 , 1996 
On April 23, 1992, August 5, 1993, and August 19, 1993, FDA issued memoranda to all registered 
blood and plasma establishments, which provided recommendations for testing for anti-HCV. 
Additional recommendations are listed below. 
1.	  The use of either the Abbott HCV EIA 2.0 or the OrthoTM HCV 2.0 Elisa Test System to 
screen donor blood remains acceptable and no changes or clarifications to previous FDA 
HCV recommendation memoranda are needed. The Chiron RIBA HCV 2.0 SIA would 
continue to be used as the supplemental test for these screening tests. 
2.	  When testing donor blood, the same version of the HCV screening test, e.g., either 2.0 or 3.0, 
should be used for all initial and duplicate repeat tests. 
3.	  For the purpose of determining re-entry to the donor pool, donors who test repeatedly reactive 
using the OrthoTM HCV Version 3.0 ELISA Test System may not be reinstated as suitable 
donors using the Chiron RIBA HCV 2.0 SIA as a supplemental test. Such donors should be 
temporarily deferred pending the availability of a licensed supplemental test containing the NS5 
antigen. 
The reason for this recommendation is that the OrthoTM HCV Version 3.0 ELISA Test System 
contains an antigen, NS5, which is not part of the Chiron RIBA 2.0 SIA design. Therefore, until 
a supplemental test is licensed that includes the NS5 antigen, re-entry is not recommended. 
It is recommended, however, that samples from donors who test repeatedly reactive with the 
OrthoTM HCV 3.0 Version ELISA Test System be stored at -20 oC or colder until a suitable
Licensed supplemental test is available. 
4.	  For purposes of donor counseling and as a aid in diagnosis, donors who test repeatedly 
reactive using OrthoTM HCV Version 3.0 ELISA Test System may be tested using the Chiron 
RIBA 2.0 SIA. However, caution should be exercised when a negative Chiron RIBA 2.0 SIA 
test result is obtained because this supplemental test does not detect antibodies to the NS5 
region. 
5.	  FDA will notify blood establishments should a supplemental test become available that is 
suitable in all cases for the evaluation of donors who test repeatedly reactive using the OrthoTM 
HCV Version 3.0 ELISA Test System. 
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