Impact of nucleic acid testing for human immunodeficiency virus and Hepatitis C virus on blood product availability, outdating, and patient safety: Results of the 2001 AABB/CAP viral market C survey

Archives of Pathology & Laboratory Medicine,  Dec 2002  by Sherman, Laurence A

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* Context.-Limited data are available about the impact of nucleic acid testing for human immunodeficiency virus and hepatitis C virus in donated blood as part of a nationwide investigational study that affected greater than 90% of the blood supply.

Objective.-To assess the impact of nucleic acid testing on supply, outdating, and patient safety.

Design.Participants in the College of American Pathologists 2001 American Association of Blood Banks/College of American Pathologists Viral Marker C survey were asked questions about supply, outdating, and implementation of a full quarantine of blood pending nucleic acid testing results. The number of respondents for each question ranged from 197 to 219 for blood centers and from 462 to 504 for hospitals.

Results.-Shortages were more common for platelets (29% and 23% of blood centers and hospitals, respectively) than for red blood cells (13%, 11 %). Similarly, outdating of platelets (13%, 11 %) was more common than out

dating of red blood cells; outdating of red blood cells was negligible for both blood centers and hospitals. Forty-two percent of blood centers did not meet the mid 2000 target date for quarantining red blood cells, and 18% were not quarantining as of September 2001. The hospital figures were 66% not quarantining in mid 2000 and 39% not quarantining as of September 2001. Higher proportions of centers and hospitals were not quarantining platelets at these 2 dates.

Conclusions.-Unfavorable trends in both blood shortages and outdating were attributed to nucleic acid testing. Greater effects may have been masked by delayed implementation of full quarantine nationwide. This delay meant continued patient risk, and lack of full benefit, in a trial that was in effect a national standard. In the future, added systems will be needed for similar new endeavors to ensure uniformity of care and to avoid shortages.

(Arch Pathol Lab Med. 2002;126:1463-1466)

n the College of American Pathologists 2001 American Association of Blood Banks/College of American Pathologists (AABB/CAP) Viral Marker C (VM-C) proficiency survey, the CAP Transfusion Transmitted Disease Committee posed supplemental questions concerning the effect of nucleic acid testing (NAT) on blood product supply outdating, and patient safety (ie, issuance of only NAT-- negative blood). The results were reported to participants.' This article is a further analysis of and brief commentary on the responses to those questions.

In mid 1999, an investigational study initiated the use of NAT for detection of human immunodeficiency virus (HIV) and hepatitis C virus (HCV) in blood donors,2,3 which continued until NAT licensure in late February 2002. The study design had distinctive features. First, after a few months, more than 90% of the blood supply in the United States was being tested by NAT, even though NAT was still classified as investigational by the Food and Drug Administration (FDA), and the usual tests for HIV and HCV were still being performed. Second, this transfer of a high-technology test, previously used only in a limited way for individual patients, to testing a million blood donors per month necessitated solving major technical and logistical problems. Third, the new NAT could not be completed until several days after collection. This delay was due to both a longer testing time compared with that of standard, licensed tests and added transportation time. The usual process involved starting standard testing and concomitantly shipping samples to the few NAT sites. For example, although the American Red Cross had a number of sites performing standard HIV and HCV testing, they had only one site, in California, performing NAT for all blood units drawn by the Red Cross over the entire country. Similarly, there were only a few NAT sites testing for those blood centers in America's Blood Centers. The details have been described,3 but initially, 3 or more days postdonation were often required before NAT results were obtained. This contrasted with the availability of results from all of the standard, required tests in less than 1 day postdonation. Because NAT was investigational, the FDA did not require completion of NAT before blood release and transfusion. Further, products were not labeled as NAT tested because NAT was not licensed. The longer testing time led to a study design with a first stage (phase I), wherein blood products would be released for transfusion based on the results of standard HIV and HCV tests, before the NAT results were known. In contrast, in the next study stage (phase II), blood products would be quarantined and not issued for transfusion until negative NAT results were received. Thus, phase II fulfilled the processes followed for an FDA-required test, except that NAT per se was still investigational. Many blood centers passed on to hospitals costs/charges for NAT testing at rates of $6 to $12 per unit of red blood cells (RBCs), regardless of whether the blood was issued before the NAT results were known. The early variation in the speed of phase II implementation and other ethical and logistic issues have been previously commented on4 and debated.4,5 A workshop in late 1999 detailed the initial results?