American Red Cross - testing for HCV and HIV

Mr. Chairman and members of the Committee, I am pleased to be here today to discuss the American Red Cross position regarding donor and product management of nucleic acid testing (NAT) for HCV and HIV. My name is Susan Stramer and I am the Executive Scientific Officer, National Testing and Reference Laboratories and Blood Services for the American Red Cross. The safety of the blood supply and the patients we serve is the number one priority of the Red Cross. As such, the Red Cross has been a leader in implementing NAT under FDA's Investigational New Drug (IND) application and has been working with the blood industry in support of rational policies for the management of NAT-reactive donors and their associated products. We believe that NAT has been effective in detecting window-period HIV and HCV infections in donors more effectively than today's currently licensed screening tests.

The Red Cross has been screening blood for HIV-1 and HCV RNA by NAT since March 1999. Since that time, we have screened over 12.4 million donations by NAT. The HCV yield is 40 seronegative, NAT confirmed-positive donations or 1 in 310,000 donations. This frequency has been consistent throughout our investigation. Our HIV yield is now 3 seronegative, NAT confirmed-positive donations, or 1 in 4.13 million donations, a rate that is not significantly different than projected yields. Approximately one out of every 22,000 donors are deferred, however, because of a seronegative donation testing NAT-reactive.

The Red Cross has also expanded the number of sites performing NAT with the opening of a lab in St. Louis and labs soon to open in Charlotte and Philadelphia. With the opening of these sites, we will have five labs performing NAT. This will increase our ability to reduce turnaround times for test results.

With existing platforms for NAT, our major challenges continue to be maintaining low false-positive and invalid run rates; both concerns are the product of lack of automated technology and the number of human manipulations involved in testing. Irrespective of these continuing concerns regarding the lack of automation of the tests, the Red Cross believes it is clear that NAT does increase the safety of the blood supply through the identification of infectious units that would not have been detected by currently licensed tests.

During the time that the Red Cross has been using NAT, donors and products have been consistently managed through an established internal algorithm submitted to FDA using the IND process. The Red Cross began using its current algorithm in January, 2000. We believe our approach is conservative and ensures stringent donor and product management. The algorithm calls for the discard of all products associated with donations testing NAT-reactive whether originally tested in a pool or by individual donation. The donors testing NAT reactive are deferred. We have also implemented the use of a second NAT technology to confirm NAT-reactive seronegative or indeterminate donor samples and the use of this supplemental test serves as a trigger for recipient tracing. This concept is the same as currently used for serology testing.

NAT-reactive donors are asked to participate in donor follow-up studies through the point at which they would have been found positive by currently licensed tests. In addition, they are requested to complete a recent risk survey. Investigations of NAT-reactive donors include testing of the collected plasma unit, when available, to confirm the initial results as well as testing of follow up samples. This sample testing includes the original NAT technology, supplemental NAT, and repeated serology tests.

The data that we have generated has been consistent in that the number of false-positive deferred donors outnumbers those that are seronegative true positive cases. As a result, we believe that these false-positive donors should be allowed to be reentered based on the accumulated data demonstrating that they are neither infected with HIV or HCV and are the victims of contamination events in the laboratory due to the manual nature of testing. Therefore, we would request that the FDA grant approval for reentry algorithms even under IND.

We also call upon the FDA to license NAT for HIV and HCV but request it when GMP and automation concerns, including stringent process controls, have been addressed. At the time of NAT licensure, requirements for redundant tests such as HIV-1 p24 antigen should be eliminated. The Red Cross, along with the whole blood industry through various working groups, have managed NAT using conservative algorithms for donor and product management that have ensured the safest possible blood supply.

Thank you for the opportunity to provide the views of the Red Cross on this important topic and I would be happy to answer any questions you may have.

Last modified: 09/15/2007 16:48:09 ET