Resource Newsletter Archive
NAT and Tissue Banking: The Time Has Come
A donor who tested negative for hepatitis C virus (HCV) in October 2000, but transmitted the virus through organ and tissue transplants, turned out to be the catalyst for improved testing in tissue banking four years later.
In 2004, an archived blood sample from that donor tested positive for HCV using the nucleic acid test (NAT), which can detect very low levels of the virus' genetic material, nucleic acid.
NAT sensitivity and specificity depend on amplification of the viral nucleic acid.
Unfortunately, NAT was not available for organ and tissue donor testing when the Oregon donor was originally tested. In the standard testing procedure being used at the time, the donor's blood test results were negative for hepatitis C.
If NAT had been available for use back then, three of the six organ recipients would not have died of hepatitis C, and 5 of the 32 tissue recipients would not have been infected.
...the Tissue Services played a critical role in the pre-clinical studies that led to the development of one of the approved NAT tests.
The possibility of repeating those tragic donation results will be reduced nationwide beginning March 9, 2005. That's when accredited tissue banks must begin testing all new donors using the nucleic acid tests (NAT) for HCV and HIV that have been proven to be so effective in three years of testing volunteer blood donors.
Of course, some tissue banks are always ahead of the curve and have employed NAT well before it has been declared mandatory. Northwest Tissue Services was among them and started using NAT on prospective donors in August 2004.
Further, the Tissue Services played a critical role in the pre-clinical studies that led to the submissions for licensing of NAT tests for cadaveric blood testing.
Risk The American Association of Tissue Banks (AATB) has established a new standard requiring NAT for the human immunodeficiency virus (HIV) and HCV using kits licensed by the Food and Drug Administration (FDA) for use on cadaveric blood samples.
AATB's Action Came on the Heels of two 2004 research studies on the effectiveness of NAT published in the New England Journal of Medicine.* D. Michael Strong, Ph. D., executive vice president of operations for Puget Sound Blood Center and laboratory director of its Northwest Tissue Services division, co-authored both.
One study reported data from three years of NAT testing of blood donations, including blood donated at Puget Sound Blood Center during that time frame, as well as donations from other independent centers and the American Red Cross.
In all, 37 million blood donations were tested with NAT for HCV and HIV. The results: NAT reduced the time HCV can remain undetected, referred to as the “window period,” from 70 to seven days, and prevented 56 HCV transmissions annually, based on a total of 13.6 million donations.
For HIV, NAT reduced the window period from 16 to nine days and prevented five transmissions a year from 13.6 million donations.