#8
EARLY DETECTION OF HIV AND HCV INFECTIONS IN DONORS BY NUCLEIC ACID TESTING (NAT).
Steven S. Geier PhD 1, Kevin D. Barfield MT 1 and Michael J. Bauer MD 1. 1 Laboratories At Bonfils, Denver, CO, USA .
It is important pretransplant to identify donors with infections that could be transmitted to recipients. Current UNOS requirements for HIV 
HCV rely on Enzyme Immuno Assays which look for antiviral antibodies as indicators of infection. Unfortunately, it takes time for an infected individual to produce antibodies.
Organ, tissue and cornea transplant patients can now benefit from earlier detection of infected donors due two NATs. NATs directly detect the presence of virus and do not have to wait for antibodies. Both NAT and antibody tests are needed to detect infected donors. NAT tests are very sensitive and can detect <100 copies of virus per ml of blood. To detect an early infection, EIA antibody takes 
22 days for HIV and 82 days for HCV, but NAT only 11 days. Even after antibodies are produced, NAT tests can often detect virus and prevent donors with false negative EIA viral antibody tests from being used. In blood donors it is estimated that NAT annually prevents about 11 HCV and 1 HIV infected donors from transmitting their infection to recipients of blood.
In our study, the Procleix
NAT test was prospectively used on over 9,000 tissue and cornea donors with no test failures and the detection of 4 HIV and 98 HCV infected donors, who were also producing anti viral antibodies. 58 archived frozen serum samples were NAT tested from previously HCV EIA Reactive donors: 22 were NAT NonReactive and 36 were HCV Reactive; average copies/ml: 1 million (45 copies - 6 million). The recovery of virus from plasma, serum and clotted blood was also evaluated. There was a 65% loss of HIV or HCV viral load in serum and clotted blood, but not in plasma.
NAT and EIA antibody testing provide transplant patients with more protection against an undetected infected donor.