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The effect of Nucleic acid testing
(NAT) in the safety of blood
transfusions
F. Kourgia, M. Vini, E. Zervou
Blood Centre of University Hospital of Ioannina,
Ioannina, Greece
• Around the world, more than 92 million blood donations
are collected every year.
•
From these, a single whole-blood donation can be
transfused in up to three people, while blood-derived
products from a single donation may be given to
hundreds of patients.
• Laboratory screening of donated blood and blood
products for infectious diseases is a key safety measure
in protecting patients and preventing the spread of
serious diseases.
• In accordance with guidelines, the minimum requirements of
blood testing include syphilis, HBV, HCV and HIV. In Greece
HTLVI/II also is tested.
• The norm for viral testing has been serology, but increasingly
NAT is been implemented where resources allow.
• NAT is a molecular technique used to detect a virus or
a bacterium
NAT improves the safety of transfusions because :
-shortens the serological silent window period a time
between when the donors have been infected and when they
show up as positive by antibody or antigen tests
and also
-detects the cases of occult HBV (HbsAg -/anti-Hbc+)
HCV
HBV
HIV
Aim:
• To determine the NAT yield ( the infectious
agent is not serologically detected but only
by NAT) for HBV, HCV and HIV in the
blood donations which conducted in the
Blood Centre of University Hospital of
Ioannina.
Methods:
• 2006-2014:
• 65.219 donations (62.460 for whole blood and 2.759
for platelets apheresis ) were tested
• For serological testing Abbott and Ortho assays were
used.
• For individual (ID) NAT testing the Procleix Ultrio
(Novartis) until the end of 2013 and after this time the
Cobas AmpliPrep (Roche) were used.
Results:
In this period:
• 1 case of HIV in the window period
• 17 cases of occult hepatitis B and
• 11 cases of possible occult hepatitis B
(NAT initially reactive, anti-HBc positive
but the repetition of NAT was negative,
probably due to a low viral load) were
identified.
Conclusion:
• The implementation of NAT detects infectious
donations that could be missed by serological
testing and so plays an important role in the
safety of blood transfusions.
• In our center we found that the HBV NAT yield
was 1/2.329 (1/3.836 clear occult HBV and
1/5.929 possible cases ) and the HIV NAT yield
was 1/65.219 blood donations.
•
National data (SKAE)
2007-2013:
• ΝΑΤ yield in 3,240,394 blood donations
• Only NAT positive
•
8 HIV
• 19 HCV
• 436 HBV
1/405049
1/70547
1/7432
Thank you