1. SoGAT meeting XXI May 28-29 (2009), Brussels, Belgium
Comparison of HBV NAT in small versus large test pools experience with the S 201 system
SoGAT meeting XXI May (2009), Brussels, Belgium
Marco Koppelman1,3,Theo Cuypers2, Harry Bos3 and Hans Zaaijer1
Sanquin Diagnostics, Amsterdam, the Netherlands
1. Blood-borne Infections (BOI)
2. Viral Diagnostic Services
3. National Screening Laboratory Sanquin (NSS)
25 April 2019

2. NAT yield cases (HBsAg (-)/HBV-DNA (+) of two testing formats
In the Netherlands no anti-HBc screening in the past
Number of HBV infections in donors in the Netherlands is low: 2007; 4 cases in repeat donors and 25 cases in new donors
Large test pools (July October 2008)
- HBV NAT in test pools of 480 donations
- AmpliScreen test for HBV DNA (Roche)
- 2,066,283 donations tested
Small test pools (November May 2009)
- HBV NAT in pools of 6 donations
- MPX test on the S 201 system (Roche)
- 458,365 donations tested
Archive sample of previous donations allow look-back to previous donations
25 April 2019

3. Sensitivity of both test formats
Type of screening
Test
Sensitivity for individual donation2
Pools of 480
Plasma1
HBV AmpliScreen
2,400 IU/ml
Pools of 6
Donor
MPX on S 201
26 IU/ml
1For release of plasma for manufacturing
2Determined by Sanquin based on dilution series of the HBV DNA WHO IS
Testing pools of 6 is approximately 100 times more sensitive than testing pools of 480
25 April 2019

4. NAT only donations pool 480 format
2 cases HBV DNA (+)/ HBsAg (-) donations
both repeat donors
25 April 2019

5. Pools of 480 format: donor 1 Date donation HBsAg HBV DNA Anti-HBc
Anti-HBs (IU/L)
NEG nt
POS (<2,000 IU/ml)
POS (241)
POS
POS (250)
Donor was vaccinated for HBV in the past
Probably a recent HBV infection (HBV gt A)
Anti-HBs of previous vaccination not detectable
Due to boostering effect, anti-HBs detectable in early phase of infection
25 April 2019

6. Pools of 480 format: donor 2 Date donation HBsAg HBV DNA Anti-HBc
Anti-HBs
NEG nt
POS (288 IU/ml)
POS
Recent HBV infection
HBV genotype G
Lower HBsAg production
Associated with HBV genotype A? (14 clones tested: genotype G only)1
1Chudy et all (2006) Hepatology 44:99-107
25 April 2019

7. NAT only donations pools 6 format
5 cases HBV DNA (+)/ HBsAg (-) donations
All repeat donors
One donation during WP of HBV infection (donor 1)
Index donation: no serological markers for HBV infection
HBV DNA load: 21,115 IU/ml
Four occult HBV infections (donors 2, 3, 4, and 5)
25 April 2019

8. Donor 2 Date donation HBsAg HBV DNA Anti-HBc Anti-HBs (IU/L) 10-1996
NEG nt
POS
POS (177)
POS (31)
POS (78)
nt= not tested
- Low HBV DNA loads (<12 IU/ml)
- Index and counseling: HBeAg (-); anti-HBe (-); anti-HBc-IgM (-)
25 April 2019

9. Donor 3 Date donation HBsAg HBV DNA Anti-HBc Anti-HBs 11-2008 NEG POS
nt= not tested
- Low HBV DNA loads (approx. 200 IU/ml)
- Counseling: HBeAg (-); anti-HBe (-); anti-HBc-IgM (-)
- Previous donations possibly implicated in post transfusion HBV infection (under investigation)
25 April 2019

10. Donor 4 Date donation HBsAg HBV DNA Anti-HBc Anti-HBs 06-2007 NEG POS
nt= not tested
- Low HBV DNA loads (<12 IU/ml)
- Index and counseling: HBeAg (-); anti-HBe (-); anti-HBc-IgM (-)
25 April 2019

11. Donor 5 Date donation HBsAg HBV DNA Anti-HBc Anti-HBs pending 05-2009
NEG
POS (<12 IU/ml)
POS
POS (86)
- Low HBV DNA loads (<12 IU/ml)
- Index: HBeAg (-); anti-HBe (-); anti-HBc-IgM (-)
25 April 2019

12. HBV NAT Yield Test format Sensitivity for individual donation
# donations tested
NAT Yield
NAT only frequency
Pools of 480
2,400 IU/ml
2,066,283 2
1,033,142
Pools of 6
26 IU/ml
458,365 5
91,673
25 April 2019

13. Summary/Conclusion
HBV NAT in small test pools has been introduced successfully in the Netherlands (MPX on S 201 system) with good performance
Detection of HBV NAT only donations increased 10x due to increased sensitivity (100x)
Major benefit of introduction of HBV NAT until now is detection of occult cases. This relatively high number of occult cases in a low endemic country is due to the fact that the donor population has not been tested for anti-HBc
25 April 2019