Anti-HBc detection in ULTRIO not-repeatable reactive blood donors

1
Anti-HBc detection in ULTRIO not-repeatable
reactive blood donors

• Piotr Grabarczyk, Ewa Brojer
• Institute of Haematology and Transfusion
  Medicine, Poland

2
HBV DNA screening in Poland

• Obligatory HBV DNA screening in all blood donors
  since January 2005
• PCR Cobas in pools of 24 donations (since 2007 in
  pools of 6)
• TMA ULTRIO in single donations

3
ULTRIO TMA not-repeatable reactives

• DEFINITION
• Triplex ()
• Discrimination HBV (-) HCV (-) HIV(-)
• VERIFICATION METHODS
• alternative NAT tests (Cobas, Arthus)
• HCV RNA(-), HIV RNA(-) and HBV DNA(-) false
  positive triplex assay
• HBV DNA positive testing for anti-HBc to
  distinguish occult and window period infection

4
S/co TMA value and anti-HBc detection in samples
reactive in ULTRIO assay(2005)
250 191 donations screened 9 positives
(triplex/dHBV) 129 not-repeatable
S/co of ULTRIOgt10
reactive (0.05)
12 HBV DNA ()
in PCR (10) 5/9 (56) anti HBc
positive
S/co of ULTRIOgt10

10/12 (83,3) anti-HBc positive
5
Aim of the study (2006)

• Analysis of S/Co distribution in samples with not
  -repeatable results of ULTRIO TMA
• Assessment of anti-HBc frequency in all samples
  with not-repeatable results in ULTRIO TMA

6
HBV DNA screening yield in 2006

• 247 263 donations
• 1 positive
  366 not-repeatable
  reactive (0,14)
• 3 (0,8)HBV DNA positive 363
  negative in
• in PCR
  PCR

S/co of TMAgt10
7
S/co of ULTRIO test in 363 HBV DNA negative
not-repeatable samples
S/co
8
Anti-HBc frequency in HBV DNA negative samples
with not-repeatable results of ULTRIO test
dependence on S/co value
Anti-HBc frequency in donors negative in TMA
assay 7
ULTRIO S/co value
9
Instead of conclusions

• Are the anti-HBc positive donors with
  not-repeatable ULTRIO results infected with
  occult HBV with virus load below sensitivity of
  the assay?
• What is the clinical significance of such
  infections?
• Can anti-HBc testing be useful in confirmatory
  procedure?