Testing of Blood Units for Transfusion transmitted Hepatitis

1. Dr. Rafiq Ahmad MB, MTMed, FASCP
Regional Laboratory & Blood Bank
Dammam Medical Complex, K.S.A
Transfusion Associated Hepatitis
1

2. Hepatitis: Inflammation of Liver
 Hepatitis viruses:
 A-E (HAV, HBV, HCV, HDV, HEV)
 HGV
 NANE (TTV, SEN-V?)
 Hepatitis associated virus:
 CMV, EBV
2

3.  TTV
Appears similar to HGV with respect to prevalence,
transmissibility, and lack of clinical significance
 SEV-V
Distinctly associated to TTV, and so to transfusion
associated non-A through E
 CMV and EBV
Generally mild, in absence to
Need special care in severe immunosupression
and some special category recipients
3

4. Post transfusion Hepatitis
HBV and HCV
 Both establish prolonged carrier states in donors
characterized by high titer viremia in absence of
symptoms
 Both cause long-term liver related mortality
4

5. Geographical distribution of HBV
prevalence
5

6. HBV genome
6

7. Geographical distribution of HCV
prevalence
HCV Prevalence
7

8. HCV genome
8

9. Source of infection of for persons
with Hepatitis C
9

10. Clinical manifestations
 Sub-clinical primarily infection
 Overt hepatitis
 Fulminant hepatitis
 Chronic carrier state
10

11. Chronic carriers of HBV
 HBsAg
 Risk- Age dependent
 ≤ 5% infected in adults become chronic HBsAg
carriers
 ≥90% infants infected parentally become chronic
carriers
 HBsAg carriers
 450 million HBsAg carriers worldwide
 Almost 10 % of these develop hepatic
insufficiency, cirrhosis, or HCC( Hepatocellular
carcinoma)
11

12. Chronic carriers of HCV
 Most people infected once become chronic HCV
carriers
 Almost 50% of them have biochemical and
histological evidence of chronic liver inflammation
 Despite this most of these remain asymptomatic
 Risk: 20% of patients may develop cirrhosis
within 20 years of chronic HCV infection, and up
to 1-5% may develop HCC if chronic HCV
persists for 20 years
12

13. Post transfusion HCV
 Post transfusion HCV is mild in children and
resolves more frequently than adults
 HCV prevalence in Saudi Arabia for children is
0.1% and for adults 0.4% to 1.7%
Shoobakshi et al: Saudi Med J 2003; 24(suppl
2): S81-6
 HCV prevalence in Eastern province has shown
decline from 1.04% in 1998 to 0.59% in 2001
 Bashawari et al: Clin Lab Haematol 2004; 26(3):
225-8
13

14. Molecular and Serological
Markers
14

15. Hepatitis Markers
HBV
 Incubation period 2-6 weeks
 HBV-DNA
 MP-NAT- first marker to appear (16-24 days)
 ID-NAT can detect almost 2 weeks before MP-
NAT
 HBsAg; 5-10 days later to HBV-DNA
 Anti-HBc appears several weeks later first as IgM
and later IgG
 The clearance of HBsAg and appears of anti-HBs
signals the resolution of infection if there is no
mutation in antigenic sites of HBV
15

16. Hepatitis Markers
 Two other markers HBeAg and anti-HBe are
useful diagnostic and prognostic markers but not
employed in donor screening
 Current EIA approximately detects about 0.2 to
0.7 ng/ml or ≥ 3x 107 of HBsAg particles
 BioRad: HBsAg monilisa: detects 0.06 ng/ml
 Architect (ChLIA detects-----)
 NAT allows to detect 10 genomic copies of HBV-
DNA, but not all appears to be infectious.
16

17. HCV
 Incubation period is up to 10 weeks
 85% of HCV infected individuals get cirrhosis
 HCV positive estimated in blood donors is 0.5 to
1.5%, but only 0.3 are chronic HCV carriers and
the rest may be false positive
17

18. Proposed genome of HCV
18

19. Molecular and Serological Markers of
HBV
InterpretationTest Reactivity
Anti-HBeHBeAgAnti-HBsAnti-HBc
IgM Total
HBsAgDNA
Window period------+
Early acute HBV
infection/chronic carrier
-+/--+/-+/-++
Acute infection-+-++++
Early convalescent
infection/possible early
chronic carrier
+/-+/--++-+/-
Chronic carrier+/-+/---+++/-
Recovered infection+-+-+--
Vaccinated or
recovered infection
--+----
Recovered
infection?/false positive
----+--
19

20. Molecular and Serological Markers of
HDV
InterpretationTest Reactivity
Anti-DeltaAnti-HBsAnti-HBcHBsA
g
HDV-
RNA
Acute or Chronic HDV infection-+-+++
Recovered Infection
-
+++--
20

21. Molecular and Serological Markers of
HCV
InterpretationTest Reactivity
HCV-RIBA
5-1-1 c100-3 c33c
c22-3
Anti-HCV-EIARNA
Probably acute or chronic HCV
infection (if RNA Positive)
Not done++/-
False Positive----+-
Probable False Positive+-+++-
Possible acute infection+/--++++
Acute early or chronic infection++--++
False Positive or late recovery++--+-
Acute or chronic infection++++++
Recovered HCC+++/-+/-+-
21

22. Blood Unit Screening
 1986-87 AABB required anti-HBc and ALT testing for
blood donors to prevent post transfusion non-A non-B
(NANB) hepatitis
 Current Markers
 HBV
 HBsAg and anti-HBc total
 Anti-HBs if anti-HBc total Positive
 NAT
 No test available for HBsAg mutant of HBV
 HCV
 EIA 3rd generation, ChLIA
 RIBA3
 NAT
22

23. Current risk of post transfusion
hepatitis B
 Recent study showed HBV in Saudi Arabia with
an average of 0.22% for adults with wild variation
between various regions from 0.33% to 0.72%,
and for children 0.5%
Madani et a;: Trans R Soc Trop Hyg 2007; 101 (3):
278-83
23

24. Current risk of pos transfusion
hepatitis C
 With NAT testing it has decreased dramatically
from 1 in 60,000 to 1 in in 100,000
 NAT has reduced the residual risk of transfusion
associated HCV infection to ≤ 1 in 2,000,000
components transfused
24

25. Algorithm for Blood Unit
Screening
25
Architect
(Negative)
NAT (Negative)
Architect
(Positive)
NAT (Negative)
Architect
(Negative)
NAT (Positive)
Architect
(Positive)
NAT (Positive)
Approval of Blood
& its Component
validity
(Donor Accepted)
Isolation of Blood Component Units (Not
to be issued), including all samples
accompanying the Positive one’s
Double repeat the test for both donor the
donor along with the blood unit sample to
make sure that no error in the sample
identity
- If the initial results and repeated results
mismatch
Keep isolation of the bags and its
components
-Examine new samples from all the bags
to
determine the Positive bag & discard by
correct
-If the initial result matches the repeated
results –
Discard the blood bag and all its
components
- Release the other Negative sample
results

26. Donor Notification & Eligibility Policy
26
Architect (Positive)
NAT (Negative)
Architect
(Negative)
NAT (Positive)
Architect
(Positive)
NAT (Positive)
Double Repeat the Positive
Sample
(Still (Positive
Result
(Negative)
Positive confirmatory Result
(- Notify the donor & donor is
permanently
deferred
-Notify to the Preventive Medicine )
Confirmatory Test must be done
(RIBA-Neutralization-Western
Blot)
According to the policy
Negative Confirmatory Results
(Notify the donor & differ for one
year)
-The donor will be accepted later
-No Need of Confirmatory Test
- The investigation will be done again at
next time

27. Conclusion
27

28. The end!
28
Thank you