Transcript II. Blood and Blood Components

Blood and Blood
Components
Dr. Soheila Zareifar
Pediatric Hematology/Oncology
Department
January 2016
Goals Of Blood Collection
Maintain viability and function
 Prevent physical changes
 Minimize bacterial contamination

Blood safety/ Transfusion
safety
SAFE
TRANSFUSION
PROCESS
SAFE BLOOD
COMPONENT
Blood Transfusion -Guidance and
Regulations
 WHO recommendations
 safe and adequate blood

supply
also clinical transfusion
process
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Appropriate use of blood
Collection samples, patient ID
compatibility testing
Administration of blood
Adverse event reporting
Hospital transfusion
committee
‘Better Blood Transfusion’
EU Optimal Blood Use
manual
 (www.optimalblooduse.eu)
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• Council of Europe
• 47 member countries
Infective risks National
Institutes of Health
Testing
started
Approximate risk of
infection per
unit of blood
Hepatitis B
1975
1 in 205,000 donations
HIV
1985
1 in 2 million
Infection
Hepatitis C
(Anti HCV and NAT testing)
1991
&1998
1 in 2 million donations
Management chronic viral hepatitis in thalassemia:
recommendations of an international panel
Marco et al Blood 2010 116 2875
no.
Ref
AntiHCV+ %
2006
Iran
732
19.3
2006
Turkey
399
4.4
2003
Thailand 104
21.2
2002
Lebanon 395
14
2001
India
21
2006
104
Malaysia 85
22.4
Iraq
67.3
559
Pakistan 35
Italy
27
Wonke B et al Clin
Pathol 1990;43:638
23.3% of 73 patients positive
Thompson et al 2011 Brit Journal of
Haematol, 153, 121–128 Thalassemia
Clinical Research Network Investigators:
169 of 697 Hep C Ab pos – 24%
60
1481 85.2
Bahrain 242
20.5
Brazil
32
46.8
Hong Kong
99
34
UK
73
23.3
Hep C antibody in
thalassemia patients
1998
Cunningham et al 2004 Blood 104, 34
5% patients aged<16yrs
23% aged 16-24yrs;
70% aged 25yrs or older
Viruses
HIV
 Hepatitis A
 Hepatitis B
 Hepatitis C
 HTLV(I,II)
 CMV
 West nile virus
 Simian foamy virus(SFV)
 SARS
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Parasite and specific bacteria
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Malaria
Babesiosis
Chagas disease
Leishmaniasis
Syphilis
Lyme disease
Other bacteria
Skin flora
Variant Creutzfeld-Jacob disease(vCJD)
Disease transmission.
Donor selection criteria and subsequent
screening of all donations are designed to
prevent disease transmission, but these do
not completely eliminate the hazards.
Hepatitis A
Hepatitis A is rarely transmitted by
transfusion.
 Any donor who has been in close contact
with Hepatitis A patient or develops
hepatitis A is deferred for 12 months.

Hepatitis B
Hepatitis B is a frequent sequel to blood
transfusion.
 Currently all blood donations are tested for
HBsAg by very sensitive third generation
techniques ( eg; ELISA ), able to detect at least
0.5 iu of HBsAg per ml of serum.
 Enzyme immunoassay (EIA) method is used with
99.9 % sensitivity.
HBsAg positive subjects are permanently
excluded from donations.
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Hepatitis C
All donated blood are tested for anti – HCV.
 Improved screening assays based on
multiple recombinant or synthetic antigens
including viral core protein are now
available.
 Individuals with a history of jaundice may be
accepted as donors 1 year after the illness
provided they tested and negative for HBsAg
and anti HCV.
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Syphilis
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The organism is more likely to be transmitted in platelet
concentrate due to their room temperature storage and
short shelf life.
Treponema pallidum does not survive well at 4º c and
red cell preparation are likely to be non infective after 4
days refrigeration. Passive transmission of the antibody
to the recepient may cause diagnostic confusion.
Any donations with positive result is discarded, any
subjects with positive tests are permanently deferred,
even after effective therapy.
Malaria
Malarial parasites remain viable in blood stored
at 4º C and easily transmitted by blood
transfusion.
 In some endemic areas, all recipients are treated
with antimalarial drugs.
 Donors who come from endemic area or have
had an attack of malaria can be accepted, their
plasma can be used for fractionation but red
cells must be discarded.
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Cytomegalovirus
Post transfusion CMV infection is not uncommon.
 The infection is characterized by fever, splenomegaly,
and atypical lymphoid cells in the peripheral blood.
 Due to its benign course, screening for past infection
among donors are not necessary.
 However, there are patient at risk of developing fatal
pneumonitis or disseminated CMV infection : premature
baby < 1500g, BM or and other organ transplant
recipient, pregnant women ( risk to fetus ).

•For them, anti – CMV free blood & components
should be provided.
•In UK, incidence of CMV antibodies in adult
population is 50 to 60 %.
•As an alternative, since CMV is cell associated,
leukodepleted blood may be used.
Human immunodeficiency virus
HIV can be transmitted both in cellular and
plasma components.
 The majority of recipient of blood or blood
products who have been infected in the past
were transfused before 1985 with unheated,
non pasteurized pooled plasma products, Factor
VIII and IX.
 HIV is heat labile, therefore prolonged heat
treatment of Factor VIII for hemophiliacs is
effective.
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Human immunodeficiency virus
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Routine screening of all donated blood started in
October 1985.
This in combination with donor education, and self
deferral has reduced the risk of HIV transmission
through contaminated blood.
With screening program, HIV transmission still occur
through donations given in the window period of
infectivity.
With current antibody screening technique, the
estimated window period is about 3 weeks.
PCR for HIV RNA is able to reduce the window period to
approximately 1 week.
Human T- cell leukemia viruses.
HTLV I and II are related retroviruses.
 HTLV I is endemic in the Caribbean, parts of Africa and
in Japan, 3 – 6 % of the population are seropositive.
 HTLV I is associated with tropical spastic Para paresis
and adult T cell – leukemia.
 Importance of HTLV II is not clear.
 Both HTLV I and II are cell associated and not
transmitted in plasma.
 Currently available test include ELISA and gelatin particle
assay, but confirmation of positive result are difficult due
to cross reactivity with other retroviruses.
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Viral Safety in Blood Transfusion
Public concern was heightened by the
disastrous consequences of HIV epidemic
in 1980s
 In France, government officials and
minister were charged with manslaughter
for allowing HIV-contaminated blood to be
used for transfusion at a time when
screening test were available (1985)
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Viral Safety in Blood Transfusion
 Red
Cross officials in Belgium,
Switzerland, Canada were also
convicted for distributing
contaminated blood during the same
period
 Public perception – blood transfusion
should involve absolute no risk of
transmitting viral infection
Viral Safety in Blood Transfusion
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Risk of transmitting infection to recipients
has been drastically reduced in the past
decades, due to
a)Improved donor selection
b)Sensitive serologic screening assays
c)Application of viral inactivation procedures
during manufacturing of plasma products
Residual Risk
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1.
2.
3.
4.
Major sources of remaining risk are:
Window period donation
Viral variants not detect by current
assays
Immunosilent donor
Laboratory testing error
Residual Risk
The greatest threat to the safety of blood
supply is the donation by seronegative
donors during the infectious window
period
 Window period donation account for 90%
or more of the residual risk (Report of the
Interorganization Task Force on NAT
Testing of Blood Donors, 2000)
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Window Period
Period precedes the development of
antibodies during the initial infection
 Eclipse phase of the window period - the
very initial phase after exposure when
virus replication is restricted to tissue sites
and there is no detectable viremia
 Infectious phase of window period is after
eclipse and before seroconversion
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Window Period
Animal study in chimpanzees (Murthy KK
et al, Transfusion 1999) suggested that
the eclipse phase is non- infectious for
HIV
 Direct detection of virus by very sensitive
method theoretically eliminate the
infective window phase if the assay
sensitive exceeds the minimum infective
dose for that virus (window period
closure)
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Residual Risk
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Risk of acquiring a transfusion-transmitted
viral infection depends not only on the
length of specific window period but also
on the incidence of the infection among
blood donors
Determination of Residual Risk
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Study the rate of infection prospectively in
transfusion recipients
Some pathogens, HIV & HCV, the risk is
so low that exceeding large number of
recipients & lengthy period are required
for the risk to be measured accurately
 Under-reporting
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USA
UK
Italy
Australia
HK
HIV
1:493,000
< 1:
2,000,000
1:408,000
1:1,200,000
1:877,147
HCV
1:103,000
<1:
200,000
1:230,000
1:250,000
1:86,137
HBV
1:63,000
1 : 50,000 –
170,000
1:63,400
1:160,000
1:3357
Source: (1) Muller-Breitkreutz K for the EPFA Working Group on Quality Assurance. Results of viral
marker screening of unpaid donations and probability of window donations in 1997. Vox Sang
2000;78:149-157 (2) Aubuchon JP, Birkmeyer JD, Busch MP. Safety of the blood supply in the United
States: opportunites and controversies. Ann Int Med 1997;127:904-909. (3) Regan FAM, Hewitt P,
Barabara JAJ, Contreras M.on behalf of the current TTI Study Group Prospective investigation of
transfusion in transmitted infection in recipients of over 20000 units of blood, Br Med J 2000;320:403-406.
(4) Tosti ME, et al, An estimate of the current risk of transmitting blood-borne infections through blood
transfusion in Itly. Br J Haemat, 2002;117:215-219.
THE END
Thank you for your attention.