1. Blood products
By Dr Sarah Rehman
Date: 10/10/14

2. Blood products Packed red blood cells (PRBC) Platelets
Fresh frozen plasma (FFP)
Cryoprecipitate
Human albumin solution (HAS)
Immunoglobulins
Coagulation factors

3. Donation
Donors have their current health assessed by the Donor Health Check (DHC)
ml of whole blood up to three times a year
Haematocrit or haemoglobin level
To ensure recipient safety the donor is also screened for health risks that might make the donation unsafe. Donors are examined for risk and signs of transmissible diseases such as:
HIV,
Malaria,
Viral hepatitis
Variant Creutzfeldt-Jacob Disease (vCJD)

4. Testing
The blood that is collected is identified for blood type (ABO and Rh), but is also tested to minimise the risk of transmissible infections. The World Health Organisation recommends four core tests as a minimum:
-Hepatitis B Surface Antigen
-Antibody to Hepatitis C
-Antibody to HIV, usually subtypes 1 and 2
-Serology for Syphylis
For patients with specific risks from transfusion, the blood may undergo further processing:
Leukoreduction is the removal of white blood cells by filtration, after which the blood product is less likely to cause alloimmunization, febrile reactions, CMV infections, and platelet refractoriness.
Irradiation, helps to inactivate pathogens (viruses, bacteria and parasites), as well as inactivating white blood cells to prevent graft-versus-host disease

5. Treated
All blood components used in the UK and Ireland since October have been leucodepleted
Microaggregate-free blood is used to prevent reactions to leucocyte and platelet antigens
Washed red cells usually have haematocrits of 70-80% and a volume of about 180ml.
Saline washing removes residual plasma (98%), and reduces the concentration of leucocytes, platelets and cellular debris.
Can only be stored for 24 hr at 1-6 ̊C.

6. Leukodepleted and irradiated
Irradiated red cells
Gamma radiation is used to destroy the lymphocytes
Prevent transfusion related graft versus host disease
Leucocyte depleted red cells
Leucocyte depleted red cells have had 99.9% of the white cells removed
Reduces risk of cytomegalovirus (CMV), Epstein-Barr and febrile reactions.

7. Storage
The most commonly used solution in the UK is SAGM, which contains sodium chloride, adenine, glucose and mannitol.
Short-term storage of blood relies on a combination of refrigeration and the addition of preservatives.
Standard temperature used is 1°- 6°C
Acid-citrate- dextrose (ACD), citrate-phosphate-dextrose (CPD) or citrate-phosphate-double dextrose (CP2D), the storage is limited to 21 days
Citrate-phosphate-dextrose-adenine (CPDA1) this can be extended to 35 days.
Red blood cells can be stored for much longer periods, even up to 10 years, by freezing (cryopreservation)
The units are then placed in special sterile containers and frozen to below -60°C

8. Issues with storage Granulocytes
Become non-functional after 24 hours of storage
Some lymphocytes may remain viable for several weeks
Platelet function declines to zero after only 48 hours of storage
Oxygen affinity:
Stored blood has depleted levels of 2,3 Diphosphoglycerate (DPG)
Coagulation:
Stored blood contains an anticoagulant
The labile coagulation factors V and VIII have a 50% decline in activity within the first 72 hours

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Temperature: The optimum storage temperature of 2°- 6°C is well below normal body temperature
Electrolytes: Constant leak of potassium out of cells and levels can exceed 30mmol/l
Calcium: Each unit of blood contains approximately 3g citrate, which binds ionized calcium
Acid/Base: During storage there is a gradual accumulation of lactic acid which can result in an acid load of mmol/l and a resultant fall in pH

10. RBC
Whole blood is rarely used, the collected blood is therefore fractionated into its respective components
Packed Red cells: A bag of RBCs have a haematocrit of between 60-70%
The main indications for transfusion is the correction of anaemia or replacement in acute haemorrhage,
A single unit of red blood cells will typically increase the Hb by 1g/dl.

11. Granulocytes
Indicated for life-threatening infections in neutropenic cancer patients
Collected by apheresis (filtration), and can only be stored for 24 hours at degree centigrade
Require cross match due to presence of RBC
Irradiated

12. Platelets Circulatory life span of 8-14 days
Platelets for transfusion are collected in two ways:
1. Pooled platelets
2. Apheresis platelets (equivalent of 4-6 units of random donor platelets)
Platelets last for 3-5 days if stored at 22 ̊C and at a pH of between 6.2 and 7.8
Each bag has a volume of ml
Platelet count in pack: > 2.4x1011 per adult dose
The risk of transmission of bacterial infection is higher with platelet transfusions than red cells

13. Fresh frozen plasma
It contains all the coagulation factors, albumin and a source of plasma cholinesterase
It is frozen within 8 hours and may be stored for up to 1 year at -30 ̊C. Under these conditions, the loss of Factors V and VIII is kept to a minimum
The frozen plasma can be thawed using a dry oven (10 minutes), microwave (2-3 minutes) or a water bath (20 minutes)
Thawed FFP is best used immediately but may be stored at 4 ̊C and infused within 24 hours, provided it is kept at this temperature or returned to the blood bank for storage within 30 minutes of being removed from a 4 ̊C fridge or transport box.
4-5 platelet concentrates, 1 unit single-donor apheresis platelets, or 1 unit fresh whole blood provide a quantity of coagulation factors similar to that contained in 1 unit FFP
The dose is ml.kg-1 (equivalent to three to four 300-ml packs of FFP)

14. Cryoprecipitate
Precipitatable cryoproteins are rich in Factor VIII, von Willibrand Factor (VWF), factor XIII, fibronectin and fibrinogen
This is the cryoglobulin fraction of plasma obtained by thawing a single donation of FFP at 4°C
Contain mg fibrinogen and 70 iu factor VIII
10 prepared units of cryoprecipitate (300 ml volumes)
1 unit of whole blood provides about 15ml of cryoprecipitate

15. HAS Available as 4.5% and 20% (salt poor albumin) solution
Contain mmol/L sodium, latter contains less sodium per gram of albumin
Albumin is heat-treated to kill viruses
It has a shelf life of 2 years and stored at room temperature

16. Immunoglobulin
IVIG is sourced from a plasma pool of donors and provides polyclonal immunoglobulins to a wide variety of pathogens
Anti-D immunoglobulin is prepared from the plasma of donors who have high levels of anti-D either following exposure to RhD positive cells during pregnancy or intentional immunisation

17. Cross-matching
Cross-matching refers to the testing for compatibility before transfusion
Determined by ABO, Rh, Kell
Electronic cross-matching relies on computer analysis of tests done on the donor unit of blood and blood samples from the intended recipient
Serological cross-matching requires that red blood cells from the donor blood are suspended in serum from the patient (recipient)

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19. Questions?