Issues related to Modified Blood Components

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Issues related toModified Blood Components

• Dr Senarath Jayasekara
• National Blood Centre
• Sri Lanka

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Modification of Blood Components

• Irradiation
• Red Cell Components
• Platelet Components
• Granulocyte Components
• Leucocyte Reduction
• Red Cell Components
• Platelet Components

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Modification of Blood Components

• Washing
• Red Cell Components
• Platelet Components
• Pathogen Inactivation
• Plasma Components
• Platelet Components
• Red Cell Components

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Modification of Blood Components

• Plasma Reduction
• Platelet Components
• Cryoprecipitate
• Frozen Components
• Red Cell Components
• Platelet Components
• Other modified products
• Rejuvenated Red Cells

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Irradiation

• For prevention of GVHD
• Two Methods
• Gamma Irradiation
• caesium-137 (137 Cs)
• cobalt-60 (60Co)
• Problems of radioactive isotope handling and
  disposal
• X-Ray
• Less expensive
• No radioactive source
• Heavier needs specially prepared floor

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Irradiation

• Performance similar (K. Janatpour et al., Vox
  Sanguinis (2005) 89, 215219
• Red Cell Components
• Selective
• Slight differences in free haemoglobin (more in
  X-ray irradiated) and potassium (more in gamma
  irradiated)
• Limits storage time
• Platelet Components
• Storage not affected
• Granulocyte Components
• Mandatory

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Leucocyte Reduction

• Leucocyte Depletion (Residual WBC count lt5 X 106)
• Indications
• Minimizing of HLA alloimmunization
• Prevention of FNHTR
• Substitute for CMV negative components
• Methods
• Filtration
• Pre-storage
• Best
• Costly
• In-line filtration of whole blood/red cells

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Leucocyte Reduction

• Methods (contd.)
• Filtration
• Post-storage
• Selective
• Does not prevent reactions due to cytokines
• Laboratory Pre issue
• Open system
• Bed-side
• Hypotensive reactions due to bradykinins
• Poor control of procedure

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Leucocyte Reduction

• Methods (contd.)
• Alternatives
• Buffy Coat removal
• Residual WBC count 1 109
• Less costly
• Suitable for selected patients
• Washing
• Cumbersome
• Risk of contamination
• Use of sterile connecting devices
• Automated Cell Washers

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Washing

• Removal of
• Plasma (residual protein lt 0.5g/unit)
• Most of WBC
• Few indications
• Reactions to plasma proteins
• Red cells for IgA deficient patients with Ab.
• Limits shelf life
• Risk of contamination
• Delay in issuing

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Washing

• Red Cell Components
• Removal of most of the plasma and WBC
• Loss of RBC (up to 20 depending on protocol)
• Shelf life 24 hours
• Platelet Components
• Practical difficulties
• Loss of platelets
• Re-suspended in PAS

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Pathogen Inactivation

• Mostly in use for plasma
• Clinical trials for other components
• Plasma Components
• Methylene Blue
• Used for single units
• In clinical use since 1992
• Available as a closed system
• Moderate reduction of some labile plasma proteins

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Pathogen Inactivation

• Plasma Components
• Solvent Detergent
• Used for pooled units
• Reduced amounts of largest vWF multimers, Protein
  C, Protein S and a 1 - antiplasmin
• Psoralens (S-59)
• Used for single units
• Inactine

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Pathogen Inactivation

• Platelet Components
• Psoralens (S-59)
• Riboflavin
• Low toxicity
• Red Cell Components
• S-303 (FRALE) trials suspended due to antibody
  development
• Inactine trials suspended due to antibody
  development
• Dimethyl-methylene blue
• Low red cell damage with quencher

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Pathogen Inactivation
Platelets and plasma
Red blood cells
Addition of S-59
Addition of S-303
Removal
Removal
UVA activation of S-59
pH activation of S-303
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Amotosalen Mechanism of Action
Pathogen Inactivation
UVA Illumination
Amotosalen (S-59)
DNA or RNAof pathogen
Docking
Permanent Crosslinking
Courtesy of Baxter Healthcare
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Pathogen Inactivation
S-303 Mechanism of Action
Unreactive By-product
S-303
Physiologic pH
DNA or RNAof pathogen
Docking Permanent Crosslinking
Courtesy of Baxter Healthcare
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Plasma Reduction

• Used mainly for platelets and cryoprecipitate
• Enable the use across ABO barrier and for those
  who cannot tolerate large volumes
• Platelet Components
• 15 - 20 loss of platelets with many protocols
• 4 6 hour shelf life if open system
• Insufficient data to support long term storage
• Cryoprecipitate
• Resuspended in saline and pooled at the time of
  issue
• Shelf life not affected

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Frozen Components

• Red Cells
• Mainly for rare blood groups
• Two techniques
• High (40) glycerol concentration
• Low (20) glycerol concentration
• Open system limits post deglycerolization storage
• Expensive equipment
• Up to 99 WBC removed

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Frozen Components

• Platelets
• DMSO used as cryoprotectant
• Sustain more damage than Red Cells during
  cryopreservation
• Post thaw recovery and function are greatly
  reduced
• Use not wide-spread
• Primary use freezing of autologous platelets

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Rejuvenated Red cells

• Mainly for rare blood groups
• Post-expiry (Up to 3 days)
• After rejuvenation
• Frozen
• Stored at 1 60C up to 24hrs, washed to remove
  inosine and used

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Thank You