Expiration

Expiration dates are critical safety and efficacy limits. They depend on the component, its preparation, storage conditions, and any subsequent manipulations. Understanding how modifications like thawing, washing, pooling, or irradiating affect the expiration date is crucial for safe transfusion practice. Always check the label for the correct expiration date and time!

This section focuses on the expiration dates assigned to blood products. These dates aren’t arbitrary; they represent the end of the period during which the product is considered safe and effective for transfusion, based on the expected decline in viability/function and potential safety risks (like bacterial growth) under defined storage conditions

Why Do Blood Products Expire?

Expiration dates are determined by regulatory agencies (like the FDA) and standards organizations (like AABB) based on scientific evidence addressing:

• Loss of Viability/Function: As discussed under “Properties of Stored Products,” cells and proteins degrade over time. The expiration date ensures a minimum level of effectiveness remains (e.g., for RBCs, ≥75% survival 24 hours post-transfusion; adequate levels of coagulation factors in plasma)
• Risk of Bacterial Contamination: For components stored at room temperature (Platelets, Granulocytes, thawed Cryo), the risk of bacterial growth increases significantly over time. The expiration limits this risk
• Accumulation of Storage Lesion Byproducts: For RBCs, the accumulation of potassium, free hemoglobin, and other metabolic byproducts in the supernatant increases over time

Factors Determining Expiration Date

The assigned expiration date depends primarily on:

• Component Type: Different components have vastly different stability (e.g., RBCs vs. Platelets vs. Plasma)
• Anticoagulant/Preservative/Additive Solution: Especially crucial for RBCs (e.g., CPD vs. CPDA-1 vs. Additive Solutions)
• Storage Temperature: Must be maintained within the required range
• Initial Processing Method: How the component was prepared
• Subsequent Modifications: Actions like washing, pooling, thawing, or irradiating can significantly shorten the original expiration date, especially if the “closed system” is compromised

Standard Expiration Dates (Under Normal Storage)

These are the typical maximum storage times from the date of collection (unless otherwise noted):

• Red Blood Cells (RBCs) - Liquid State (1-6°C)
  • ACD / CPD / CP2D: 21 days
  • CPDA-1: 35 days
  • Additive Solutions (AS-1, AS-3, AS-5, AS-7): 42 days
• Platelets (20-24°C with continuous agitation)
  • Typically 5 days. Can sometimes be extended to 7 days if specific FDA-approved bacterial detection methods or pathogen reduction technologies are used
• Plasma (Frozen State, ≤ -18°C)
  • FFP, PF24, Cryo-Reduced Plasma: 1 year
• Cryoprecipitated AHF (Frozen State, ≤ -18°C)
  • 1 year
• Granulocytes (20-24°C, without agitation)
  • 24 hours: (due to rapid loss of function and bacterial risk)
• Frozen Red Blood Cells (Glycerolized, ≤ -65°C)
  • 10 years

Expiration Dates After Modification or Thawing

This is where things change significantly, often due to entering an “open system” (potentially exposing the component to ambient air/microbes) or due to the inherent instability of the product once thawed or altered

• Thawed Plasma (FFP, PF24, etc.)
  • Stored at 1-6°C: Expires 24 hours after thawing
  • Relabeled as “Thawed Plasma”: Can be stored at 1-6°C for up to 5 days from thawing (note: Factor V and VIII levels will be significantly reduced compared to FFP/PF24)
• Thawed Cryoprecipitate
  • Stored at 20-24°C:
    • Single units (unpooled): Expire 6 hours after thawing
    • Pooled (in an open system): Expire 4 hours after pooling/entry
• Washed or Volume-Reduced RBCs/Platelets (Open System)
  • RBCs stored at 1-6°C: Expire 24 hours after washing
  • Platelets stored at 20-24°C: Expire 4 hours after washing
• Irradiated RBCs
  • Stored at 1-6°C: Expires on the original outdate OR 28 days from the date of irradiation, whichever comes first
  • Rationale: Irradiation damages the RBC membrane, increasing potassium leak and potentially reducing viability over time
• Pooled Platelets (Open System)
  • Stored at 20-24°C: Expire 4 hours after pooling
• Deglycerolized RBCs (Post-Thaw)
  • Stored at 1-6°C:
    • If deglycerolized using an open system: Expire 24 hours after deglycerolization
    • If deglycerolized using a validated closed system: Can have longer expiration (e.g., up to 14 days, depending on the system/validation)
• Leukoreduced Components (Closed System)
  • If leukoreduction is performed using a sterile, closed system (e.g., in-line filter during collection or sterile connecting devices), the original expiration date of the component is maintained

Handling of Expired Units

• Expired units must not be transfused
• They must be clearly identified and removed from transfusion service inventory
• Discarded according to institutional policy for biohazardous waste

Key Terms

• Expiration Date: The last day (and sometimes time) a blood component is considered suitable for transfusion under specified storage conditions
• Shelf Life: The total allowable storage time for a blood component from collection to expiration
• Open System: A system or procedure where the sterility of the component is potentially compromised by exposure to the environment (e.g., pooling units using needles/syringes, washing cells). Results in a significantly shortened expiration time (usually 4 or 24 hours)
• Closed System: A system where the component remains sterile throughout processing (e.g., using sterile connecting devices, in-line filters). Maintains the original expiration date
• Pooling: Combining the contents of multiple units of the same component (e.g., platelets, cryoprecipitate) into a single container for transfusion
• Washing: A process where plasma or supernatant is removed from cellular components by adding and removing saline, usually in an open system
• Irradiation: Treatment with gamma rays or X-rays to inactivate T-lymphocytes; affects RBC membrane and shortens expiration to 28 days post-irradiation or original outdate, whichever is sooner
• Deglycerolization: The process of removing glycerol from previously frozen RBCs before transfusion