Stored Blood is Deficient in Factor VIII
Stored blood is deficient in factor VIII (option c), which deteriorates significantly during blood storage.
Explanation of Factor VIII Deficiency in Stored Blood
Factor VIII is particularly susceptible to degradation during blood storage compared to other coagulation factors. This has important clinical implications for transfusion medicine and the management of bleeding disorders.
Evidence for Factor VIII Deterioration
- Cryoprecipitate was developed specifically to concentrate factor VIII from plasma because factor VIII is rapidly lost during standard blood storage 1
- When whole blood is stored in cold conditions, there is a "drastic time-dependent decrease" in factor VIII activity, with levels dropping to approximately 53±15% of baseline after just 6 hours of cold storage 2
- The process of freezing and thawing plasma causes significant loss of factor VIII activity, which is why specialized processing methods like cryoprecipitation were developed 1
Storage Effects on Other Coagulation Factors
- Factor II (prothrombin), factor VII, factor IX, and factor XI are more stable during blood storage
- Prothrombin complex concentrates (PCCs) typically contain factors II, IX, and X (with or without factor VII), which remain relatively stable during processing 1
- The long half-life of factor X (approximately 30 hours) and factor II (approximately 60 hours) compared to factor VIII contributes to their better preservation during storage 1
Clinical Implications
This factor VIII deficiency in stored blood has several important clinical consequences:
- Patients with hemophilia A (factor VIII deficiency) cannot be effectively treated with standard stored blood products
- Specialized factor VIII concentrates or cryoprecipitate must be used for treating hemophilia A 1
- Fresh frozen plasma (FFP) has variable levels of factor VIII depending on processing time and storage conditions 1
- Cold storage of blood samples can lead to misdiagnosis of hemophilia A or von Willebrand disease due to artificially low factor VIII levels 2
Blood Product Considerations
Different blood products contain varying amounts of factor VIII:
- Cryoprecipitate is specifically enriched in factor VIII, fibrinogen, von Willebrand factor, and factor XIII 1
- Fresh frozen plasma contains factor VIII but at variable and often reduced levels compared to fresh blood 1
- Prothrombin complex concentrates (PCCs) typically contain factors II, IX, X (with or without VII) but not factor VIII 1
Understanding the deficiency of factor VIII in stored blood is crucial for proper management of patients with bleeding disorders and for appropriate use of blood products in clinical practice.