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Published on: April 6, 2017
Cryoprecipitate prepared from plasma treated with methylene blue plus light: increasing the fibrinogen concentration
V S Hornsey1, D A Young, A Docherty
1SNBTS, National Science Laboratory, Edinburgh, EH17 7QT, Scotland, UK. valerie.hornsey@snbts.csa.scot.nhs.uk
Abstract:
When cryoprecipitate is prepared from plasma which has been treated with methylene blue plus light (MB) for the purpose of virus inactivation, clottable fibrinogen content is 40% lower compared with units prepared from untreated plasma. Initial studies showed that when frozen MB plasma units were removed to +2 to +6 degrees C for 4 h and then returned to -40 degrees C prior to cryoprecipitation, fibrinogen recoveries increased from 24 to 42%. Although fibrinogen yield improved when plasma units were stored at +2 to +6 degrees C for varying lengths of time, FVIII levels decreased with increasing time. Conditioning for 8 h was studied in more detail. Groups of two plasma units were mixed together, divided into two equal units, frozen/thawed and treated with MB. One of each pair was stored continually at -40 degrees C, whereas the other was removed to +2 to +6 degrees C for 8 h. Samples were assayed for fibrinogen, FVIII, VWF:Ristocetin cofactor activity (RCo), VWF:Ag and VWF:Collagen binding (CB). The cryoprecipitate fibrinogen content increased to a mean of 207 mg unit(-1). VWF:Ag, VWF:RCo and VWF:CB recoveries also increased. FVIII recovery decreased from 50 to 45% (mean 124 iu unit(-1)). Conditioning has been validated for routine production of cryoprecipitate from imported plasma.
Insights
Methylene blue plus light virus inactivation reduces fibrinogen in cryoprecipitate. A controlled temperature conditioning step significantly improves fibrinogen recovery, crucial for blood product manufacturing.
Area of Science:
- Blood Product Manufacturing
- Plasma Processing
- Virus Inactivation Technologies
Background:
- Virus inactivation using methylene blue plus light (MB) treatment in plasma reduces clottable fibrinogen content in cryoprecipitate by 40%.
- Cryoprecipitate is a vital blood component rich in fibrinogen and Factor VIII, essential for treating bleeding disorders.
Purpose of the Study:
- To investigate a conditioning method to improve fibrinogen yield in cryoprecipitate produced from MB-treated plasma.
- To assess the impact of this conditioning on other key cryoprecipitate components, including Factor VIII and von Willebrand factor (VWF) multimers.
Main Methods:
- Plasma units treated with MB plus light were subjected to a conditioning step involving storage at +2 to +6°C for 8 hours before cryoprecipitation.
- Cryoprecipitate was analyzed for fibrinogen, Factor VIII (FVIII), VWF:Ristocetin cofactor activity (RCo), VWF:Ag, and VWF:Collagen binding (CB) levels.
- Comparative analysis was performed between cryoprecipitate from conditioned plasma and plasma stored continuously at -40°C.
Main Results:
- The conditioning method increased mean cryoprecipitate fibrinogen content to 207 mg/unit.
- Recoveries of VWF:Ag, VWF:RCo, and VWF:CB also showed significant increases following conditioning.
- Factor VIII recovery decreased slightly from 50% to 45% (mean 124 IU/unit) after conditioning.
Conclusions:
- A controlled temperature conditioning step effectively enhances fibrinogen and VWF recovery in cryoprecipitate from MB-treated plasma.
- This validated conditioning process is suitable for routine production, optimizing yield for essential blood components.
- While FVIII recovery is marginally reduced, the substantial improvement in fibrinogen makes this method beneficial for cryoprecipitate manufacturing.
