Short-term deviations in temperature during storage of plasma at -40°C do not affect its quality.

BACKGROUND: Little data are available on the suitability of frozen plasma for transfusion when stored outside its normal temperature, which is the focus of investigation in this study. STUDY DESIGN AND METHODS: Plasma was pooled and split to create 10 identical units on each of 24 occasions (12 Group A and O). Plasma was frozen and stored at -40°C for 2 weeks and then one of each of the 10 identical units was subjected to one of the following deviations in storage temperature: -18°C for 1 week, 1 month, or 2 months; -10°C for 1 week, 1 month, or 2 months; 4°C for 4, 24, or 72 hours; or stored at -40°C (control) before returning all units to -40°C. RESULTS: Factor VIII was only significantly reduced when plasma was stored at 4°C for 24 hours or more or -10°C for 1 week. For all other arms of the study, the majority of units of plasma (>75%) remained above 0.70 IU/mL and more than 95% were above the lower limit of normal (0.50 IU/mL). The prothrombin time ratio only increased after storage at -10°C for 1 month or more, and the activated partial thromboplastin time ratio after storage at 4°C for 24 hours. None of the deviations in storage resulted in a decrease in fibrinogen activity. CONCLUSION: These data suggest that plasma that has been stored at -40°C and exposed to storage temperatures and times of up to 4 hours at 4°C, 1 week at -10°C or 2 months at -18°C meets EU guidelines and is suitable for transfusion.

Prion reduction of red blood cells: impact on component quality.

BACKGROUND: A filter has been developed (P-Capt, MacoPharma) to remove infectious prions from red blood cells (RBCs). We sought to assess 1) its operational use, 2) the quality of filtered components, and 3) whether filtration resulted in any significant changes to blood group antigens. STUDY DESIGN AND METHODS: A total of 272 leukoreduced RBC units, including units processed using "top-and-top" (TAT) and "bottom-and-top" (BAT) methods, were prion reduced using the P-Capt filter. All RBCs were assessed using standard in vitro tests of RBC quality. Changes to blood group antigen expression were also investigated, including the exposure of cryptantigens and the ability of filtered RBCs to be crossmatched. RESULTS: Ninety-nine percent of TAT units and 58% of BAT units had a hemoglobin (Hb) content of more than 40 g. Hemolysis increased immediately after filtration, but units remained within UK specification throughout storage. Prion reduction resulted in the loss of 7 to 8 g of Hb and reductions in hematocrit of 6% to 9% due to the filter containing 40 mL of saline, adenine, glucose, and mannitol. Other RBC quality data, including extracellular potassium, 2,3-diphosphoglycerate, and adenosine triphosphate were similar to historical control data. There was no evidence of any immunologic changes of clinical relevance to the RBC membrane after filtration. CONCLUSIONS: Prion filtration does not appear to have a detrimental effect on basic in vitro measures of RBC quality or on blood group antigens as assessed by in vitro methods. However, prion filtration using the P-Capt filter results in loss of Hb.

Blood components produced from whole blood using the Atreus processing system.

BACKGROUND: The Atreus 2C+ system (Gambro BCT) automates whole blood (WB) processing into a single device. This study compared the quality of red blood cells (RBCs), fresh-frozen plasma (FFP), and buffy coats (BCs) made from WB held with or without active cooling. STUDY DESIGN AND METHODS: WB was collected into Atreus disposables and stored with (n = 20) or without (n = 20) active cooling for 14 to 18 hours at 22 +/- 2 degrees C before processing with the Atreus. Two RBC leukodepletion filters were assessed, and markers of RBC quality were tested to Day 42. BCs were held for 3 hours before testing, plasma was tested, and samples were frozen for coagulation analysis. RESULTS: RBCs met UK specifications for volume, hemoglobin content (48 +/- 5 g), and hematocrit (Hct). Hemolysis, adenosine triphosphate, 2,3-diphosphoglycerate, potassium, glucose, and lactate throughout storage were all within expected ranges. No differences were seen in RBC produced from WB held with or without active cooling. FFP units met UK specification for volume, total protein, cellular contamination, and coagulation factors. No differences were seen in FFP produced from WB held with or without active cooling. The Hct of BCs produced from WB held without active cooling was lower than in BCs from WB held with active cooling; no differences in activation were seen. CONCLUSION: From these in vitro data, blood components produced using the Atreus appear suitable for clinical use, with no clinically significant difference in the quality of components from WB held at ambient temperature overnight with or without active cooling.

The effect of storing whole blood at 22 degrees C for up to 24 hours with and without rapid cooling on the quality of red cell concentrates and fresh-frozen plasma.

BACKGROUND: Storage of whole blood (WB) for less than 24 hours at ambient temperature is permitted in Europe, but data directly comparing storage with and without active cooling are lacking, which was investigated and compared to current standard methods. STUDY DESIGN AND METHODS: WB was stored in one of four different ways for 24 hours after donation before processing on Day 1 to red cell concentrates (RCCs) in saline-adenine-glucose-mannitol and fresh-frozen plasma (FFP; n = 20 each): 1) at 22 degrees C in plastic trays, 2) in cooling devices (Compocool II, NPBI), 3) at 4 degrees C, or 4) processed from WB without storage less than 8 hours from donation (Day 0). RESULTS: 2,3-Diphosphoglycerate (2,3-DPG) in RCCs were lower after ambient storage compared with those processed on Day 0 or after 4 degrees C storage. Rapid cooling slowed the loss of 2,3-DPG but levels were undetectable by Day 21 with any method. On Day 42 of RCC storage, there was no significant difference between storage methods in levels of adenosine triphosphate or hemolysis. Potassium levels were lower in RCCs from WB stored at ambient compared with those produced on Day 0, regardless of the use of cooling plates. FFP produced from WB on Day 0 or after storage at ambient with or without active cooling met UK specifications (>75% of units >0.70 IU/mL Factor VIII). CONCLUSION: These data suggest that RCCs and FFP produced from WB that has been stored at ambient temperature with or without active cooling are of acceptable quality compared with those produced using current standard methods in the United Kingdom.

The effect of methylene blue photoinactivation and methylene blue removal on the quality of fresh-frozen plasma.

BACKGROUND: T: he effects of using fresh or frozen-thawed plasma, WBC reduction of plasma before freezing, and the use of two different methylene blue (MB) removal filters on the quality of MB-treated plasma were compared. STUDY DESIGN AND METHODS: In a paired study (n = 11/arm) plasma was frozen within 8 hours of collection, thawed, MB photoinactivated, and then filtered using one of two MB removal filters. Fresh plasma (n = 16) and plasma WBC reduced before freezing (n = 19) were MB inactivated. RESULTS: Freeze-thawing resulted in loss of activity of FXII and VWF of 0.06 and 0.04 units per mL, respectively, but no significant loss of activity of factors II through XI or fibrinogen. Further loss of activity occurred after MB treatment: FII (0.07 IU/mL), FV (0.11 U/mL), FVII (0.08 IU/mL), FVIII (0.28 IU/mL), F IX (0.12 IU/mL), FX (0.16 IU/mL), FXI (0.28 U/mL), FXII (0.15 U/mL), VWF antigen (0.05 IU/mL), VWF activity (0.06 U/mL), and fibrinogen (0.79 g/L). Losses due to this step were significantly (5-10%) lower in fresh plasma compared to frozen-thawed plasma. Neither MB removal filter resulted in significant loss of activity of any factor studied. CONCLUSION: MB removal, by either of the available filters, has little impact on the coagulation factor content of plasma, but freezing of plasma before MB treatment results in a small additional loss.