The quality of plasma collected by automated apheresis and of recovered plasma from leukodepleted whole blood

BACKGROUND: There exists a current lack of information about the composition of the different types of plasma. No direct comparisons between apheresis plasma (AP) and recovered plasma (RP) derived from in-line-filtered whole blood (WB) have been published to date. STUDY DESIGN AND METHODS: Sixty AP units, 100 RP units from in-line-filtered WB held for 3 hours at 20 degrees C between donation and freezing, and an additional 100 RP units held for 15 hours at 20 degrees C before freezing were analyzed for coagulation factors and inhibitors, total protein, immunoglobulin G (IgG), and hemostasis and proteolysis activation markers. The influence of twice freezing and thawing on clotting factors V, VIII, and XI was also examined. RESULTS: AP contains substantially greater activities of factor (F) V, FVIII, F IX, and FXI than RP frozen within 3 hours after WB donation. Prolonged holding of RP at 20 degrees C for more than 15 hours caused an additional reduction in FVIII, FXI, and protein S activities. Significantly greater levels of prothrombin fragments 1 and 2, platelet factor 4, and neutrophil elastase were found in RP compared with AP. IgG was lower in AP compared with RP. Twice freezing and thawing caused a marked drop in FV, FVIII, and FXI activity. CONCLUSION: Higher FVIII and F IX potencies in AP compared with RP can be expected to result in greater yields when used for purification of these clotting factors. AP is presumably more efficient than RP for treating coagulopathies. RP, however, may contain higher IgG levels than AP.     

Stability of coagulation factors in plasma prepared after a 24‐hour room temperature hold

BACKGROUND: The manufacture of fresh‐frozen plasma (FFP) requires that plasma be frozen within 8 hours of collection and 24‐hour frozen plasma requires 1 to 6°C refrigeration before freezing. Manufacture of plasma after a room temperature hold for 24 hours, while convenient, could compromise clotting factor levels. STUDY DESIGN AND METHODS: Pairs of FFP and 24‐hour room temperature–frozen plasma (PLT‐rich plasma [PRP]‐24HRTFP) were manufactured from PRP after a room temperature hold for 8 and 24 hours, respectively. Additional whole blood (WB) donations were kept at room temperature for 24 hours before plasma manufacture (WB‐24HRTFP). The frozen plasma products were stored at −18°C, thawed, and then stored at 1 to 6°C, with coagulation factor assays performed for up to 7 days. RESULTS: On the day of thaw, Factor (F)VIII was lower in PRP‐24HRTFP by 13% (p = 0.002) but not in WB‐24HRTFP (p = 0.3) compared to FFP. All other clotting factors were within normal range. During the postthaw period FVIII and FV declined 25 and 6%, respectively, in WB‐24HRTFP and 23 to 50% in the paired products; however, the difference between both types of 24HRTFP and FFP is insignificant by Day 7 (p > 0.05). Other clotting factors either were unchanged or showed minimal reduction (<15%). CONCLUSION: Plasma manufactured after a 24‐hour room temperature hold contains coagulation factors comparable to FFP except for a possible reduction of up to 20% in FVIII. This plasma appears suitable as a transfusable product and extension of liquid storage to 7 days merits consideration.     

The quality of fresh-frozen plasma produced from whole blood stored at 4 degrees C overnight

BACKGROUND: The aim of this study was to assess whether the quality of FFP produced from whole blood stored at 4 degrees C overnight is adequate for its intended purpose. STUDY DESIGN AND METHODS: Fresh-frozen plasma (FFP) separated from whole blood (n = 60) leukodepleted (LD) after storage at 4 degrees C overnight (18-24 hr from donation, Day 1 FFP) was compared with that LD within 8 hours of donation (Day 0 FFP, the current standard method). RESULTS: In more than 95 percent of Day 1 FFP units, levels of factor (F) II, FV, FVII, FVIII, F IX, FX, FXI, and FXII were greater than 0.50 U per mL except for von Willebrand factor (VWF) antigen and FVIII, where 92 and 87 percent of units, respectively, contained greater than 0.50 IU per mL. Compared with historical data on FFP stored for 8 hours, fibrinogen, FV, FVIII, and FXI were reduced by 12, 15, 23, and 7 percent, respectively, but other factors were not significantly reduced. Levels of VWF-cleaving protease activity were not different between FFP prepared from paired units of blood (n = 3) held for 8 or 24 hours, but were below the reference range in an additional 2 of 6 units held for 24 hours. The activities of protein S, protein C, antithrombin III, and alpha(2)-antiplasmin were reduced by less than 10 percent in Day 1 FFP (n = 20), but with final levels above the lower limit of the normal range in greater than 95 percent of units. Activated FXII antigen was not significantly raised in plasma stored for 18 to 24 hours, but levels of prothrombin fragment 1 + 2 were slightly increased (0.88 ng/mL, 18-24 hr; 0.65 ng/mL, < 8 hr). CONCLUSION: These data suggest that there is good retention of relevant coagulation factor activity in plasma produced from whole blood stored at 4 degrees C for 18 to 24 hours and that this would be an acceptable product for most patients requiring FFP.     

Coagulation parameters of thawed fresh-frozen plasma during storage at different temperatures

Once thawed, fresh-frozen plasma (FFP) should be used, according to guidelines, within 24 h. In hospital practice, this may be associated with wastage. This study has been performed to investigate the coagulation levels of thawed quarantine FFP as used in the Netherlands. Five units of quarantine FFP, obtained by plasmapheresis, were thawed and by sterile docking divided into satellite bags (SB). SB 2-4 were stored at room temperature (RT) for, respectively, 1, 3 and 6 h and SB 5-9 at 4 degrees C for 6, 12 and 24 h and 1 and 2 weeks. At each time point, activated partial thromboplastin time (APTT), prothrombin time (PT), fibrinogen, factor V (FV), factor VIII (FVIII) and ADAMTS13 activity were measured. During storage at RT for up to 6 h, no major differences were found in the levels of FV, PT, fibrinogen and ADAMTS13 activity. FVIII activity showed a decrease of 16% and the APTT was prolonged by 6%. During storage at 4 degrees C for 2 weeks, FV and FVIII were reduced by 35 and 45%, respectively. The APTT and PT were prolonged by 17 and 15%, respectively. Fibrinogen was decreased by 8%. No change in ADAMTS13 activity was found. FFP stored at RT for 6 h or at 4 degrees C for 2 weeks can provide sufficient support for adequate haemostasis except for patients with a known deficiency for FVIII and can be used for plasmapheresis in patients with thrombotic thrombocytopenic purpura (TTP).     

Coagulant stability and sterility of thawed S/D-treated plasma

BACKGROUND: Units of frozen S/D-treated plasma (SDP) must be transfused within 24 hours after thawing. To avoid waste, an attempt was made to determine how long SDP could be therapeutically effective after thawing and storing it at 20 degrees C. STUDY DESIGN AND METHODS: The microbiologic safety and the activity of labile coagulation factors were evaluated in units stored at 20 degrees C of thawed SDP units and FFP within 24 hours of collection (FFP24). Five SDP and FFP24 samples of each ABO blood group were cultured and assayed for coagulation factors daily over 5 days. Assays included FV, FVII, FVIIa, FVIII, F IX, FXI, protein S, antiplasmin, fibrinogen, prothrombin times (PTs), and activated partial thromboplastin times (aPTTs). RESULTS: None of the 80 bacterial cultures demonstrated growth under either aerobic or anaerobic conditions. FV, FVIII, F IX, FXI, fibrinogen, and the aPTT appeared to be stable in both thawed FFP24 and SDP. The PT increased slightly in thawed FFP24 and insignificantly in SDP. FVII decreased slightly in FFP24 but remained in the normal range, and FVIIa was low and constant. FVII was increased in SDP and FVIIa was markedly increased. Protein S decreased from initial normal values in FFP24 to very low values. Protein S was very low immediately after thawing in the SDP and continued to decline. Antiplasmin was normal and stable in thawed FFP24 but was low in SDP and remained constant after thawing. CONCLUSION: Sterile SDP that is stored at 20 degrees C provides sufficient coagulant activity of labile FV and FVIII to transfuse it for up to 5 days after thaw. Caution is warranted by decreases in Protein S and antiplasmin, clinical evidence of coagulopathy in some recipients of SDP, and a recent manufacturer's warning.     

Analysis of prolonged storage on coagulation Factor (F)V,FVII, and FVIII in thawed plasma: is it time to extend the expiration date beyond 5 days?

BACKGROUND: According to AABB standards, fresh‐frozen plasma (FFP) should be thawed at 30 to 37°C and expire after 24 hours. An increase in the aggressive management of trauma patients with thawed plasma has heightened the risk of plasma waste. One way to reduce plasma waste is to extend its shelf life, given that the full range of therapeutic efficacy is maintained. We evaluated the effect of prolonged storage at 1 to 6°C on the activity of Factor (F)V, FVII, and FVIII in plasma thawed at 37 or 45°C. STUDY DESIGN AND METHODS: Group O plasma from healthy donors (n = 20) was divided into 10 pairs and frozen and stored at not more than ?18°C. One sample from each pair was thawed at 37 or 45°C, and all were stored at 1 to 6°C. Samples were analyzed for FV, FVII, and FVIII activity on Days 0, 5, 10, 15, and 20. RESULTS: Plasma thawing time was 17% less at 45°C than at 37°C. No differences were observed between thawing groups in coagulation activity of FV, FVII, and FVIII during the 20‐day storage period (p > 0.12). In both groups, the activity of FV and FVIII decreased over time but remained within a normal range at 10 days. CONCLUSION: Although levels of plasma clotting factors are reduced in storage, therapeutic levels of FV and FVIII are maintained in thawed plasma stored for up to 10 days at 1 to 6°C. Thawing of FFP at 45°C decreases thawing time but does not affect the activity of FV, FVII, and FVIII.     

Stability of solvent/detergent-treated plasma and single-donor fresh-frozen plasma during 48 h after thawing.

The aim of this study was to compare the quality of solvent/detergent (SD) treated plasma, Octaplas, and single-donor fresh-frozen plasma (FFP) units during 48-h storage after thawing. Octaplas bags of different blood groups and individual FFP units were thawed and stored at either +4 degrees C or at room temperature (RT) for 48 h. Samples drawn during the observation period were investigated on various coagulation factor and protease inhibitor activities using standard coagulation and chromogenic assays. The generation of FVIIa was followed as a marker of coagulation factor activation. All investigated coagulation factors and protease inhibitors were stable for at least 8h during storage of Octaplas at +4 degrees C. FVIII levels started to decline earlier in FFP than in Octaplas at both storage temperatures. Stored Octaplas OD660 values were more stable during the storage period than FFP OD660 values, whereas VWF multimeric patterns were comparably stable in both types of plasma. In conclusion, this stability study has demonstrated that thawed Octaplas maintains its high quality, even with a time safety margin, for 8 h at +4 degrees C and for 6 h at RT. In general, there was more variability in coagulation factor levels among different FFP units compared with different Octaplas batches.     

Coagulation function in fresh-frozen plasma prepared with two photochemical treatment methods: methylene blue and amotosalen

BACKGROUND: Pathogen inactivation of plasma intended for transfusion is now the standard of care in Belgium. Two methods for treatment of single plasma units are available: amotosalen plus ultraviolet A light and methylene blue plus visible light. This study compared the quality and stability of plasma treated with these two methods. STUDY DESIGN AND METHODS: Plasma units made from a pool of two ABO-matched fresh apheresis units were photochemically treated with either amotosalen (PCT-FFP) or methylene blue (MB-FFP). A total of 12 paired samples were evaluated. Plasma coagulation function was assessed at three time points: immediately after treatment, after 30 days of frozen storage, and an additional 24 hours at 4 degrees C after thawing. Comparison between PCT-FFP and MB-FFP was assessed with the paired t test and a p value of less than 0.05 indicated statistical significance. RESULTS: Based on statistical analysis, mean levels of factor (F)II, FXII, FXIII, von Willebrand antigen, ADAMTS-13, D-dimers, and protein C were equivalent between PCT-FFP and MB-FFP for all three time points. PCT-FFP exhibited shorter mean prothrombin time, activated partial thromboplastin time (two time points), and thrombin time and higher mean levels of fibrinogen, FXI, and protein S than MB-FFP. Retention of FV, FVII, FVIII, FX, or von Willebrand factor:ristocetin cofactor in PCT-FFP was either equivalent to or higher than MB-FFP. MB-FFP contained higher mean levels of plasminogen, antithrombin, and plasmin inhibitor than PCT-FFP. Retention of F IX in MB-FFP was higher than PCT-FFP only after the 4 degrees C storage after thawing. CONCLUSION: There is adequate preservation of therapeutic coagulation factor activities in both PCT-FFP and MB-FFP. The overall coagulation factor levels and stability of PCT-FFP were better preserved than MB-FFP.     

The impact of the intensity of serial automated plasmapheresis and the speed of deep-freezing on the quality of plasma

BACKGROUND: Data are lacking on the impact that the intensity of serial donor plasmapheresis has on the quality of source plasma. A study was conducted to examine the quality of source plasma produced by intensive plasmapheresis and slow deep-freezing and to compare it to source plasma manufactured by moderate plasmapheresis and rapid freezing. STUDY DESIGN AND METHODS: Seventy-five plasma samples from intensive plasmapheresis programs (Group 1) and 75 plasma units from moderate plasmapheresis programs (Group 2) were examined. The plasma had been deep-frozen either slowly at -30 degrees C in walk-in freezers (Group 1) or rapidly within 1 hour to a core temperature below -30 degrees C (Group 2). Determinations were made of the plasma levels of citrate; total protein; albumin; IgG; fibrinogen; factors II, V, VII, VIII, and IX; vWF; antithrombin; protein C; D-dimers; and prothrombin fragments 1+ 2. RESULTS: Plasma units of Group 2 contained substantially greater levels of citrate, IgG, FVIII, and FV than samples of Group 1 (p<0.0001). Plasma levels of total protein, albumin, and fibrinogen also were higher in Group 2 (p<0.0001, p = 0.007, and p = 0.006, respectively). Neither plasmapheresis intensity nor freezing procedure had any influence on the levels of factors II, VII, and IX, antithrombin, or protein C. There was no evidence of substantial coagulation activation in the plasma units of either group. However, higher FVIII clotting activity/chromogenic substrate activity ratios in rapidly frozen plasmas and a significant correlation between these ratios and prothrombin fragment 1+ 2 levels suggest that rapid freezing yields both more native FVIII and greater partial activation of FVIII. CONCLUSION: Source plasma collected from donors undergoing intensified plasmapheresis contains markedly lower levels of IgG than plasma units produced by moderate serial plasmapheresis. The combination of intensified plasmapheresis and slower freezing of source plasma results in substantially lower levels of FV and FVIII than does moderate plasmapheresis with rapid freezing. Prospective studies should establish the optimum conditions required for the safe and economic production of source plasma for fractionation.     

Storage of thawed plasma for a liquid plasma bank: impact of temperature and methylene blue pathogen inactivation

BACKGROUND: Rapid transfusion of fresh‐frozen plasma (FFP) is desired for treating coagulopathies, but thawing and issuing of FFP takes more than 40 minutes. Liquid storage of plasma is a potential solution but uncertainties exist regarding clotting factor stability. We assessed different storage conditions of thawed FFP and plasma treated by methylene blue plus light (MB/light) for pathogen inactivation. STUDY DESIGN AND METHODS: Fifty thawed apheresis plasma samples (approx. 750 mL) were divided into three subunits and either stored for 7 days at 4°C, at room temperature (RT), and at 4°C after MB/light treatment. Clotting factor activities (Factor [F] II, FV, FVII through FXIII, fibrinogen, antithrombin, von Willebrand factor antigen, Protein C and S) were assessed after thawing and on Days 3, 5, and 7. Changes were classified as “minor” (activities within the reference range) and “major” (activities outside the reference range). RESULTS: FFP storage at 4°C revealed major changes for FVIII (median [range], 56% [33%‐114%]) and Protein S (51% [20%‐88%]). Changes were more pronounced when plasma was stored at RT (FVIII, 59% [37%‐123%]; FVII, 69% [42%‐125%]; Protein S, 20% [10%‐35%]). MB/light treatment of thawed FFP resulted in minor changes. However, further storage for 7 days at 4°C revealed major decreases for FVIII (47% [12%‐91%]) and Protein S (49% [18%‐95%]) and increases for FVII (150% [48%‐285%]) and FX (126% [62%‐206%]). CONCLUSION: Storage of liquid plasma at 4°C for 7 days is feasible for FFP as is MB/light treatment of thawed plasma. In contrast, storage of thawed plasma for 7 days at RT or after MB/light treatment at 4°C affects clotting factor stability substantially and is not recommended.     

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°C in plastic trays, 2) in cooling devices (Compocool II, NPBI), 3) at 4°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°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.     

Refreezing previously thawed fresh-frozen plasma. Stability of coagulation factors V and VIII:C

With the growth in autologous blood programs and the increased scrutiny of the indications for transfusion of fresh-frozen plasma (FFP), an increase has been seen in the number of occasions on which FFP was requested and thawed but then not transfused. The coagulation properties of FFP units that were refrozen and then rethawed were therefore studied. Fifty-eight units of plasma were studied, with each experimental unit of FFP paired with an identical control unit. Experimental units were frozen, stored at -65 degrees C, thawed, stored at 1 to 6 degrees C for various periods of time up to 24 hours, and then refrozen, stored at -65 degrees C, rethawed, and stored again in the refrigerator for up to 24 hours. Control units were frozen once at the time the experimental units were first frozen and thawed once at the time of the second thaw of the experimental units. Aliquots of plasma were sampled periodically and were later batch-tested for prothrombin time (PT), activated partial thromboplastin time (aPTT), and factor V and VIII:C activity. The results of coagulation testing of the twice-frozen plasmas were always within the normal range. There was a slight but statistically valid prolongation of the PT and aPTT and a decrease in the factor V and VIII:C levels for twice-frozen plasma compared with control plasma. The greatest decline occurred in the level of factor VIII:C. The measured deterioration in coagulation of twice-frozen FFP is unlikely to be of clinical importance. Refreezing FFP may eventually prove useful for rare donor, autologous, and massive transfusion programs.     

Protein composition and activation markers in plasma collected by three apheresis procedures

BACKGROUND: Scientific and technical advances made in transfusion medicine sustain the need for more comprehensive understanding of the impact of collection procedures on the quality of plasma for fractionation and for transfusion. This prospective work evaluated protein composition and markers of activation in plasma donations collected with three different automatic collection procedures (performed on Haemonetics machines), including a new procedure using a high-separation core-molded bowl. STUDY DESIGN AND METHODS: A total of 90 collection procedures have been performed from a population of 37 donors, under comprehensively standardized conditions. Plasma aliquots were taken from the plasma units within 30 minutes of the end of the collection procedures and immediately frozen at -70 degrees C. Content in an extended range of proteins and of markers of activation of the coagulation and fibrinolytic systems has been measured using standard in vitro testing methods. RESULTS: Plasma donations had normal mean total protein, IgG, IgM, and fibrinogen content. The mean levels in coagulation FV, FVII, FVIII, and FXI and in antithrombin were above the standard international requirements. There was no sign of activation of the hemostasis system, as assessed by activated FVII, thrombin antithrombin complex, Prothrombin fragment 1+2, and D-dimers. Activated complement component C3 and C5 were low. CONCLUSION: Data indicates the good and consistent protein composition of plasma obtained by those automatic apheresis procedures. In particular, the new high-separation core procedure yields a high-quality plasma meeting requirements for transfusion and fractionation.     

Evaluation and comparison of coagulation factor activity in fresh-frozen plasma and 24-hour plasma at thaw and after 120 hours of 1 to 6°C storage

BACKGROUND: Current transfusion-related acute lung injury reduction strategies include avoiding transfusion of plasma products collected from female donors or female donors that have been pregnant to reduce transfusion of plasma-containing HLA antibodies. Such a policy considerably decreases the number of donors available for generation of fresh-frozen plasma (FFP). To increase the supply of FFP, substitution of 24-hour plasma (FP24) and thawed plasma (TP) derived from either FFP or FP24 may be viable substitutes. To justify such a policy the coagulation factor content of FFP, FP24, and TP derived from both product types was assessed.
STUDY DESIGN AND METHODS: Coagulation factor (F)II, FV, FVII, FVIII, F IX, and FX; protein C (PC) and protein S (PS); von Willebrand factor antigen and ristocetin cofactor; fibrinogen; and antithrombin activities were analyzed in nonpaired FFP and FP24 at the time of product thaw and again after 120 hours of 1 to 6°C storage.
RESULTS: At thaw, mean FVIII and PC activities were lower in FP24 than FFP. Mean PC and PS activities were lower in FP24- than FFP-derived 120-hour-old TP. No other differences in mean activity reached significance. Activity levels were generally lower in TP; FVIII, FV, and FVII showed the largest changes. However, prestorage leukoreduction appears to improve the stability of FV.
CONCLUSION: FFP, FP24, and the derived TP all contain adequate coagulation factor activities to maintain hemostatic activity. As FFP becomes less available, increased use of FP24 and TP are viable alternatives for most clinical situations.     

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°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.     

Characterization of blood components separated from donated whole blood after an overnight holding at room temperature with the buffy coat method

BACKGROUND: With buffy coat (BC) processing of whole blood (WB) donations, increase in WB storage time to facilitate overnight holding before the separation of blood components would be a logistically attractive development. This study undertakes a comparative in vitro characterization of blood components prepared from WB samples that were either processed within 8 hours or stored overnight at room temperature before processing by the BC method. STUDY DESIGN AND METHODS: The WB units (400 mL) collected were either processed within 8 hours (fresh blood) or stored overnight (overnight blood) at room temperature. WB units were separated into individual‐component red blood cells (RBCs), BC, and plasma. The in vitro quality of these blood components (RBCs, pooled platelet concentrates [PCs], and plasma) was analyzed during storage. RESULTS: Levels of 2,3‐diphosphoglycerate (2,3‐DPG) were found to be significantly lower immediately after processing, compared with the fresh WB samples, in RBCs that had been separated from an overnight‐hold sample. However, this difference was not apparent after 14 days of storage. In pooled PCs, measurements for glucose, lactate, PO₂, PCO₂, extent of shape change, and hypotonic shock response were similar. The platelet yield in PCs prepared from an overnight‐hold WB sample was significantly higher, while CD62P expression and annexin V binding were lower (p < 0.05). For frozen plasma (FP), no significant differences were observed for the coagulation factors (F)II, FVII, FV, F IX, FX, and FXI; fibrinogen; and von Willebrand factor content between the 8‐ and 24‐hour FP. The FVIII was the component that was most sensitive to the prolongation of production time and it only had 80% of the activity of the 8‐hour FP. CONCLUSION: These data suggest that blood components (RBCs, pooled PCs, and FP) separated from WB that has been stored overnight at room temperature by the BC method are of acceptable quality.     

机采血小板悬液在保存过程中凝血因子Ⅷ、Ⅸ生物活性的变化

为了研究机采血小板悬液22℃振荡保存不同时间的凝血因子Ⅷ、Ⅸ生物活性的变化,采用SYSMEXCA-1500型全自动血凝仪对用CS-3000plus血细胞分离机采集的18份血小板悬液于22℃振荡保存条件下,测定0、12、24、48、72、96、120小时7个时间段的FⅧ∶C和FⅨ∶C的活性。结果表明:机采血小板FⅧ∶C在0时活性为(100.51±44.02)%,保存12-120小时,其活性衰减了10%-40%;FⅨ∶C在0时活性为(120.93±20.50)%,保存24-120小时,其活性衰减了10%-35%。结论:机采血小板悬液于22℃振荡保存时凝血因子Ⅷ、Ⅸ仍保持有较高的生物学活性。     

Characterization of blood components prepared from whole-blood donations after a 24-hour hold with the platelet-rich plasma method

BACKGROUND: The preparation of platelet (PLT) concentrates (PCs) from PLT-rich plasma (PRP) requires that whole blood (WB) be processed within 8 hours of collection. Increasing WB storage time to 24 hours would be logistically attractive. This study compares the in vitro quality of blood components prepared from WB stored for 8 and 24 hours at room temperature before processing with the PRP method. STUDY DESIGN AND METHODS: WB units were collected from ABO-matched blood donors. To reduce individual variations, paired donations were drawn in parallel, pooled, and split back in the collection bag. One unit was held for 6 to 8 hours and the other for 22 to 24 hours at 20 to 24 degrees C. Prestorage leukoreduced components were prepared with the PRP as intermediate product and analyzed during storage. RESULTS: RBC units prepared after an 8- or 24-hour hold were comparable in terms of hemolysis, sodium, pH, and ATP levels. RBC 2,3- diphosphoglycerate (2,3-DPG) was significantly lower in RBCs prepared from 24-hour hold donations immediately after processing but not after 20 days of storage. Residual white blood cells were approximately fivefold higher (p < 0.05) in 24-hour RBC units. For PCs, measurements for glucose, ATP, lactate, pH, extent of shape change, hypotonic shock response, and CD62p activation were similar. No differences were observed in the von Willebrand factor, factor (F)V, FVIII, and fibrinogen content of fresh-frozen plasma. CONCLUSIONS: The decrease in FVIII and RBC 2,3-DPG can be acceptable as a compromise to improve blood component logistics, but leukoreduction efficiency must be improved before considering the adoption of an overnight storage of WB before PRP processing.     

Cryoprecipitate prepared from plasma treated with methylene blue plus light: increasing the fibrinogen concentration

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.     

Conversion to the buffy coat method and quality of frozen plasma derived from whole blood donations in Canada

BACKGROUND: Canada converted from the platelet‐rich plasma (PRP) method to the buffy coat (BC) method of processing whole blood donations between 2006 and 2008. We measured coagulation variables in plasma units during this transition, in 2006 (PRP only), 2007 (BC and PRP), and 2008 (BC only) to test the hypothesis that this conversion would not affect frozen plasma (FP) quality. STUDY DESIGN AND METHODS: Fresh‐frozen plasma (FFP; frozen within 8 hr of collection) or FP (frozen within 24 hr of collection) units were shipped on dry ice from 12 plasma manufacturing sites, thawed, and characterized using an automated coagulation analyzer, at a single testing site. RESULTS: FP made by the BC method (FP‐BC) exhibited fibrinogen, Factor (F)V, ABO‐matched FVIII, and antithrombin levels at least as high as FP made by the PRP method (FP‐PRP) and supported global clotting, as measured by prothrombin time or activated partial thromboplastin time, to an indistinguishable extent as FP‐PRP. FP‐BC and FP‐PRP did not differ in ABO‐matched FVIII levels, but both contained 30% to 35% less FVIII than FFP. There was no discernible effect of the site of manufacturing on plasma quality. FP‐BC units leukoreduced by centrifugation contained more FV activity than those leukoreduced by filtration, but the difference was unlikely to be of clinical significance. CONCLUSION: Our data suggest that no reduction in FP quality, at least in the characteristics we tested, accompanied the switch from the PRP to the BC method processing of whole blood donations in Canada.