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).     

Coagulation parameters in apheresis and leukodepleted whole-blood plasma during storage

BACKGROUND: Thawing fresh-frozen plasma (FFP) may cause delay in delivery, and one approach to circumvent this is to store plasma at +4 degrees C. Thawed plasma is commonly discarded after a few days of storage, owing to the assumption that coagulation factor activity decreases to clinically unacceptable levels. STUDY DESIGN AND METHODS: Eighteen apheresis plasma (AP) units were collected from blood donors. The collected plasma was divided into two equal parts: one part frozen at -74 degrees C as FFP and one part stored at +4 degrees C as fresh liquid plasma (FLP). Thirty-nine units of whole blood (WB) were collected from blood donors and leukodepleted by inline filtration, followed by plasma separation. Twenty plasma units were frozen at -74 degrees C as FFP and 19 plasma units were stored at +4 degrees C as FLP for 28 days. Plasma aliquots were collected before freezing and immediately after thawing FFP and before and during storage of FLP at Days 14 and 28. Factor (F)V, FVIII, D-dimers, and C1-esterase inhibitor levels were assessed. RESULTS: No significant differences in coagulation factor levels were assessed between FLP prepared from AP and FLP prepared from WB. FV and FVIII levels decreased on average 25 and 50 percent, respectively, at Day 14 of storage. C1-esterase inhibitor and D-dimers levels were not affected. CONCLUSION: Leukodepleted apheresis and WB plasma stored for 14 days retain sufficient levels of FV and FVIII activity for maintenance of normal hemostasis and could therefore be considered useful in selected clinical situations.     

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.     

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.     

Rapid controlled thawing of fresh-frozen plasma in a modified microwave oven

A microwave oven has been specifically modified to permit rapid thawing of fresh-frozen plasma (FFP) by using a rotating disc with a temperature sensor to hold the plasma bag. This modification makes it possible to mix the FFP continuously during thawing, and automatically shuts the oven off when the plasma reaches 21 degrees C. Comparisons were made between FFP thawed in the modified microwave oven and FFP thawed conventionally in a 37 degrees C waterbath. The following tests were done: total protein, albumin, and immunoglobulin concentrations; plasma fibrinogen, factor VIII, and factor IX activities; protein electrophoresis, albumin aggregation, hemolytic complement activity, and plasma particle count and size. In no case was there a significant difference between plasma thawed in the microwave oven compared with that thawed in the waterbath. Further, microwave thawing was reliable and rapid; all units of FFP thawed in less than 6 minutes, and the thawed plasma did not vary by more than 6 degrees C from the preselected final temperature of 21 degrees C. Thus, it appears that controlled thawing of FFP in a microwave oven specifically designed for this purpose is an effective and reliable method and has many advantages over conventional thawing of FFP.     

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.     

Thawing of fresh-frozen plasma with a new microwave oven

In the Federal Republic of Germany fresh-frozen plasma (FFP) is still the most important therapeutic agent for acquired coagulation disorders. However, thawing by waterbath (WB) requires about 30 minutes, which is too slow in emergency situations and carries the risk of bacterial contamination of the FFP. There are conflicting data about the use of microwaves for thawing. Therefore, we examined a new microwave oven (MWO; 2450 +/- 50 MHz), which was developed with our cooperation and allows thawing of FFP in 5 minutes, heating FFP to a surface temperature of 21.5 degrees C. A shaking WB (30 min, 37 degrees C) was also used in parallel for comparison. We measured activated partial thromboplastin time (aPTT), nonactivated PTT (NaPTT), fibrinogen, factors VIII:C, X, and XI, fibrinopeptide A, beta-thromboglobulin (beta-TG), thrombin-AT III-complexes, factor VIII-related antigen, C3c, C4, and the plasticizer di(2-ethylhexyl)phthalate (DEHP) in 84 units of FFP as paired samples from 42 double aphereses. Immediately after thawing there was no significant difference in the coagulation test results of FFP with low-cell contamination, regardless of the thawing procedure. Two hours later, after storage at room temperature, FFP thawed by MWO showed even less change than that thawed by WB (NaPTT, p less than 0.01; FX, p less than 0.01). The differences became more evident in comparison with FFP with higher cell contamination and could be observed immediately after thawing (FVIII:C p less than 0.001; FXI, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

A biochemical comparison of a pharmaceutically licensed coagulation active plasma (Octaplas) with a universally applicable development product (Uniplas) and single-donor FFPs subjected to methylene-blue dye and white-light treatment.

The strive for more standardised and highly efficacious products is one of the important mainstays in modern haemotherapy. Coagulation active plasma for transfusion is the product of choice when treating hereditary or acquired isolated or complex coagulopathies, when no specific concentrate is available. The aim of this study was to perform an extensive biochemical comparison of the pharmaceutically licensed coagulation active plasma named Octaplas with an identical, but universally applicable, development product (Uniplas, working title) and single-donor fresh-frozen plasma (FFP) units subjected to a medical device treatment using a combination of methylene-blue dye and subsequent white-light exposure (MB plasma). Our study showed that there are differences in the biochemical characteristics between Octaplas and MB plasma, while Uniplas revealed the same quality as Octaplas. The variability of selected plasma proteins in the 20 individual MB plasma units tested was high compared to Octaplas/Uniplas. Beyond the reported decreased levels of protein S and plasmin inhibitor found in Octaplas/Uniplas, and the significant loss of fully functional fibrinogen in MB plasma and its impact on selected global coagulation parameters, the latter product additionally revealed several coagulation factor activities outside the ranges given for normal single-donor FFP. It is important for plasma prescribers to be aware of the major inherent differences between Octaplas and MB plasma.     

Comparison and stability of ADAMTS13 activity in therapeutic plasma products

BACKGROUND: The von Willebrand factor (VWF)-cleaving protease, ADAMTS13, is often deficient in cases of thrombotic thrombocytopenic purpura (TTP). The primary treatment of TTP is therapeutic plasma exchange (TPE) utilizing a variety of plasma products that help restore ADAMTS13 activity. However, multiple replacement products are available to choose from. Thawed plasma products have a variable refrigerated shelf life depending on the product type; stability of ADAMTS13 in thawed products stored at 1 to 6 degrees C has not been determined. STUDY DESIGN AND METHODS: ADAMTS13 activity was measured in three types of plasma products and cryoprecipitate. Fresh-frozen plasma (FFP) aliquots and cryoprecipitate-poor plasma (CPP) products were produced from 10 whole-blood (WB) donations. Twenty-four-hour plasma products were manufactured from 10 additional WB donations. ADAMTS13 activity in these products at time of thaw and after 5 days of storage at 1 to 6 degrees C was measured with a modified version of the FRETS-VWF73 fluorogenic assay. ADAMTS13 activity at time of thaw was measured in 10 units of cryoprecipitate and five related CPP products. RESULTS: ADAMTS13 is present in similar amounts in FFP, CPP, and 24-hour plasma products. Storage at 1 to 6 degrees C for up to 5 days did not significantly diminish ADAMTS13 activity. The concentration of ADAMTS13 in cryoprecipitate was significantly higher than that observed in plasma products. CONCLUSION: FFP, CPP, and 24-hour plasma products should be equally effective for ADAMTS13 restoration through TPE and should remain so for the duration of the shelf life of the thawed products.     

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.     

Study of coagulation factor activities in apheresed thawed fresh frozen plasma at 1-6 degrees C for five days

The concern for the loss of activities of coagulation factors in thawed fresh frozen plasma kept at 1-6 degrees C for long periods has prevented transfusion services from using thawed plasma beyond 24 hours of storage. There is no mention of the method of collection of the plasma and/or the study of the bacterial growth in the studies reported in the literature. The present project was undertaken to investigate coagulation factor activities and bacterial growth in apheresed fresh plasma. Twenty apheresed plasma units from different blood groups were used. After the 24-hour expiration time of the thawed plasma kept at 1-6 degrees C, aliquots were taken at day 1, day 3, and day 5 of expiration time and were immediately frozen at -70 degrees C. Samples were assayed for activities of coagulation factors II, V, VII, VIII, X, XI, and fibrinogen (Fib). Our study reveals no statistically significant change in activities of coagulation factors II, VII, X, XI, and fibrinogen from day 1 to day 5 storage of plasma at 1-6 degrees C; however, there is a mean decrease of 8.8 and 14.3% in activities of factors V and VIII, respectively. All culture samples taken on day 5 storage were negative at 7 days. In conclusion, our results do not show a significant change in the activity of most coagulation factors in the thawed apheresis plasma stored at 1-6 degrees C over a 5-day period. Hence, it is feasible to transfuse the plasma beyond the 24-hour period without compromising the clinical outcome of patients with coagulopathy.     

Thrombin generation capacity is impaired in methylene-blue treated plasma compared to normal levels in single-donor fresh-frozen plasma, a licensed solvent/detergent-treated plasma (Octaplas) and a development product (Uniplas).

Impaired capacity of thrombin generation (TG) was found in single-donor fresh-frozen plasma (FFP) units subjected to medical device treatment by a combination of methylene-blue dye and subsequent white-light exposure (MB plasma, MBP) compared to normal levels in non-MB-treated single-donor FFP, the licensed plasma product Octaplas, and a product under development (Uniplas; working title) applicable independently from the recipient's blood group. This result held true for MBP units obtained from two different European sources revealing a more significant TG impairment using the local inactivation system in blood banks ("in-house") than an industrial MB treatment. Supplementation of functional fibrinogen to physiological levels did not normalise the altered TG capacity in MBP, whereas addition of Octaplas did. No clear-cut correlation between coagulation factor levels in MBP and hampered TG capacity was found, suggesting a composite effect of impairment. A thorough elucidation and evaluation regarding the possible clinical impact of these findings seems prudent.     

Coagulation parameters of CPD fresh-frozen plasma and CPD cryoprecipitate-poor plasma after storage at 4 degrees C for 28 days

A pilot study was performed on the storage of plasma and cryosupernatant plasma at 4 degrees C for up to 28 days. Eight bags, four of CPD fresh-frozen plasma (FFP) and four of CPD cryosupernatant plasma (CSP, plasma without cryoprecipitate), were sampled during storage for assays of pH; factors V, VIII, IX, and XI; fibrinogen; prothrombin time; activated partial thromboplastin time (APTT); plasma protein electrophoresis; viscosity; and C1q binding. No changes were found in viscosity or the plasma protein electrophoretic pattern, and there was no detectable immune complex formation. The fibrinogen concentration remained constant, and the prothrombin time showed a gradual increase of 2.5 seconds for both groups of plasma. The labile coagulation factor V decreased gradually for FFP and CSP to 58 and 64 percent of its initial value, respectively (51 +/− 8% and 54 +/− 6% of the value of fresh pooled plasma). Factor VIII decreased to 36 percent of its initial value in FFP (48 +/− 14% of fresh pooled plasma). In CSP, factor VIII decreased after 28 days to 7 percent of its initial value (7 +/− 1% of fresh pooled plasma). The APTT increased for FFP from 28 to 35.8 +/− 1.1 seconds and for CSP from 36 to 49.5 +/− 4.9 seconds. The only chemical change observed for both plasmas was a rise in pH, from 7.27 to 7.56, after 28 days. The results of this pilot study indicate that FFP can be stored at 4 degrees C for 28 days with sufficient recovery of coagulation factors to maintain hemostasis.(ABSTRACT TRUNCATED AT 250 WORDS)     

ADAMTS-13 levels in fresh, stored, and solvent detergent treated plasma.

BACKGROUND: ADAMTS-13 is implicated in the pathophysiology of thrombotic thrombocytopenic purpura (TTP). Plasma exchange is thought to be effective through removal of a harmful substance or provision of a required material such as ADAMTS-13. As various methods are used to prepare plasma we determined the effects of storage and solvent detergent treatment on the ADAMTS-13 levels in plasma. METHODS: Samples from fresh plasma and fresh frozen plasma (FFP) were stored at 22 degrees C and ADAMTS-13 levels were measured at 0, 12, 24, 48 and 72 h. Samples were also taken from solvent detergent treated plasma (SDP) and cryosupernatant plasma (CSP). Total protein, albumin, fibrinogen and immunoglobulins were also measured. RESULTS: In fresh plasma, the levels of both the 175 and 140 Kd subunits of von Willebrand factor were consistent at 1.38 and 1.35 OD units from 0 to 48 h indicating normal ADAMTS-13 activity. The Vitex SDP produced slightly more of the 140 Kd subunit than did Octapharma SDP which gave equivalent fragments. Cryosupernatant plasma was the same as normal plasma. None of these values changed over 48 h. There was a 28% decrease in FVIII in fresh plasma over 24 h. Fibrinogen and albumin were unchanged. CONCLUSION: ADAMTS-13 levels are not significantly decreased by storage of plasma at room temperature for up to 48 h. Both CSP and SDP also contained essentially normal levels of ADAMTS-13 and therefore could be used for treatment of patients with TTP.     

Vitamin K-dependent coagulation factors and fibrinogen levels in FFP remain stable upon repeated freezing and thawing

BACKGROUND: FFP is considered adequate for transfusion up to 24 hours after thawing and is currently used most often to replace deficient clotting factors, such as in warfarin overdose. We set to examine the levels of vitamin K-dependent factors (i.e., prothrombin, FVII, F IX, FX), as well as fibrinogen, upon twice freezing and thawing of FFP. If factor levels in refrozen FFP remain within normal limits, this component can possibly be transfused, thus avoiding wastage of precious blood components. STUDY DESIGN AND METHODS: Twenty units of FFP, five units of each blood group A, B, AB, and O, were thawed, and aliquots were taken for measurement of coagulation factors. The plasma units were then kept for 24 hours at 4 degrees C, at which point a second aliquot was taken, The remaining FFP units were refrozen and kept at -80 degrees C for 1 week. The above procedure was then repeated. Coagulation-factor activity and fibrinogen level were measured by the coagulation analyzer. RESULTS: The mean levels of prothrombin, FVII, F IX, FX, and fibrinogen of each blood group (A, B, AB, and O) were calculated for each of four time points and found not statistically different (p > 0.05). Therefore, the rest of the analysis was done for all 20 FFP units as one group. The mean +/- SD levels of each coagulation factor at each time point demonstrated that all levels were within normal limits of all factors measured and that for none of the factors was there a significant decay of activity. CONCLUSIONS: The levels of prothrombin, FVII, F IX, FX, and fibrinogen remain stable and adequate for transfusion in twice-thawed-and-refrozen FFP. This component can be safely used for transfusion as a source of vitamin K-dependent clotting factors and fibrinogen.     

The effect of methylene blue phototreatment on plasma proteins and in vitro coagulation capability of single-donor fresh-frozen plasma

BACKGROUND: Photodynamic virus inactivation of fresh-frozen plasma (FFP) may result in its impaired coagulation capability. STUDY DESIGN AND METHODS: Double-volume plasmapheresis samples from 11 donors were divided in pairs of 250 mL. One group underwent methylene blue (MB) phototreatment (MB-FFP). The other group was treated according to the standards of the American Association of Blood Banks for preparation and storage of FFP. Parameters of hemostasis and clinically important plasma proteins were tested in native plasma, thawed MB-FFP, thawed FFP, and twice-frozen and thawed FFP (FFP-II). RESULTS: Mean activities of factor V (73.4 vs. 94.5%; p < 0.01), factor VIII (58.1 vs. 86.7%; p < 0.001), and fibrinogen (1.8 vs. 2.8 g/L; p < 0.001) were reduced in MB-FFP as compared to those in FFP. The comparison of MB-FFP to FFP-II revealed reduced activities of factor VIII (58.1 vs. 85.2%; p < 0.001) and fibrinogen (1.8 vs. 2.8 g/L; p < 0.001) but no changes in factor V. Activated partial thromboplastin time in MB-FFP was prolonged beyond the upper normal range (+5.3 sec; p < 0.001) and prothrombin time increased in MB-FFP versus FFP (+0.96 sec; p < 0.001). CONCLUSION: MB phototreatment reduces the in vitro coagulation capacity of FFP, most likely as a result of the effects of an additional freezing and thawing procedure and photooxidation-induced protein damage.     

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.     

Anaphylatoxins in fresh-frozen plasma

BACKGROUND: Fresh-frozen plasma (FFP) is widely used in patients with coagulation disorders and simultaneous complement activation. Complement activation in FFP itself is poorly investigated. STUDY DESIGN AND METHODS: The concentration of anaphylatoxins C3a and C5a, the complement precursors C1q and factor B, and complement function were measured in 40 consecutively administered FFP units in two pediatric neonatal intensive care units. In 12 samples, the measurements were also performed after incubation with inulin. RESULTS: In 15 of 40 FFP units, both anaphylatoxin concentrations were below the upper cutoff levels reported for healthy humans (C3a, 500 microg/L; C5a, 5 microg/L). Anaphylatoxin levels were higher in FFP units produced by apheresis than in those from blood donation. Complement activation of FFP by inulin increased anaphylatoxin concentration, whereas C1q and factor B levels, and complement function remained unchanged. CONCLUSION: Elevated concentrations of anaphylatoxin are frequently found in FFP units produced by apheresis. Studies are necessary to investigate the reasons for complement activation and the possibilities of prevention during apheresis. As the concentrations of complement precursors and complement function did not change with activation in FFP, these studies should include measurement of the anaphylatoxins C3a and C5a.     

A New Rapid Method for Thawing Fresh Frozen Plasma

The use of fresh frozen plasma (FFP) often results in unused thawed units because of the time required to thaw FFP prior to use. A rapid thawing technique was studied, utilizing a microwave oven. Resultant levels of coagulation factors were compared with conventional slow thawing in a 37 C water bath. Mean prefreezing, rapid thaw and conventional thaw values were fibrinogen 246, 223, 238 mg/100 ml; prothrombin 101, 103, 105 per cent; factor V; 102, 79, 86 per cent; factor VIII 94, 77, 75 per cent; factor IX 103, 92, 90 per cent; factors VII/X 101, 107, 103 per cent; and factor × 84, 79, 82 per cent. No significant differences existed between rapid thawing and conventional thawing for any coagulation factor studied. Average thawing times were five minutes for rapid thawing (RT) and 25 minutes for conventional thawing. Although careful establishment of thawing time is required for each oven, microwave thawing permits better utilization of FFP for surgery and speeds delivery in emergencies, without destroying coagulation proteins.     

Economic evaluation of pooled solvent/detergent treated plasma versus single donor fresh-frozen plasma in patients receiving plasma transfusions in the United States

This study assessed the cost-effectiveness of Octaplas? versus fresh frozen plasma (FFP) in patients receiving plasma transfusions in the United States (US). Acute and long-term complications of plasma transfusions were modelled in a decision tree followed by a Markov model, using a healthcare payer perspective. Over a lifetime time horizon, patients receiving Octaplas? accumulate slightly more life years (0.00613 [95% uncertainty interval (95%UI): 0.00166–0.01561]) and quality-adjusted life years (QALY) (0.023 [95%UI: 0.012–0.044]) at lower cost compared with those treated with FFP. Octaplas? demonstrated to be the dominant treatment option over FFP (95%UI: Dominant–US$ 15,764/QALY).