Comparative stability of canine and feline hemostatic proteins in freeze-thaw-cycled fresh frozen plasma

Stability of coagulation factors in feline fresh frozen plasma intended for transfusion after 1 year of storage

OBJECTIVES

The most common use of plasma transfusion is for haemostatic purposes, but coagulation factor activities in stored feline plasma are unknown. The concentration and stability of coagulation factors I (fibrinogen), II, V, VII, VIII, IX, X, XI and XII in feline fresh frozen plasma (fFFP) stored for 1 year were studied.

METHODS

Fifty-five units of fFFP were produced from 55 fresh whole-blood donations obtained from indoor healthy blood donor cats. Twenty-one units were stored for <2 weeks (T0) and 34 were stored for 1 year (T1). After the completion of storage, specific coagulation factor activities for factors II, V, VII, VIII, IX, X, XI and XII were tested using modified one-stage activated partial thromboplastin or prothrombin time assays. Fibrinogen was determined using the Clauss method.

RESULTS

Significantly decreased activities were observed for factors II (T0: 101.94% ± 19.06%; T1: 73.23% ± 39.06% [P = 0.001]), VII (T0: 102.78% ± 24.69%; T1: 60.08% ± 38.17% [P <0.001]), VIII (T0: 77.52% ± 30.39%; T1: 50.32% ± 23.8% [P = 0.001]), XI (T0: 88.76% ± 22.73%; T1: 66.28% ± 22.2% [P = 0.001]) and XII (T0: 89.50% ± 21.85%; T1: 55.46% ± 23.18% [P <0.001]) when comparing units at time 0 and after 1 year of storage. No significant difference was observed for factors IX (T0: 84.86% ± 29.35%; T1: 71.37% ± 22.23% [P = 0.064]) and X (T0: 96.24% ± 25.1%; T1: 83.91% ± 49.54% [P = 0.236]). Unexpectedly, a significant increase was observed for factor V (T0: 71.94% ± 24.14%; T1: 97.89% ± 62.33%; P = 0.046). Fibrinogen was 2.76 ± 1.09 g/l at T1. Factors VIII, XII and VII had the lowest mean activities after 1 year.

CONCLUSIONS AND RELEVANCE

Although a decrease in most coagulation factors activities was noted with storage, 1-year-old fFFP was haemostatically active in vitro. The most suitable factors for quality control assessment of fFFP are factors VII and VIII. Approximately 13-20 ml/kg of fFFP is required to administer a minimum of 10 IU/kg coagulation factor activity.

Hemostatic Activity of Canine Never-Frozen Liquid Plasma Collected for Transfusion

This study measured the changes of hemostatic activity in liquid plasma (LP) over 7 days of storage. Five canine plasma units, divided into two aliquots were evaluated: one stored refrigerated at 2–6°C as never-frozen LP and one frozen at −18°C as fresh frozen plasma (FFP). Clotting times, coagulation activities of factor (F) V, VIII, X, XI, antithrombin (AT), and von Willebrand (vWF), fibrinogen and D-dimers (DD) content were assessed before storage (baseline value), and after 12, 24, 48 h and 7 days (D7) in LP stored refrigerated, and on day 7 in FFP. At baseline median values of all factor activity were greater than 80%, and for clotting times, AT, fibrinogen and DD content, were within the canine reference range. Some hemostatic parameters changed significantly over 7 days and at the end of storage in LP. However, median activities of FV, FVIII, FX and FXI, coagulation time, AT, fibrinogen and DD content remained within reference ranges at all time points. The only exception was for vWF which median activity was lower than reference range for all storage time points. Activity of FVIII was significant lower in LP at D7 when compared to activity in FFP, with values of 62 vs. 118%, respectively. DD content showed a median value higher than reference range in FFP at D7. Despite some statistically significant changes at the end of 7-day storage period, never-frozen LP maintained median factor activities >80% for most factors. The clinical impact of the drop over time of vWF activity is unknown.

An in vitro study of canine cryopoor plasma to correct vitamin K-dependent coagulopathy in dogs

OBJECTIVE

To compare the efficacy of fresh frozen plasma (FFP) with cryopoor plasma (CPP) to treat vitamin K-dependent factor deficiency in a canine in vitro setting.

DESIGN

In vitro laboratory study.

SETTING

University veterinary medical teaching hospital.

ANIMALS

Seven units of FFP and 6 units of CPP from unique canine donors from the university veterinary blood bank.

INTERVENTIONS

Canine FFP was adsorbed by oral barium sulfate suspension to mimic vitamin K-dependent coagulopathy. A sequential mixing study was completed by adding FPP or CPP to the adsorbed plasma. Measurements of prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen, and factor activities of factors II, VII, and IX (FII, FVII, and FIX) were compared between the 2 treatment groups.

MEASUREMENTS AND MAIN RESULTS

When comparing the sequential addition of CPP or FPP to adsorbed plasma, the following had no statistical significance: PT (P = 0.94), aPTT (P = 0.66), FII (P = 0.05), and FIX (P = 0.90). There was a dose-dependent decrease with PT and aPTT and a dose-dependent increase with FII and FIX. In contrast, after the addition of either CPP or FFP, there was a significant difference between the treatment groups for the concentration of fibrinogen (P = 0.005) and activity of FVII (P = 0.044), with FFP resulting in a greater concentration of fibrinogen and CPP resulting in a greater concentration of FVII. Measurements of factor X (FX) were initially included in the study but were later excluded because FX appeared to be continually adsorbed even after the addition of CPP or FFP.

CONCLUSIONS

CPP partially corrected the coagulation times and concentration of vitamin K-dependent coagulation factors to the same degree as FFP. CPP, generally less expensive than FFP, may provide an alternative treatment option for vitamin K-dependent coagulopathies, although in vivo testing is needed.

Effects of refrigerated storage on hemostatic stability of four canine plasma products

OBJECTIVE

To assess clotting times, coagulation factor activities, sterility, and thromboelastographic parameters of liquid plasma (LP), thawed fresh frozen plasma (FFP-T), and 2 novel formulations of freeze-dried plasma (FDP) stored refrigerated over 35 days.

SAMPLE

6 units of canine LP and FFP-T from a commercial animal blood bank and 5 units each of 2 formulations of canine FDP.

PROCEDURES

Prothrombin time; activated partial thromboplastin time; activities of coagulation factors II, V, VII, VIII, IX, X, XI, and XII; and thromboelastographic parameters were determined for each product on days 0 (baseline), 3, 7, 14, 21, 28, and 35. For each day, a sample of each product was also submitted for aerobic bacterial culture.

RESULTS

Small changes in coagulation factor activities and mild increased time to initial clot formation in LP and FFP-T were noted over the 35-day storage period. Activities of factor VIII in FDP1 and factor XII in FDP2 were < 50% at baseline but varied throughout. Compared with FFP-T, time to initial clot formation was increased and clot strength was preserved or increased for the FDPs throughout the study. One FDP had decreased pH, compared with other products. No plasma product yielded bacterial growth.

CONCLUSIONS AND CLINICAL RELEVANCE

Liquid plasma and FFP-T would be reasonable to use when stored refrigerated for up to 35 days. Both FDP products showed variability in coagulation factor activities. Studies investigating the usefulness of these plasma products (FDPs) in dogs and the variable days of refrigerated storage (all products) are warranted. (Am J Vet Res 2020;81:964-972).

Retrospective evaluation of fresh frozen plasma use in 121 cats: 2009-2016

OBJECTIVES

To document indications for fresh frozen plasma (FFP) use in cats, doses administered, and frequency of adverse transfusion reactions (ATR).

DESIGN

Retrospective observational study from January 2009 to November 2016.

SETTING

Large urban referral and emergency facility.

ANIMALS

One hundred twenty-one client-owned cats that received FFP.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Signalment, indication(s), dose, pre- and posttransfusion total plasma protein, prothrombin time, activated partial thromboplastin time, as well as possible ATR, primary disease process, and outcome were recorded. Doppler blood pressure was increased posttransfusion (mean pre 99.5 ± 30.8 mm Hg; post 108.5 ± 32.5 mm Hg, P = .027). Cats were significantly less likely to be coagulopathic posttransfusion (P < 0.001). Most common indications were suspected coagulopathy (n = 105, 83%), hemorrhage (n = 45, 35%), and hypotension (n = 32, 25%). Median dose was 6 mL/kg (interquartile range = 3 mL/kg) and was negatively correlated with body weight (r = -.598, P < 0.001). Possible ATR occurred in 17 of 108 (16%, 95% confidence interval [CI], 10-24%) of transfusions. Increased body temperature was most common in 11 of 108 (10%, 95% CI, 5-18%), followed by tachypnea/dyspnea in 8 of 108 (7%, 95% CI, 3-13%). Common primary disease processes included liver disease (n = 41, 34%), neoplasia (n = 19, 16%), and sepsis (n = 15, 12%). Overall mortality was 54%. Improvement of clotting times was associated with increased odds of survival (odds ratio = 2.4; 95% CI, 1.1-5.3; P = 0.023).

CONCLUSIONS

Clinician justifications for FFP transfusions are comparable to that reported in dogs; however, the mL/kg dose is lower. Coagulopathy and blood pressure significantly improve posttransfusion. Possible ATR were as frequent as that reported with feline packed RBCs transfusions and classified as mild.

Effects of storage over a 36-month period on coagulation factors in a canine plasma product obtained by use of plasmapheresis

OBJECTIVE

To evaluate stability of coagulation factors in canine plasma obtained by use of plasmapheresis and stored over a 36-month period.

SAMPLE

Canine plasma obtained by use of plasmapheresis acquired from a commercial blood bank.

PROCEDURES

Coagulation testing for fibrinogen concentration and activity of factors II, V, VII, VIII, and IX and von Willebrand factor was performed on canine plasma obtained by use of plasmapheresis. Samples were obtained for testing at 6-month intervals from plasma stored for up to 36 months.

RESULTS

A simple mixed linear regression model was created for each analysis. Median value for the fibrinogen concentration was > 150 mg/dL for all time points, except at 467, 650, and 1,015 days of storage. Median value for factor VIII was > 70% only at 650 days. Median value for factor V was > 50% through 650 days. Median value for factors VII and X was > 50% through 833 days, and median value for factors II and VII was > 50% through 1,015 days. Median value for von Willebrand factor was > 50% for the entire study (1,198 days). Median value for factor X was always < 50%.

CONCLUSIONS AND CLINICAL RELEVANCE

Coagulation factors degraded over time at variable rates, and all labile factors remained at > 50% activity for longer than 1 year. Plasma collected by plasmapheresis potentially offers prolonged life span of some clotting factors. Plasmapheresis is an acceptable form of canine plasma collection for transfusion purposes, and further studies should be performed to determine all of its benefits.

Comparison of multiple thawing techniques on thaw time and stability of hemostatic proteins in canine plasma products

OBJECTIVES

To compare thawing times of fresh frozen canine plasma between a 37 °C warm water bath, running water bath and dry plasma thawer and compare haemostatic protein stability after thawing in a warm water bath or dry plasma thawer.

MATERIALS AND METHODS

To measure thawing times, a 240-mL bag of frozen plasma was thawed in warm water bath, running water bath or dry plasma thawer-10 times for each method. To evaluate stability of haemostatic proteins, fresh canine donor plasma samples were split into 120-mL bags and 3-mL control aliquots before freezing. Bags were thawed by warm water bath or dry plasma thawer and aliquots equilibrated to room temperature. Concentrations of haemostatic proteins, albumin, D-dimers, prothrombin time and partial thromboplastin time were obtained.

RESULTS

The running water bath had the shortest thaw time: median thaw time of 15 minutes versus 18 minutes for both the dry plasma thawer and warm water bath. Statistically significant differences in partial thromboplastin time, factor VII, factor X, von Willebrand factor, and von Willebrand factor collagen binding assay were detected among groups but were unlikely to be clinically relevant.

CLINICAL SIGNIFICANCE

A traditional running water bath provided the fastest thawing time but the dry plasma thawer resulted in the most stable haemostatic proteins.

Comparison of albumin, colloid osmotic pressure, von Willebrand factor, and coagulation factors in canine cryopoor plasma, cryoprecipitate, and fresh frozen plasma

OBJECTIVE

To compare albumin concentrations, coagulation factors activity, and colloid osmotic pressure (COP) of cryoprecipitate (CRYO) and cryopoor plasma (CPP) to that of source fresh frozen plasma (FFP).

DESIGN

Prospective in vitro study.

SETTING

University teaching hospital.

ANIMALS

Ten healthy, non-Greyhound dogs enrolled in an academic teaching hospital blood donor program.

INTERVENTIONS

Fresh blood was obtained from canine blood donors and separated into FFP and packed red blood cells. The source FFP was further separated into CRYO and CPP. Albumin and fibrinogen concentrations, COP, activities of coagulation factors II, V, VII, VIII, IX, X, and von Willebrand factor (vWf) were assessed for each FFP, CRYO, and CPP.

MEASUREMENTS AND MAIN RESULTS

The mean albumin concentration and COP in CPP were significantly higher compared with those found in FFP, with 31.7 g/L (±6) in CPP compared to 28.9 g/L (±0.5) in FFP (P < 0.001) and 14.5 mm Hg (±0.7) in CPP compared to 12.7 mm Hg (±0.3) in FFP (P = 0.03), respectively. CRYO had significantly higher concentrations of fibrinogen (median 3.46 g/L, 95% CI 2.65-4.27), and higher activities of factor VIII (mean activity 427.0%, ±95.4) and vWf (mean activity 504.7%, ±41.39) as compared to the other products. The activities of vitamin K dependent factors II, VII, and X were similar in CPP compared to FFP, although factor IX activity was lower in CPP. There was no significant difference in factor II or VII activities between the 3 products.

CONCLUSIONS

The mean albumin concentration and COP were highest in CPP, suggesting that CPP may be a potential alternative to FFP for oncotic support and albumin replacement. CRYO contained higher activities of vWf and factor VIII than other products and could be used to treat vWf deficiency and hemophilia A. As vitamin K dependent coagulation factors II, VII, and X in CPP were similar to FFP, CPP may be an option for replacement of most of vitamin K dependent factors.

Controversies in the use of fresh frozen plasma in critically ill small animal patients

OBJECTIVE

To review the literature supporting or discouraging the use of fresh frozen plasma (FFP) transfusion in critically ill patients.

DATA SOURCES

Human and animal publications were searched using PubMed without time limits and the following keywords were used: "fresh frozen plasma," "coagulopathy," "hypocoagulable state," "hypercoagulable states," and "critical illness."

HUMAN DATA SYNTHESIS

The commonly used tests of coagulation (eg, prothrombin time, activated partial thromboplastin time, international normalized ratio) are poorly predictive of clinical bleeding. FFP use in critically ill patients is unlikely to result in improved outcomes and may be associated with increased risks.

VETERINARY DATA SYNTHESIS

There is insufficient evidence to make definitive conclusions regarding the use of FFP in critically ill animals, but clinical studies are underway that may provide further data that clarify the optimal use of FFP in animals.

CONCLUSIONS

The use of FFP in critically ill patients remains controversial. In the absence of clinical bleeding or a risk for clinical bleeding associated with a planned procedure, treatment use of FFP is not recommended in human patients. There are insufficient data in critically ill animals to enable formulation of recommendations. Further research is warranted in dogs and cats to establish evidence-based guidelines.

Coagulation factor and hemostatic protein content of canine plasma after storage of whole blood at ambient temperature

Background

Standard practice in canine blood banking is to produce fresh frozen plasma (FFP) by separating and freezing plasma produced from blood within 8 hours of collection. Within canine blood donation programs, this can limit the number of units collected.

Hypothesis/Objectives

The aim was to compare the coagulation factor and hemostatic protein content (CF&HPC) of plasma produced from blood stored at ambient temperature for 8, 12, and 24 hours. Another aim was to compare the CF&HPC between Greyhound types and other breeds.

Animals

None.

Methods

In vitro study. A convenience sample of 58 units of canine blood from a blood donor pool was processed to prepare and freeze plasma 8, 12, or 24 hours following collection.

Results

Regardless of time of processing, the units contained therapeutic CF&HPC. Frozen plasma prepared after 24 hours had significantly higher factor VIII (P = .014) and factor X (P = .03) when compared with the frozen plasma prepared at 8 hours. Factor X (P < .01), fibrinogen (P < .01), and vWF (P = .04) were significantly lower in plasma collected from Greyhound types than in plasma collected from other breeds.

Conclusions and Clinical Importance

Storing whole blood for up to 24 hours is a suitable method for producing FFP. Lower values for some coagulation factors and hemostatic proteins in plasma produced from Greyhound types would not preclude these dogs as FFP donors.

Evaluation of coagulation in dogs with partial or complete extrahepatic biliary tract obstruction by means of thromboelastography

OBJECTIVE

To characterize in vitro coagulation status in a cohort of dogs with extrahepatic biliary tract obstruction (EHBO) and to evaluate these patients for hypercoagulability by means of thromboelastography.

DESIGN

Prospective cohort study. Animals-10 dogs with EHBO and 19 healthy control dogs.

PROCEDURES

Partial or complete EHBO was confirmed via exploratory celiotomy. Venous blood samples were collected for evaluation of prothrombin time (PT) and activated partial thromboplastin time (APTT); fibrinogen and D-dimer concentrations; protein C and antithrombin activities; and factor VII, VIII, and XI coagulant activities in plasma as well as thromboelastography in whole blood. Thromboelastography variables were measured from the thromboelastography tracing, and a coagulation index was calculated. Thromboelastography results were compared with those of healthy control dogs previously evaluated by the same laboratory.

RESULTS

Hypercoagulability was diagnosed in all dogs with EHBO on the basis of a high coagulation index. Thromboelastography variables, including maximal amplitude, α-angle, and coagulation index, were significantly higher, and K (clot formation time) and R (reaction time) were significantly lower in these dogs than in control dogs. All dogs with EHBO had PT and APTT within respective reference ranges. Plasma D-dimer and fibrinogen concentrations were above reference ranges in 8 and 7 dogs, respectively, and protein C and antithrombin activities were below reference ranges in 3 and 1 dogs, respectively.

CONCLUSIONS AND CLINICAL RELEVANCE

In vitro hypercoagulability was commonly detected in dogs with naturally occurring EHBO. The traditional view of EHBO as a disease that causes hypocoagulability may need to be reconsidered.

Protein C activity in dogs: adaptation of a commercial human colorimetric assay and evaluation of effects of storage time and temperature

Objectives of this study were to adapt a commercial human protein C (PC) colorimetric assay for use in dogs and to investigate effects of various storage conditions. The human assay was modified by using pooled canine plasma for calibration and by increasing the activation time. PC activity was measured in fresh canine plasma and in plasma stored under various conditions. PC activity of some stored samples was significantly different from that of fresh plasma; however, differences were small. No difference was detected in samples stored under similar conditions but analyzed in different laboratories using similar methodology. Results of this study indicate that the human colorimetric assay is suitable for canine samples if pooled canine plasma is used for calibration, that Clinical and Laboratory Standards Institute sample storage guidelines developed for testing in humans are appropriate for dogs, and that comparisons of results from laboratories using similar methodology are legitimate.