Trace Levels of Factor Viii in Substrate Plasma

Cf, Hirst; Hewitt, J; Poller, L.

doi:10.1111/j.1365-2141.1992.tb08224.x

Cited by 3 publications

(5 citation statements)

References 3 publications

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“…Although attempts were made to minimize variability by using single lots of reagents, standards, and substrate plasmas, interassay CVs for factors VII and IX were >10%. Different substrate plasmas contained different residual levels of clotting factor activity, and these trace levels affect the linearity of standard curves 14 , 15 . In this study, the relatively high FVII:C and low FIX:C in the test plasmas may have been caused in part by variation in residual activities of the substrate plasmas.…”

Section: Discussionmentioning

confidence: 68%

“…Different substrate plasmas contained different residual levels of clotting factor activity, and these trace levels affect the linearity of standard curves. 14,15 In this study, the relatively high FVII:C and low FIX:C in the test plasmas may have been caused in part by variation in residual activities of the substrate plasmas. A single set of dilutions of the CP2D reference plasma was used to derive standard curves for all factors on each assay date.…”

Section: Wardrop Brooksmentioning

confidence: 86%

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Stability of Hemostatic Proteins in Canine Fresh Frozen Plasma Units

Wardrop

Brooks

2001

Veterinary Clinical Pathol

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The stability of hemostatic proteins, including coagulation factors II, VII, VIII, IX, and X and von Willebrand factor (vWf), in canine fresh frozen plasma (FFP) units stored for up to 1 year was studied. Plasma units from 7 donor dogs were subjected to 4 treatments following collection, including storage at -30 degrees C for 3 months, 6 months, and 1 year and storage at -20 degrees C for 6 months. Coagulant factor activity and vWf concentrations were measured at these times. Significant differences between prestorage and poststorage values were noted for factors VIII, IX, and X, and vWf. Differences seemed to be least pronounced for plasma stored for 3 months; however, a significant interaction between prestorage and poststorage differences and the 4 treatment groups could not be demonstrated. On the basis of factor content in the present study, 15-20 mL/kg of FFP stored for up to 1 year was capable of providing approximately 10-15 U/kg of vWf and factors VIII, IX, X, and II, whereas 10 mL/kg FFP provided at least 10 U/kg of factor VII.

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Section: Discussionmentioning

confidence: 68%

Section: Wardrop Brooksmentioning

confidence: 86%

Stability of Hemostatic Proteins in Canine Fresh Frozen Plasma Units

Wardrop

Brooks

2001

Veterinary Clinical Pathol

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“…In an attempt to account for this variability, each factor activity was measured twice for every unit and repeated if >10% discrepancy was observed, and a single lot of reagents was used, as different reagents and substrate plasmas could contain different residual levels of coagulation factor activity, affecting the linearity of standard curves. 32 Another limitation was that when calculating the recommended dose, information on the number of IUs required for clinical effectiveness was extrapolated from canine publications and calculated along with in vitro results of the present study. Further feline in vivo studies should be performed to confirm our dose recommendation.…”

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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

Blasi-Brugué

Ferreira

Sánchez

et al. 2022

Journal of Feline Medicine and Surgery

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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.

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“…An example of this is provided by the observations on the apparent influence of vWF on observed factor VIII activity (51,52). The presence of trace amounts of factor VIII in the substrate plasma also can influence results (78). Finally, there is evidence that each factor VIII-deficient plasma will give a somewhat unique slope for the standard curve.…”

Section: In Vitro Assay Systems For Factor VIIImentioning

confidence: 99%

Issues with the Assay of Factor VIII Activity in Plasma and Factor VIII Concentrates

Lundblad¹,

Kingdon²,

Mann³

et al. 2000

Thromb Haemost

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SummaryA review of the literature suggests that assays accurate for the determination of factor VIII in plasma samples may not necessarily retain this accuracy when used for the determination of factor VIII in high-purity factor VIII concentrates such as Hemofil ® M. Review of assay data suggests that it is imperative to obtain maximal activation of the factor VIII in the sample with thrombin when using an assay system of isolated coagulation factors such as the two-stage assay or the various chromogenic substrate assays. Based on a combination of ease and reproducibility of performance and correlation of in vivo and in vitro measurements, it is recommended that the one-stage activated partial thromboplastin time performed with plasma from an individual with severe hemophilia A be used for the measurement of factor VIII potency. Chromogenic substrate assays can be used if care is taken to assure optimal activation of factor VIII by thrombin in the assay and the presence of sufficient factor IXa, phospholipid and calcium ions to stabilize factor Villa during the assay process.

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Trace Levels of Factor Viii in Substrate Plasma

Cited by 3 publications

References 3 publications

Stability of Hemostatic Proteins in Canine Fresh Frozen Plasma Units

Stability of Hemostatic Proteins in Canine Fresh Frozen Plasma Units

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

Issues with the Assay of Factor VIII Activity in Plasma and Factor VIII Concentrates

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