Characteristics of the factor VIII protein and Factor XIII in various factor VIII concentrates

Reliability of Microwave Heating for Hemoderivative Thawing

The spoiling of coagulation factors, proteic patterns and specific activity has been comparatively determined in fresh frozen plasma, cryoprecipitates and hemodiagnostic sera, thawed in a 37 degrees C water bath and in a microwave oven. Effects of conventional and microwave heating are not significantly different, while results of the latter technique are rapid and aseptic. Previously, heating performances of a commercial microwave oven have been investigated for deionized water, saline solutions, and bovine serum. Furthermore, plastic containers of hemoderivatives have been tested to assure that no toxic products are released during microwave heating.

Comparison of coagulation factor XIII content and concentration in cryoprecipitate and fresh-frozen plasma

BACKGROUND

For patients with plasma coagulation factor XIII (pFXIII) deficiency, recommended means of replacement include infusions of fresh-frozen plasma (FFP), cryoprecipitate, or (where available) factor (F)XIII concentrates. Quantitative differences in pFXIII concentration in FFP and cryoprecipitate are not well defined and were, therefore, the subject of this study.

STUDY DESIGN AND METHODS

FFP and cryoprecipitate (10 bags each from blood group O donors) were analyzed to quantify pFXIII activity and antigen. Coagulation FVIII, fibrinogen, and von Willebrand factor (VWF) were also quantitated.

RESULTS

Mean (+/-SD) pFXIII activity in cryoprecipitate and FFP bags was 60 +/- 30 and 288 +/- 77 U per bag, respectively, and pFXIII antigen and activity levels were concordant. Other comparisons (mean +/- SD) between cryoprecipitate and FFP, respectively, were as follows: coagulation FVIII activity, 133 +/- 37 and 265 +/- 83 U per bag; fibrinogen content (Clauss kinetic assay), 183 +/- 44 and 725 +/- 199 mg per bag; VWF antigen content, 181 +/- 53 and 218 +/- 70 U per bag; VWF ristocetin cofactor activity, 168 +/- 34 and 221 +/- 65 U per bag; VWF collagen-binding activity, 164 +/- 40 and 208 +/- 71 U per bag; and fluid (plasma) volumes per bag, 21.3 +/- 2.7 and 245 +/- 29 mL.

CONCLUSION

In contrast to other cryoprecipitable coagulation proteins, pFXIII is only mildly enriched in cryoprecipitate when compared with FFP (approx. two- to threefold). Although both products can provide effective pFXIII replacement, FFP may be preferred when infusion volume is not a major consideration and pFXIII concentrates are not available. VWF is substantially enriched in cryoprecipitate (approx. ninefold compared with its concentration in FFP), with VWF activity content exceeding that of FVIII by approximately 26 percent on average.

A reversed activity staining procedure for detection of an acquired antibody against factor XIII in a girl with factor XIII deficiency

A new method for detection of inhibitors against factor XIII is described. Agarose gel electrophoresis with normal platelet poor plasma as a factor XIII source included in the gel was combined with reversed activity staining. The procedure was applied to a 10-year-old girl with factor XIII deficiency where substitution therapy had failed. Plasma samples from the patient inhibited the factor XIII catalysed incorporation of the fluorescent monodansylthiacadaverine into casein at a position corresponding to the migration of gamma-globulins. Treatment with Sepharose-bound protein A effectively adsorbed the factor XIII antibody in the patient's plasma.

Chromatographic preparation of a therapeutic highly purified von Willebrand factor concentrate from human cryoprecipitate

A therapeutic highly purified von Willebrand factor (vWF) concentrate has been prepared from cryoprecipitate by a three-step chromatographic procedure. After solvent/detergent treatment to inactivate viruses, the cryoprecipitate solution was chromatographed on DEAE-fractogel TSK 650 M to separate vWF from most cryoprecipitate proteins, including factor VIII (FVIII) and fibrinogen. A second DEAE-fractogel TSK 650 M was then performed to further purify vWF and to allow concentrating it to over 100 U ristocetin cofactor activity/ml. The last step on immobilized gelatin removed fibronectin and increased the purity of vWF. vWF was recovered with about 18 and 40% yield in antigen and collagen-binding (CB) activity, respectively, from cryoprecipitate. vWF was obtained in an essentially pure state corresponding to a purification factor of over 10,000-fold from plasma. Immunonephelometric and SDS-PAGE analyses of the concentrate did not reveal any detectable cryoprotein contaminants, especially fibrinogen, fibronectin, immunoglobulins and albumin. The content in intermediate- and high-molecular-weight multimers in the concentrate was similar or higher than that of plasma, as the ion-exchanger selectively favored the binding and concentration of the larger multimeric forms while reducing the amount of the smaller forms with abnormal structure and low activity. Other characteristics of the concentrate included a CB activity to antigen ratio of 1.69 and a high capacity (86%) to correct platelet adhesion in a perfusion system. Clinical use of this standardized vWF concentrate has been shown to be efficacious in the treatment of vWF patients.

Polar secretion of von Willebrand factor by endothelial cells

Human umbilical vein endothelial cells cultured on a collagen lattice were used to study the polarity of von Willebrand factor (vWF) secretion. Endothelial cells cultured under these conditions allow direct measurements of substances released at both the apical and basolateral surface. The constitutive secretion of vWF was compared to the release of vWF from their storage granules after stimulation (regulated secretion). The basal, constitutive release of vWF occurs into both the apical and subendothelial direction. The rate of accumulation of vWF to the subendothelial direction is about three times higher than the amount of vWF secreted into the lumenal medium per unit of time. However, upon stimulation of confluent endothelial cell monolayers with phorbol myristate acetate, endothelial cells predominantly secrete vWF at the lumenal surface. Under these conditions, vWF does not accumulate in the collagen matrix. Thus, endothelial cells are able to organize themselves into a polarized monolayer, in such a way that vWF secreted by the regulated pathway accumulates at the lumenal site, whereas resting endothelial cells release vWF predominantly at the opposite, basolateral surface.

Biochemical and in vivo properties of commercial virus-inactivated factor VIII concentrates

The following commercial virus-inactivated factor VIII concentrates were studied in vitro: AHF-Kabi and Octonativ, KabiVitrum; Hemofil T, Hyland; Factorate HP and Monoclate, Armour; Nordiocto, Nordisk Gentofte (dry heated); Kryobulin TIM3, Immuno (steam treated); Profilate, Alpha (heated as dry material slammed in heptane); Hemate P, Behring (wet heated) and Octa-V.I., Octapharma (solvent/detergent treated). The concentration of VIII:C was lowest in AHF-Kabi, whereas it ranged from 24 to 53 IU/ml in the high purity concentrates, except for Monoclate in which it ranged from 91-128 IU/ml. All concentrates but Octa-V.I. had higher values for VIII:Ag than for VIII:C. von Willebrand factor with normal distribution of multimers could only be demonstrated in AHF-Kabi and Hemate P. In vivo studies were performed in 12 severe hemophiliacs. Recovery and half-life of VIII:C did not differ between the various concentrates. Hemate P was given to 5 patients with severe von Willebrand's disease, in all of whom a correction of the hemostatic defect was seen.

Cryoprecipitate and Factor VIII commercial concentrates: in vitro characteristics and in vivo compartmental analysis

In vitro and in vivo characteristics of cryoprecipitates and three commercial factor VIII concentrates (Kryobulin, Hemofil and Koate) were comparatively studied. Factor VIII:C/VIIIR:Ag ratio was very low in all commercial concentrates without differences among them. Conversely, the decrease of factor VIIIR:WFRCof was proportional to the degree of purity. Factor VIII:C/VIIIR:WFRCof ratio was shown to be a reliable index of factor VIII complex denaturation. Crossed electroimmunoassay showed a faster migration of factor VIIIR:Ag only in commercial concentrates. Using a two-compartmental open model that accounts for endogenous synthesis of factor VIII:C, single-dose kinetics of factor VIII:C were studied in 23 patients with classic hemophilia. Good agreement between measured and fitted values of factor VIII:C plasma concentration was observed. beta half-life was shorter in high purity concentrates and longer in intermediate purity concentrates and cryoprecipitates.

Quantitation of factor XIII by SDS polyacrylamide gel electrophoresis

An electrophoretic method for the determination of f.XIII, based on the capability of f.XIIIa to cross-link fibrin clots (5) was studied, and the great sensitivity of the method confirmed. Thus, with suitable technical conditions, f.XIII activities less than 0.1% of that in normal human plasma could be detected. The results obtained in plasma from various patients and in f.XIII concentrates (cryoprecipitates) corresponded well with those obtained with the dansylcadaverine method (3) and with the urea solubility test, with two exceptions: In a patient with severe congenital f.XIII deficiency, only the present method was sensitive enough to detect any f.XIII-activity (about 0.1%), and in a patient with an inhibitor against f.XIIIa, the dansylcadaverine method failed to detect this. The present method is too laborious for routine screening, but is recommended as an alternative references method. It may prove especially suitable to detect minute amounts of f.XIII.

Improvement of plasma quality as raw material for factor VIII:C concentrates. Storage of whole blood and plasma and interindividual plasma levels of fibrinopeptide A

Blood collected into different anticoagulants was stored in small tubes at +4 degrees C for up to 26 h. Seven blood coagulation analyses were performed under standardized conditions. High yield and stability of factor VIII:C were found for ACD and CPD-adenine. No changes could be found in the other six parameters tested. Whole blood in blood bags could be stored for 2-4 h at +4 degrees C with maximal yield of F VIII:C, with blood stored overnight the recovery was 65%. In plasma F VIII:C was stable for at least 2 h at room temperature. F VIIIR:Ag and F VIIIR:RCoF were stable in both whole blood and plasma. No activation by plasmin as measured by B beta 15-42 could be demonstrated. The initial FPA levels, reflecting thrombin activation, in the donated blood differed individually and in some blood bags very high concentrations were found. The levels of FPA were not correlated to the time for collection of a bag of blood.

An in vivo study of a new factor VIII high purity preparation

The efficacy of high purity preparations of factor VIII complex are usually lacking effect on the bleeding time in von Willebrand's disease. In this report we have studied the efficacy of a new high purity factor VIII preparation in two von Willebrand and two hemophilia A patients. The prolonged bleeding time in the patients with von Willebrand's disease was corrected after infusion of the preparation and a secondary rise in factor VIII procoagulant activity (VIII:C) demonstrated. The biological half-life time of VIII:C, in the two hemophilia A patients, was about 15 hrs. The investigation shows that this particular preparation is capable of correcting the prolonged bleeding time in von Willebrand's disease.

The effect of storage of whole blood on the association of factor VIII-related antigen and factor VIII-coagulant antigen

To evaluate the extent of denaturation of factor VIII-coagulant activity (VIII: C) during production of factor VIII concentrates, the factor VIII-coagulant antigen (VIII: CAg)/VIII: C ratio was measured in plasma, cryoprecipitate and cryosupernatant from fresh and stored blood. This ratio was close to unity for both cryoprecipitate and other concentrates, suggesting that VIII: CAg is lost concurrently with VIII: C during cryoprecipitation and further fractionation. Storage of blood (18 h, 22 degrees C) before processing resulted in a 30% loss of VIII: C from the separated plasma; however, VIII: CAg was not affected. In cryoprecipitate prepared from this plasma, VIII: C and VIII: CAg both were 30% lower than when prepared from fresh plasma. In the corresponding cryosupernatant, however, more VIII: CAg but less VIII: C was present compared with fresh material. Gel chromatography revealed that the rise of VIII: CAg in cryosupernatant prepared from stored blood, was due to an increased amount of VIII: CAg of low molecular weight, not being associated with factor VIII-related antigen. Such an increase in dissociated VIII: CAg was not detected in the plasma prior to cryoprecipitation. It is concluded that during storage of blood, molecular changes are induced in the factor VIII-VWF complex, possibly by limited proteolysis, which make the complex more liable to dissociation during subsequent cryoprecipitation.

The effect of intranasal DDAVP on coagulation and fibrinolytic activity in normal persons

DDAVP (1-desamino-8-D-arginine vasopressin) was administered intranasally to 20 normal persons and blood was collected at various intervals up to 72 h. Plasma concentrations of VIII:C, VIIIR:Ag and fibrinolytic activity were increased by DDAVP with peak levels observed 1 h after the administration. Factors V, IX, XI, XII, XIII, P-APT time, platelets, platelet factor 3, P&P, AT III, alpha 2AP, fibrinogen and FDP were unchanged by the treatment. No side effects or changes in plasma Na or osmolality were observed. The present data demonstrate the selectivity of the effect of DDAVP on the coagulation system and points towards the possibility of using DDAVP in blood donors to increase plasma contents of factor VIII.

The 'in vivo' survival characteristics of factor VIII procoagulant antigen (VIII:C Ag) in haemophilia A subjects

Initial half disappearance times and biological half-lives were determined for factor VIII procoagulant antigen (VIII:C Ag) and compared with VIII procoagulant (VIII:C) survival for each of two commercial concentrates, transfused into seven severe (less than 1 i.u./dl) non-bleeding haemophiliacs. The results show that VIII:C Ag has similar half disappearance and biological half-life to that of factor VIII:C. The relevance of these results to recently published findings is discussed.

Alterations of factor VIII von Willebrand factor in clinical conditions associated with an increase in its plasma concentration

Factor VIII-related antigen (VIIIR:Ag) was consistently higher than factor-VIII procoagulant activity (VIII:C) in 57 patients with clinical conditions characterized by acute-phase reactions. Two different methods for measuring VIII:C (one- and two-stage assays) and VIIIR:Ag (electroimmunodiffusion and immunoradiometric assay) gave concordant results in the majority of cases. In 43% of plasma samples, crossed immunoelectrophoresis in agarose gel was characterized by the appearance of an additional, fast-moving precipitin peak which was immunologically identical with the major, slower-moving VIIIR:Ag peak. The fast-moving peak was detected in all the patients with clinical conditions typically associated with increased plasma proteolysis (DIC, acute pancreatitis, during thrombolytic therapy). It was present in a smaller proportion of cases with liver and renal failure and malignancies and in the post-operative period. The additional VIIIR:Ag peak is thought to be the result of in vivo factor VIII/von Willebrand factor fragmentation by proteolytic enzymes.

Factor VIII:C and VIII:CAg response in patients with haemophilia A and von Willebrand's disease after administration of different factor VIII concentrates or plasma

Factor VIII procoagulant activity (VIII:C) and factor VIII procoagulant antigen (VIII:CAg) were studied in seven patients with haemophilia A after administration of three different factor VIII concentrates or plasma. The in vivo recovery of VIII:CAg was less than that of VIII:C and the disappearance rate of VIII:CAg was much higher either when concentrates or plasma were given. The half-life of VIII:C was thus about 12 h but of VIII:CAg only about 3 h or less. Six patients with von Willebrand's disease were studied after administration of AHF-Kabi. In contrast to haemophilia A the discrepancy between VIII:C and VIII:CAg disappearance rates was not present in von Willebrand's disease, since both VIII:C and VIII:CAg showed a typical progressive increase. We conclude that factor VIII:C given to haemophilia patients does not behave like native VIII:C, not even when fresh plasma is used. Patients with von Willebrand's disease are capable of forming a normal VIII:C when appropriately stimulated.