PARADOXICAL INCREASE IN HUMAN FACTOR VIII AFTER INFUSION OF PORCINE FACTOR VIII CONCENTRATE IN A PATIENT WITH ACQUIRED VARIANT VON WILLEBRAND'S DISEASE

1987 ◽  
Author(s):  
J Ball ◽  
R G Malía ◽  
M Greaves ◽  
F E Preston
Keyword(s):  
Molecular Weight ◽  
Factor Viii ◽  
Human Factor ◽  
De Novo ◽  
Similar Time ◽  
Von Willebrand's Disease ◽  
Von Willebrand’S Disease ◽  
Human Factor Viii ◽  
Plasma Factor ◽  
Abnormal Pattern

A patient with acquired variant von Willebrand's disease was given an infusion of 2000 units of high purity porcine factor VIII (Hyate). Quantitative factor VIII parameters were assessed following infusion and human factor VIII multimers were analysed by radioimmunoelectrophoresis and autoradiography. We have previously described the patient to have acquired von Willebrand's disease due to a circulating inhibitor to the factor VIII complex (B. J. Haematol-, 54,233,1983). Prior to infusion plasma from the patient contained factor VIIIC, RRCo, and vWFAg at less than 10 u/dl- Plasma factor VIII multimers showed an abnormal pattern with no high molecular weight bands present despite a normal triplet structure in the low molecular weight forms. After the infusion of porcine factor VIII concentrate a large increase in the levels of plasma VIIIC was detected with a disappearance half-life of 3.5 hours. A specific non-crossreacting immunoradiometric assay (IRMA) showed that plasma levels of porcine vWFAg did not rise significantly after the infusion. Despite this, human vWFAg levels were notably elevated at 1 hour (40 u/dl by Laurell) and 2 hours (30 u/dl by IRMA) post infusion. Similarly, ristocetin induced platelet aggregation and plasma RRCo levels showed significant elevations , 2 hours after the infusion. Factor VIII multimers assessed on plasma samples taken over a similar time period revealed the transient appearance of a normal compliment of human factor VIII multimeric forms 2 hours after the infusion of porcine factor VIII concentrate. This study indicates that the abnormal pattern of factor VIII multimeric bands present in inhibitor-related variant acquired von Willebrand's disease can be transiently normalised by infused porcine factor VIII concentrate. Whether this represents antibody displacement or de novo synthesis is yet to be determined.

Studies on the Characterization of Factor VIII and a Co-factor VIII

1974 ◽  
Vol 31 (02) ◽  
pp. 328-338
Author(s):  
M. M. P Paulssen ◽  
H. L. M. A Vandenbussche-Scheffers ◽  
P. B Spaan ◽  
T de Jong ◽  
M. C Planje
Keyword(s):  
Molecular Weight ◽  
Factor Viii ◽  
The Body ◽  
Haemophilia A ◽  
Von Willebrand's Disease ◽  
Von Willebrand’S Disease ◽  
Polysaccharide Content ◽  
Plasma Factor ◽  
Two Factors

SummaryFactor VIII occurs in the body in two different forms. In lymph factor VIII is bound to chylomicra. In plasma, factor VIII is bound to a protein.After delipidation of chylomicra we obtained a glycoprotein with a high polysaccharide content and a molecular weight of approx. 160,000.In plasma, factor VIII is attached to a protein which is present in normal concentrations in plasma of patients with haemophilia A and in serum (co-factor VIII).This factor is deficient in both the plasma and the serum of patients with von Willebrand’s disease.The binding between factor VIII and co-factor VIII is reversible.Some properties of these two factors are described.

The Fractionation Properties of Human Factor VIII (Antihaemophilic Factor)

1960 ◽  
Vol 04 (02) ◽  
pp. 253-260 ◽  
Author(s):  
Franco Gobbi
Keyword(s):  
Factor Viii ◽  
Human Factor ◽  
Maximum Yield ◽  
Factor Vii ◽  
Precipitation Method ◽  
Salting Out ◽  
Human Factor Viii ◽  
Plasma Factor ◽  
Two Factors ◽  
Thromboplastic Activity

SummaryThe fractionation properties of human Factor VIII (antihaemophilic factor, AHF, antihaemophilic globulin) have been studied using a plasma of congenital afibrinogenaemia as a starting material.From a fibrinogen-free plasma, Factor VIII does not precipitate with ethanol at a final concentration of 8%; on the contrary the maximum yield is reached at an ethanol concentration of 25%.With a precipitation method carried out by a one to ten dilution of plasma with distilled water and acidification by N/10 hydrochloric acid to a pFI 5.2, Factor VIII does not precipitate with the euglobulin fraction; when normal plasma is used, such a precipitation is almost complete.With the salting-out fractionation method by ammonium sulphate, Factor VIII precipitates at a concentration between 25 and 33% of saturation either from fibrinogen-free and from normal human plasma.A non-specific thromboplastic activity appears in the fractions prepared by every method. This activity, which is probably due to the activation of seric accelerators, is easily removed by Al(OH)s adsorption. Thus, in order to insure the specificity of Factor VIII assays, the preliminary adsorption of the fractions is indispensable before testing their antihaemophilic activity.Fibrinogen and Factor VIII have different and definite precipitation patterns. When these two factors are associated the fractionation properties of AHF appear quite modified, showing a close similarity to those of fibrinogen. This fact can explain the technical difficulties encountered in the attempt to purify the antihaemophilic factor, and the lack of reproducible procedures for removing fibrinogen without affecting Factor VII.

scholarly journals Factor VIII/von Willebrand factor in subendothelium mediates platelet adhesion

Blood ◽  
1985 ◽  
Vol 65 (4) ◽  
pp. 823-831 ◽  
Author(s):  
VT Turitto ◽  
HJ Weiss ◽  
TS Zimmerman ◽  
II Sussman
Keyword(s):  
Factor Viii ◽  
Von Willebrand Factor ◽  
Vessel Wall ◽  
Platelet Adhesion ◽  
Human Factor ◽  
Rabbit Aorta ◽  
Human Factor Viii ◽  
Plasma Factor ◽  
Von Willebrand ◽  
Willebrand Factor

The present studies were undertaken to determine whether factor VIII/von Willebrand factor (vWF) present in the vessel wall (in addition to that in plasma) may mediate the attachment of platelets to subendothelium. Subendothelium from everted rabbit aorta was exposed to human citrated blood flowing through an annular perfusion chamber at 40 mL/min (wall shear rate of 2,600 s-1 for five minutes). The vessel segments were incubated at 37 degrees C for one hour with various dilutions of either goat-anti-rabbit factor VIII/vWF serum or an IgG fraction prepared from the serum. Control segments were incubated with serum or IgG from a nonimmunized goat. Values of platelet contact (C), platelet adhesion (C + S), and thrombus formation (T) on the subendothelium were evaluated by a morphometric technique. Compared with vessels incubated with fractions prepared from a normal goat, a significant decrease in platelet adhesion (C + S), ranging from 45% to 65%, was observed on vessels incubated with various dilutions (1:5 to 1:50) of either serum or IgG fractions of goat-anti-rabbit factor VIII/vWF. A similar decrease in platelet adhesion was observed with vessels incubated with an F(ab')2 fragment against rabbit factor VIII/vWF prepared in the goat. When goat-anti-rabbit factor VIII/vWF IgG was added to rabbit blood (1:75 dilution), platelet adhesion was reduced to the same extent (65%) on normal rabbit vessels and on vessels pre-incubated with goat-anti-rabbit factor VIII/vWF. Immunofluorescence studies revealed the presence of rabbit factor VIII/vWF in the subendothelium of rabbit aorta and the continued binding of the goat-anti-factor VIII/vWF antibodies on subendothelium during the perfusion studies. No uptake of human factor VIII/vWF on the rabbit subendothelium was observed by this immunologic technique; human factor VIII/vWF was found to be entirely associated with the attached human platelets. Thus, factor VIII/vWF in the vessel wall may mediate platelet attachment to subendothelium in a manner similar to that of plasma factor VIII/vWF.

scholarly journals Multimeric composition of factor VIII/von Willebrand factor following administration of DDAVP: implications for pathophysiology and therapy of von Willebrand's disease subtypes

Blood ◽  
1982 ◽  
Vol 59 (6) ◽  
pp. 1272-1278 ◽  
Author(s):  
ZM Ruggeri ◽  
PM Mannucci ◽  
R Lombardi ◽  
AB Federici ◽  
TS Zimmerman
Keyword(s):  
Factor Viii ◽  
Von Willebrand Factor ◽  
Resting State ◽  
Bleeding Time ◽  
Type I ◽  
Von Willebrand's Disease ◽  
Von Willebrand’S Disease ◽  
Plasma Factor ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract We have studied the modifications in the multimeric composition of plasma factor VIII/von Willebrand factor and the bleeding time response following administration of 1-Deamino-[8-D-arginine]-Vasopressin (DDAVP) to patients with different subtypes of von Willebrand's disease. In type I, all multimers were present in plasma in the resting state, though they were decreased in concentration. Administration of DDAVP resulted in an increased concentration of these forms as well as the appearance of larger forms than were previously present. There was concomitant correction of the bleeding time. In type IIA, large multimers were absent in the resting state, and although DDAVP induced an average threefold increase in the plasma concentration of factor VIII/von Willebrand factor, the larger multimers did not appear and the bleeding time, although shortened, was not corrected. In contrast, the larger multimers that were also absent from type IIB plasma in the resting state rapidly appeared following DDAVP administration. However, their appearance was transitory and the bleeding time, as in IIA patients, was shortened but not corrected. The characteristic multimeric composition of platelet factor VIII/von Willebrand factor in given subtypes predicted the alteration in plasma factor VIII/von Willebrand factor induced by DDAVP. These studies provide evidence that the different subtypes of von Willebrand's disease represent distinct abnormalities of factor VIII/von Willebrand factor. They also suggest that complete hemostatic correction following DDAVP can be routinely expected only in type I von Willebrand's disease, and only if factor VIII/von Willebrand factor can be raised to normal levels.

scholarly journals Clinical experience with polyelectrolyte-fractionated porcine factor VIII concentrate in the treatment of hemophiliacs with antibodies to factor VIII

Blood ◽  
1984 ◽  
Vol 63 (1) ◽  
pp. 31-41 ◽  
Author(s):  
PB Kernoff ◽  
ND Thomas ◽  
PA Lilley ◽  
KB Matthews ◽  
E Goldman ◽  
...  
Keyword(s):  
Factor Viii ◽  
Clinical Experience ◽  
Human Factor ◽  
Intermediate Level ◽  
Human Factor Viii ◽  
Plasma Factor ◽  
Post Infusion ◽  
Clinical Responses ◽  
Circulating Antibodies

Circulating antibodies to factor VIII (anti-VIII, “inhibitors”) occurring in patients with hemophilia neutralize porcine factor VIII less readily than human factor VIII in vitro. Over an 18-mo period, 8 patients with anti-VIII were treated with 45 courses (297 infusions) of polyelectrolyte-fractionated porcine factor VIII concentrate (PE porcine VIII). Where no anti-PE porcine VIII was detectable, mean post- infusion rise in plasma factor VIII was 1.29 U/dl/units infused/kg. Above 13 Old Oxford units of anti-PE porcine VIII and 48 Bethesda units of anti-human VIII, there were no postinfusion rises in plasma factor VIII. Where postinfusion rises were detected, clinical responses were good and conventional methods could be used to guide dosage. Ten percent of infusions were followed by febrile reactions, but these were usually mild and decreased in frequency and severity with increasing exposure. Multiple and prolonged courses of therapy were given to some patients without evidence of loss of clinical or laboratory efficacy. PE porcine VIII could provoke anamnestic rises of anti-VIII in susceptible patients, but appeared to have a lower immunogenic potential than human VIII. PE porcine VIII is a rational and effective therapeutic alternative for patients with anti-VIII, particularly those with intermediate level inhibitors who cannot be managed effectively using human factor VIII.

Rabbit Antibodies Against the Procoagulant Activity (VIII:C) of Human Factor VIII

1981 ◽  
Vol 46 (04) ◽  
pp. 699-705 ◽  
Author(s):  
T H Tran ◽  
G A Marbet ◽  
F Duckert
Keyword(s):  
Factor Viii ◽  
Human Factor ◽  
Gel Filtration ◽  
Procoagulant Activity ◽  
Solid Matrix ◽  
Factor Viii Activity ◽  
Physiological Conditions ◽  
Human Factor Viii ◽  
Plasma Factor ◽  
Factor Viii Antigen

SummaryThe procoagulant activity VIII:C was separated from factor VIII antigen (VIIIR:Ag) by gel filtration in the presence of 0.25 mol/l calcium chloride. Antibodies (anti-VIII:C) were obtained by immunization of rabbits with VIII:C. The last step of the purification procedure of antibodies consists of an adsorption on VIIIR:Ag-Sepharose 2 BCL as immunoadsorbent to remove contaminating traces of antibodies against VIIIR:Ag. The anti- VIII:C titer remains unchanged during this adsorption (29 Bethesda units per mg). In solution, anti-VIII:C neutralies factor VIII activity (in plasma, cryoprecipitate or in purified form) and the fragment VIII:C without reacting with VIIIR:Ag. Once immobilized on a solid matrix, i.e.2% agarose, it loses over 95% of its inhibitory capacity. The immobilized anti-VIIIR:Ag binds stoichiometrically the antigen and the activity of plasma factor VIII. These results together suggest that factor VIII is composed of 2 different entities, but undissociated under physiological conditions. Immunophysical analyses as a function of pH and temperature of anti-VIII:C and its complex with factor VIII show properties similar to those of homologous antibodies. The antigen determinants of VIII:C (VIII:CAg) are destroyed at low pHs or high temperatures, and VIII:C can no more form a complex with anti-VIII:C. Purified anti-VIII:C is also used in a two-stage assay to detect VIII:CAg or cross-reacting material in some severe haemophiliacs.

scholarly journals Apparent molecular weight of purified human factor VIII procoagulant protein compared with purified and plasma factor VIII procoagulant protein antigen

Blood ◽  
1983 ◽  
Vol 62 (5) ◽  
pp. 1114-1117 ◽  
Author(s):  
MJ Weinstein ◽  
CA Fulcher ◽  
LE Chute ◽  
TS Zimmerman
Keyword(s):  
Molecular Weight ◽  
Factor Viii ◽  
Apparent Molecular Weight ◽  
Discontinuous System ◽  
Major Band ◽  
Molecular Weights ◽  
Human Factor Viii ◽  
Plasma Factor ◽  
Factor Viii Concentrates ◽  
Electrophoretic Techniques

Abstract We have compared apparent molecular weights of purified factor VIII procoagulant protein (VIII:C) and VIII:C antigen (VIII:CAg) by two different NaDodSO4 gel electrophoretic techniques. In a discontinuous NaDodSO4–7.5% polyacrylamide system, reduced and unreduced VIII:C, purified from commercial factor VIII concentrates by a monoclonal antibody immunoadsorption technique, showed a major doublet at mol wt 0.79 and 0.8 X 10(5) and less intense bands extending up to 1.9 X 10(5). In NaDodSO4–4% polyacrylamide/0.5% agarose gels (NaDodSO4–4% PAAGE), purified VIII:C had a major band of mol wt 1.0 X 10(5), with minor bands of mol wt 0.96, 1.1, 1.4, 1.6, 1.8, 2.2, and 2.4 X 10(5). In NaDodSO4–4% PAAGE of 125I-anti-VIII:C-Fab-VIII:CAg complexes, the major and minor forms of VIII:CAg in purified VIII:C had the same molecular weight as above when calculated by subtracting the molecular weight of 125I-Fab from 125I-Fab-VIII:CAg. In both plasma and factor VIII concentrate, a band of mol wt 2.4 X 10(5) predominated, and minor VIII:CAg forms of mol wt 2.6, 1.8, 1.2 and 1.0 X 10(5) were also visible. We conclude that the molecular weight of plasma VIII:CAg forms agree with those derived from protein stains of purified VIII:C in the NaDodSO4–4% PAAGE system, but that consistently lower molecular weight values are obtained for purified VIII:C in the discontinuous system. Both native and either disaggregated or proteolyzed VIII:C species are present in the purified VIII:C preparation.

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