Altered Serum Factor Vlll-Related Antigen (VIII: AGN)/von Willebrand Factor (VIII: vWf) in Haemophiliacs with Inhibitors to Factor VIII Procoagulant Activity (VIII: C)

1981 ◽  
Vol 45 (01) ◽  
pp. 068-072 ◽  
Author(s):  
J O Ballard ◽  
J C Sanders ◽  
M E Eyster
Keyword(s):  
Factor Viii ◽  
Von Willebrand Factor ◽  
High Titer ◽  
Normal Subjects ◽  
Procoagulant Activity ◽  
Crossed Immunoelectrophoresis ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Altered Serum

SummaryInhibitors to factor VIII (anti-F VIII) developing in patients with classic haemophilia have apparent specificity for the factor VIII procoagulant activity (VIII: C), rather than the factor VIII-related antigen (VIII :AGN) and von Willebrand factor (VIII :vWf) regions of the factor VIII complex.Since procoagulant function is absent following in vitro clotting, but serum retains VIII: AGN/vWf properties, we searched for differences in VIII :AGN and VIII :vWf of inhibitor serum that might relate to the presence of anti-F VIII.Rocket immunoelectrophoresis and the washed platelet ristocetin assay were performed on the plasma and serum of nine haemophiliacs with inhibitors, 23 non-inhibitor haemophiliacs and six normal subjects. Unlike normal and non-inhibitor haemophilic sera, that from five of nine inhibitor patients demonstrated absent VIII : vWf and significantly lower VIII: AGN (p <0.05). Furthermore, VIII: AGN of faster mobility was detected on crossed immunoelectrophoresis of the sera of three inhibitor patients. Thrombin clotting of plasma from haemophiliacs with high titer anti-F VIII was associated with a greater loss of VIII: vWf than seen with non-inhibitor haemophilic plasma. This effect was independent of the presence of platelets.These data indicate that in vitro clotting is associated with alteration in the serum VIII: AGN/vWf of some haemophiliacs with anti-F VIII.

Factor VIII Structure and Function: Progress and Problems

1979 ◽  
Author(s):  
T.S. Zimmerman
Keyword(s):  
Factor Viii ◽  
Von Willebrand Factor ◽  
Bleeding Time ◽  
Procoagulant Activity ◽  
Factor Vii ◽  
Serine Esterase ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Ristocetin Cofactor

The last several years have seen considerable progress in our understanding of Factor VIII. Factor VIII has been shown to exist in vitro as different size multimers of the 200,000 MW subunit. The von Willebrand “bleeding time” factor appears to reside in the larger multimers whereas the Factor VIII procoagulant activity is associated with all of the different size forms. It has been suggested that this size heterogeneity results from in vitro changes. The role of carbohydrate in the Factor VIII von Willebrand function has been the subject of considerable study. It is clear that altering the carbohydrate composition of the Factor VIII molecule reduces or abolishes its ristocetin cofactor. Initial studies of Factor VIII carbohydrate in von Willebrand's disease showed it to be decreased. However, more recent studies of larger numbers of patients showed normal carbohydrate content in the great majority, even in those who lack von Willebrand factor activity. The ristocet in cofactor test has been of great help in defining relationships of the von Willebrand factor to factor VIII procoagulant activity yet the ability of ristocetin cofactor activity to truly reflect the bleeding time abnormality is open to question. The relationship of the Factor VII procoagulant activity to the Willebrand factor also remains a subject of controversy. Though Factor VIII procoagulant activity can clearly be separated from the von Willebrand factor in vitro, the in vivo relationship is unclear. Recent evidence has suggested that Factor VIII procoaguJant activlly may function as a serine esterase. However, the precise manner in which Factor VIII procoagulant activity exerts clot promoting functions is still a mystery.

Clinical cases of using coagulation factor VIII with von Willebrand factor in parturient women with type III von Willebrand disease

2020 ◽  
Author(s):  
И.В. Куртов ◽  
Е.С. Фатенкова ◽  
Н.А. Юдина ◽  
А.М. Осадчук ◽  
И.Л. Давыдкин
Keyword(s):  
Factor Viii ◽  
Von Willebrand Factor ◽  
Coagulation Factor ◽  
Von Willebrand Disease ◽  
Coagulation Factor Viii ◽  
Vitro Fertilization ◽  
Type 3 ◽  
Von Willebrand ◽  
Willebrand Factor

Болезнь Виллебранда (БВ) может представлять определенные трудности у рожениц с данной патологией. Приведены 2 клинических примера использования у женщин с БВ фактора VIII свертывания крови с фактором Виллебранда, показана эффективность и безопасность их применения. У одной пациентки было также показано использование фактора свертывания крови VIII с фактором Виллебранда во время экстракорпорального оплодотворения. Von Willebrand disease presents a certain hemostatic problem among parturients. This article shows the effectiveness and safety of using coagulation factor VIII with von Willebrand factor for the prevention of bleeding in childbirth in 2 patients with type 3 von Willebrand disease. In one patient, the use of coagulation factor VIII with von Willebrand factor during in vitro fertilization was also shown.

scholarly journals Selective absence of large forms of factor VIII/von Willebrand factor in acquired von Willebrand's syndrome. Response to transfusion

Blood ◽  
1979 ◽  
Vol 54 (3) ◽  
pp. 600-606 ◽  
Author(s):  
D Meyer ◽  
D Frommel ◽  
MJ Larrieu ◽  
TS Zimmerman
Keyword(s):  
Factor Viii ◽  
Von Willebrand Factor ◽  
Von Willebrand Disease ◽  
Procoagulant Activity ◽  
Factor Viii Related Antigen ◽  
Cofactor Activity ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Ristocetin Cofactor ◽  
Ristocetin Cofactor Activity

Abstract A previously healthy elderly man with mucocutaneous bleeding was found to have a benign monoclonal IgG gammapathy associated with criteria for severe von Willebrand disease (Factor VIII procoagulant activity, Factor-VIII-related antigen, and ristocetin cofactor activity, less than 10% of normal). Associated qualitative abnormalities of factor VIII/von Willebrand factor were demonstrated by radiocrossed immunoelectrophoresis and immunoradiometric assay. The late clinical onset and negative family history are in favor of an acquired form of vWD. The monoclonal gammapathy and abnormalities of factor VIII/von Willebrand factor have been stable over a 10-yr period. No inhibitor to Factor VIII procoagulant activity, ristocetin cofactor activity, or Factor-VIII-related antigen could be demonstrated. Following transfusion of cryoprecipitate (with a normal cross immunoelectrophoretic pattern), there was a rapid removal of the large forms of Factor.-VIII-related antigen, paralleled by a decay of ristocetin cofactor activity. The transfusion study of this patient with acquired von Willebrand disease type II (variant of von Willebrand disease) serves to emphasize the relationship between polydispersity of Factor VIII/von Willebrand Factor and functional heterogeneity.

scholarly journals Immunologic studies of native and modified human factor VIII/von Willebrand factor

Blood ◽  
1979 ◽  
Vol 54 (2) ◽  
pp. 310-321 ◽  
Author(s):  
ME Switzer ◽  
PA McKee
Keyword(s):  
Molecular Weight ◽  
Factor Viii ◽  
Von Willebrand Factor ◽  
Proteolytic Enzymes ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Procoagulant Activity ◽  
Human Factor Viii ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract Factor VIII/von Willebrand factor (FVIII/vWF) is a glycoprotein with a molecular weight greater than one-million daltons. Two activities are associated with this large molecule: FVIII procoagulant activity and vWF activity. Incubation of FVIII/vWF with proteolytic enzymes causes rapid inactivation of the FVIII procoagulant activity but has little effect on the vWF activity or antigenicity. In an attempt to gain insight into the structural features required for these two activities, antisera were raised in rabbits to normal, thrombin-inactivated, and plasmin-inactivated FVIII/vWF. All of these proteolytically modified forms of FVIII/vWF cross-reacted with each of the rabbit antisera; each blocked the ability of a human inhibitor to inactivate native active FVIII/vWF. Each of the antisera was a potent inhibitor of vWF activity and inactivated vWF activity at the same titer. The antisera were much less potent inhibitors of FVIII activity than of vWF activity. Antibodies to thrombin-inactivated FVIII/vWF or normal FVIII/vWF had about the same ability to inactivate FVIII procoagulant activity. Surprisingly, those to plasmin-inactivated FVIII/vWF still retained about 50% of this inhibitory capacity. A comparison of the three types of antigens by polyacrylamide gel electrophoresis in sodium dodecyl sulfate-6 M urea demonstrated that the structure of thrombin- inactivated FVIII/vWF was indistinguishable from that of normal FVIII/vWF, while plasmin-inactivated FVII/vWF was completely cleaved to lower molecular weight fragments. Some of the reported variations in the ability of rabbit antibodies to inhibit procoagulant activity may be due to partial degradation of the starting antigen. The retention by FVIII/vWF protein of its immunologic properties even after extensive proteolytic degradation suggests that under nondenaturing conditions, the conformation of the native and degraded molecules are very similar.

Stabilization of the Antihemophilic Factor (VIII :AHF) by the Von Willebrand Factor (VIII :VWF): A Possible Model for Von Willebrand’s Disease

1977 ◽  
Author(s):  
H. J. Weiss ◽  
I. I. Sussman ◽  
L. W. Hoyer
Keyword(s):  
Factor Viii ◽  
Von Willebrand Factor ◽  
Von Willebrand's Disease ◽  
Von Willebrand’S Disease ◽  
Crossed Immunoelectrophoresis ◽  
Factor Viii Antigen ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Antihemophilic Factor

When compared with VIII:AHF in normal citrated plasmas, VIII:AHF activity showed increased lability at 37°C in the ‘late’ post-transfusion plasmas (VIII:AHF≫VIII:VWF) of a patient with von Willebrand’s disease, but not in the ‘early’ post-transfusion plasmas in which VIII:AHF~VIII:VWF. VIII:AHF was also labile in the baseline plasmas of 3 patients with von Willebrand’s disease in whom VIII:AHF≫VIII:VWF. In two of these patients the mobility of Factor VIII antigen (on crossed Immunoelectrophoresis) was increased. (VIII:AHF was not excessively labile in 4 other patients in whom VIII :AHF~VIII:VWF). In all of the above cases, VIII:AHF was stabilized by the addition of either purified von Willebrand factor or plasmas of patients with hemophilia, but not by plasmas of patients with severe von Willebrand’s disease. Thus, VIII:VWF may serve to stabilize VIII:AHF and this might explain the post-transfusion findings in von Willebrand’s disease.

scholarly journals Immunologic studies of native and modified human factor VIII/von Willebrand factor

Blood ◽  
1979 ◽  
Vol 54 (2) ◽  
pp. 310-321
Author(s):  
ME Switzer ◽  
PA McKee
Keyword(s):  
Molecular Weight ◽  
Factor Viii ◽  
Von Willebrand Factor ◽  
Proteolytic Enzymes ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Procoagulant Activity ◽  
Human Factor Viii ◽  
Von Willebrand ◽  
Willebrand Factor

Factor VIII/von Willebrand factor (FVIII/vWF) is a glycoprotein with a molecular weight greater than one-million daltons. Two activities are associated with this large molecule: FVIII procoagulant activity and vWF activity. Incubation of FVIII/vWF with proteolytic enzymes causes rapid inactivation of the FVIII procoagulant activity but has little effect on the vWF activity or antigenicity. In an attempt to gain insight into the structural features required for these two activities, antisera were raised in rabbits to normal, thrombin-inactivated, and plasmin-inactivated FVIII/vWF. All of these proteolytically modified forms of FVIII/vWF cross-reacted with each of the rabbit antisera; each blocked the ability of a human inhibitor to inactivate native active FVIII/vWF. Each of the antisera was a potent inhibitor of vWF activity and inactivated vWF activity at the same titer. The antisera were much less potent inhibitors of FVIII activity than of vWF activity. Antibodies to thrombin-inactivated FVIII/vWF or normal FVIII/vWF had about the same ability to inactivate FVIII procoagulant activity. Surprisingly, those to plasmin-inactivated FVIII/vWF still retained about 50% of this inhibitory capacity. A comparison of the three types of antigens by polyacrylamide gel electrophoresis in sodium dodecyl sulfate-6 M urea demonstrated that the structure of thrombin- inactivated FVIII/vWF was indistinguishable from that of normal FVIII/vWF, while plasmin-inactivated FVII/vWF was completely cleaved to lower molecular weight fragments. Some of the reported variations in the ability of rabbit antibodies to inhibit procoagulant activity may be due to partial degradation of the starting antigen. The retention by FVIII/vWF protein of its immunologic properties even after extensive proteolytic degradation suggests that under nondenaturing conditions, the conformation of the native and degraded molecules are very similar.

Association Between Bleeding Time and Platelet Adherence to Artery Subendothelium

1984 ◽  
Vol 52 (02) ◽  
pp. 144-147 ◽  
Author(s):  
K S Sakariassen ◽  
P A Bolhuis ◽  
Margaretha Blombäck ◽  
L Thorell ◽  
Birger Blombäck ◽  
...  
Keyword(s):  
Von Willebrand Factor ◽  
Bleeding Time ◽  
Blood Platelets ◽  
Normal Subjects ◽  
Commercial Preparation ◽  
Normal Platelet ◽  
Platelet Adherence ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryThe efficacy of five different factor VUI-von Willebrand factor (FVIII-VWF) preparations in mediating adherence of blood platelets to damaged vessel walls was tested in an annular perfusion chamber utilizing human arteries and reconstituted blood.FVIII-VWF-purified by Sepharose CL-4B chromatography and von Willebrand factor prepared from this preparation by dissociation with 0.25 M CaCl2 followed by Sepharose CL-6B chromatography were equally effective in mediating platelet adherence as FVIII-VWF in cryoprecipitate and in plasma from normal subjects. A commercial concentrate of FVIII-VWF (Hemofil, Hyland) used for the treatment of haemophiliacs did not mediate platelet adherence at normal levels of FVIII-VWF related properties. A recently developed high-purity FVIII-VWF preparation (Concentrate II) containing multimers of high molecular weight normalized the platelet adherence. Platelet adherence in plasma obtained from two patients with von Willebrand’s disease (VWD) was impaired, but plasma samples obtained following treatment with Concentrate II mediated normal platelet adherence. The normalization of platelet adherence paralleled the normalization of the bleeding time.This platelet adherence assay offers an inexpensive and efficient in vitro tool to test the efficacy of FVIII-VWF preparations designed for VWD patients. Preparations such as cryoprecipitate and Concentrate II mediated the platelet adherence and normalized the bleeding time. The commercial preparation did not mediate platelet adherence and had no effect on the bleeding time.

scholarly journals Immunologic studies on human factor VIII (anti-hemophilic factor A, AHF) components produced by low-ionic-strength dialysis

Blood ◽  
1976 ◽  
Vol 47 (2) ◽  
pp. 253-264 ◽  
Author(s):  
BN Bouma ◽  
JA van Mourik ◽  
S de Graaf ◽  
JM Hordijk-Hos ◽  
JJ Sixma
Keyword(s):  
Ionic Strength ◽  
Factor Viii ◽  
Von Willebrand Factor ◽  
Human Factor ◽  
Procoagulant Activity ◽  
Factor Activity ◽  
Human Factor Viii ◽  
Low Ionic Strength ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract Since dialysis of human factor VIII against buffers of low ionic strength yielded two distinct components, and since the factor VIII fraction isolated from normal plasma showed von Willebrand factor activity as defined by the corrective effect on abnormal platelet retention and ristocetin aggregation in von Willebrand's disease, the present studies were performed to determine if the correcting activities could be attributed to one or both of the components. Dialysis of factor VIII against buffers of low ionic strength led, however, to a decrease in factor VIII procoagulant activity and the reduction of the correcting activities, which suggested that the intact aggregate was required for procoagulant activity and for von Willebrand factor activity. In this respect dialysis of factor VIII at low ionic strength differed from dissociation at high salt concentrations. The two low ionic strength components were identified by the use of a rabbit antiserum against factor VIII, and could be distinguished on the basis of specific antigenic structures. Dialysis of factor VIII at low ionic strength led to a decrease in antigenic determinants closely related to factor VIII function. Specific antibodies to the low ionic strength components inhibited factor VIII activity in normal plasma, but the residual factor VIII was higher than that after inhibition with antibodies against intact factor VIII. Both antibodies interfered with von Willebrand factor activity.

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