scholarly journals Multiple Molecular forms of Factor VIII Antigen in Normal Individuals and von Willebrand’s Disease Patients

1977 ◽  
Author(s):  
T. Zimmerman ◽  
J. Kimball ◽  
T. Edgington ◽  
C. Abildgaard
Keyword(s):  
Factor Viii ◽  
Molecular Forms ◽  
Type I ◽  
Type Ii ◽  
Von Willebrand's Disease ◽  
Von Willebrand’S Disease ◽  
Multiple Molecular Forms ◽  
Normal Individuals ◽  
Factor Viii Antigen

Factor VIII antigen is present in normal individuals in multiple molecular forms which can be separated according to size. The smaller forms have little or no ristocetin co-factor activity. In order to evaluate the possibility that Factor VIII antigen forms of large size may be an artifact of in vitro aggregation, we have ultracentrifuged plasma on a 20% sucrose cushion at 37 C for 10 min at 254,000 xg (peak). The rate of clearing of Factor VIII antigen was compared to that of other plasma proteins. The results indicate that Factor VIII-related antigen forms of high S exist even when plasma is maintained at physiological temperature and analyzed with minimal delay, suggesting that these larger molecular forms also exist as such in vivo.In von Willebrand’s disease (vWd) all forms of Factor VIII antigen may be present but decreased in quantity (Type I) or large forms may be missing with smaller forms present in normal or increased quantities (Type II). Factor VIII antigen was isolated from plasma of three patients with Type I and three patients with Type II vWd by counter immunoelectrophoresis. The Factor VIII antigen was then reduced and electrophoresed on SDS-containing Polyacrylamide gels. The presence of carbohydrate was evaluated by staining with perchloric acid-Schiff’s reagent (PAS). The 210,000 MW Factor VIII antigen subunit from each patient was PAS-positive. Though subtle changes in carbohydrate content or composition could not be evaluated by this technique, a total defect of glycosylation is unlikely in this sample of vWd patients.

scholarly journals Multiple Molecular Forms of Factor VIII Antigen in Normal Individuals and Von Willebrand’s Disease Patients

1977 ◽  
Author(s):  
T. S. Zimmerman ◽  
J. R. Kimball ◽  
T. S. Edgington ◽  
C. F. Abildgaard
Keyword(s):  
Factor Viii ◽  
Small Sample ◽  
Molecular Forms ◽  
Type I ◽  
Type Ii ◽  
Von Willebrand's Disease ◽  
Von Willebrand’S Disease ◽  
Multiple Molecular Forms ◽  
Normal Individuals ◽  
Factor Viii Antigen

Factor VIII antigen is present in normal individuals in multiple molecular forms which can be separated according to size. The intermediate and larger forms preferentially bind to platelets in the presence of ristocetin. In order to evaluate the possibility that Factor VIII antigen forms of large size may be an artifact of in vitro aggregation, we have ultracentrifuged plasma on a 20% sucrose cushion at 37°C for 10 min at 254,000 xg (peak). The rate of clearing of Factor VIII antigen was compared to that of IgM, fibrinogen, IgG, α1-antitrypsin and the S rate calculated to be between 15 and 18. These results indicate that Factor VIII-related antigen forms of high S exist even when plasma is maintained at physiological temperature and analyzed with minimal delay, suggesting that these large molecular forms also exist as such in vivo.Two types of von Willebrand’s disease (vWd) have been identified according to size of Factor VIII antigen forms present in plasma. In Type I all forms of Factor VIII antigen are present but are decreased in quantity. In Type II large forms are missing and smaller forms are present in normal or increased quantities. Factor VIII antigen was isolated from plasma of one patient with Type I and two patients with Type II vWd by counter Immunoelectrophoresis. The Factor VIII antigen was then reduced and electrophoresed on SDS-containing polyacrylamide gels. The presence of carbohydrate was evaluated by staining with perchloric acid-Schiff’s reagent (PAS). The 210,000 MW Factor VIII antigen subunit from each patient was PAS-positive. Though subtle changes in carbohydrate content or composition could not be evaluated by this technique, a total defect of glycosylation is unlikely in this small sample of vWd patients.

scholarly journals Von Willebrand's disease in the German shepherd dog : clinical communication

2000 ◽  
Vol 71 (2) ◽  
Author(s):  
R.G. Lobetti ◽  
T. Dippenaar
Keyword(s):  
Factor Viii ◽  
Type I ◽  
Type Ii ◽  
German Shepherd ◽  
Excessive Bleeding ◽  
Von Willebrand's Disease ◽  
Clinical Communication ◽  
Von Willebrand’S Disease ◽  
German Shepherd Dog ◽  
Von Willebrand’S Factor

Two litters of Germanshepherd dogs were evaluated for a haemorrhagic tendency that was characterised by excessive bleeding from the umbilicus at birth, haemorrhage and haematoma formation at vaccination, excessive bruising, and lameness due to haemarthrosis. Platelet counts, clotting times and Von Willebrand's factor (VWF) assays were assessed in all dogs. Factor VIII determination was performed in 1 puppy and its parents. Based on the clotting times and VWF assay, 6 puppies (4 male and 2 female) showed type I Von Willebrand's disease (VWD), 5 (4 male and 1 female) possible type II VWD, and 4 were unaffected. One puppy with possible type II VWD had very low factor VIII activity; its sire had a normal factor activity, whereas the dam was in the low-normal range. This article reports type I and possible type II VWD in 2 related litters of German shepherd dogs, the latter being rare in German shepherd dogs.

Reactivity of Small Molecular Forms of Human Factor VIII/von Willebrand Factor with Botrocetin and Anti-Factor VIII-Coated Latex Particles

1985 ◽  
Vol 54 (02) ◽  
pp. 463-465 ◽  
Author(s):  
M Furlan ◽  
B A Perret ◽  
E A Beck
Keyword(s):  
Factor Viii ◽  
Von Willebrand Factor ◽  
Molecular Forms ◽  
Type Ii ◽  
Von Willebrand's Disease ◽  
Latex Particles ◽  
Von Willebrand’S Disease ◽  
Disulfide Reduction ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryTwo recently developed tests for measurement of factor VIII/von Willebrand factor (FVIII/vWF), i.e. platetelet agglutination by botrocetin and a kinetic latex antigen assay, were compared with ristocetin cofactor and electroimmunoassay, in respect with FVIII/vWF size-distribution. FVIII/vWF was measured in six cases of atypical von Willebrand’s disease (type II), in gel-filtered fractions of normal cryoprecipitate and in the course of depolymerization of purified normal FVIII/vWF by disulfide reduction. Small molecular forms of FVIII/vWF from normal and variant type II plasma, and those derived by disulfide reduction of high-molecular weight FVIII/vWF, showed remarkably decreased reactivity in ristocetin-, botrocetin- and latex-assay. We conclude that for botrocetin-induced platelet agglutination, as well as for agglutination of antibody-coated latex particles, multiple interactions with repeating subunits of FVIII/vWF are required. As a practical consequence, the combined measurement of FVIII/vWF by the latex test and electroimmunoassay provides a simple tool for discriminating between the classical von Willebrand’s disease and its variants.

Gel Filtration Patterns of Factor VIII Coagulant Antigen and Factor VIII Related Antigen in Normal and von Willebrand’s Disease

1983 ◽  
Vol 50 (02) ◽  
pp. 509-512
Author(s):  
Juan Chediak ◽  
Ian Peake ◽  
Arthur Bloom
Keyword(s):  
Molecular Weight ◽  
Factor Viii ◽  
Gel Filtration ◽  
Low Molecular Weight ◽  
Type I ◽  
Type Ii ◽  
Von Willebrand's Disease ◽  
Factor Viii Related Antigen ◽  
Von Willebrand’S Disease ◽  
Coagulant Activity

SummaryGel filtration (sepharose 2B CL) patterns of factor VIII coagulant antigen (VIIIC :Ag) and factor VIII related antigen (VIIIR: Ag) were obtained using normal plasma and plasma from patients with von Willebrand’s disease. The latter group consisted of five individuals with normal mobility of factor VIIIR :Ag on cross-immunoelectrophoresis (Type I) and five others with abnormal (increased) mobility (Type II). Results showed that the elution of VIIIC: Ag was delayed in those subjects whose ratio of VIIIR :Ag to VIIIC :Ag was reduced. It has previously been reported that VIIIR :Ag exerts a stabilizing influence on the coagulant activity of factor VIII (VIII: C); our data suggests that when VIIIR :Ag is deficient, abnormal (low molecular weight) forms of VIIIC: Ag circulate.

Factor VIII Antigen in the Vessel Walls in Von Willebrand's Disease and Haemophilia A

2009 ◽  
Vol 13 (1) ◽  
pp. 33-38 ◽  
Author(s):  
L. Holmberg ◽  
P. M. Mannucci ◽  
I. Turesson ◽  
Z. M. Ruggeri ◽  
I. M. Nilsson
Keyword(s):  
Factor Viii ◽  
Haemophilia A ◽  
Von Willebrand's Disease ◽  
Von Willebrand’S Disease ◽  
Factor Viii Antigen ◽  
Vessel Walls

scholarly journals Characterization of the defect of the factor VIII/von Willebrand factor protein in von Willebrand's disease

Blood ◽  
1982 ◽  
Vol 59 (3) ◽  
pp. 542-548 ◽  
Author(s):  
HR Gralnick ◽  
MC Cregger ◽  
SB Williams
Keyword(s):  
Sialic Acid ◽  
Factor Viii ◽  
Von Willebrand Factor ◽  
Platelet Rich Plasma ◽  
Molecular Forms ◽  
Von Willebrand's Disease ◽  
Von Willebrand’S Disease ◽  
Platelet Receptor ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract The factor VIII/von Willebrand factor (f.VIII/vWf) protein was purified from the plasma of a patient with von Willebrand's disease (vWd). The patient had all of the classic laboratory findings of vWd except for the ristocetin-induced platelet aggregation of his own platelet-rich plasma. The disease has been documented in three generations. Comparison of the purified normal and vWd f.VIIi/vWf protein revealed several abnormalities, including decreased concentration of f.VIII/vWf antigen; decreased specific vWf activity; absence of the larger molecular forms of the f.VIII/vWf protein; carbohydrate deficiencies affecting the sialic acid, penultimate galactose and N- acetylglucosamine moieties; and decreased binding of the f.VIII/vWf protein to its platelet receptor. These studies indicate the multiplicity of biochemical and functional abnormalities associated with the f.VIII/vWf protein in vWd. f.VIII/vWf protein to normal f.VIII/vWf protein that had been treated with 2-mercaptoethanol (2-ME) to reduce the multimer size and then treated with specific exoglycosidases to remove the sialic acid and penultimate galactose residues revealed similar biologic properties.

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.

A Subset of High Titer Acquired Hemophilia Patients May Benefit from Treatment with High Dose Factor VIII.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3476-3476
Author(s):  
Shannon Meeks ◽  
John F Healey ◽  
Ernest T Parker ◽  
Pete Lollar
Keyword(s):  
Factor Viii ◽  
Hemophilia A ◽  
High Titer ◽  
High Dose ◽  
Type I ◽  
C2 Domain ◽  
Type Ii ◽  
Acquired Hemophilia ◽  
Proteolytic Activation

Abstract Abstract 3476 Poster Board III-413 Approximately 30% of patients with severe hemophilia A will develop inhibitory antibodies (Abs) to factor VIII (fVIII inhibitors). The immune response to fVIII currently is the most significant complication in the management of patients with hemophilia A. In addition, autoimmune Abs to fVIII can develop in non-hemophiliacs, producing acquired hemophilia A, which frequently produces life- or limb-threatening bleeding. Patients with autoimmune hemophilia often have Abs with type II kinetics in which there is incomplete inactivation of fVIII at saturating concentrations of inhibitor. We have characterized the antibody response to the C2 domain of human fVIII in a murine hemophilia model and described 5 structural groups of Abs. Groups A, AB, and B are classical anti-C2 Abs that block fVIII and fVIIIa binding to phospholipid. Groups BC and C consist of non-classical anti-C2 Abs that inhibit the proteolytic activation of fVIII but do not block the binding of fVIII to phospholipid. Subsequently, we identified classical and non-classical anti-C2 Abs in human fVIII inhibitor plasmas. Most murine non-classical Abs have inhibitor titers greater than 10,000 Bethesda units/mg IgG. In a murine in vivo bleeding model, both type I classical C2 Abs, type II non-classical C2 Abs, and a type I anti-A2 Ab produced similar amounts of blood loss that were significantly greater than control mice injected with 180 U/kg of fVIII alone. Increasing the dose of fVIII to 360 U/kg overcame the bleeding diathesis produced by the type II MAbs, but not the type I Abs. These results were consistent with the in vitro Bethesda assay in which a type I anti-A2 Ab, 4A4, completely inhibited both 1 U/mL and 3 U/mL fVIII, while there was 40% residual activity at saturating concentrations of a type II anti-C2 Ab, 2-77, at either concentration of fVIII. To determine if similar in vitro characteristics exist in patients with acquired hemophilia, plasmas from 3 patients with high titer type II inhibitors were studied. All 3 plasmas primarily had C2 domain epitope specificity that included non-classical Abs. Plasma A7 additionally had detectable anti-A2 activity. Recovery of fVIII activity after a 2 h incubation at 37 °C at nominal added concentrations of 1 mL and 3 U/mL fVIII was compared (Table 1). At 3 U/mL added fVIII, recovery of activity in plasmas A4 and A5 was 1.1 U/mL and 0.51 U/mL, respectively, despite the presence of inhibitor titers of 18 and 11 Bethesda units (BU) per mL. The presence of anti-A2 Abs, which typically have type I kinetics, may have contributed to the overall lower recovery of activity in plasma A7. These results suggest that treatment with high-dose fVIII rather than bypassing agents may be warranted in patients with an inhibitor response dominated by non-classical anti-C2 Abs. Table 1 Patient Plasma Inhibitor Titer (BU/mL) Recovered Activity at 1U/mL FVIII (U/mL) Recovered Activity at 3 U/mL FVIII (U/mL) A4 18 0.31 1.1 A5 11 0.18 0.51 A7 62 0.07 0.12 Disclosures: No relevant conflicts of interest to declare.

scholarly journals Serial studies in von Willebrand's disease: variability versus "variants"

Blood ◽  
1980 ◽  
Vol 56 (4) ◽  
pp. 712-716 ◽  
Author(s):  
CF Abildgaard ◽  
Z Suzuki ◽  
J Harrison ◽  
K Jefcoat ◽  
TS Zimmerman
Keyword(s):  
Factor Viii ◽  
Repeated Testing ◽  
Laboratory Findings ◽  
Von Willebrand's Disease ◽  
Von Willebrand’S Disease ◽  
Normal Individuals ◽  
Coagulant Activity ◽  
History Of ◽  
Ristocetin Cofactor

The variability of laboratory findings in von Willebrand's disease (vWd) was evaluated by performing serial studies of bleeding time (BT), factor VIII coagulant activity (VIII:C), factor-VIII-related antigen (VIIIR:Ag) and ristocetin cofactor (VIIIR:Rcof) in 50 individuals from 25 families with this disorder. The types of results were characterized from 1 to 16 based on the possible combinations of findings using these four tests. The only patients observed to have consistently abnormal results of all four tests were three individuals with homozygous vWd. Individuals with autosomal dominant vWd were found to have a variety of results and all 16 possible types were observed. Although a consistent pattern was present within some families, others with equivalent history of bleeding demonstrated widely variable types of results. The results within some families, others with equivalent history of bleeding demonstrated widely variable types of results. The results of serial studies of the same tests in 10 normal individuals indicated relative stability, with nearly all values within the usual range of normal, but some independent variation of factor-VIII-related activities was observed. These studies indicate that: (1) the results of BT, VIII:C, VIIIR:Ag, and VIIIR:Rcof vary considerably from time to time in many individuals with vWd, (2) a classification of “variants” of vWd based solely on such studies may be inappropriate, particularly if the tests are not repeated, and (3) repeated testing may be required to establish the diagnosis of vWd in some individuals.

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