Comparison of the <i>in vitro</i> characteristics of von Willebrand factor in British and commercial factor VIII concentrates

Lawrie, Andrew; Harrison, Paul; Wilbourn, Barry; Dalton, R.G.; Savidge, Geoffrey F.

doi:10.1111/j.1365-2141.1989.tb00227.x

Cited by 43 publications

(36 citation statements)

References 13 publications

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“…Moreover, not all intermediate-purity factor VIII products possessed significant (greater than 50%) protease activity. The heterogeneous nature of factor VIII concentrates has long been recognized (Lawrie et al, 1989), and it is accepted that this has a profound effect on the efficacy of factor VIII concentrates in the treatment of von Willebrand's disease (Pasi et al, 1990;Mannucci et al, 1992). Presumably, a similar phenomenon is at play here and reflects methodological differences in manufacturing.…”

Section: Discussionmentioning

confidence: 99%

von Willebrand factor‐cleaving protease activity in congenital thrombotic thrombocytopenic purpura

et al. 2000

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Summary. Thrombotic thrombocytopenic purpura (TTP) is characterized by microangiopathic haemolytic anaemia (MAHA), thrombocytopenia, fluctuating neurological impairment, renal dysfunction and fever. Both acquired and congenital forms are recognized. Recurrent episodes, which may be predictable (occurring every 21±28 d), are seen in congenital disease and may be treated by infusion with fresh-frozen plasma (FFP). Congenital TTP has recently been associated with deficiency of a novel von Willebrand factor (VWF)-cleaving protease. To investigate whether residual protease activity dictates clinical manifestations, we determined protease activity in three patients with congenital TTP of varying severity. Intrinsic VWF-cleaving protease activity of a range of plasma-derived products was also assessed as one patient had been successfully maintained for many years, initially using an intermediate-purity factor VIII concentrate (Kryobulin) and then cryoprecipitate. All three patients had a severe absolute deficiency of VWF-cleaving protease activity (, 3%) up to 5 months after clinical symptoms. Three relatives were also found to have a mild reduction in protease activity (25±50%). Nevertheless, the intrinsic VWF-cleaving protease activity of plasma-derived products correlated with their clinical efficacy: significant (100%) protease activity was found in FFP, cryosupernatant, solvent±detergent-treated plasma, cryoprecipitate and Kryobulin. Two clinically ineffective factor VIII products (Fahndi and Haemate P) possessed only low protease activity (6´25% and 12´5% respectively). Although this suggests that VWF-cleaving protease activity is central to the pathogenesis of congenital TTP, either small differences in protease activity below 3% or hitherto unknown factors have a profound influence on clinical phenotype. The possible use of factor VIII concentrates in the treatment of this condition also warrants further investigation.

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Section: Discussionmentioning

confidence: 99%

von Willebrand factor‐cleaving protease activity in congenital thrombotic thrombocytopenic purpura

et al. 2000

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“…For collagen binding experiments, microtiter wells were coated with 50 l of either a suspension of collagen type I (50 g/ml) or of BSA (5 mg/ml) in 67 mM phosphate buffer, pH 7.2, by incubation at 37°C overnight (27). For decorin binding experiments, microtiter wells were coated with 50 l of either decorin (10 g/ml) or BSA (5 mg/ml) in Dulbecco's phosphate-buffered saline by incubation at 37°C overnight.…”

Section: Materials-[12-3 H]cholesteryl Linoleate T-butoxycarbonyl-lmentioning

confidence: 99%

“…Isolation and Modification of Lipoproteins-Human LDL (d ϭ 1.019 -1.050 g/ml) and HDL 3 (d ϭ 1.125-1.210 g/ml) were isolated from plasma of healthy volunteers by sequential ultracentrifugation (23 Adsorption of Proteins to Microtiter Wells-A suspension of collagen was obtained by dissolving 1 mg/ml collagen type I in 0.1 M acetic acid followed by dialysis against 67 mM phosphate buffer, pH 7.2, for 2-3 days at 4°C (27). For collagen binding experiments, microtiter wells were coated with 50 l of either a suspension of collagen type I (50 g/ml) or of BSA (5 mg/ml) in 67 mM phosphate buffer, pH 7.2, by incubation at 37°C overnight (27).…”

Section: Materials-[12-3 H]cholesteryl Linoleate T-butoxycarbonyl-lmentioning

confidence: 99%

The Proteoglycan Decorin Links Low Density Lipoproteins with Collagen Type I

Pentikäinen

Öörni

Lassila

et al. 1997

Journal of Biological Chemistry

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Decorin is a small dermatan sulfate-rich proteoglycan which binds to collagen type I in vitro and in vivo. In atherosclerotic lesions the contents of low density lipoprotein (LDL), decorin, and collagen type I are increased, and ultrastructural studies have suggested an association between LDL and collagen in the lesions. To study interactions between LDL, decorin, and collagen type I, we used solid phase systems in which LDL was coupled to a Sepharose column, or in which LDL, decorin, or collagen type I was attached to microtiter wells. The interaction between LDL and decorin in the fluid phase was evaluated using a gel mobility shift assay. We found that LDL binds to decorin by ionic interactions. After treatment with chondroitinase ABC, decorin did not bind to LDL, showing that the glycosaminoglycan side chain of decorin is essential for LDL binding. Acetylated and cyclohexanedione-treated LDL did not bind to decorin, demonstrating that both lysine and arginine residues of apoB-100 are necessary for the interaction. When collagen type I was attached to the microtiter plates, only insignificant amounts of LDL bound to the collagen. However, if decorin was first allowed to bind to the collagen, binding of LDL to the decorin-collagen complexes was over 10-fold higher than to collagen alone. Thus, decorin can link LDL with collagen type I in vitro, which suggests a novel mechanism for retention of LDL in collagen-rich areas of atherosclerotic lesions.Deposition of low density lipoproteins (LDL) 1 in the extracellular matrix of the arterial intima is an important step in the development of atherosclerosis (1). LDL interacts with the various components of the extracellular matrix. These components include proteoglycans (PG), elastin, and collagen. Binding of LDL to PG has been characterized in detail (2). Interaction between LDL and elastin has also been reported (3). In contrast, interaction between native LDL and collagen has received little attention (4, 5).Collagen is the major connective tissue component of atherosclerotic arteries, comprising up to 40% of the total protein in fibrous plaques and 60% in advanced lesions (6). Most of the collagen (50 -75%) in a normal artery or in a diseased intima is of type I (7-9). Immunofluorescence microscopy has located LDL along collagen fibers in atherosclerotic lesions (10, 11).Electron microscopic and immunoelectron microscopic studies have also suggested an association between LDL and collagen in the arterial intima (12)(13)(14).Decorin (15) is a small PG having a core protein with a molecular mass of 45 kDa and a single dermatan sulfate-rich side chain. Decorin has been shown to bind to and modify the fibrillar structure of collagen type I (16, 17), and importantly, to co-localize with collagen type I in primary atherosclerotic plaques (18).The present study concerns the interaction between native LDL and collagen type I in the absence and presence of decorin. In the absence of decorin, there was no significant interaction between LDL and collagen type I. However, w...

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“…The assay was performed essentially as previously described by Lawrie et al (35). Briefly, calf skin collagen type I (Sigma Chemical Co.) was dissolved in 0.1 M acetic acid and dialyzed overnight at 4°C against 67 mM phosphate buffer, pH 7.2.…”

Section: Binding Ofvwfto Collagenmentioning

confidence: 99%

A monoclonal antibody recognizes a von Willebrand factor domain within the amino-terminal portion of the subunit that modulates the function of the glycoprotein IB- and IIB/IIIA-binding domains.

Tornai

Arnout²,

Deckmyn³

et al. 1993

J. Clin. Invest.

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We developed a monoclonal antibody, 1C1E7, against vWf that increases ristocetin-induced platelet aggregation in a dose-dependent manner and lowers the threshold concentration of ristocetin needed to obtain a full aggregatory response. The platelet aggregatory effect of asialo vWf (ASvWf) also is enhanced by 1CIE7, in the presence or absence of glycoprotein (GP) Ilb/IlIa receptor antagonism. In the presence of ristocetin, both intact 1ClE7 and its Fab fragments enhance specific binding of '25I-vWf to platelets. With 1ClE7, the intermediate and higher molecular weight multimers of vWf are preferentially bound to both GP lb and GP IIb/IIIa. Thrombin-induced 125I-vWf binding to GP IIb/Illa also is increased by 1ClE7. Maximal binding of 1C1E7 to vWf corresponds to 0.97 mol/mol vWf monomer with a Kd of 4.7 x 10-10 M. 1ClE7 reacts with a 34 /36-kD tryptic fragment (III-T4) and a 34-kD plasmic fragment (P34), which localizes the epitope between amino acid residues 1 and 272; this was confirmed by NH2-terminal amino acid sequencing. Finally, platelet aggregation by ASvWf was associated with a sharp rise in intracellular Ca2+ only in the presence of 1C1E7. An antibody-mediated conformational change of vWf may result in an improved presentation of the GP Ib-and GP IIb/ IIIa-binding domains of mainly the larger multimers; the increased density of vWf on the platelet surface leads to platelet activation. The antibody may thus recognize a domain of relevance for vWf physiology. (J. Clin. Invest. 1993. 91:273-282.)

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Comparison of the in vitro characteristics of von Willebrand factor in British and commercial factor VIII concentrates

Cited by 43 publications

References 13 publications

von Willebrand factor‐cleaving protease activity in congenital thrombotic thrombocytopenic purpura

von Willebrand factor‐cleaving protease activity in congenital thrombotic thrombocytopenic purpura

The Proteoglycan Decorin Links Low Density Lipoproteins with Collagen Type I

A monoclonal antibody recognizes a von Willebrand factor domain within the amino-terminal portion of the subunit that modulates the function of the glycoprotein IB- and IIB/IIIA-binding domains.

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