Plasma Collagen Cofactor Correlates with von Willebrand Factor Antigen and Ristocetin Cofactor but Not with Bleeding Time

Aihara, Morio; Kimura, Asano; Chiba, Yoichi; Yoshida, Yutaka

doi:10.1055/s-0038-1647520

Cited by 8 publications

(3 citation statements)

References 17 publications

(20 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…vWF binds to collagen and activated platelets and mediates collagen‐induced or ristocetin‐induced platelet aggregation depending on its molecular weight [ 16, 22–25]. The higher the molecular weight, the more pronounced this effect is.…”

Section: Discussionmentioning

confidence: 99%

Characterization of factor VIII/von Willebrand factor concentrates using a modified method of von Willebrand factor multimer analysis

Hj¹,

Hermentin²,

Cuesta-Linker³

et al. 1998

Haemophilia

View full text Add to dashboard Cite

In order to provide patients with von Willebrand disease a factor VIII (FVIII)/von Willebrand factor (vWF) concentrate of reproducible quality, an SDS-agarose gel electrophoresis method has been established to determine the content of the high molecular weight multimers (band 11 and higher) of vWF. This method has been used to characterize the content of high molecular weight vWF multimers in Humate P/Haemate P, a commercial FVIII/vWF concentrate. The average content of high molecular weight vWF multimers of 47 batches of Humate P/Haemate P has been determined to be 84.1% of the corresponding bands in normal human plasma. Use of this multimer analysis method for the characterization of five further commercial products revealed clear differences with respect to the high molecular weight vWF multimer content. Furthermore, there is a linear correlation (r2 = 0.73) between the content of high molecular weight vWF multimers and the specific activity of vWF (determined as vWF:RCoF/vWF:Ag). The method described here for analysis of the content of high molecular weight vWF multimers is a reliable and reproducible method to characterize this class of factor concentrates with respect to vWF multimer composition.

show abstract

Section: Discussionmentioning

confidence: 99%

Characterization of factor VIII/von Willebrand factor concentrates using a modified method of von Willebrand factor multimer analysis

Hj¹,

Hermentin²,

Cuesta-Linker³

et al. 1998

Haemophilia

View full text Add to dashboard Cite

show abstract

“…The effects of MAbs on the assay for CCo were investigated by incubating 5 J.1l of MAbs with the mixtures of 0.2 ml each of FWP and NHP for 1 min at 37° C. Inhibitory effects of MAbs were expressed as percentage of CCo in NHP using 100% as reference, which was the mixture of 0.2 ml FWP, 0.2 ml NHP and 5 J.1l cacodylate buffer. The assay for CCo was performed by a modification of previously described methods (12,22). In short, FWP in CBS containing 5% BSA were mixed with equal volume of serial dilutions of NHP.…”

Section: Fwp Adhesion To Collagenmentioning

confidence: 99%

Glycoprotein Ib Has a Partial Role in Platelet-von Willebrand Factor Collagen Interaction

et al. 1988

Self Cite

View full text Add to dashboard Cite

SummaryThe adhesion of human fixed washed platelets (FWP) to collagen was decreased after treatment with Serratia marcescens protease (SP), which removed 95% of the glycocalicin from platelet membrane glycoprotein (GP) lb. However, the diminished adhesion of SP treated FWP to collagen could still be increased in the presence of purified von Willebrand factor (vWF). This ability of vWF to increase FWP adhesion to collagen is defined as collagen cofactor (CCo). The adhesion of FWP to collagen was not affected by a monoclonal antibody (MAb) to GP Ilb/IIIa (10E5), that inhibits ADP and collagen induced platelet aggregation. On the other hand, it was decreased by 50% by a MAb to GP lb (6D1), that inhibits ristocetin induced platelet aggregation. Adhesion of FWP in buffer to collagen was completely inhibited by Ricinus communis agglutinin I or concanavalin A, while Lens culinalis agglutinin and wheat germ agglutinin showed 50% inhibition. The FWP adhesion to collagen in the presence of vWF (normal plasma) was unaffected by MAbs to GP Ilb/IIIa (10E5, P2, HPL1) but was decreased to 32-38% by MAbs to GP lb (6D1, AN51, HPL11). A MAb to vWF (CLB-RAg 35), that inhibits ristocetin induced binding of vWF to platelets, decreased the CCo of normal plasma by 70%. The MAb, CLB-RAg 201, that inhibits the binding of vWF to collagen, completely inhibited the CCo of normal plasma. In conclusion, our data suggest that (1) GP lb has a partial role in FWP adhesion to collagen; (2) the binding of vWF to collagen is required for the expression of CCo; (3) CCo is partly mediated through GP lb; but (4) other platelet membrane protein(s) besides GP lb or GP Ilb/IIIa must also be involved in FWP-vWF-collagen interactions.

show abstract

“…Also the vWF:CBA assay is a functional assay in which another functional characteristic of the protein is measured (6, 7). The vWF:CBA is determined in an ELISA-based procedure in which primarily HMW multimers are detected (11,17). This test also contributes to the diagnosis of type 2A, 2B and type 2M patients as these subtypes tend to give low vWF:CBA values due to the absence of HMW vWF forms in the plasma of most of such patients.…”

Section: Introductionmentioning

confidence: 99%

A Reliable and Reproducible ELISA Method to Measure Ristocetin Cofactor Activity of von Willebrand Factor

Vanhoorelbeke¹,

Cauwenberghs²,

Vauterin³

et al. 2000

Thromb Haemost

View full text Add to dashboard Cite

SummaryThe ristocetin induced binding of vWF to GPIb, which is routinely tested in a platelet agglutination assay, can be reproducibly studied in an ELISA where plasma vWF binds to a captured rGPIbα-fragment (His1-Val289) in the presence of ristocetin. This binding is specific since the vWF-GPIb interaction could (i) be blocked by inhibitory antiGPIb or anti-(vWF A1 domain) monoclonal antibodies (mAbs) and (ii) be enhanced by an anti-vWF mAb that also facilitates ristocetin induced platelet agglutination. Further studies were undertaken to determine whether the test could be used to differentiate vWF from patients with different types of von Willebrand’s disease. The median vWF:RiCof activity in controls (n = 24) was 0.75 U/ml, in type 1 vWD patients (n = 17) 0.28 U/ml, in type 2A (n = 18) 0.055 U/ml, in type 2B (n = 4) 0.094 U/ml and in type 3 (n = 3) <0.0005 U/ml. Moreover, the values correlated well with those obtained from the vWF:RiCof-agglutination assay (r = 0.873). The vWF:RiCof-ELISA has several advantages: the use of a recombinant fragment instead of donor platelets results in a more reproducible test with a low inter-and intra-assay variability (<14% CV), the test can further be readily automated and for a single determination, only minimal amounts of patient plasma are required (8 µl).

show abstract

Plasma Collagen Cofactor Correlates with von Willebrand Factor Antigen and Ristocetin Cofactor but Not with Bleeding Time

Cited by 8 publications

References 17 publications

Characterization of factor VIII/von Willebrand factor concentrates using a modified method of von Willebrand factor multimer analysis

Characterization of factor VIII/von Willebrand factor concentrates using a modified method of von Willebrand factor multimer analysis

Glycoprotein Ib Has a Partial Role in Platelet-von Willebrand Factor Collagen Interaction

A Reliable and Reproducible ELISA Method to Measure Ristocetin Cofactor Activity of von Willebrand Factor

Contact Info

Product

Resources

About