Further Studies on Aggregation of Platelet-Type von Willebrand’s Disease Platelets by Human von Willebrand Factor

1986 ◽  
Vol 55 (03) ◽  
pp. 338-341 ◽  
Author(s):  
H Takahashi ◽  
W Tatewaki ◽  
M Hanano ◽  
R Nagayama ◽  
A Shibata

SummaryPlatelet-type von Willebrand’s disease (vWD) is a bleeding disorder characterized by a heightened interaction between platelets and von Willebrand factor (vWF) as the result of an intrinsic platelet abnormality (probably in GPIb). Platelet aggregability was nearly normal in response to thrombin, wheat germ agglutinin and Ricinus communis agglutinin in this disorder. Unmodified platelets showed no aggregation upon the addition of peanut agglutinin. Partially purified human vWF induced little aggregation of washed patient platelets, but the aggregation was greatly enhanced in the presence of plasma devoid of vWF. Monoclonal antibodies directed against GPIb and GPIIb/IIIa as well as EDTA completely inhibited vWF-induced aggregation. These results indicate that human vWF induces aggregation of platelet-type vWD platelets in the presence of divalent cations and some plasma cofactor(s), and that both GPIb and GPIIb/IIIa are involved in this aggregation.

1983 ◽  
Vol 49 (02) ◽  
pp. 087-090
Author(s):  
S Mikami ◽  
M Ueda ◽  
M Yasui ◽  
Y Takahashi ◽  
M Nishino ◽  
...  

SummaryThe nature of sugar chain of factor VTII/von Willebrand factor in plasma of normal subjects and patients with von Willebrand’s disease (vWd) was examined by crossed affinoimmunoelectrophoresis using anti-human factor VIII rabbit serum, with inserted Ricinus communis agglutinin-120 (RCA-120) agarose layer (RCA – CIE). Molecular weights of factor VlU-related antigen (VIIIR: Ag) were estimated by SDS polyacrylamide gel electrophoresis — crossed affinoimmunoelectrophoresis (SDS PAGE – RCA – CIE).VIIIR :Ag, in normal plasma and in classical form of vWd, showed two precipitin peaks on RCA – CIE. The slower moving component of VIIIR :Ag with molecular weights over 3×106 daltons from normal subjects and patients with classical form of vWd showed a high affinity for RCA-120. The faster moving component of VIIIR: Ag below 3×106 daltons from the abovementioned subjects and patients with a variant form (Type IIA) showed a very weak affinity for RCA-120.These results suggested that all of VIIIR: Ag in these variant cases may have a deficiency of galactose residues reactive with RCA, in addition to an incomplete polymerization of VIIIR: Ag, similar to that of the faster moving component of normal subjects.


1984 ◽  
Vol 52 (03) ◽  
pp. 267-270 ◽  
Author(s):  
Hoyu Takahashi ◽  
Akira Shibata

SummaryThe interaction of platelets and von Willebrand factor (vWF) in platelet-type von Willebrand’s disease (vWD) was characterized using formalin-fixed platelets from the patients. Formalin-fixed patient platelets were agglutinated directly by human vWF in normal plasma and type IIB vWD plasma, but not in type IIA vWD plasma. In the presence of a small amount of normal vWF, ristocetin-induced agglutination of patient platelets was enhanced with low concentrations of ristocetin. Wheat germ agglutinin and EDTA inhibited vWF-induced agglutination, although EDTA had no effect on ristocetin (plus vWF)-induced agglutination. These results demonstrate that vWF-induced agglutination of platelet-type vWD platelets is independent of active platelet metabolism but requires divalent cations, and suggest that platelet membrane glycoprotein I (GPI) would be involved in this agglutination.


1988 ◽  
Vol 60 (02) ◽  
pp. 182-187 ◽  
Author(s):  
Morio Aihara ◽  
Ken Tamura ◽  
Ryuko Kawarada ◽  
Keizou Okawa ◽  
Yutaka Yoshida

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.


2002 ◽  
Vol 88 (09) ◽  
pp. 421-426 ◽  
Author(s):  
Stefan Lethagen ◽  
Christina Isaksson ◽  
Charlotta Schaedel ◽  
Lars Holmberg

SummaryHereditary defects of the von Willebrand factor (VWF) gene cause von Willebrand’s disease (VWD) which shows great variability dependent on the nature and location of the mutation. We here describe the characteristics of a substitution of methionine for threonine 1156 in the D3 domain of the VWF, i.e. the domain involved in the intracellular multimerization of pro-VWF dimers. A VWD patient with severe symptoms was a compound heterozygote for the T1156M mutation and a null allele (Q2470X) on the other chromosome. This led to marked reduction of plasma VWF concentration to about 0.05 U/ml and an abnormality of VWF multimers as in type 2A VWD. Expression in vitro of the mutation demonstrated that 1156M-VWF is secreted from COS-7 cells in a much reduced amount and lacking large multimers. When coexpressed with normal VWF 1156M-VWF decreased the secretion of normal VWF in a dose-dependent manner, the secreted VWF showing all the multimers. Two relatives of the propositus were single heterozygotes for the T1156M mutation and were either asymptomatic or had the manifestations of mild type 1 VWD. The expression data and studies of platelet VWF indicate that the T1156M mutation results in intracellular retention of VWF rather than impaired synthesis. Three other members of the family were heterozygotes for the Q2470X mutation and demonstrated the variable expressivity of a null allele.


Blood ◽  
1982 ◽  
Vol 59 (3) ◽  
pp. 542-548 ◽  
Author(s):  
HR Gralnick ◽  
MC Cregger ◽  
SB Williams

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.


1987 ◽  
Vol 17 (4) ◽  
pp. 182-188 ◽  
Author(s):  
Hoyu Takahashi ◽  
Tsuneyasu Tsukada ◽  
Wataru Tatewaki ◽  
Masaharu Hanano ◽  
Masayoshi Sanada ◽  
...  

Blood ◽  
1986 ◽  
Vol 68 (3) ◽  
pp. 668-672 ◽  
Author(s):  
L Holmberg ◽  
E Berntorp ◽  
M Donner ◽  
IM Nilsson

Abstract In eight members of one family, platelets in platelet-rich plasma aggregated at much lower ristocetin concentrations than normal. Ivy bleeding time was variously prolonged, and von Willebrand factor antigen (vWF:Ag), ristocetin cofactor activity, and factor VIII coagulant activity were decreased. Most of the affected members had had slight to rather severe bleeding symptoms. Platelet-type von Willebrand's disease (vWD) could be ruled out. All multimers of vWF:Ag were found in plasma as well as platelets. Administration of 1-desamino- 8-D-arginine vasopressin (DDAVP) to the propositus did not cause thrombocytopenia, and platelet-poor plasma obtained immediately after did not aggregate normal platelets. The molecular defect in this family, inherited as an autosomal dominant, resembles the one in type IIB because of the response to ristocetin but differs from IIB because all vWF:Ag multimers are present in plasma and the response to DDAVP is atypical. We conclude that this family has a new subtype of vWD and propose that structural as well as functional criteria should be used for a proper classification of vWD.


Blood ◽  
1986 ◽  
Vol 67 (2) ◽  
pp. 465-468 ◽  
Author(s):  
HR Gralnick ◽  
SB Williams ◽  
LP McKeown ◽  
ME Rick ◽  
P Maisonneuve ◽  
...  

Abstract 1-D-Amino(8-D-arginine)-vasopressin (DDAVP) infusion in three patients with type IIa von Willebrand's disease (vWD) resulted in a normalization of the factor VIII coagulant, factor VIII-related antigen, and von Willebrand factor (vWF) (ristocetin cofactor) activities and the bleeding time. The normalization of these hemostatic parameters persisted for four hours. Over the same time period there was a marked increase in the quantity of the vWF multimers when blood was collected in the presence of protease inhibitors. The vWF multimers present were even larger than the normal. When blood was collected in the absence of protease inhibitors, a smaller increase in the plasma vWF multimers was observed and fewer of the intermediate and larger vWF multimers were seen; multimers larger than those present in normal plasma were not visualized. The platelet vWF multimers and activities did not change with or without inhibitors. These studies suggest that there is a subgroup of patients with type IIa vWD who respond to DDAVP with complete normalization of their hemostatic abnormalities and whose vWF is sensitive to proteolysis.


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