Two Cases of von Willebrand’s Disease with Specific Inhibitors of Ristocetin Induced Aggregation of Normal Platelets

1975 ◽  
Author(s):  
M. Blombäch ◽  
N. Egberg
Keyword(s):  
Platelet Aggregation ◽  
Factor Viii ◽  
Electrophoretic Pattern ◽  
Severe Form ◽  
Normal Serum ◽  
Factor Viii Activity ◽  
Von Willebrand's Disease ◽  
Von Willebrand’S Disease ◽  
Prolonged Bleeding Time ◽  
Induced Aggregation

Ten patients (8 females and 2 males) with severe form of von Willebrand’s disease were investigated for the occurrence of inhibitors blocking Ristocetin induced aggregation of normal platelets. All these patients had been multiply transfused and had the classical signs of von Willebrand’s disease, prolonged bleeding time, less than 10% of normal factor VIII activity and correspondingly low factor VIII antigen levels, normal ADP induced platelet aggregation but no Ristocetin induced aggregation. In none of these patients circulating anticoagulants neutralizing factor VIII activity had been demonstrated. Plasma samples from 2 of these patients were found to block Ristocetin induced platelet aggregation of normal plasma. In one of these patients the inhibitor was found to be of IgG type. This patient otherwise had a normal serum electrophoretic pattern. The inhibitor of the other patient is being investigated.

scholarly journals Abnormalities of factor VIII and platelet aggregation--use of ristocetin in diagnosing the von Willebrand syndrome

Blood ◽  
1975 ◽  
Vol 45 (3) ◽  
pp. 403-412 ◽  
Author(s):  
HJ Weiss
Keyword(s):  
Platelet Aggregation ◽  
Factor Viii ◽  
Platelet Rich Plasma ◽  
Second Phase ◽  
Von Willebrand's Disease ◽  
Von Willebrand’S Disease ◽  
Low Concentrations ◽  
Platelet Defects ◽  
Von Willebrand ◽  
Induced Aggregation

Ristocetin was used to study platelet aggregation in platelet-rich plasma and to assay the von Willebrand factor activity of factor VIII (VIII-VWF). Ristocetin-induced platelet aggregation (RIPA) was decreased in 13 of 18 patients with von Willebrand's disease (VWD) who had decreased plasma levels of VIII-VWF. The five patients with normal RIPA appeared to have mild VWD but did not constitute a separate subclass. RIPA was also abnormal in some patients with intrinsic platelet defects, but in no case was the defect corrected by normal plasma. The latter type of correction appears to be specific for VWD. Aspirin ingestion inhibited the second phase of RIPA (at low concentrations of ristocetin only) but did not affect the initial phase of aggregation or the level of VIII-VWF. We also studied a group of patients who had both abnormalities of the factor VIII complex and intrinsic platelet defects, such as impaired collagen-induced aggregation, as well. The findings in these patients and in those with typical von Willebrand's disease appear to comprise a spectrum of disorders (the von Willebrand syndrome) in which some abnormality of the factor VIII complex is associated with impaired platelet function. At present, ristocetin would appear to be a useful reagent for evaluating patients with bleeding disorders and for studying patients with the von Willebrand syndrome.

scholarly journals Abnormalities of factor VIII and platelet aggregation--use of ristocetin in diagnosing the von Willebrand syndrome

Blood ◽  
1975 ◽  
Vol 45 (3) ◽  
pp. 403-412 ◽  
Author(s):  
HJ Weiss
Keyword(s):  
Platelet Aggregation ◽  
Factor Viii ◽  
Platelet Rich Plasma ◽  
Second Phase ◽  
Von Willebrand's Disease ◽  
Von Willebrand’S Disease ◽  
Low Concentrations ◽  
Platelet Defects ◽  
Von Willebrand ◽  
Induced Aggregation

Abstract Ristocetin was used to study platelet aggregation in platelet-rich plasma and to assay the von Willebrand factor activity of factor VIII (VIII-VWF). Ristocetin-induced platelet aggregation (RIPA) was decreased in 13 of 18 patients with von Willebrand's disease (VWD) who had decreased plasma levels of VIII-VWF. The five patients with normal RIPA appeared to have mild VWD but did not constitute a separate subclass. RIPA was also abnormal in some patients with intrinsic platelet defects, but in no case was the defect corrected by normal plasma. The latter type of correction appears to be specific for VWD. Aspirin ingestion inhibited the second phase of RIPA (at low concentrations of ristocetin only) but did not affect the initial phase of aggregation or the level of VIII-VWF. We also studied a group of patients who had both abnormalities of the factor VIII complex and intrinsic platelet defects, such as impaired collagen-induced aggregation, as well. The findings in these patients and in those with typical von Willebrand's disease appear to comprise a spectrum of disorders (the von Willebrand syndrome) in which some abnormality of the factor VIII complex is associated with impaired platelet function. At present, ristocetin would appear to be a useful reagent for evaluating patients with bleeding disorders and for studying patients with the von Willebrand syndrome.

Circulating anticoagulant in a family with prolonged bleeding time and factor VIII deficiency

Blood ◽  
1977 ◽  
Vol 49 (5) ◽  
pp. 799-806 ◽  
Author(s):  
M Diez-Ewald ◽  
EC Lian ◽  
R Nunez ◽  
D Deykin ◽  
DR Harkness
Keyword(s):  
Platelet Aggregation ◽  
Factor Viii ◽  
Bleeding Time ◽  
Factor Viii Activity ◽  
Clot Retraction ◽  
Factor Viii Related Antigen ◽  
Factor Viii Deficiency ◽  
Prolonged Bleeding ◽  
Prolonged Bleeding Time ◽  
Aggregation Activity

Abstract A circulating anticoagulant against factor VIII activity was demonstrated in the plasma of a boy from a family with both factor VIII deficiency and prolonged bleeding time. However, the factor VIII- related antigen, ristocetin-induced platelet aggregation activity, platelet retention in glass bead columns, platelet aggregation with adenosine 5′-diphosphate, collagen and epinephrine, and clot retraction among affected members were normal. The electrophoretic mobility of factor VIII-related antigen on crossed immunoelectrophoresis was normal. The inactivation of factor VIII activity by the inhibitor was time dependent and was nonlinear as the concentration of the inhibitor was increased. Immunotyping showed that the inhibitor was IgG with k light chains.

Studies on a Variant of Factor VIII Resulting in ’von Willebrand’s Disease»

1975 ◽  
Author(s):  
F. G. H. Hill ◽  
M. C. K. Chan ◽  
R. M. Hardisty
Keyword(s):  
Factor Viii ◽  
Bleeding Time ◽  
Von Willebrand's Disease ◽  
Von Willebrand’S Disease ◽  
Prolonged Bleeding ◽  
Prolonged Bleeding Time

A variant of von Willebrand’s disease in a 14-year-old girl is described, characterised by a prolonged bleeding time and defective ristocetin aggregation (VIIIWF 6%), with VIIIRAg 70-110% and VIIIC 40-60%. The electrophorotic mobility of her VIIIRAg in agarose at pH 9.2 was intermediate between normal VIIIRAg and that of the patient of Kernoff et al, (1), and identical with that of Case 4 of Peake et al. (2). Further characteristics of the factor VIII molecule in this patient’s plasma and platelets will be presented, including antigenic, physicochemical and functional propeertis.1. Kernoff, P. B. A. et al. (1974). Brit. J. Haemat. 26, 435.2. Peake, I. R. et al. (1974). N. Engl. J. Med. 291, 113.

scholarly journals Circulating anticoagulant in a family with prolonged bleeding time and factor VIII deficiency

Blood ◽  
1977 ◽  
Vol 49 (5) ◽  
pp. 799-806
Author(s):  
M Diez-Ewald ◽  
EC Lian ◽  
R Nunez ◽  
D Deykin ◽  
DR Harkness
Keyword(s):  
Platelet Aggregation ◽  
Factor Viii ◽  
Bleeding Time ◽  
Factor Viii Activity ◽  
Clot Retraction ◽  
Factor Viii Related Antigen ◽  
Factor Viii Deficiency ◽  
Prolonged Bleeding ◽  
Prolonged Bleeding Time ◽  
Aggregation Activity

A circulating anticoagulant against factor VIII activity was demonstrated in the plasma of a boy from a family with both factor VIII deficiency and prolonged bleeding time. However, the factor VIII- related antigen, ristocetin-induced platelet aggregation activity, platelet retention in glass bead columns, platelet aggregation with adenosine 5′-diphosphate, collagen and epinephrine, and clot retraction among affected members were normal. The electrophoretic mobility of factor VIII-related antigen on crossed immunoelectrophoresis was normal. The inactivation of factor VIII activity by the inhibitor was time dependent and was nonlinear as the concentration of the inhibitor was increased. Immunotyping showed that the inhibitor was IgG with k light chains.

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