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Von willebrand disease with an increased ristocetin‐induced platelet aggregation and a qualitative abnormality of the factor VIII protein
Author(s) -
Takahashi Hoyu,
Sakuragawa Nobuo,
Shibata Akira
Publication year - 1980
Publication title -
american journal of hematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.456
H-Index - 105
eISSN - 1096-8652
pISSN - 0361-8609
DOI - 10.1002/ajh.2830080308
Subject(s) - ristocetin , chemistry , platelet , von willebrand factor , medicine , platelet aggregation , proband , endocrinology , immunoelectrophoresis , von willebrand disease , abnormality , antigen , immunology , biochemistry , psychiatry , mutation , gene
Two cases of von Willebrand disease (VWD) that revealed an increased ristocetin‐induced platelet aggregation (RIPA) and a qualitative abnormality of the factor VIII protein are reported. The threshold concentration of ristocetin giving a 30% increase in light transmission was 0.5 mg/ml in the proband and 0.4 mg/ml in her father (normal: 1.16 ± SD 0.18 mg/ml) although both patients showed reduced plasma von Willebrand factor activity (VIIIR:WF). In both patients, the amount of factor VIII related antigen (VIIIR:AG) in their platelets were normal, but an increased binding affinity of platelets to plasma factor VIII was demonstrated. The qualitative abnormality of the factor VIII protein was characterized by an increased anodal migration of VIIIR:AG in crossed immunoelectrophoresis (CIE), a delayed elution pattern as demonstrated by gel filtration on Sepharose 2B, and a decreased precipitation with concanavalin A (Con A). The response to DDAVP was also investigated.