A monoclonal antibody directed against human von Willebrand factor induces type 2B-like alterations.

摘要: Summary. We have previously described a monoclonal antibody (mAb), 1C1E7, against von Willebrand factor (VWF), that increases ristocetin-induced platelet aggregation (RIPA) and induces preferential binding of the high-molecular-weight multimers VWF to GPIb. Further investigations using rotational viscometer at shear rate 4000 s )1 could now demonstrate shear-induced (SIPA) is significantly increased with 1C1E7 this be completely inhibited by anti-GPIb mAb 6D1. In contrast, adhesion collagen surface 2600 , rectangular perfusion chamber, was in presence 1C1E7. When citrated whole blood incubated spontaneous GPIb demonstrated flow cytometric analysis. Parallel this, decrease highest molecular weight plasma found. Platelets bound on their were able form macroaggregates but no longer adhere. These phenomena are very similar alterations Willebrand’s disease type 2B. The epitope localized N-terminal part subunit; therefore distant conformational change A1 domain suggested.