Potential supplementary utility of combined PFA-100 and functional von Willebrand factor testing for the laboratory assessment of desmopressin and factor concentrate therapy in von Willebrand disease.

Abstract

We performed a retrospective audit of cross-laboratory testing of desmopressin and factor concentrate therapy to assess the potential utility of supplementary testing using the PFA-100 with functional von Willebrand factor (VWF) activity testing. Data were evaluated for a large number of patients with von Willebrand disease of type 1, type 2A or type 2M, as well as a comparative subset of individuals with haemophilia or carriers of haemophilia. Laboratory testing comprised pre and postdesmopressin, or pre and postconcentrate, evaluation of factor VIII, VWF antigen (VWF:Ag) and VWF ristocetin cofactor activity as traditionally performed, supplemented with collagen-binding (VWF:CB) testing and PFA-100 closure times. In brief, both therapies tended to normalize VWF test parameters and closure times in individuals with type 1 von Willebrand disease, with the level of correction in closure times related to the level of normalization of VWF, particularly the VWF:CB. However, although occasional correction of closure times was observed in patients with type 2A or type 2M von Willebrand disease, these did not in general normalize PFA-100 closure times either with desmopressin or factor concentrate therapy. In these patients, improvement in closure times was more likely in those in whom VWF:CB values normalized or when VWF:CB/VWF:Ag ratios normalized. This study confirms that there is a strong relationship between the presenting levels of plasma VWF and PFA-100 closure times, and that the supplementary combination of PFA-100 and VWF:CB testing might provide added clinical utility to current broadly applied testing strategies limited primarily to VWF:Ag, VWF ristocetin cofactor and factor VIII:coagulant. Future prospective investigations are warranted to validate these relationships and to investigate their therapeutic implications.

• Authors: Emmanuel J Favaloro, Jim Thom, David Patterson, Sarah Just, Maria Baccala, Tracy Dixon, Muriel Meiring, Jerry Koutts, John Rowell, Ross Baker
• Journal: Blood coagulation & fibrinolysis : an international journal in haemostasis and thrombosis (Blood Coagul Fibrinolysis) Vol. 20 Issue 6 Pg. 475-83 (Sep 2009) ISSN: 1473-5733 [Electronic] England
• PMID: 19584715 (Publication Type: Evaluation Study, Journal Article)

Chemical References

• Blood Coagulation Factors
• von Willebrand Factor
• prothrombin complex concentrates
• Factor VIII
• Deamino Arginine Vasopressin

Topics

• Blood Coagulation Factors (therapeutic use)
• Deamino Arginine Vasopressin (therapeutic use)
• Drug Monitoring (instrumentation, methods)
• Factor VIII (analysis)
• Hemophilia A (blood, drug therapy)
• Heterozygote
• Humans
• Platelet Function Tests (instrumentation)
• Retrospective Studies
• Time Factors
• von Willebrand Disease, Type 1 (blood, drug therapy)
• von Willebrand Disease, Type 2 (blood, drug therapy)
• von Willebrand Diseases (blood, drug therapy)
• von Willebrand Factor (analysis)