Effect of desmopressin on von Willebrand factor multimers in Doberman Pinschers with type 1 von Willebrand disease.
OBJECTIVE
To assess the effect of desmopressin (DDAVP) administration in Doberman Pinschers with type 1 von Willebrand disease (vWD) on plasma von Willebrand factor (vWF) multimers through determination of vWF collagen binding activity (vWF:CBA; a functional vWF assay dependent on the presence of high-molecular-weight [HMWI multimers), comparison of vWF antigen concentration (vWF:Ag) to vWF:CBA, and vWF multimer size distribution.


METHODS
16 Doberman Pinschers with type 1 vWD and 5 clinically normal control dogs.


METHODS
Plasma vWF:Ag and vWF:CBA assays and vWF multimer analysis were performed before and 1 hour after administration of DDAVP (1 microg/kg, SC).


RESULTS
Following DDAVP administration, dogs with type 1 vWD had an increase in mean baseline values of plasma vWF:Ag and vWF:CBA from 10% to 17% for both variables. The mean vWF Ag:CBA ratio at baseline (0.95) was similar after DDAVP administration (0.97), indicating concordant increases in plasma vWF concentration and activity. In control dogs, mean plasma vWF:Ag and vWF:CBA increased from baseline values of 64% to 113% and 58% to 114%, respectively, and the vWF Ag:CBA ratios were unchanged (1.1 vs 1.0) after DDAVP administration. Plasma vWF multimer analysis revealed proportional increases in band intensity for all multimer sizes following DDAVP administration, in comparison to baseline for the control dogs and Doberman Pinschers with vWD, consistent with vWF Ag:CBA ratios of approximately 1.


CONCLUSIONS
Beneficial effects of DDAVP on primary hemostasis in Doberman Pinschers with type 1 vWD cannot be explained by preferential increases in HMW vWF multimers.
Callan
Mary Beth
MB
Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
Giger
Urs
U
Catalfamo
James L
JL
D000818:Animals; D003894:Deamino Arginine Vasopressin / Q000494:pharmacology*; D004283:Dog Diseases / Q000097:blood / Q000188:drug therapy*; D004285:Dogs; D005260:Female; D006490:Hemostatics / Q000494:pharmacology*; D008297:Male; D046912:Multiprotein Complexes / Q000187:drug effects; D014842:von Willebrand Diseases / Q000097:blood / Q000188:drug therapy / Q000662:veterinary*; D014841:von Willebrand Factor / Q000187:drug effects* / Q000378:metabolism
D006490:Hemostatics; D046912:Multiprotein Complexes; D014841:von Willebrand Factor; D003894:Deamino Arginine Vasopressin