Von Willebrand Factor and ADAMTS-13 in 23 Doberman Pinschers Dogs

VERA, EZEQUIEL; KRIMER, A; FARÍAS, CRISTINA; AMARAL, MARIA MARTA; POWAZNIAK, YANINA; KEMPFER, ANA CATALINA; LAZZARI, MARÍA ANGELA

Syd

Congreso; XXth International Society on Thrombosis and Haemostasis Congress; 2005

Objective: To study type-1 von Willebrand disease (VWD) phenotype and genotype and ADAMTS-13 values in 23 Doberman Pinschers dogs.Methods: Genotyping for von Willebrand factor (VWF). VWF : Ag by ELISA. Ultralarge VWF multimers (% ULVWF) by SDS- gel electrophoresis analyzed by densitometric scanning. ADAMTS-13 as previously described (Kempfer, BCF 2003 and Gerritsen, TH 1999). The VWF : Ag and ADAMTS-13 values were compared with normal human values (NHV) and expressed as mean ± SD (U/dL).Results: Genotype analysis: 4 dogs (17.4%) were homozygous (Ho1-Ho4) for vWD, 17 (73.9%)were heterozygous (He1-He17), and 2 (8.7%) did not have the defect (X1, X2). Some dogs areconsanguineous: groups of three He, two He and He1 is stepbrother of X1. VWF : Ag results were: Ho = 10 ± 4, He = 36 ± 12 and X = 53 ± 15 (NHV = 104 ± 41, n= 27). Ho showed statistical differences (P < 0.001) respect to He and X. Twenty dogs had ULVWF values into NHV range (-7 to 15%, n= 18) and ADAMTS-13 values = 54 ± 17 (NHV = 95 ± 37, n= 18).There were no statistical differences by sex or age. The table, showed the data of threedogs with high % ULVWF and diminished ADAMTS-13 with the ratio VWF :  g/ADAMTS-13 > 1.Conclusion: there is a strong association between VWF : Ag and homozygous state only. Three out of 23 (13%) have some laboratory characteristics of thrombotic thrombocytopenic purpura (TTP). These findings suggest that these dogs can be an excellent tool to study the pathogenesis and treatment of TTP.