GI01 - ADAMTS13 Activity in Dogs with Chronic Enteropathies

Abstract:
Background
Chronic enteropathies (CE) predispose dogs to thromboembolic disease, but the underlying mechanisms are poorly understood. Humans with CE have decreased activity of a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS-13), a von Willebrand factor (vWF) cleaving enzyme, and increased circulating vWF. The primary aim of this study is to determine whether dogs with CE have reduced ADAMTS13 activity, increased plasma vWF antigen concentration (vWF:Ag), and increased vWF:collagen binding activity (vWF:CBA) compared to healthy control dogs.

Hypothesis/Objectives
Dogs with CE have reduced ADAMTS13 activity, increased vWF:Ag, and increased vWF:CBA compared to healthy control dogs.

Animals
Sixteen privately-owned dogs with CE and 37 healthy dogs were recruited from a hospital population.

Methods
Prospective observational study. Dogs will be identified as having CE using histopathology. ADAMTS13 activity will be measured using a commercially available ELISA kit (Diapharma). ADAMTS13 activity will be assessed in 20 dogs with CE and 40 healthy control dogs. Plasma vWF:Ag and vWF:CBA will be assessed in 20 dogs with CE and 20 healthy control dogs.

Results
Preliminary analysis reveals that vWF:Ag and vWF:CBA are significantly decreased in dogs with CE compared to healthy dogs (P = 0.005 and P = 0.03, respectively). ADAMTS13 activity is not significantly different between dogs with CE and healthy dogs (P = 0.12).

Conclusions and clinical importance
Circulating vWF:Ag and vWF:CBA are reduced in dogs with CE. ADAMTS13 activity is not reduced in dogs with CE and is unlikely to be a mechanism for hypercoagulability associated with CE.