Anti-Endothelial Cell Antibodies in Dogs with Immune-Mediated Hemolytic Anemia and Other Diseases Associated with High Risk of Thromboembolism

Dogs with immune-mediated hemolytic anemia (IMHA) and certain inflammatory diseases are at high risk of developing thromboembolic disease. The presence of anti-endothelial cell autoantibodies (AECA) has been associated with an increased risk of thromboembolism in humans. AECA will be detected more often in dogs at risk of thromboembolism than in healthy control animals or dogs with diseases not associated with a higher risk of thromboembolism. Ninety-one sick dogs and 22 healthy control dogs. Retrospective case-controlled study. Serum was screened for the presence of AECA. Dogs were identified for the study based on the risk of thromboembolism as determined by clinical impression and the underlying disease process. Flow cytometry and normal canine endothelial cells were used to screen serum samples from sick and healthy control dogs for the presence of AECA. In addition, serum from dogs with confirmed thromboemboli was also screened for the presence of AECA by immunohistochemistry. AECA were detected in 2/91 sick dogs, both with infectious diseases, but were not found in healthy dogs. Anti-endothelial antibodies were not detected in 21 dogs with IMHA and 20 dogs with systemic inflammatory response syndrome, sepsis, or both. We conclude that AECA are rarely detectable in dogs considered at high risk of thromboembolism. These findings suggest that AECA may not play an important role in the pathogenesis of thromboembolism in dogs with IMHA and other inflammatory diseases.