Antiphospholipid Antibodies in Dogs with Immune Mediated Hemolytic Anemia, Spontaneous Thrombosis, and Hyperadrenocorticism

Abstract

Background The pathophysiology of thrombus formation in canine IMHA and other diseases remains unclear. Antiphospholipid antibodies (aPL) are an important cause of thrombosis in humans and might cause thrombosis in dogs. Hypothesis Dogs with IMHA, spontaneous thrombosis, and hyperadrenocorticism will have increased levels of aPL and lupus anticoagulants (LA), compared with healthy and sick dogs. Animals Thre aPL were measured in healthy controls (n = 40–45); sick dogs without thrombosis (n = 86); IMHA (n = 37); spontaneous thrombosis (ST, n = 11); and hyperadrenocorticism (n = 17). Four groups of dogs were also tested for the presence of LA: healthy controls (n = 40); sick dogs without thrombosis (n = 13); IMHA (n = 13); and ST (n = 5). Methods Prospective cohort study. Dogs were tested for aPL by an ELISA and for LA by the dilute Russell's Viper venom time (dRVVT). Median values were compared by Kruskal–Wallis (aPL) or ANOVA (LA), and an odds ratio for development of thrombosis in dogs positive for aPL was calculated. Results aPL are uncommon in healthy dogs. A total of 13/86 sick dogs without thrombosis, 7/37 dogs with IMHA, 1/11 dogs with ST, and 3/17 dogs with HAC were positive for protein binding‐dependent aPL. There was no significant difference in the number of dogs positive for aPL for any of the study groups, and there was no increased risk for thrombosis in dogs positive for aPL. No dogs had LA. Conclusions Our preliminary research does not support a strong role for aPL for the development of thrombosis in dogs with IMHA and other thombotic diseases, although future studies are warranted.

Consensus on the Rational Use of Antithrombotics in Veterinary Critical Care (CURATIVE): Domain 1—Defining populations at risk

“…A series of prospective controlled investigations (LOE 2, Good) identify increased tissue factor expression, platelet activation, procoagulant microparticles, and neutrophil extracellular traps, in dogs with IMHA compared to controls. Conversely, antiphospholipid antibodies were not implicated as a potential cause for thrombosis in dogs (LOE 2, Good) . Four additional studies used thromboelastography (TEG) to assess the whole blood coagulation status in dogs with IMHA.…”

Congenital protein C deficiency and thrombosis in a dog

“…An immunoturbidimetric antigenic assay for free protein S and ELISA for protein C failed to provide readings as the captured antibodies did not cross‐react with canine proteins. Antiphospholipid antibodies have been reported in dogs, but persistence of lupus anticoagulant, anticardiolipin antibodies, anti‐β2 glycoprotein antibodies, or antiprothrombin antibodies was not demonstrated in this case.…”

Hiperadrenocorticismo atípico e hipotiroidismo canino

“…Uno de los hallazgos paraclínicos más persistente en la paciente fue la disminución del recuento eritrocitario. En una baja proporción de perros con HAC se identificaron anticuerpos antifosfolipídicos de membrana eritrocitaria (14), siendo un hallazgo poco común. El hipotiroidismo concomitante en la paciente, sumado al proceso de enfermedad crónica, podría explicar la anemia que resolvió tras el tratamiento con levotiroxina.…”