Prothrombotic and Inflammatory Effects of Intravenous Administration of Human Immunoglobulin G in Dogs

Background Intravenous administration of human immunoglobulin G (hIVIgG) has been suggested to potentiate thromboembolism in dogs, but supportive scientific reports are lacking. Objectives To determine if hIVIgG therapy promotes hypercoagulability and inflammation in dogs. Animals Twelve healthy Beagle dogs. Methods Prospective, experimental trial. An hIVIgG/saline solution was infused IV at 1 g/kg BW over 8 hours to 6 dogs, and physiological saline was infused to the other 6 dogs. Blood samples were drawn before, during, and after infusion for serial measurement of indicators of coagulation and inflammation. Data were analyzed by 2-way repeated measures analysis of variance. Results Dogs administered hIVIgG developed mildly decreased blood platelet concentrations without thrombocytopenia (median, 200 x 103/mu L; range, 150-302 x 103/mu L; P < .01), leukopenia (median, 3.5 x 103/mu L; range, 20-62 x 103/mu L; P < .001), and mildly increased plasma total protein concentrations (median, 6.3 g/dL; range, 5.6-6.7 g/dL; P < .001). Administration of hIVIgG was also associated with increases in fibrin/fibrinogen degradation products in all dogs (either 5 mu g/mL or 10 mu g/dL), thrombin-antithrombin III complexes (median, 7.2 ng/mL; range, 4.9-14.2 ng/mL; P < .001), and C-reactive protein concentrations (median, 2.5 mg/dL; range, 0.5-4.3 mg/dL; P < .01). Conclusion and Clinical Importance Administration of hIVIgG to dogs promotes hypercoagulability and an inflammatory state. This should be further evaluated and considered when using hIVIgG in dogs with IMHA or other prothrombotic conditions.