Objective: To evaluate the efficacy and safety of intravenous administration of human immune globulin in the treatment of dogs with immune-mediated hemolytic anemia (IMHA).
Design: Prospective clinical trial.
Animals: 10 dogs with confirmed primary IMHA that had failed to respond to conventional immunosuppressive treatment (administration of prednisone and cyclophosphamide or azathioprine).
Procedure: Diagnosis of IMHA was confirmed by detecting spherocytosis or autoagglutination in blood smears and by excluding secondary causes of IMHA. Dogs were treated with human immune globulin (1 g/kg [0.45 g/lb] of body weight, i.v.) during a 6- to 12-hour period. Prednisone treatment was continued in all dogs, and cyclophosphamide treatment was continued in 4.
Results: Median duration of prior immunosuppressive treatment was 12.5 days. Short-term response could not be evaluated in 2 dogs, because they were given blood transfusions within 7 days after immune globulin treatment. However, there was a significant increase in mean Hct and hemoglobin concentration in 8 other dogs from day 0 to 28 after treatment. Five dogs had clinically meaningful responses to treatment. Three dogs were alive 12 months after treatment. There were not any adverse effects that could be definitively attributed to immune globulin treatment; however, thrombocytopenia was observed in 6 dogs after treatment, and evidence of thromboembolism was detected at necropsy in 5 of the 7 dogs that died.
Clinical implications: Human immune globulin may be useful for short-term stabilization of some dogs with IMHA; however, it did not appear to improve long-term survival.