Retrospective evaluation of the short-term response of human intravenous immunoglobulin therapy in the management of canine immune-mediated thrombocytopenia (2010-2015): 27 cases.

Objective: To describe the short-term response, early prognostic markers, and survival after treatment of canine immune-mediated thrombocytopenia (ITP) with human intravenous immunoglobulin (hIVIG) and methylprednisolone.

Design: Retrospective cohort study.

Settings: Private referral veterinary medical center.

Animals: Twenty-seven client-owned dogs with primary or secondary ITP.

Interventions: All dogs received 2 mg/kg IV methylprednisolone once daily and a single infusion of 5% hIVIG administered over 6-12 hours.

Measurements And Main Results: A substantial increase in platelet count within 60 ± 12 hours post-hIVIG infusion (T) was observed in 19 of the 27 (70%) dogs with ITP (responders). Thirty-four variables, including serum immunoglobulin (Ig) G concentration 24 ± 12 hours post-hIVIG infusion (TIgG) and increase in serum IgG concentration 24 ± 12 hours post-hIVIG infusion (TΔ), were compared between responders and nonresponders at 5 different time points. Mortality rates of responders and nonresponders were evaluated 14 days post-hIVIG infusion. Serum TIgG and serum TΔ were both significantly higher at T in responders. All responders were alive 14 days post-hIVIG infusion, and their mortality rate was significantly lower compared with nonresponders.

Conclusions: Responder dogs had an excellent 14-day survival rate. Serum TIgG and serum TΔ concentrations accurately predicted response status at 60 hours post-hIVIG infusion.