Evaluation of membrane-based therapeutic plasma exchange as adjunctive treatment for immune-mediated hematologic disorders in dogs.

Background: Therapeutic plasma exchange (TPE) has been used increasingly to treat immunological diseases in dogs, although data concerning its efficacy are lacking.

Hypothesis/objectives: To describe the clinic and the outcome of dogs with immune-mediated hematological disorders (IMHD) treated with membrane filtration TPE.

Animals: One hundred forty-six dogs diagnosed with IMHD, including 17 dogs treated with and 129 control dogs treated without TPE.

Methods: Retrospective study of cases selected with a search of all medical records for dogs diagnosed with IMHD (2010-2019). Primary outcomes included the assessment of safety and efficacy of adjunctive TPE compared to medical treatment alone.

Results: The TPE group included 7 dogs with immune-mediated hemolytic anemia (IMHA), 5 dogs with immune-mediated thrombocytopenia (IMT), and 5 dogs with combined IMHA-IMT; the control group included 63 dogs with IMHA, 47 dogs with IMT, and 19 dogs with IMHA-IMT. Dogs treated with TPE were more often refractory to initial immunosuppression (71%) than controls (43%; P = .04). Complications were observed in 15/43 TPE treatments (35%). The response rate of dogs treated with TPE was 83% in IMHA (controls, 65%; P = .5) and 80% in IMT (controls, 70%; P = .71). Overall, 12/17 dogs (71%) treated with TPE reached complete remission, 2/17 (12%) partial remission, and 3/17 (18%) died or were euthanized. Eighty-two percent of the dogs treated with TPE survived to discharge (controls, 69%; P = .4).

Conclusions And Clinical Importance: Despite a bias toward dogs refractory to initial immunosuppression, dogs treated with adjunctive TPE had a similar outcome as dogs treated medically.