Hemophagocytic syndrome in a cat with immune‐mediated hemolytic anemia

Abstract

and anemia. At the time of presentation, the cat was lethargic and weighed 4.62 kg. Physical examination revealed splenomegaly with pale mucous membranes.Its heart rate was 200 beats per minute with normal heart sounds, and the rectal temperature was 39.3°C. We carried out a complete blood count (Celltac α; Nihon Kohden, Tokyo, Japan) and serum biochemical analysis (TBA-120 FR; Canon Medical Systems, Ohtahara, Japan). Hematologic findings indicated moderate regenerative anemia (packed cell volume [PCV], 16.3%; manual aggregate reticulocyte count, 309 520/μL), severe leukopenia (1200/μL) characterized by neutropenia (672/μL) and lymphopenia (528/μL), and mild thrombocytopenia (130 000/μL). Giemsa-stained peripheral blood smears indicated a severe regenerative response. Platelet clumps were absent on the smear. Serum biochemical analysis revealed hyperbilirubinemia (0.35 mg/dL; reference range, 0.02-0.09 mg/ dL), increased lactate dehydrogenase activity (297 IU/L; reference range, 9-268 IU/L), and high serum amyloid A (35.1 μg/mL; reference range, 0.0-5.5 μg/mL; IMMUNO AU10V; FUJIFILM, Tokyo, Japan) (Table 1). Coagulation test results, including prothrombin time, activated partial thromboplastin time, fibrinogen concentrations, and