Spurious reticulocyte profiles in a dog with babesiosis

Abstract

A 9-year-old, female Maltese dog was referred to the Veterinary School of Toulouse with a 2-day history of anorexia and weakness. On clinical examination, the dog had hyperthermia (39.7°C), abdominal discomfort, and polypnea. Significant laboratory findings included pigmenturia, hyperbilirubinemia, hypercreatininemia, hyperfibrinogenemia, abnormal Snap canine pancreas-specific lipase, and pancytopenia with a nonregenerative anemia. A peripheral blood smear revealed numerous intraerythrocytic large Babesia but no polychromasia. There was a discrepancy between the absolute automated reticulocyte count (Sysmex reticulocyte count: 60 × 10 /L; RI 19.4-150.1 × 10 /L) and the manual reticulocyte count (3.6 × 10 /L) as well as the absence of polychromasia. The optical red blood cell scattergram showed an abnormal isolated reticulocyte cluster at the location of low-fluorescence ratio cells. These findings were interpreted as erythrocytes parasitized by large Babesia. The discrepancy between the Sysmex reticulocyte count and the manual reticulocyte count has been reported previously in people with falciparum malaria and numerous intra-erythrocytic Plasmodium falciparum organisms. This spurious reticulocyte profile and reticulocyte count were observed with the Sysmex XT-2000iV and the ProCyte using the same fluorescent dye polymethine but not with the LaserCyte using new methylene blue which does not stain Babesia organisms on a blood smear performed for manual reticulocyte counting.

Pseudoreticulocytosis by the ADVIA 2120 Hematology Analyzer and Other Hematologic Changes in a Cynomolgus Macaque (Macaca fascicularis) With Malaria

“…infection. 21,22 In the present case, atypical reticulocyte scatter plots were evident on study days 22 to 43 which coincided with high organism burdens.…”

“…Pseudoreticulocytosis in dogs with large Babesia spp. protozoal infection has also been documented when using laser flow cytometry analyzers with fluorescence capabilities, 21,22 with the findings attributed to reticulocyte stain uptake by the organism. Similar to the current case, abnormal reticulocyte scatter plots have been described in other studies with high burdens of malarial organisms in humans 15-19 or in dogs with large Babesia spp.…”

Ultramicroscopic Erythrocytes Profile as a Component of the Babesiosis Pathogenesis

“…An objective confirmation of the latter was the increase in the content of young reticulocytes. This indicator increased due to the absolute rise in the number of reticulocytes or as a consequence of a decrease in the mass of circulating erythrocytes (anemia) [10][11][12].…”

Changes in erythrocytopoesis indices in dogs with babesiosis

“…The development of babesiosis in dogs is a complex process which is determined by a number of biological, natural-climatic and socioeconomic factors (Iguchi et al, 2014). The pathogenesis of this disease is determined by the specific type of pathogen and the corresponding reactions occurring in the organism of the affected animal, which, in turn, depend on the biology and life cycle of the Babesia canis and the conditions in which the interaction of the macro-and microorganism occurs (Al Izzi et al, 2013;Bajer et al, 2016;Piane et al, 2016). The peculiarity of the pathogenesis of the disease is the reproduction of the causative agent of babesiosis in the organism of a susceptible animal inside the erythrocytes of the capillaries in the internal organs, and then in the erythrocytes of the blood stream.…”