ABSTRACT
BACKGROUND: Reticulocyte hemoglobin content provided by the Siemens ADVIA (CHr) is an established marker of iron deficiency. The IDEXX ProCyte Dx hematology analyzer now provides a similar variable, reticulocyte hemoglobin equivalent (RET-He). OBJECTIVES: The objective was to evaluate RET-He and its diagnostic utility in dogs, and to calculate a cutoff value for diagnosing iron-deficient erythropoiesis (IDE). Furthermore, the prevalence of RET-He values below this cutoff value was established. METHODS: One hundred and seventy-one CBCs of healthy dogs were used to establish a RI. Stability of RET-He was evaluated by repeated measurements over 48 hours (n = 10). The 25-run coefficient of variation (CV) was calculated, and correlation and bias between measurements of RET-He and CHr were assessed (n = 190). A cutoff value for diagnosing IDE was calculated. The utility of RET-He in the detection of IDE was evaluated in 123 dogs. The prevalence of low RET-He values was assessed retrospectively in a multicenter study (2012-2014) under participation of 7 veterinary clinics. RESULTS: Reticulocyte hemoglobin equivalent with an RI of 22.2 to 28.6 pg was statistically stable over 48 hours (P = .10). The CV was 1.8%. A fair correlation (ρ = 0.74) between RET-He and CHr with a small bias of -0.6 pg was found. The cutoff value for diagnosing IDE was 20.9 pg (sensitivity: 85%; specificity: 99%). The prevalence of RET-He values below 20.9 pg was 10.3% (1084/10,553 dogs). CONCLUSIONS: RET-He on the ProCyte Dx is a precise screening tool in dogs to detect iron-deficient erythropoiesis.
Subject(s)
Anemia, Iron-Deficiency/veterinary , Dog Diseases/blood , Erythropoiesis , Hemoglobins/metabolism , Iron Deficiencies , Reticulocytes/metabolism , Anemia, Iron-Deficiency/blood , Anemia, Iron-Deficiency/diagnosis , Animals , Dog Diseases/diagnosis , Dog Diseases/epidemiology , Dogs , Female , Iron/blood , Male , Predictive Value of Tests , Prevalence , Prospective Studies , Retrospective StudiesABSTRACT
BACKGROUND: Reticulocyte hemoglobin content (RET-He) is a diagnostic marker for iron deficiency (ID) in people and dogs. OBJECTIVES: The aim of our study was to evaluate the clinical utility of RET-He in the diagnosis of different causes of iron-deficient erythropoiesis (IDE). METHODS: Canine CBCs were separated into 2 groups according to RET-He values, < 20.9 pg or ≥ 20.9 pg. Erythrocyte and reticulocyte variables were compared between dogs with decreased and normal RET-He values. Additional data for a subgroup of dogs were collected, and dogs with low RET-He values were categorized as having ID, inflammatory disorders (INFL), portosystemic shunt (PSS), miscellaneous diseases (MISC), or combinations of these diseases (ID+INFL, ID+PSS). Hematologic variables were compared between dogs of the different disease groups. RESULTS: Overall, 10.3% (1084/10,553) of canine CBCs showed decreased RET-He values. Significant differences between dogs with decreased and normal RET-He values were found for all erythrocyte and reticulocyte variables. The majority (68.9%, 747/1084) of dogs with low RET-He values was anemic; 28.9% (216/747) of those anemic dogs had microcytosis and hypochromasia. In the subgroup of dogs, 8.9% (205/2306) had low RET-He values. According to their diagnosed diseases, anemic dogs (138/205) could be categorized as ID (17/138; 12.3%), INFL (16/138; 11.6%), PSS (30/138; 21.7%), ID+INFL (63/138; 45.7%), ID+PSS (8/138; 5.8%), and MISC (4/138; 2.9%). Distribution in nonanemic dogs (67/205) was similar, except for a lower number of dogs with PSS. CONCLUSIONS: Low RET-He values indicate IDE even in dogs with other CBC variables within the RIs.
