Peer-reviewed veterinary case report
Comparison of white blood cell differential percentages determined by the in-house LaserCyte hematology analyzer and a manual method.
- Journal:
- Veterinary clinical pathology
- Year:
- 2006
- Authors:
- Papasouliotis, Kostas et al.
- Affiliation:
- School of Clinical Veterinary Science · United Kingdom
Plain-English summary
This study looked at how well a new machine called the LaserCyte, which analyzes blood samples from pets, compares to a traditional manual method for counting different types of white blood cells (WBCs) in dogs and cats. Researchers collected blood samples from 44 dogs and 42 cats and found that the results for neutrophils and monocytes (types of white blood cells) differed significantly between the two methods. While there was some agreement for eosinophils in cats, overall, the LaserCyte did not match the manual counts very well, especially in cases where the blood showed unusual results. The study concluded that while the LaserCyte can be useful, it may not always provide accurate WBC counts compared to the manual method, particularly for most cell types.
Abstract
BACKGROUND: The LaserCyte hematology analyzer (IDEXX Laboratories, Chalfont St. Peter, Bucks, UK) is the first in-house laser-based single channel flow cytometer designed specifically for veterinary practice. The instrument provides a full hematologic analysis including a 5-part WBC differential (LC-diff%). We are unaware of published studies comparing LC-diff% results to those determined by other methods used in practice. OBJECTIVE: To compare LC-diff% results to those obtained by a manual differential cell count (M-diff%). METHODS: Eighty-six venous blood samples from 44 dogs and 42 cats were collected into EDTA tubes at the Forest Veterinary Centre (Epping, UK). Samples were analyzed using the LaserCyte within 1 hour of collection. Unstained blood smears were then posted to Langford Veterinary Diagnostics, University of Bristol, and stained with modified Wright's stain. One hundred-cell manual differential counts were performed by 2 technicians and the mean percentage was calculated for each cell type. Data (LC-diff% vs M-diff%) were analyzed using Wilcoxon signed rank tests, Deming regression, and Bland-Altman difference plots. RESULTS: Significant differences between methods were found for neutrophil and monocyte percentages in samples from dogs and cats and for eosinophil percentage in samples from cats. Correlations (r) (canine/feline) were .55/.72 for neutrophils, .76/.69 for lymphocytes, .05/.29 for monocytes and .60/.82 for eosinophils. Agreement between LC-diff% and Mdiff% results was poor in samples from both species. Bland-Altman plots revealed outliers in samples with atypical WBCs (1 cat), leukocytosis (2 dogs, 9 cats), and leukopenia (16 dogs, 11 cats). The LaserCyte generated error flags in 28 of 86 (32.6%) samples, included 7 with leukopenia, 8 with lymphopenia, 7 with leukocytosis, 1 with anemia, and 1 with erythrocytosis. When results from these 28 samples were excluded, correlations from the remaining nonflagged results (canine/feline) were .63/.65 for neutrophils, .67/.65 for lymphocytes, .11/.33 for monocytes, and .63/.82 for eosinophils. CONCLUSION: Although use of a 100-cell (vs 200-cell) M-diff% may be a limitation of our study, good correlation between WBC differentials obtained using the LaserCyte and the manual method was achieved only for feline eosinophils.
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Search related cases →Original publication: https://pubmed.ncbi.nlm.nih.gov/16967412/