Comparison between manual and automated total nucleated cell counts using the ADVIA 120 for pleural and peritoneal fluid samples from dogs, cats, horses, and alpacas

Abstract

Analysis of body fluids includes an estimate of total nucleated cell count (TNCC). Automated methods may enhance the accuracy and timeliness of TNCC results. The purpose of this report was to assess the ability of the ADVIA 120 hematology analyzer to accurately count nucleated cells in pleural and peritoneal fluids from animals, compared with manual counts. Pleural and peritoneal fluids submitted in EDTA tubes to our laboratory over a 17-month period were used in the study. TNCC/microL was determined by a manual method, using a hemocytometer, and by an automated method, using the ADVIA 120. Correlation of results was determined by Passing-Bablok regression, Bland-Altman plots, and Pearson correlation analysis. Samples from dogs (n=36), cats (n=36), horses (n=59), and alpacas (n=11) were analyzed. High correlation in TNCC between methods was found for peritoneal fluid (n=93, r=.959), pleural fluid (n=49, r=.966), and all fluids combined (n=142, r=.960) (P<.001). Variation between methods was greater in samples with TNCCs<1000/microL (r=.62, P<.001). The ADVIA systematically overestimated the number of cells in all fluid samples by 95 cells/microL (confidence interval=19.2-190.5/muL). The ADVIA 120 reliably determines TNCC in pleural and peritoneal effusions and can be recommended for routine veterinary laboratory analysis.