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Urine sediment examination: Potential impact of red and white blood cell counts using different sediment methods
Author(s) -
Chase Julia,
Hammond Jeremy,
Bilbrough Graham,
DeNicola Dennis B.
Publication year - 2018
Publication title -
veterinary clinical pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.537
H-Index - 51
eISSN - 1939-165X
pISSN - 0275-6382
DOI - 10.1111/vcp.12674
Subject(s) - repeatability , urine , centrifugation , chromatography , red blood cell , white blood cell , sediment , chemistry , medicine , biology , paleontology
Background Centrifugation is the primary method used to perform urine sediment analyses, but evaluation of other methods is required to validate centrifugation. Objectives Non‐urine materials were used to examine the repeatability (precision) and effectiveness (recovery) of four sediment methodologies on red blood cell (RBC) and white blood cell (WBC) counts. Methods Four urine sediment methods were compared using commercially available quality control material (QCM) and fresh canine RBCs in a diluent. Treatments included (a) 5 mL centrifugation at 390 g for 5 minutes; (b) 1.5 mL centrifugation at 3900 g for 45 seconds; (c) 60 µL of neat (unspun urine) in a microtiter well; and (d) 30 µL of neat on a slide with a coverslip. A within‐run precision using QCM was followed by a one‐run comparison test performed with a suspension of canine erythrocytes. RBC morphology was also examined. Results All results are listed in order of Methods A‐D. Percent coefficients of variation (%CVs) for WBCs were 23.2%, 33.7%, 15.0%, and 27.2%. Red blood cells %CVs were 34.3%, 29.2%, 16.2%, and 24.4%. Average WBC counts in ten fields of view (FOV) ± 1 SD were 26.4 ± 6.1, 14.2 ± 4.8, 32.8 ± 4.9, and 1.6 ± 0.4. Average RBC counts in 10 fields of view (FOV) ± 1 SD were 45.3 ± 15.5, 23.9 ± 7.0, 38.4 ± 6.2, and 2.6 ± 0.6. The one‐run comparison test reports average RBC counts per FOV at 55.2, 23.4, 92.8, and 13.8. The percentages of abnormal RBCs were 92.2%, 74.8%, 7.0%, and 55.1%. Conclusions Method C had the best reproducibility, a lower frequency of cell morphology abnormalities, and similar cellular counts to those of Methods A and B.