Automated counting of nucleated cells in equine synovial fluid without and with hyaluronidase pretreatment.

This study aims to test a quicker and more precise method than microscopy for counting the number of cells in horse joint fluid. More specifically, it compares a traditional human count against an automated method, and checks how pretreatment with a certain enzyme (hyaluronidase) affects the automated results.

Research Objectives

• The research evaluates two methods for counting equine synovial fluid cells: the traditional manual method and the automated impedance method using a Medonic CA620-VET hematology analyzer.
• It seeks to ascertain if hyaluronidase pretreatment of the samples affords any significant changes in the automated results.

Methods

• Equine synovial fluid samples were collected and analysed in approximately two days.
• The samples were analysed before and after pretreatment with hyaluronidase for 5 to 30 minutes
• Intra-assay coefficients of variation (CV) were determined. CV is a measure of variability that describes the standard deviation as a percentage of the mean.
• A hemacytometer count and microscopic evaluation were used as vantage methods against which automated results were compared.

Results

• Most of the untreated samples were flagged by the analyzer for potential errors, while none of the hyaluronidase-treated samples were flagged.
• The correlation between automated and manual counts of nucleated cells in untreated samples and pretreated samples was high. This indicates a strong agreement between the traditional microscopic method and the automated impedance method for cell count.
• The pseudomedian difference, a measure of the variance between two sample sets, was low. This further evidences the congruence between the manual and automated methods.
• The intra-assay CVs for samples with medium and high cellularity were significantly lower for automated nucleated cell counts (ANCC) compared with manual nucleated cell counts (MNCC).
• Automated differential cell counts were not accurately obtained. This suggests that while the automated method may be suitable for an overall count, it may not be as precise for distinguishing between different types of cells.

Conclusions

• The results reveal that automated total cell counts using the Medonic analyzer correlate well with manual counts in equine synovial fluid. However, pretreatment with hyaluronidase is necessary to minimize error flags.
• On the downside, the research found that automated differential cell counts are not accurate for synovial fluid, indicating that this method might not be effective for counting specific types of cells within the fluid.