Comparison of two automated urine cytometry systems: Sysmex® UF-1000i and Beckman Coulter® DxU 850 Iris

Abstract

Background: Urinary tract infection, defined as the presence of bacteria or yeast in the urinary tract, is the most common community-acquired infection after respiratory infections. The cytobacteriological examination of urine (CBEU) remains the primary diagnostic test for urinary tract infections and is the most frequently conducted test in microbiology laboratories. Direct examination is a crucial step of CBEU, enabling the assessment of cytology, including leukocytes and red blood cells, as well as the identification of crystals, epithelial cells, and microorganisms when present in significant quantities. This examination also provides preliminary results that can guide clinical decision-making. While the standard method for urine cytology is a microscopic examination, automation offers several advantages, including standardized results with higher repeatability, improved reproducibility, increased sample throughput, and seamless data transfer to laboratory information systems. Objectives: This study aimed to compare the performance of two automated urine cytology systems: Sysmex UF-1000i and the Beckman Coulter DxU 850 Iris. Methods: We described the methodology and technology underlying each system and assessed their analytical performance. The UF-1000i uses flow cytometry for the objective characterization and identification of particles based on forward scattering, fluorescence, and adaptive typing analysis. In contrast, the DxU-850 Iris, a urine microscopy analyzer, employs proprietary digital flow morphology technology alongside automatic particle recognition software to isolate, identify, and characterize digital images of particles. Conclusion: Our comparison showed that both systems performed exceptionally well, delivering results that are comparable, and, in some cases, superior to, those obtained through the reference method of optical microscopy.