An approach to standardization of urine sediment analysis via suggestion of a common manual protocol

ABSTRACT

Introduction The results of urine sediment analysis have been reported semiquantitatively. However, as recent guidelines recommend quantitative reporting of urine sediment, and with the development of automated urine sediment analyzers, there is an increasing need for quantitative analysis of urine sediment. Here, we developed a protocol for urine sediment analysis and quantified the results. Methods Based on questionnaires, various reports, guidelines, and experimental results, we developed a protocol for urine sediment analysis. The results of this new protocol were compared with those obtained with a standardized chamber and an automated sediment analyzer. Reference intervals were also estimated using new protocol. Results We developed a protocol with centrifugation at 400 g for 5 min, with the average concentration factor of 30. The correlation between quantitative results of urine sediment analysis, the standardized chamber, and the automated sediment analyzer were generally good. The conversion factor derived from the new protocol showed a better fit with the results of manual count than the default conversion factor in the automated sediment analyzer. Conclusions We developed a protocol for manual urine sediment analysis to quantitatively report the results. This protocol may provide a mean for standardization of urine sediment analysis.

Key Words:

• Microscopy
• flow cytometry
• laboratory routines and automation
• specimen collection and transportation
• laboratory standardization
• urinalysis

Acknowledgements

We would like to thank the members of the Clinical Chemistry Committee of KSLM and KSCC for their support during this survey and study.

Disclosure statement

The authors report no conflict of interest. The authors alone are responsible for the content and writing of the paper.