Automated flow cytometry compared with an automated dipstick reader for urinalysis

Area of Science:

• Clinical Chemistry
• Medical Technology
• Laboratory Diagnostics

Background:

• Automated urinalysis aims to improve efficiency and accuracy in clinical laboratories.
• The Sysmex UF-100 is a novel flow cytometer designed for automated urine particle analysis.
• Comparison with established methods is crucial for validating new diagnostic technologies.

Purpose of the Study:

• To evaluate the performance of the Sysmex UF-100 flow cytometer in automated urinalysis.
• To compare UF-100 results with an automated dipstick reader and microscopic sediment analysis.
• To assess the clinical utility of the UF-100 for routine urinalysis.

Main Methods:

• A cross-check analysis was performed on 1001 urine samples.
• Sysmex UF-100 flow cytometer results were compared against an automated dipstick reader.
• Microscopic sediment data served as a reference for certain parameters.

Main Results:

• Good agreement was observed between UF-100 and dipstick data for erythrocytes (r=0.636) and leukocytes (r=0.785).
• The UF-100 accurately detected lysed erythrocytes and showed a higher bacterial count in nitrite-positive samples.
• Increased bacterial counts and decreased leukocyte scatter were noted in stored urine; microscopic review is needed for casts and yeast.

Conclusions:

• The Sysmex UF-100 demonstrates reliable performance for key urinalysis parameters, correlating well with automated dipstick methods.
• Computer-assisted cross-checking of UF-100 and dipstick data can create an efficient system for reducing manual microscopic urinalysis.
• While effective for screening, confirmation by microscopy is recommended for specific findings like casts and yeast cells.