Performance analysis of urine formed element analyzer EH-2090 was found to have good accuracy in detecting RBCs and WBCs when compared to manual microscopic.

ABSTRACT

Background: EH-2090 is Mindray's new-generation fully automatic urine formed element analyzer (hereinafter referred to as EH-2090). Currently, there are no studies on EH-2090, so we evaluated the analytical and clinical performance of this instrument to verify that it can meet daily clinical needs, and used manual microscopy as a reference method. Methods: The analytical performance of the EH-2090 was first evaluated for repeatability, linearity, reproducibility, and carryover. We collected urine samples from outpatient and inpatient departments of Peking University Shenzhen Hospital. Uncentrifuged urine was compared with the EH-2090 using the Fuchs-Rosenthal counting method-a quantitative reference method for microscopy-for comparative studies in terms of red blood cell (RBC) and white blood cell (WBC) counting accuracy. Passing-Bablok regression analysis was performed for RBC and WBC counts. Two laboratory technicians performed centrifugation and manual analysis (microscopy) to evaluate its performance at detecting RBCs, WBCs, and casts, sensitivities and specificities were calculated. Results: The EH-2090's between-run reproducibility, within-day reproducibility, between-day reproducibility, and within-laboratory reproducibility for formed components of urine all met the laboratory requirements. There was a good correlation between the counting accuracy of RBCs (r=0.965, P<0.0001) and WBCs (r=0.894, P<0.0001) by the EH-2090 and the Fuchs-Rosenthal method. The positive coincidence rates of RBC and manual microscopy were 86.08% and 92.41%, respectively, and the negative coincidence rates were 88.39% and 85.81%, respectively. The positive coincidence rates before and after the WBC review were 89.33% and 92.00%, respectively, whereas the negative ones were 77.64% and 83.23%, respectively. The positive coincidence rates before and after cast review were 77.78% and 82.05%, respectively, and the negative ones were 97.09% and 93.60%, respectively. Conclusions: The EH-2090 has good analytical and clinical performance. Its RBC and WBC counting accuracy correlates well with the quantitative reference method of microscopy.