Performance evaluation of the new fully automated urine particle analyser OF-5000 compared to the reference method of the Fuchs-Rosenthal chamber

Background" OF-5000 is the new fully automated urine particle analyser. We validated its performance. Methods: 736 urines were analysed and results were compared by two pathologists on uncentrifuged samples, using Fuchs-Rosenthal chamber. Results: AUC of ROC curve ranged between 0.86 and 0.99. Sensitivity was > 0.90 for all the elements and similar for RBC and yeasts. Specificity ranged between 0.74 and 0.89 for total cast, epithelial/non-squamous/renal-tubular cells and RBC. For all the other parameters specificity was > 0.90. Comparison with Fuchs Rosenthal chamber was very good for all the parameters; r ranged between 0.52 and 0.99 except for pathological cast because of the lack of the pathological samples in medium and higher ranges. Linearity performance (R-2) was 1.00, 1.00 and 0.99 respectively for RBC, WBC and epithelial cells (EC). No carry-over was observed. The within-run imprecision was 25.42%,13.81%,1.36% for RBC; 37.50%,10.16%,1.41% for WBC and 35.25%, 17.85%,6.30% for EC at low, near the cut off level and high concentrations, respectively. The between-run imprecision was 6.90%,1.60% for RBC, 4.10%,1.90% for WBC and 7.60%,7.30% for EC, using low and high positive quality controls, respectively. Conclusion: OF-5000 is an analyser of great interest to detect urine particle related to pathological process of kidney and urinary tract.