Performance of yeast-like cell counting (YLCC) using the Sysmex UF-1000i for clinical candiduria screening

Candiduria is common in clinical practice. However, an effective and convenient assay to screen for candiduria is still needed. This study aimed to evaluate the performance of the Sysmex UF-1000i urine analyzer for yeast-like cell counting (YLCC) to screen for candiduria prior to urine culture. We retrospectively analyzed data from 5233 urine samples from 1813 patients, including 837 males and 976 females. Urine culture and urinalysis-obtained YLCC data were used to estimate the performance of YLCC in diagnosing candiduria. Different cutoff values were used to calculate sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). The YLCC-positive rates differed according to the Candida colony-forming units (CFU) counts in the urine samples. A sharp drop in YLCC-positive rate (from 64.3 to 22.0%) was observed between the urine groups with 10⁴ CFUs and 10³ CFUs. A cutoff value of 0 YLCs/μL results in the highest Youden index (0.71) with 77.04% sensitivity and 93.68% specificity. In a group of 34 hospitalized candiduria patients with serial urinalysis data, 25 were YLCC-positive before urine culture. In conclusion, YLCC with the Sysmax UF-1000i could serve as an auxiliary technique to exclude culture-negative specimens prior to urine culture. Positive YLCC results could imply candiduria, especially when persistent YLCC-positive results were observed.