Automated flow cytometry compared with an automated dipstick reader for urinalysis

Recently, the Sysmex UF-100 flow cytometer was developed to automate urinal ysis. We compared UF-100 test results with those of an automated dipstick r eader. A cross-check of UF-100, dipstick, and microscopic sediment data was performed in 1001 urine samples. Good agreements (P <0.001) were obtained between UF-100 and dipstick data for erythrocytes (r = 0.636) and leukocyte s (r = 0.785). Even in urine with low conductivity, the UF-100 could detect lysed erythrocytes. The UF-100 bacterial count was higher among nitrite-po sitive urine samples (P <0.0001) and was positively correlated with the UF- 100 leukocyte count (r = 0.745; P <0.001). In stored urine (24 h), bacteria l counts increased, whereas the forward light scatter of leukocytes decreas ed (P <0.01). Casts and yeast cells reported by the UF-100 should be confir med by microscopic review because false positives occurred. We suggest that a computer-assisted cross-check of UF-100 and dipstick data allows a clini cally acceptable sieving system to reduce the workload of microscopic sedim ent urinalysis.