Determination of cut-off values for leucocytes and bacteria for urine flow cytometer (UF-100) in urinary tract infections.

Leucocytes and bacteria in urine are the important indices for diagnosing urinary tract infections. Urine specimens from 260 patients were examined for leucocytes and bacteria with the UF-100 flow cytometer (Sysmex Corporation, Japan). The results obtained with the UF-100 were compared with those obtained by bacteriologic cultures of the same urine samples. Bacteriologic samples were found to be positive in 48 urine samples. The best detected cut-off value for bacteria is 3800/microL (senstivity = 73%, specificity = 78%) and 25/microL for leucocytes (sensitivity = 73%, specificity = 92%). In addition, comparison of leucocyte count by manually and with UF-100 shows good correlation (r = 0.91). A flow cytometric urinalysis analyzer operates in a time saving manner, increases throughput and decrease microscopy review rates. It also provides a reliable information to clinicians prior to bacteriologic culture results, in terms of leucocyte and bacteria count.