Diagnosis of Acute Urinary Tract Infections Using Sysmex UF-100

• Diagnosis of Acute Urinary Tract Infections Using Sysmex UF-100

AUTHOR(S)

Gianluca GESSONI, Sara VALVERDE, Luigi PENZO, Patrizia MATURI,
Alda GIACOMINI, Francesco ANTICO and Fabio MANONI

Clinical Pathology Department, Ospedale Civile

SUMMARY

The authors report 29 months experience in the diagnosis of acute urinary tract infection using the UF-100 flow cytometer. Some 39,987 urine samples were examined. Each sample was analysed by UF-100 to assess bacteriuria and leukocyturia quantitatively. Samples with less than 25 leukocytes/µL and/or 3,000 bacteria/µL were considered negative and reported without further examination. Urine samples with leukocytes and/or bacteria over these cut-off values were submitted for culture. False negatives were detected by culture of resubmitted samples.

Of the total 39,987 samples examined, 28,471 ( 71.2% ) were negative and 11,516
( 28.8% ) were positive using UF-100 for screening. Significant bacterial growth on culture did not occur in 1,563 ( 3.9% ) of positive samples by UF-100 ( false positives ). There were 493 false negative samples ( 1.2% ). The analytical performance of our protocol is described by the following results: sensitivity 0.95, specificity 0.95, positive predictive value 0.86, negative predictive value 0.98 and incidence of correctly classified samples 0.95.

In our opinion, quantification of leukocytes and bacteria in urine using the UF-100 flow cytometer is a useful method of screening for urinary tract infection.

KEY WORDS

Rapid Diagnosis Screening, Fully Automated Urine Cell Analyzer, UF-100, Urinary Tract Infection