title: Usefulness of quantifying leukocytes in first-voided urine to predict positivity for Chlamydia trachomatis in asymptomatic men at high risk for chlamydial infection.
abstract: Chlamydia trachomatis causes acute non-gonococcal urethritis, but some infected men are asymptomatic. We examined leukocytes in uncentrifuged first-voided urine (FVU) from asymptomatic men at high risk for chlamydial infection by automated urine particle analyzers to assess whether the quantification of urinary leukocytes could predict chlamydial infection in these men. We enrolled 209 asymptomatic men, whose female sexual partners had been diagnosed as having a genital chlamydial infection. Their FVU specimens were examined for quantification of leukocytes with automated urine particle analyzers and tested for Neisseria gonorrhoeae, C. trachomatis, Mycoplasma genitalium, Mycoplasma hominis, Ureaplasma parvum, and Ureaplasma urealyticum by nucleotide acid amplification tests. Eleven men positive for N. gonorrhoeae or M. genitalium were excluded from further analysis. In the remaining 198 men, 84 positive for C. trachomatis (42.4%) had 1.8-1666.9 white blood cells (WBCs)/μl (median, 43.3 WBCs/μl) in their FVU, whereas 114 negative for C. trachomatis had 0.1-1378 WBCs/μl (median, 4.8 WBCs/μl). A receiver operating characteristic (ROC) curve was constructed to examine the sensitivity and specificity of leukocytes counts for predicting chlamydial infection. A cut-off point of leukocyte counts of 12.5 WBCs/μl was determined from the ROC curve, resulting in a sensitivity of 86.9% and specificity of 88.6% for predicting chlamydial infection. Leukocyte quantification in FVU by automated urine particle analyzers showed good performance in predicting the positivity and negativity for chlamydial infection in asymptomatic men. This test could potentially develop into a relevant tool for preselecting asymptomatic men prior to C. trachomatis screening.
authors.affiliation: iClinic, 5-9-6 Naga-machi, Taihaku-ku, Sendai 982-0011, Japan.
authors.forename: Shin
authors.initials: S
authors.lastname: Ito
authors.affiliation: Department of Urology, Graduate School of Medicine, Gifu University, 1-1 Yanagido, Gifu, Gifu 501-1194, Japan.
authors.forename: Kengo
authors.initials: K
authors.lastname: Horie
authors.affiliation: Department of Urology, Graduate School of Medicine, Gifu University, 1-1 Yanagido, Gifu, Gifu 501-1194, Japan.
authors.forename: Kensaku
authors.initials: K
authors.lastname: Seike
authors.affiliation: Department of Urology, Graduate School of Medicine, Gifu University, 1-1 Yanagido, Gifu, Gifu 501-1194, Japan.
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Yasuda
authors.affiliation: Department of Urology, Graduate School of Medicine, Gifu University, 1-1 Yanagido, Gifu, Gifu 501-1194, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Tsuchiya
authors.affiliation: Department of Urology, Graduate School of Medicine, Gifu University, 1-1 Yanagido, Gifu, Gifu 501-1194, Japan.
authors.forename: Shigeaki
authors.initials: S
authors.lastname: Yokoi
authors.affiliation: Department of Urology, Graduate School of Medicine, Gifu University, 1-1 Yanagido, Gifu, Gifu 501-1194, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Nakano
authors.affiliation: Department of Urology, Graduate School of Medicine, Gifu University, 1-1 Yanagido, Gifu, Gifu 501-1194, Japan. Electronic address: deguchit@gifu-u.ac.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Deguchi
mesh_terms: D002690:Chlamydia Infections / Q000175:diagnosis / Q000652:urine*; D002692:Chlamydia trachomatis / Q000302:isolation & purification*; D006801:Humans; D007958:Leukocyte Count; D007962:Leukocytes / Q000473:pathology*; D008297:Male; D011237:Predictive Value of Tests; D012372:ROC Curve; D012189:Retrospective Studies; D012747:Sexual Partners; D014556:Urine / Q000382:microbiology*
keywords: Automated quantitative urine particle analyzers; Chlamydia trachomatis; Urinary leukocytes