Liquid-Based Cytology Detects Urinary Pathogens

Liquid-based urine cytology (LB-URC) has been evaluated for cytological diagnosis and detection of Human papillomavirus (HPV), Mycoplasma, and Ureaplasma.

Liquid-based cytology (LBC) samples of urine sediment can be used to detect HPV and other microorganisms' DNA, while evaluating the cytological findings of urine sediment tests based on Papanicolaou staining and performing in situ hybridization (ISH).

At the Kanazawa University Hospital (Japan) 141 male patients with urethritis (urethritis group) and 154 male patients without urethritis (controls) were enrolled in a study between April 2009 and April 2010. Each patient provided a midstream urine specimen. All patients with urethritis were tested for the presence of Neisseria gonorrhoeae and Chlamydia trachomatis in urethral swabs. The HPV status for each patient was determined. Mycoplasma, Ureaplasma, and HPV genomes were determined by polymerase chain reaction (PCR)-based methods. Papanicolaou tests were performed for cytological evaluation and localization of HPV DNA in urothelial cells was examined by ISH.

HPV DNA was detected in 29 (21.0%) urethritis cases and in 5 (3.3%) controls. HPV genotyping was performed using HPV GenoArray test kits (HybriBio Limited; Hong Kong SAR, China) and HPV type 16 (HPV 16) was most commonly found in urethritis patients. Morphological changes suggestive of HPV infection were seen in 20.7% of the HPV-positive samples, and ISH using the Dako GenoPoint System (Dako; Carpinteria, CA, USA) demonstrated the presence of HPV DNA in both squamous and urothelial cells in HPV-positive samples.

Mycoplasma genitalium, M. hominis, Ureaplasma parvum, and U. urealyticum were detected using a multiplex PCR assay in 14.5%, 10.9%, 6.5%, and 12.3% of urethritis patients, respectively. The authors concluded that that LB-URC is a promising method for molecular analysis of microorganisms in the urinary tract and that HPV infection occurs in urothelial cells, especially in gonococcal urethritis. The study was published in the February 2012 issue of the Journal of Clinical Microbiology.

Related Links:
Kanazawa University Hospital
HybriBio Limited
Dako