Cytological Features Associated with Ureaplasma Urealyticum in Pap Cervical Smear

Purpose: Ureaplasma urealyticum is associated with several obstetric complications and increases the importance of risk management in pregnant women. Furthermore, U. urealyticum has been identified as a cofactor that interacts with human papillomavirus infection in cervical cancer onset. The aim of this study was to assess specific cytological features of U. urealyticum infection in Pap smears to determine whether additional microbiological testing should be performed for pregnant women with a high possibility of U. urealyticum infection. Methods: Liquid-based cytology specimens (LBC) from cervical swabs of a total of 55 women, including 33 pregnant women who were negative for intraepithelial lesion or malignancy (NILM) on Pap testing and with U. urealyticum diagnosed without any other infectious microbes and 22 U. urealyticum-negative controls, were used in this study. We evaluated the localization of U. urealyticum by immunofluorescence, cytological features of secondary changes in squamous cells caused by inflammation, and the specimen background in Pap smears. Results: Based on analysis of Pap smears, a significant relationship was observed between U. urealyticum infection and cannonballs (p < 0.05) as well as predominance of coccoid bacteria (p < 0.05). A large number of U. urealyticum were detected in cannonballs by immunofluorescence. Conclusion: In the present study, cytological features in Pap smears of U. urealyticum infected samples, which have hardly been understood thus far, were assessed. The cytological features included cannonballs and predominance of coccoid bacteria. Our results might help in determining whether additional microbiological testing should be performed for pregnant women with a high possibility of U. urealyticum infection.