REVIEW Chlamydia trachomatis infection: implications for HPV status and cervical cancer Jani Silva • Fa ´tima Cerqueira • Rui Medeiros Received: 2 July 2013 / Accepted: 4 December 2013 Ó Springer-Verlag Berlin Heidelberg 2013 Abstract Genital Chlamydia trachomatis (CT) infections have been identified as a major health problem concern. CT is associated with adverse effect on women reproduction and also associated with cervical hypertrophy and induc- tion of squamous metaplasia, providing a possible rela- tionship with human papillomavirus (HPV) infection. Infection by high-risk HPV types is crucial to the patho- genesis of invasive cervical cancer (ICC), but other co- variants/cofactors must be present for the development of malignancy. CT biological effect may damage the mucosal barrier, improving HPV infection, or may interfere in immune response and viral clearance supporting the per- sistence of HPV infection. Moreover, CT-related chronic cervical inflammation, decrease of lower genital tract antigen-presenting cells, inhibition of cell-mediated immunity, and anti-apoptotic capacity may influence the natural history of HPV infection, namely persistence pro- gression or resolution. Although several epidemiological studies have stated a positive association involving CT and HPV-related cervical neoplastic lesions and/or cervical cancer (CC), the specific role of this bacterium in the pathogenesis of cervical neoplasia has not been completely clarified. The present review summarizes several studies on CT role in cervical cancer and suggests future research directions on HPV and CT interaction. Keywords Chlamydia trachomatis Á Human papillomavirus Á Infection Á Cervical cancer Introduction Chlamydia trachomatis (CT) is an obligate intracellular pathogen that infects human epithelial cells of the genital tract, as well as ocular tissue. Worldwide, CT is the most prevalent sexually transmitted infection (STI) and has been identified as a major public health problem. The World Health Organization (WHO) estimates that almost 100 mil- lion chlamydial cases occur each year [1]. In 2009, CT infection in Europe was reported more often in women than men, with an overall rate of 217/100,000 and 152/100,000, respectively [2]. Despite its mostly asymptomatic infection, CT-related genitourinary infections are a major cause of morbidity in the sexually active women. Furthermore, CT causes gynaecological sequelae, including pelvic inflamma- tory disease, ectopic pregnancy and tubal factor infertility [3]. J. Silva Á R. Medeiros (&) Grupo Oncologia Molecular-CI, Laborato ´rios Piso 4, Instituto Portugue ˆs de Oncologia do Porto FG, EPE, Rua Dr. Anto ´nio Bernardino Almeida, 4200-072 Porto, Portugal e-mail: ruimedei@ipoporto.min-saude.pt J. Silva Faculty of Medicine, University of Porto, Porto, Portugal J. Silva Á F. Cerqueira Á R. Medeiros CEBIMED, Faculty of Health Sciences, Fernando Pessoa University, Porto, Portugal J. Silva Á R. Medeiros LPCC, Research Department, Portuguese League Against Cancer (LPCC-NRN), Lisbon, Portugal F. Cerqueira CEQUIMED, Faculty of Pharmacy, University of Porto, Porto, Portugal R. Medeiros Molecular Biology Laboratory-Virology Service, Portuguese Institute of Oncology of Porto (IPO Porto), Porto, Portugal R. Medeiros ICBAS, Abel Salazar Institute for the Biomedical Sciences, University of Porto, Porto, Portugal 123 Arch Gynecol Obstet DOI 10.1007/s00404-013-3122-3