Cervical microbiota in women with cervical intra-epithelial neoplasia, prior to and after local excisional treatment, a Norwegian cohort study

Johanna Wiik,Tone Møller Tannæs,Maria Kyrgiou,Christine Monceyron Jonassen,Anita Mitra,Verena Sengpiel,Staffan Nilsson,Tom Tanbo,Katrine Sjøborg

doi:10.1186/s12905-019-0727-0

Abstract

BackgroundLocal treatment for cervical intraepithelial neoplasia (CIN) by Loop Electrosurgical Excision Procedure (LEEP) has been correlated with reproductive morbidity, while the cervicovaginal microbiota is also known to affect the risk of preterm delivery. CIN and treatment by LEEP might change the cervical microbiota. The main aim of this study was to describe the cervical microbiota before and after LEEP and assess its associaton with cone depth and HPV persistence. Further, we aimed to compare the microbiota to references with normal cervical cytology.MethodsBetween 2005 and 2007, we prospectively identified 89 women planned for LEEP in a Norwegian hospital and recruited 100 references with a normal cervical cytology. Endocervical swabs were collected prior to treatment and at six (n = 77) and 12 months (n = 72) post LEEP for bacterial culture and PCR, and post LEEP for DNA testing for human papillomavirus (HPV). We compared the cervical microbiota composition before and after treatment and between women planned for LEEP vs references.ResultsThere was a reduction in the number of non-Lactobacillus bacterial species six and 12 months after LEEP compared to before treatment and a tendency towards a concomitant increase in Lactobacillus. No association between the detection of cervical bacteria, HPV persistence or cone depth was found.Women planned for LEEP carried significantly more Bacteroides spp., Gardnerella vaginalis, Mycoplasma hominis and Ureaplasma parvum as well as a greater number of bacterial species than the references.ConclusionsLocal excisional treatment appears to alter the cervical microbiota towards a less diverse microbiota. Women with CIN have a more diverse cervical microbiota compared to women with normal cervical cytology.

Highlights

Local treatment for cervical intraepithelial neoplasia (CIN) by Loop Electrosurgical Excision Procedure (LEEP) has been correlated with reproductive morbidity, while the cervicovaginal microbiota is known to affect the risk of preterm delivery
Recent studies using generation sequencing techniques suggest that increased diversity of the vaginal microbiota combined with reduced relative abundance of Lactobacillus spp. is involved in human papillomavirus (HPV) acquisition and persistence, and in the development of CIN and cancer [7,8,9,10,11]
To study if LEEP resulted in a change of different bacterial species in each individual we focused on the women with a change in detection of bacteria after LEEP compared to before LEEP

Summary

Introduction

Local treatment for cervical intraepithelial neoplasia (CIN) by Loop Electrosurgical Excision Procedure (LEEP) has been correlated with reproductive morbidity, while the cervicovaginal microbiota is known to affect the risk of preterm delivery. Persistent genital infection with high-risk human papillomavirus (HPV) is causally associated with cervical cancer and its precursors (cervical intra-epithelial neoplasia; CIN) [1]. Health in the female reproductive tract is commonly associated with low microbial diversity and dominance by one or a few species of Lactobacillus [3]. Recent studies using generation sequencing techniques suggest that increased diversity of the vaginal microbiota combined with reduced relative abundance of Lactobacillus spp. is involved in HPV acquisition and persistence, and in the development of CIN and cancer [7,8,9,10,11]

Objectives

Methods

Results

Discussion

Conclusion