Association between vaginal microflora, high-risk hpv infection and hpv e6/e7 expression in high grade cervical intraepithelial neoplasia

 Introduction: Role of persistent high-risk HPV infection is essential in development of cervical precancerous lesions. HPV achieves persistent expression by integration of E6 and E7 oncogenes into host genome. Vaginal flora changes can result in proinflammatory environment, that facilitates E6 and E7 expression. Aim of the study was to assess an association between HPV E6/E7 expression, vaginal microflora and high-risk HPV infection in women with high grade cervical intraepithelial neoplasia. Methods: Cross-sectional study was performed in July 2016-June 2017. 62 patients aged 18 to 50 referred for colposcopy to Riga East Clinical University Hospital and with histologically proven CIN 2 or worse were included in the study. Material from cervix was tested for HR HPV DNA types 16/18, 31, 33, 45, 58 and high-risk HPV E6/E7 RNA with real time PCR. Wet mount microscopy of vaginal material was performed using phase-contrast microscope and interpreted according to modified Donders-Schrӧder scale. Data analysis was performed with MS Excel 2019. Results: E6/E7 RNA expression was positive in 58/62 patients. 42/62 patients were HR-HPV positive and 41 of them had E6/E7 expression. From 20 HPV negative patients 17 were E6/E7 positive. 30/62 women had abnormal vaginal flora. In HPV positive group 18/42 had abnormal vaginal flora vs. 12/20 in HPV negative group. (p=ns). In E6/E7 RNA positive group 28/58 had vaginal flora changes vs. 2/4 in E6/E7 negative group. In HR HPV positive/ HPV E6/E7 positive group 18/41 had abnormal vaginal flora vs. 2/3 in HR HPV negative/ HPV E6/E7 negative group (p=ns). Conclusions: In the current study we were not able to find an association between vaginal flora changes, HPV E6/E7 expression and high-risk HPV infection. Larger studies are needed to further asses these associations.