The determination of HPV E6/E7 mRNA ratios in patients with abnormal smear cytology

Objective: To analyze HPV E6/E7 mRNA (16, 18, 31, 33, 45) ratios in patients with abnormal smear cytology and to evaluate its efficiency in detecting CIN lesions.Material and method: All cases with abnormal cytologies described by Bethesda System and obtained via conventional pap smear in Celal Bayar University, Manisa maternity hospital and KETEM are included in this study. By evaluating these cases, Nuclisens EasyQ HPV E6/E7 mRNA (16, 18, 31, 33, 45) test is applied. This test is carried out in the microbiology laborotory of Celal Bayar University. The data concerning demographic and clinical features of the cases with HPV E6/E7 mRNA positivity and negativity are recorded. The factors affecting the positivity of HPV E6/E7 mRNA are evaluated. The cases with abnormal cytology are managed according to the ASCPP guideline. The sensitivity, specificity, positive and negative predictive values of HPV E6/E7 mRNA test are calculated after the diagnosis of CIN. Chi-square and Mc Nemar tests are used for the rest of statistical analyses.Results: HPV E6/E7 mRNA was found to be positive in 55.3% of the cases with abnormal cytology. Furthermore, it was positive in 92.8% of HGSIL, 100% of ASC-H, 100% of AGC-NOS and 27.6% of ASC-US cases. In cases with abnormal cytology, HPV type 16 (%38.6) is isolated most commonly, HPV type 18 being the second (%24.6). Regarding the age, parity, number of sexual partners and contraceptive methods, there was no significant difference between HPV E6/E7 mRNA positive and negative cases, whereas positive HPV E6/E7 mRNA was significantly higher in smokers. In respect of detecting CIN, the sensitivity was found to be 100%, specificity 27%, positive predictive value 27% and negative predictive value 100%. Any case with CIN was established if there was negative result of HPV type 16, 18, 31, 33, 45 E6/E7 mRNA test with abnormal smear cytology.Conclusion: approximately in half of cases with abnormal cytology, HPV E6/E7 mRNA was positive. Furthermore, it was more prominent with cases except ASC-US. The high sensitivity and low false negative ratios make the HPV E6/E7 mRNA test to become efficient in clinical use.Key words: Smear, cytology, human papilloma virus, mRNA, E6/E7 protein