Prognostic value of high-risk HPV viral load in the development of cervical intraepithelial neoplasia

Persistent human papillomavirus (HPV) is recognized as an etiological factor in the development of cervical intraepithelial neoplasia (CIN). High-risk HPV viral load may indicate viral DNA activity in a woman’s body. However, the significance of viral load as a predictor of CIN remains controversial. Objective. To determine the prognostic value of HPV viral load in the development of CIN of varying severity and cervical cancer. Patients and methods. A molecular biological analysis of cervical mucus with the quantitative determination of low-risk (HPV types 6, 11, 44) and high-risk (HPV types 16, 18, 26, 31, 33, 35, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66, 68, 73, 82) HPV DNA by a real-time PCR was performed in 99 patients. Results. High-risk HPV types were detected in 71 of 99 patients. Of 71 patients with HPV, 34 were negative for intraepithelial lesion or malignancy (NILM), 13 had low-grade squamous intraepithelial lesions (LSIL), 12 had high-grade squamous intraepithelial lesions (HSIL), and 12 had cervical cancer (CC). Significant differences in total viral load levels were found between patients with NILM and LSIL (p = 0.0009), while patients with HSIL had significantly lower total viral load levels compared to LSIL (p = 0.04). The prognostic value (AUC) of total HPV viral load for detecting LSIL/HSIL/CC was 0.77 (95% CI: 0.67–0.85) and HPV-16 viral load was 0.71 (95% CI: 0.55–0.84). The logistic regression analysis adjusted for the age of patients showed that the chance of detecting LSIL/HSIL/CC increases with the number of high-risk HPV types: at an average level (more than 3 lg per 105 cells) of viral load by 1.7 times, at a high level (more than 5 lg per 105 cells) by 3.7 times. When even average HPV-16 titer is revealed, the chance of detecting cervical pathology increases by 2 times; in the presence of high HPV-16 titer, abnormal cytological smears were detected in all patients. Conclusion. This study shows that the highest level of viral load was detected in patients with LSIL. If the viral load exceeds 5 lg per 105 cells, the risk of abnormal cytological smears increases by 3.7 times. Key words: human papillomavirus, cervical intraepithelial neoplasia, cervical cancer, viral load