Viral load and integration status of HPV58 associated with cervical lesion severity in women of Northeast China

Abstract

Objective: We aimed to evaluate the viral load and integration status of human papillomavirus 58 in women with different grades of cervical lesions to determine whether viral load and integration status are related to malignant transformation in HPV58-infected women.

Methods: A total of 212 cervical specimens were collected from women in Northeast China who had undergone human papillomavirus genotyping and were HPV58-positive. The HPV58 viral load was determined using real-time polymerase chain reaction, and the integration status was discriminated using the ratio of HPV58 E2 gene copy number to E6 gene copy number.

Results: The median HPV58 viral load in women with normal cervix or cervicitis, low-grade squamous cell intraepithelial lesion, high-grade squamous cell intraepithelial lesion and cervical cancer was 352.12, 864.21, 1199.75 and 693.04 copies/genome, respectively. High significance was obtained when comparing the viral load of infected women presenting normal/cervicitis with that of the women either with precancerous cervical lesions or cervical cancer (P < 0.05). The HPV58 genome was in the episomal form in 35 samples (16.5%), mixed episomal and integrated forms in 165 (77.8%) samples, and completely integrated into the host genome in 12 (5.7%) samples. The HPV58 E2/E6 copy number ratio in the cervical cancer group was significantly lower than that in the other groups (P < 0.01).

Conclusions: The HPV58 viral load in patients with precancerous cervical lesions or cervical cancer increases significantly with disease progression. The HPV58 E2/E6 copy number ratio in patients with cervical cancer is lower than that for less severe cervical lesions, suggesting a high degree of viral integration may be a considerable risk factor for cervical cancer.

Keywords: HPV58; viral load; integration; E2/E6; cervical lesion.