[Association between high risk human papillomavirus DNA load and cervical lesions in different infection status]

Objective: To explore the relationship between high risk HPV (HR-HPV) DNA load and cervical lesions in HR-HPV single/ multiple infections. Methods: Two thousand six hundred and forty-six women from Shanxi, Henan and Xinjiang were recruited into a cervical cancer screening program. Cervical exfoliated cell specimens collected from all of the participants were detected by hybrid capture Ⅱ (HC2), cytological diagnosis was performed according to the Bethesda System, and pathological diagnosis was interpreted using cervical intraepithelial neoplasia (CIN) terminology.Totally 571 cervical specimens were selected and retested to ascertain the HPV types and single/ multiple infections by liner array, a PCR-based method. Semi-quantitative result of HR-HPV DNA load (pg/ml) was estimated by HR HC2.According to the taxonomy of "International Human Papillomavirus Reference Center" , 13 HR-HPVs, including HPV16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59 and 68, which could be detected by HR HC2 were divided into 4 subgroups. Results: The positive rate of HR-HPV in normal cervix (436 cases), CIN1 (88 cases), CIN2+ (47 cases) group were 29.82%, 85.23% and 100%, respectively. The overall prevalence and median viral load increased coordinating with the pathological degree of cervical lesions (P<0.001). The positive rate and viral load of single infection with HR-HPV belongs to α9 species increased coordinating with the pathological degree of cervical lesions (P<0.05). The viral load of single infection with HR-HPV belongs to α7 species in CIN1 group was higher than those of normal group and CIN2+ group, but without statistical significance (P=0.130). The viral load of multiple infections in CIN1 group was 559.13 pg/ml, significantly higher than 37.73 pg/ml of normal histology (P=0.025), but without significant difference of 332.91 pg/ml of CIN2+ group (P=0.790). The median viral load of HPV single infection in CIN1 group was 167.93 pg/ml, significantly lower than 559.73 pg/ml of multiple infections (P=0.044). The incidence of co-infection with HR-HPVs belong to α9 species was 80.56%, dominated in all patterns of multiple infections and their median viral load increased coordinating with the pathological degree of cervical lesions, but without significant difference (P>0.05). The incidence of co-infection with HR-HPVs belong to α7 species was 66.67%, their median viral load in CIN1 group was higher than that of CIN2+ group, but without statistical significance (P>0.05). Conclusions: Viral loads of single/ multiple infections with HR-HPVs belong to different species show different tendencies coordinating with the pathological degree of cervical lesions. Women with high grade of cervical lesion were dominantly infected with high viral load of HR-HPVs belong to α9 species, and the viral load of multiple infections is higher than that of single infection in low grade of cervical lesion.