Association of human papillomavirus viral load with HPV16 and high-grade intraepithelial lesion

Abstract
The aim of the present study was to evaluate the relationship between viral type and copy number of human papillomavirus (HPV) with respect to the grade of cervical disease, and also to identify the existence of an HPV type-dependent viral load effect. DNA from 275 exocervical specimens, previously evaluated for histologic diagnosis, were evaluated for HPV presence, HPV type, and viral load. Viral load determination was performed using the low stringency PCR method (LS-PCR). Significant differences were found between the samples infected with HPV16 with respect to the samples infected with other 'high-risk' viral types (HPV -18, -31, -33 or -51) and 'low-risk' types (P < 0.05). However, highly significant differences were found between the viral loads observed in the high-grade squamous intraepithelial lesions group and normal epithelium (OR = 8.53) or the low grade ones (OR = 3.10). Moreover, a high viral load was detected in the condyloma acuminatum group compared to the normal epithelia samples (p< 0.05). This work confirms the genotype-specific association of viral load to the presence of HPV16. Also, a trend to higher viral loads could be seen in the more compromised cervical lesions. An unexpected level of viral particles appeared associated to the condylomas. This fact could be explained by a productive infection with high levels of viral replication.