Multiple Human Papillomavirus Infections with High Viral Loads Are Associated with Cervical Lesions but Do Not Differentiate Grades of Cervical Abnormalities

Multiple human papillomavirus (HPV) genotypes often coexist within cervical epithelia and are frequently detected together in smears of different grades of cervical neoplasia. Describing the association between multiple infections and cervical disease is important in generating hypotheses regarding its pathogenesis. We analyzed the prevalence of multiple HPV infections and their attribution to cervical disease in a screening population of 999 consecutive BD SurePath liquid-based cervical cytology samples enriched with atypical squamous cells of undetermined significance (ASCUS) (n = 100), low-grade squamous intraepithelial lesions (LSIL) (n = 100), and high-grade squamous intraepithelial lesions (HSIL) (n = 97). HPV genotyping was performed only on cytology specimens using a broad-spectrum GP5(+)/6(+) -PCR/multiplex HPV genotyping (BSGP5(+)/6(+) -PCR/MPG) assay that detects and quantifies 51 HPV genotypes and 3 subtypes. Using a recently defined high viral load cutoff, the quantitative data were scored as high or low viral load. In the 36-month follow-up, 79 histologically confirmed cervical intraepithelial neoplasia grade 2 or greater (CIN2+) cases were identified. In the screening population, there was a trend of having more multiple infections at a younger age. Multiple HPV infections were common. Multiple HPV types were most prevalent in LSIL (75.9% of HPV positives), followed by HSIL (65.5%), ASCUS (64.6%), and negative for intraepithelial lesion or malignancy (NILM) (36.8%). On average, 3.2 and 2.5 HPV types were detected per LSIL and HSIL sample, respectively. Multiple HPV types with high viral loads were most prevalent in LSIL (62.6% of high viral load positives), followed by HSIL (51.9%), ASCUS (40.7%), and NILM (19.3%). Patients with multiple high viral loads showed a 4- to 6-fold-higher risk of having cervical precancerous cytological lesions than did patients with single high viral loads. Compared to NILM, multiple infections, especially with multiple high viral loads, were significantly associated with cytological precancerous lesions. However, the presence of multiple infections did not distinguish low-grade from high-grade cytological lesions.