[403] Subclinical Human Papillomavirus Infections Are Common among Women under Thirty Years of Age

MF Evans, CSC Adamson, TL St. John, CA Weaver, K Cooper, DL Weaver. University of Vermont, Burlington, VT; Fletcher Allen Health Care, Burlington, VT

Background: The aim of this study was to conduct a thorough survey of the range and frequency of human papillomavirus (HPV) infections in young women with normal cervical cytology. These data are required for understanding HPV natural history and the wider context of clinical HPV screening, and for substantiating the ages at which exposure to high-risk (hr) HPV infections occurs.
Design: Cervical cytology samples diagnosed as negative for an intraepithelial lesion or malignancy (NILM) were collected from 214 women aged 13-19, 166 women aged 20-24, and 186 women aged 25-29 years. Purified DNA extracts were initially screened for HPV by PCR using GP5+/6+ and PGMY09/11 primers. Samples that tested HPV negative by these assays were also screened using FAP59/64 primers. HPV genotypes were identified by dot blot hybridization (GP5+/6+ assay) and/or by cycle sequencing (PGMY09/11 and FAP59/64 assays).
Results: Table 1 summarizes the findings.

Table 1

Age Range in Years	13-19	20-24	25-29
Number of Patients	214	166	186
Median Age	17.00	22.00	27.00
Any HPV Type Positive	85¹(39.7%)	88² (53.0%)	58³ (31.2%)
High-Risk (hr) HPV∗ Positive	49¹′ (22.9%)	57²′ (34.3%)	32³′ (17.2%)
HPV16 or 18 Positive	31 (14.5%)	38 (22.9%)	20 (10.6%)

¹27 different types detected; ²36 types; ³25 types; ∗HPV16, 18, 31, 33, 35, 39, 45, 51, 52, 58, 59, 66, 68, 73 or 82; ¹′ 10 different hr types detected; ²′ 14 hr types; ³′ 8 hr types

In total, 45 different HPV types were detected among 231/566 (40.8%) HPV positive NILM patients. 'Any HPV', 'hrHPV', and 'HPV16 or 18', were each significantly more common in the '20-24' age group than in the '13-19' or '25-29' age groups (P<0.02, P<0.02, P<0.05 respectively).
Conclusions: These data demonstrate that subclinical HPV infections are extremely common in young women, especially in the 20-24 age group, 53.0% of whom were HPV positive with 34.3% being positive for hrHPV types. In all age groups, HPV16 or 18 were the most common hrHPVs supporting the implementation of current HPV vaccines at an early age. The exposure of adolescents to a wide range of other hrHPVs supports the development of additional vaccines. The findings are consistent with limiting negative cytology hrHPV testing primarily to women ≥30, with the detection of persistent hrHPV infections as an aid for identifying lesions of histopathological significance, and with the development of novel markers of cervical neoplasia.
Category: Cytopathology

Tuesday, March 23, 2010 9:30 AM

Poster Session III # 72, Tuesday Morning