Open Access Highly Accessed Research article

Determinants of seropositivity among HPV-16/18 DNA positive young women

Carolina Porras1*, Christina Bennett1, Mahboobeh Safaeian1, Sarah Coseo1, Ana Cecilia Rodríguez2, Paula González2, Martha Hutchinson3, Silvia Jiménez2, Mark E Sherman1, Sholom Wacholder1, Diane Solomon1, Leen-Jan van Doorn4, Catherine Bougelet5, Wim Quint4, Mark Schiffman1, Rolando Herrero2, Allan Hildesheim1 and the Costa Rica HPV Vaccine Trial (CVT) Group1

Author Affiliations

1 Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA

2 Proyecto Epidemiológico Guanacaste, Fundación INCIENSA, Liberia, Costa Rica

3 Women and Infants' Hospital, Providence, Rhode Island; USA

4 DDL Diagnostic Laboratory, Voorburg, The Netherlands

5 GlaxoSmithKline Biologicals, Rixensart, Belgium

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BMC Infectious Diseases 2010, 10:238  doi:10.1186/1471-2334-10-238

Published: 11 August 2010



Not all women infected with HPV-16/18 have detectable levels of HPV-16/18 antibodies, those who seroconvert develop low antibody levels, and seroconversion occurs typically several months post-infection. We evaluated determinants of seropositivity among 646 women infected with HPV-16 and/or HPV-18.


Data are from the enrollment visit of the NCI-sponsored Costa Rica HPV Vaccine Trial. Sera were tested for HPV-16/18 antibodies by ELISA; cervical specimens were tested for HPV DNA using HC2 and SPF10/LiPA25. Odds ratios (OR) and 95% confidence intervals (CI) were computed.


Among HPV-16/18 DNA positives, seropositivity was 63.0% and 57.5%, respectively. Among HPV-16 DNA positives, seropositivity increased with lifetime number of sexual partners (p-trend = 0.01). Women with abnormal cytology and/or high viral load had a 1.63-2.79-fold increase in the detection of antibodies compared to women with normal cytology/low viral load. Current users of oral contraceptives had a 1.88-fold (95%CI, 1.14-3.09) increased detection of antibodies and current users of injectables had a 3.38-fold (95%CI, 1.39-8.23) increased detection compared to never users. Among HPV-18 DNA positive women, seropositivity was associated with current oral contraceptive use (OR 2.47; 95%CI 1.08-5.65).


Factors associated with sustained HPV exposure (abnormal cytology, elevated HPV viral load, increasing lifetime partners) were predictive of HPV-16 seropositivity. Hormonal contraceptive use was associated with seropositivity suggesting an effect of hormones on immune responses to HPV. Patterns were less consistent for HPV-18. Follow up of incident HPV infections to evaluate seroconversion and their determinants is needed.