Human papillomavirus type 16 viral load in relation to HIV infection, cervical neoplasia and cancer in Senegal.

BACKGROUND

The importance of human papillomavirus (HPV) viral load in the pathogenesis of cervical cancer among HIV-infected and HIV-uninfected women has not yet been established.

METHODS

In this cross-sectional study, HPV-16 viral loads were measured using previously-collected and frozen cervical swab samples from 498 HPV-16 positive Senegalese women (368 HIV-seronegative, 126 HIV-1 and/or HIV-2 seropositive). The real-time polymerase chain reaction assay was used to quantify HPV-16 E7 copy number normalized by human cellular DNA (β-actin), and viral loads were log10 transformed. Associations between HPV-16 viral load, degree of cervical abnormality, and HIV status were assessed using multinomial and linear regression methods.

RESULTS

Compared to women with normal cytology, the likelihood of CIN1 (ORa: 1.21, 95% CI 0.93-1.57), CIN2-3 (ORa: 2.38, 95% CI 1.72-3.29) and cancer (ORa: 2.12, 95% CI 1.52-2.96) was found to increase for each 1-unit log10 increase in HPV-16 viral load. Compared to HIV-negative women, HIV-positive women had higher average HPV-16 viral load values (βa: 0.39, 95% CI 0.03-0.75), even after accounting for degree of cervical abnormality.

CONCLUSION

In our study of women including those with cancer, HPV-16 viral load was associated with a higher likelihood of cervical abnormalities. However, substantial overlaps across categories of disease severity existed. Higher viral load among HIV-infected individuals may indicate that HIV infection influences HPV viral replication factors.