Human papillomavirus type 16 (HPV-16) viral load and persistence of HPV-16 infection in women infected or at risk for HIV

Background: Persistent HPV-16 infection is a marker for risk of progression to high-grade cervical lesions. The predictive value of HPV-16 viral loads for persistent HPV-16 infection was assessed longitudinally in a cohort of 1055 sexually active women. Methods: HPV-16 viral loads were measured with real-time PCR targeting the E6 gene in 948 genital specimens collected from 139 women (100 HIV-seropositive, 39 HIV-seronegative). Results: Forty of 139 participants were classified as having persistent HPV-16 infection (lasting more than 12 months) and 27 women had transient infection. CD4 counts were negatively correlated with HPV-16 loads (R = -0.29, p = 0.02). In multivariate analysis controlling for age, HIV, race and CD4 counts, peak HPV-16 viral loads (odds ratio (OR) 1.3, 95% confidence interval (Cl) 1.0-1.7) and CD4 cell counts (OR 2.0, 95% Cl 1.1-3.6) were associated with persistence of HPV-16 infection. Women with ≥107 HPV-16copies/μg cellular DNA were infected for a longer period of time than women with a lower viral load after controlling for age, CD4 count and HIV status (p = 0.01). Conclusion: Higher HPV-16 viral loads were predictive of persistence of HPV-16 infection, a marker risk for potential progression to high-grade pre-cancerous and cancerous lesions of the cervix.