Objective: Our objective was to determine the association between viral load of high risk human papilloma virus (HPV) using the Hybrid Capture II (HC II) system and cervical intraepithelial neoplasia (CIN) lesion stage.
Methods: A total of 182 consecutive women with confirmed diagnoses of CIN 1-3 and 182 healthy women with negative Pap were included. All subjects underwent structured interviews focused on socioeconomic and reproductive factors. HC II testing was used to detect human papilloma virus (HPV) DNA. Viral load was measured by light measurements expressed as relative lights unit (RLU) ratio (specimens/control). Log(10)RLU ratios were categorized for analysis into four groups: negative (</=0); low viral load (0.01-1.0), middle viral load (1.01-2.0), and high viral load (2.0-3.6). Frequencies and association measurement odds ratio (OR) adjusted by unconditional multinomial regression (UMR) were used in analysis.
Results: A total of 75 of 80 (93.7%) patients with CIN 2-3, 82 of 101 (79.4%) with CIN 1, and 36 of 182 (19.8%) controls were positive for HPV DNA. The higher the viral load of HPV DNA infection observed, the higher the probability of being associated with stage of CIN (P <0.001). Association between low viral load HPV and CIN 1 was 16.8 (7.2-39) compared with the highest association observed with high viral load and CIN 2-3 (OR(a) = 365.8, 94.7-1412). Both control and cases in the oldest women presented the highest viral load.
Conclusions: We found high frequencies of HPV DNA in CIN 1 and in CIN 2-3 patients. A clear association between viral load of HPV DNA was determined by HC II assay and CIN stage.