Type-Specific Viral Load and Physical State of HPV Type 16, 18, and 58 as Diagnostic Biomarkers for High-Grade Squamous Intraepithelial Lesions or Cervical Cancer

Abstract

Purpose High rate of false-positive tests is a major obstacle to use human papillomavirus (HPV) detection as a diagnostic tool for high-grade squamous intraepithelial lesions or cervical cancer (HSIL+). We investigated whether type-specific viral load or physical state of HPV 16, 18, and 58 are useful biomarkers for HSIL+. Materials and Methods Type-specific viral loads of E6 and E2 genes in cervical cells from 240, 83, and 79 HPV 16-, 18-, and 58-infected women, respectively, were determined using real-time polymerase chain reaction. Viral loads were normalized to cellular DNA (copy/cell). Total and integrated viral loads and physical state were compared between HSIL+ and controls, and diagnostic value was determined using receiver operating characteristic analysis. Results Viral loads of HPV 16, 18, and 58 were significantly different in lesions in the same patho-logic grade. High type-specific total viral loads were significantly associated with HSIL+ (odds ratio [OK 14.065, 39.472, and 7.103 for HPV 16,18, and 58, respectively). High integrated viral load was related to HSIL+ in women with HPV 16 (OR, 8.242), and integrated state was associated with HSIL+ in women with HPV 18 (OR, 9.443). Type-specific total viral load was significantly associated with HSIL+ (area under curve, 0.914, 0.937, and 0.971 for HPV 16, 18, and 58, respectively), indicating an excellent performance in detecting HSIL+. Conclusion Type-specific total viral load may be a powerful diagnostic marker for HSIL+ in HPV 16-, 18-, and 58-infected HSIL+ lesions. If demonstrated in all other high-risk HPV types, this method can lead to a paradigm shift in the strategy of equivocal cytologic abnormalities.