Immunochemical analysis of human papillomavirus L1 capsid protein in liquid-based cytology samples from cervical lesions.

Objective: To investigate using detection of human papillomavirus (HPV) L1 capsid protein to predict the course of mild or moderate cervical intraepithelial neoplasia (CIN).

Study Design: Immunocytochemical analysis using antibody against HPV L1 capsid protein was carried out on 274 Pap tests from women positive for high-risk HPV detected by hybrid capture, with cytologic diagnoses of atypical squamous cells of undetermined significance (ASCUS), low-grade squamous intraepithelial lesion (LSIL), atypical squamous cell cannot exclude high-grade squamous intraepithelial lesion (HSIL) (ASC-H), HSIL and squamous cell carcinoma (SCC). Histologic diagnosis was available for patients after initial cytologic diagnosis.

Results: L1 capsid protein was positive in 69.79% of cervicitis, 83.53 % of CIN 1, 41.81% of CIN2, 3.13% of CIN3 and 0% of SCC. Cytologic diagnosis revealed a higher expression rate in LSIL than in ASCUS and HSIL + SCC. In 71 ASCUS/LSIL without treatment, no L1-positive cases progressed in cytology; 18.75% of L1-negative cases progressed to ASC-H/HSIL.

Conclusion: The decreased expression of HPV L1 may correlate with progressed cytopathology. The expressions of HPV L1 in liquid-based cell specimens implied the histopathology diag- nosis of cervix. Expression of HPV L1 may have significance in treating ASCUS and LSIL.