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

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