Expression of cytokeratins 8 and 17 as a diagnostic marker of cervical intraepithelial neoplasia

Abstract

Cytokeratins belong to the most fundamental markers of epithelial differentiation. Their composition reflects both a cell type and the differentiation status. The aim of this study was to investigate the expression of keratins 8 and 17 in normal cervical epithelium, mature and immature metaplastic epithelium as well as in various grades of intraepithelial neoplasia and squamous cell carcinomas. Fifty-eight smears representing 20 normal, 23 LGSILs, 12 HGSILs and 3 cervical carcinomas were stained with anticytokeratin 8 (clone 35bH11) and anticytokeratin 17 (clone Ks17E3). Expression of both keratins was examined and the percentages of immunoreactive normal, metaplastic, intraepithelial neoplastic and malignant cells were determined. Evaluation of tissue sections was also performed. Keratin 17 was identified in all SILs and carcinomas. It was also present in 3/20 (15%) of normal cervical smears that contained immature metaplastic cells. Keratin 8 was found in the majority of LGSIL cases 20/23 (86.9%), in all HGSIL and malignant lesions as well as in endocervical columnar epithelial cells and in 5/20 (25%) normal smears with immature metaplastic cells. Both keratins showed a more extensive and intense expression in severe lesions. Evaluation of tissue sections revealed expression of CK8 and CK17 of various intensity in most of the premalignant and malignant cases. Premalignant and malignant cells showed similarities in cytokeratins 8 and 17 expression. Both CKs were not expressed in normal ectocervical epithelium. The study of the expression of CK8 and CK17 may contribute in detection of cervical intraepithelial neoplasia.