Demonstration of changes in cytokeratin expression in condylomata accuminata in relation to the presence of human papilloma virus as shown by a combination of immunohistochemistry and in situ hybridization.

Human papillomavirus (HPV) can be detected in, and is probably involved in the etiology of, the majority of anogenital neoplasias. Infection with the virus induces a number of events in the infected epithelial cells that may lead to the development of benign or malignant tumors. One change that can be detected in the infected cells is in squamous differentiation, which is reflected by the pattern of cytokeratin polypeptide expression. By studying this pattern in relation to the presence of the virus, an indication may be obtained of the influence of the virus on the cellular differentiation in individual cells. By using a combination of DNA in situ hybridization and immunohistochemistry, for HPV and cytokeratin polypeptides, respectively, we studied the presence of HPV6 or HPV11 in condylomata accuminata derived from anogenital skin in relation to the cytokeratin polypeptides K1, 4, 8, 10, 14, and 18. We found that in many samples the presence of the skin-type cytokeratins K1 and K10 was decreased, whereas K13, and to a lesser degree K4, appeared. The cellular localization of these aberrations in cytokeratin expression could be related to the presence of HPV6 or 11 DNA in the tissue.