Immunohistochemical localization of filaggrin in benign, premalignant and malignant cervical tissue.

Epithelial distribution of filaggrin, a histidine-rich protein related to squamous terminal differentiation, was investigated in 87 cervical biopsies using an avidin-biotin-peroxidase technique with a monoclonal anti-human filaggrin antibody (AKH1). Normal squamous cervical epithelium exhibited a positive homogeneous immunoperoxidase stain in the upper parabasal, intermediate and superficial cell layers. Similar findings were obtained in cervical condylomas, although full-thickness staining was observed in 35.7% of the cases (P < 0.001). Filaggrin expression in CIN was inversely related to the severity of the lesion (P < 0.001). An irregular staining pattern was present in most high-grade C…