MIB1, A PROMISING MARKER FOR THE CLASSIFICATION OF CERVICAL INTRAEPITHELIAL NEOPLASIA

Formalin-fixed and paraffin-embedded tissue specimens of normal and dy splastic cervical epithelia (five CIN1, seven CIN2, five CIN3, and fiv e normal) were assessed by an immunoperoxidase technique, using the mo noclonal antibody MIB1, regonizing a formalin-fixation-resistant epito pe on the cell proliferation-associated Ki-67 antigen. An image analys is system was used to measure four parameters associated with prolifer ative activity: the Ki-67 labelling index CLI), the number of Ki-67-po sitive nuclei per unit length of basement membrane, and the maximum va lue and 90th percentile of the relative distances of Ki67-positive nuc lei from the basement membrane. All these four proliferation-related p arameters were highly correlated with the grade of dysplastic change i n the epithelium (0.90<r<0.97, p<0.0001). The best correlation was fou nd for the 90th percentile of the relative distance and with this para meter all CIN lesions could be correctly classified. The means and sta ndard deviations of the Ki-67 LIs in normal epithelium, CIN1, CIN2, an d CIN3 lesions were 0.07 +/- 0.03, 0.16 +/- 0.03, 0.25 +/- 0.06, and 0 .39 +/- 0.06, respectively. These findings support the theory that CM involves a progressive dysfunction of the proliferative activity of ce rvical epithelial cells. Image analysis of MIB1 is a promising alterna tive method for the objective, reproducible, and reliable classificati on of dysplastic changes in cervical epithelium.