Study comparative of Ki-67 expression in oral lichen planus and oral leukoplakia. Quantitative analysis.

OBJECTIVE

The aim of the present study has been to determine the proliferative differences in oral lichen planus and leukoplakia by means the quantification of Ki- 67 expression.

STUDY DESIGN

The tissue analyzed were the following ones: oral lichen planus (n=10), oral leukoplakia (n=10), dysplasia (n=10). Normal oral mucosa (n=10) was used as the control group. The antibody employed was monoclonal PP-67 (Sigma). Immunoperoxidase detection was employed using the streptavidin- biotin complex. The quantification was carried out by a program of image analysis system Qwin colour RGB. In all cases 10 fields differences were scored. For analytic study were used analysis of the variance and Scheffe's exact test were used. The statistical significance level was considered to be P < 0.05.

RESULTS

In all tissues analyzed there was some grade of proliferation in the basal layer, and in dysplasias so much in basal as suprabasal layer. Of the analytic results we emphasize that there were differences statistically significant among mean of the positive nuclei per mm of length in normal mucosa and leukoplakia (p=0.031), and between normal mucosa, lichen planus and leukoplakia with dysplasias. In these three cases the values were p=0.000.

CONCLUSION

Ki-67 antigen is a marker of nuclear proliferation that allows to settle down the differences proliferatives between lichen planus and oral leukoplakia. Therefore it should take in consideration to think in successive studies that guide therapeutic attitude in these lesions in function of its positivity.