Anti WT1 antiboby application's in the diagnosis of melanocític diseases

Abstract

INTRODUCTION: Several studies seek to define markers for differentiating benign and malignant melanocitic diseases. In 2006, merge the firsts studies investigating the role of the anti WT1, with contradictory results. OBJECTIVES: To describe the positivity patterns for anti WT1, related to size, age, sex, positivity percentuals, distribution and intensity; to verify these variables' accuracy to predict melanoma's diagnosis. MATERIAL AND METHODS: Were analyzed 249 skin biopsies of melanocitic lesions in patients of both sexes, in addition to clinical data, morphological and immunohistochemical p o s i t i v i t y f o r a n t i W T 1 . RESULTS/DISCUSSION: Most melanomas (69.1%) was found in males; 71% of lesions with more than 75% of positive cells (p < 0.001) were melanomas. The dermal and junctional distribution and intensity, showed little difference, especially in the dermis; very large confidence intervals (CI), confirmed the low precision of these variables. Only positivity above 75% of cells, age and sex, showed greater diagnostic chance (Odds Ratio-OR: 3.25; OR: 1; 07 and OR: 2.41; p = 0.003). The sensitivity and specificity for more than 75% of cells were 57% (48%-65%) and 78.1% (70%-84%) - IC: 95%, respectively. Most nevi showed dermal positivity (focal or diffuse, strong or weak). The melanomas showed greater junctional positivity, similar to previous studies. CONCLUSION: These results showed intermediate accuracy using the anti WT-1, lower than that observed with traditional antibodies; considering this, the insertion of the anti WT1 in a joint panel, may contribute to the diagnostic decision. Ke ywords: Immunohistochemistr y. Melanoma.WT1 proteins.