Análise da imunoexpressão de IL-6, TGF-Β1 e KI-67, densidade de mastócitos e colágeno em queilite actínica

Abstract

Actinic cheilitis (AC) is a potentially malignant oral lesion associated with chronic exposure to ultraviolet radiation with high potential of transformation into lip cancer. The aim of this study was to evaluate the immunoexpression of IL-6, TGF-β1 and ki-67 in addition to the density of mast cells and collagen in actinic cheilitis. A total of 50 paraffin blocks were used, 25 of which were diagnosed as AC and 25 of normal lip mucosa from mucocele samples, all of them stored in the Oral Pathology Laboratory. Five cuts of each sample were made; 3 for immunohistochemical reaction by the biotinylated streptavidin technique for the detection of IL-6, TGF-β1 and Ki-67. 2 sections for histochemical examination; 1 cut for the detection of mast cells by Toluidine Blue staining and 1 cut for the evaluation of total collagen and with yellow/red birefringence by the Picrosirius Red method. For microscopic evaluation 5 fields (400x) were used to count cells that present cytoplasmic and/or nuclear positivity in the primary antibodies listed. In order to count the mast cells and to measure the percentage of total collagen and with yellow/red birefringence Image J® software was used. The sum of the marked fields of each slide was considered as sample unit and then, submitted to quantitative analysis. There was a higher prevalence of AC in males (80%) with mean age of 54 ± 16 years and greater occurrence of mild (68%) than moderate (32%) dysplasia, and a higher statistically significant immunostaining for all antibodies and the number of mast cells in the AC group compared with the normal epithelium (p=0.05). IL-6 and Ki-67 showed correlation with dyskeratosis (p=0.045). Ki-67 also manifested a correlation in the stroma with IL-6 and the percentage of total collagen. TGF-β1 showed significant nuclear marking in the control group (p=0.042) and exhibited correlation with the percentage of total collagen. It is concluded that there is a greater immunoexpression of IL-6, TGF-β1 and ki-67, as well as higher mast cell density in the actinic cheilite samples, however independently of their marking location and without association with the different degrees of dysplasia.