Avaliação imunoistoquímica de CD4, CD8, Galectinas-1, -3 e -7 no líquen plano oral e reação liquenoide oral

Abstract

Introduction: Oral lichen planus (OLP) is a chronic inflammatory disorder that affects oral mucosa and sometimes skin, characterized by an immune response mediated by T lymphocytes to keratinocytes present in epithelial tissue, and its etiology is uncertain. Meanwhile, oral lichenoid reactions (OLR) are lesions that present clinical and histopathological characteristics that resemble OLP, and their etiopathogenesis is linked to use of drugs or hypersensitivity reactions. Objective: Quantitatively evaluate the immunoexpression of CD4, CD8, galectins- 1, -3 and -7 in cases of OLP and OLR, associating it with clinical parameters (sex, age, ethnicity, anatomical location of lesions and clinical subtype) and morphological (type of epithelium, presence of Civatte bodies, germinal centers, thickness of epithelium and subepithelial lymphocyte band). Material and methods: We evaluated 33 cases of OLP, categorized into 23 cases of reticular OLP and 10 cases of erosive OLP, in addition to 04 cases of OLR. To evaluate clinical parameters, records of the Oral Histopathology Laboratories of the Universidade Estadual da Paraíba (UEPB) and Universidade Federal de Minas Gerais (UFMG) were used. Morphological evaluation was performed under light microscopy by two previously calibrated examiners, through the ImageJ program, a quantitative analysis of thickness in micrometers of the epithelium and subepithelial lymphocytic band was performed over 05 consecutive fields, 03 measurements were made per field. For immunohistochemical analysis, we used the mean positivity for anti-CD4 and anti-CD8 antibodies, and evaluation of the positivity index for anti-galectins-1, -3 and -7 antibodies in immunoinflammatory cells. For statistical analysis, Fisher's Exact and Mann-Whitney tests were performed (p<0.05). Results: Morphologically, cases of OLP stand out for hyperplastic epithelium (19/33; 57.6%) and presence of Civatte bodies (24/33; 72.7%), while cases of OLR have a higher prevalence of germinal centers (03 /04; 75.0%) (p=0.002). Thickness of epithelial tissue was greater in cases of OLP with a median of 483.47 μm (384.81 – 699.83) (p=0.019), although there was no statistically significant difference between thickness of subepithelial lymphocyte band (p>0 .05). There was no statistically significant difference between CD4+ and CD8+ immunoexpression in OLP and OLR cases (p>0.05), although erosive subtype of OLP showed higher CD4+ immunoexpression (p=0.055). Galectin-1 showed higher cytoplasmic immunoexpression in OLR cases (p=0.011). Nuclear and cytoplasmic immunoexpression of galectin-3 showed no statistically significant difference between OLP and OLR cases, as well as between the reticular and erosive clinical subtypes of OLP (p>0.05). There was no immunoexpression of galectin-7 in immune cells in cases of OLP and OLR. There was a positive correlation of CD4 and CD8 immunoexpression in cases of OLP (r=0.441; p=0.010) and reticular OLP (r=0.520; p=0.006), as well as correction of cytoplasmic and nuclear galectin- 1 for reticular OLP (r=0,619; p=0.003) and erosive (r=0.623; p=0.043), as well as correlation of cytoplasmic and nuclear galectin-3 for erosive LPO (r=0.839; p=0.003). Conclusions: A thinner epithelial tissue thickness and the presence of germinal centers are important for the diagnosis of OLR. A higher level of CD4+ in erosive LPO may point to a possible role in the differentiation of lymphocyte subpopulations in these cases. Galectin-1 and -3 participate in the modulation of the immune response of LPO and OLR, and the cytoplasmic immunoexpression of galectin-1 is a possible mercury-mediated pro-apoptotic lymphocyte pathway. Galectin-7 does not play a direct mechanism in the immune response of LPO and OLR.