Although with intact mucosa at colonoscopy, chagasic megacolons have an overexpression of Gal-3 / Embora com mucosa íntegra à colonoscopia, megacólons chagásicos apresentam superexpressão de Gal-3

ABSTRACT Objective To evaluate the density of anti-galectin-3-immunostained cells, collagen percentage, mast cell density and presence of pathological processes in intestinal muscle biopsies of patients. Methods Thirty-five patients who underwent intestinal biopsy were selected from 1997 to 2015. Patients were divided into three groups: chagasic patients with mucosal lesion (n=13), chagasic patients with intact mucosa (n=12) and non-chagasic patients with no mucosal lesion (n=10). Histological processing of the biopsied fragments and immunohistochemistry for galectin-3 were performed. Additional sections were stained with hematoxylin and eosin to evaluate the general pathological processes, picrosirius for evaluation of collagen and toluidine blue to evaluate the mast cell density. Results Patients of mucosal lesion group had a significantly higher frequency of ganglionitis and myositis when compared to the chagasic patients with intact mucosa and non-chagasic group. The density of anti-galectin-3-immunostained cells was significantly higher in the chagasic patients with intact mucosa group when compared to the non-chagasic group. The group of chagasic patients with intact mucosa presented a higher percentage of collagen in relation to the patients with mucosal lesion and to the non-chagasic group, with a significant difference. There was no significant difference in mast cell density among the three groups. Conclusion The higher density of anti-galectin-3-immunostained cells in patients in the chagasic patients with intact mucosa group suggested the need for greater attention in clinical evaluation of these patients, since this protein is associated with neoplastic transformation and progression.

RESUMO Objetivo Avaliar a densidade de células imunomarcadas por anti-galectina-3, a percentagem de colágeno, a densidade de mastócitos e a presença de processos patológicos na musculatura intestinal de pacientes biopsiados. Métodos Foram selecionados 35 pacientes submetidos à biópsia de intestino entre 1997 a 2015. Os pacientes foram divididos em três grupos: chagásicos com lesão de mucosa (n=13), chagásicos com mucosa íntegra (n=12) e não chagásicos sem lesão de mucosa (n=10). Foram realizados processamento histológico dos fragmentos biopsiados e imunohistoquímica para galectina-3. Cortes adicionais foram corados por hematoxilina e eosina, para avaliar os processos patológicos gerais, pelo picrosírius, para avaliação do colágeno, e pelo azul de toluidina, para avaliar a densidade de mastócitos. Resultados Os pacientes do grupo chagásicos com lesão de mucosa apresentaram frequência significativamente maior de ganglionite e miosite quando comparados aos dos grupos chagásico com mucosa íntegra e não chagásicos. A densidade das células imunomarcadas por anti-galectina-3 foi significativamente maior no grupo chagásicos com mucosa íntegra quando comparada ao grupo não chagásico. O grupo de chagásicos com mucosa íntegra apresentou maior percentagem de colágeno em relação aos grupos chagásicos com mucosa lesada e ao grupo de não chagásicos, com diferença significativa. Não houve diferença significativa com relação à densidade de mastócitos entre os três grupos. Conclusão A maior densidade de células imunomarcadas por anti-galectina-3 nos pacientes do grupo chagásico com mucosa íntegra sugere a necessidade de maior atenção na avaliação clínica desses pacientes, uma vez que essa proteína está associada com transformação e progressão neoplásica.

Role of pro-angiogenic marker galectin-3 in follicular neoplasms of thyroid.

The role of pro-angiogenic marker galectin-3 (GAL-3) was examined in differential diagnosis of follicular neoplasms of thyroid into histological subsets of follicular adenoma (FA), follicular carcinoma (FC) and follicular variant of papillary thyroid carcinoma (FVPTC). The study included 22 cases from January 2006 to June 2011 comprising of FA (n = 12), FC (n = 3) and FVPTC (n = 7). Immunohistochemical evaluation of GAL-3 was performed on representative histologic sections from the resected thyroid specimens. The proportion of stained cells and intensity of staining in tumor blood vessels were evaluated. GAL-3 expression showed that angiogenesis was prominent in malignancy (FC and FVPTC) and negative in non-neoplastic thyroid parenchyma and benign condition (FA). GAL-3 expression was found to differentiate benign from malignant follicular neoplasms. Focal and diffuse positivity for GAL-3 was found to be associated with FC and FVPTC respectively, thus GAL-3 can be used as a immunohistochemical marker in the differential diagnosis of follicular neoplasms of thyroid based on the type of expression. Limitation of this study was relatively less number of cases studied; however, this data need to be corroborated in larger cohort.