Hiperinsulinismo congênito em crianças brasileiras: histopatologia, proliferação das células do pâncreas e genética dos canais K+ / ATP / Congenital hyperinsulinismin in brazilian neonates: histopathology, cells proliferation and KATP channels genes

AUTOR(ES)

Silvana Maria Lovisolo

DATA DE PUBLICAÇÃO

2009

RESUMO

Congenital hyperinsulinism (CHI) is a rare pancreatic endocrine cell disease which most severe cases are found to be, at least in half of patients, associated with genetic defects in the -cell KATP channels. The aim of this study was to evaluate eleven Brazilian patients diagnosed, by standard criteria, as CHI non responsive to clinical therapy, and submitted to pancreatectomy, regarding: histology, -cell proliferation (IHC Ki-67 / insulin) and -cell KATP channels genes mutations in blood samples. For comparison of histology and -cell proliferation, 19 pancreatic control samples were included. According histology, ten patients were classified as diffuse and one as focal form. Nucleomegaly and -cells with abundant cytoplasm were absent in controls, and observed only in the group of diffuse CHI patients. Ki- 67-LI was useful to differentiate the adenomatous areas of the focal form CHI neonate from loose clusters of islets found in two diffuse form and one control samples. Proliferation was much higher in the focal CHI adenomatous areas, but diffuse CHI patients also have statistically higher Ki-67-LI than controls. This is the first genetic study of CHI patients in Brazil, and no mutations or new polymorphisms were found in the ABCC8 gene (SUR 1) (exons 33-37) or in the only exon of KCNJ11 gene (Kir 6.2) in 4/4 patients evaluated. On the other hand, enhanced -cell proliferation seems to be a constant feature in these patients both in diffuse and focal forms

ASSUNTO(S)

imunoistoquímica/métodos immunohistochemistry/methods cell proliferation potassium channels hyperinsulinism/congenital insulina/secreção insulin/secretion hiperinsulinismo/congênito proliferação de células canais de potássio

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