Morphological characterization of mitochondrial alterations in hepatic steatosis of cause not defined in childhood group / Caracterização morfologicas das alterações mitocondriasis na esteatose hepatica de causa não determinada em grupo pediatrico

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Hepatic steatosis unrelated to alcoholism may occur separately or be part of fatty liver disease (NAFLD). It encompasses a wide spectrum of morphologic alterations, ranging from steatosis to a more severe stage accompanied by fibrosis and cirrhosis. The aim of our study was to assess and characterize childhood steatosis of not defined cause carrying out morphologic and morphometric analysis of liver tissue. Eighteen biopsies from 16 patients with age varying from 3 months to 10 years, with vague abdominal pain and/or minimal hepatomegaly associated with slight and persistent increase in hepatic enzymes had been analyzed through light microscopy and transmission electron microscopy. On those patients, "pure" steatosis was detected, meaning it was not followed of fibrose or any other significant histological alterations. In light microscopy total steatosis was semi-quantified with estimative of macro- and microvesicular steatosis percentage and determination of predominant steatosis, classified from 1 to 4 and estimate the percentage of hepatocytes affected by steatosis microvesicular in comparison to hepatocytes affected by macrovesicular; in electron microscopy it was determined the degree of mitochondrial density in the hepatocytes and mean mitochondrial surface area using in both cases the TPS Dig version 1.30. Ten patients between 1 and 14 years old who had a normal diagnosis on liver biopsy were used as a control group. The results had shown microvesicular predominance of steatosis in the studied patients (61%) with significant increase of mitochondrial surface area values: 1,52 ± 0,08 µm2 in the control group, 1,49 ± 0,07 µm2 in the macrovesicular steatosis group and 2,92 ± 0,36 µm2 in the microvesicular steatosis group. Significant alterations in mitochondrial density were not observed, neither related to predominant micro nor macrovesicular steatosis (72 ± 2 mitochondrias/hepatocytes in the control group, 70 ± 11 mitochondrias/hepatocytes in the macrovesicular steatosis group and 66 ± 8 mitochondrias/hepatocytes in the microvesicular steatosis group). A correlation between variations in transaminases levels and both types of steatosis was also not observed, since for the microvesicular steatosis group the average values was AST = 62.9 ± 35.0, ALT = 125.9 ± 129.0 and GGT = 210.5 ± 278.3 and for the macrovesicular steatosis AST = 82.1 ± 97.5, ALT = 57.4 ± 41.4 e GGT = 185.8 ± 141.7. In our study group, "pure" steatosis, with little or no clinical symptoms, associate or not to alterations of transaminases and that did not correlate with obesity or known metabolic diseases is predominantly microvesicular and was related to increased mitochondrial volume. In the primary mitochondrial hepatopathies (PMH), especially for respiratory chain defects, this alteration is common. Due to these probable mitochondrial alterations, this steatosis doesn t have to be called "pure", being able, also, to correspond to the portion distal in the long specter of the NAFLD. It is important to emphasize that although the small number of clinical and laboratorial manifestations of these children, it is essential their systematic accompaniment. There is necessity of more attention to the cases with steatosis in pediatric group where microvesicular form predominance occurs

ASSUNTO(S)

figado liver fatty liver esteatose hepatica

ACESSO AO ARTIGO

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