非酒精性脂肪肝病肝组织超微结构特点

Ultrastructural Features of Liver Tissues in Non-alcoholic Fatty Liver Disease

目的:阐明非酒精性脂肪肝病(NAFLD)的超微结构特点。方法:收集我校和其他单位送检的3例单纯性非酒精性脂肪肝,16例NASH患者和4例NAFLD肝硬化患者的肝穿刺组织。用2.5%戊二醛、1%锇酸双固定、Epon 812包埋,超薄切片70nm,醋酸铀和柠檬酸铅染色后,JEM-2000EX透射电镜观察。结果:单纯性脂肪肝患者主要表现为大小不等的脂滴沉积、以小脂滴为主,可互相融合。NASH患者的肝细胞都可出现大量脂滴积聚,为大小脂滴混合型、内容物主要为中等电子密度、比较均一的甘油三酯,部分脂滴周围可见磷脂成分,NASH患者肝细胞内脂滴也互相融合。肝细胞线粒体的超微结构改变包括多形性线粒体、基质颗粒增多、线粒体增大和嵴的丧失是主要的电镜异常发现,线粒体内还可见副晶格样包涵体。部分NASH患者肝细胞内可见Mallory小体。NASH患者肝细胞周围可见淋巴细胞浸润。肝血窦Kupffer细胞增生不明显,NAFLD肝硬化患者Disse间隙和肝细胞间可见胶原纤维增生。结论:NAFLD具有较为明确的超微结构改变,电镜检查有助于诊断。

Objective： To investigate the ultrastructural features of liver tissues in non-alcoholic fatty liver disease（NAFLD）.Methods：23 cases of NAFLD were collected,included 3 cases of steatosis,16 cases of nonalcoholic steatohepatitis（NASH） and 4 cases of liver cirrhosis.The percutaneous liver aspiration biopsy was performed,the biopsy tissues were fixed in 2.5% glutaraldehyde,postfixed in 1% osmium tetroxide,embedded with Epon 812,70 nm ultrathin sections were prepared.Ultrathin sections were stained with uranyl acetate and lead citrate and examined with a JEM-2000EX transmission electron microscope at 80 kV.Results： The number and size of lipid droplets vary in steatosis,small lipid droplets was seen frequently and they can fuse each other.The numerous lipid droplets was found in NASH.The macrovesicular and microvesicular or mixed types of steatosis were existed in the same cell.The content of lipid droplets was mainly medium electron dense triglyceride,and phospholipid was found in the periphery of some lipid droplets.The fused lipid droplets were also found in NASH.Ultrastructural changes in mitochondria of hepatocytes included polymorphic and enlarged mitochondria,increased metrical granules,fragmentated cristae.The paracrystalline inclusions of mitochondria and Mallory body were also found in NASH.Lymphocytic infiltration is sometimes present in the in the vicinity of hepatocytes in NASH.The proliferation of Kupffer cells was not obvious.Increased collagen fibers were found in Disse spaces and intercellular spaces of hepatocytes in liver cirrhosis.Conclusions： The characteristic ultrastructural changes was found in NAFLD,electron microscopy might be of help in the diagnosis of NAFLD.