抗线粒体抗体在MELAS综合征脑活检组织的表达观察

A study on the expression of anti-mitochondrial antibody in the brain of patients with MELAS syndrome

目的对线粒体脑肌病伴随乳酸血症和卒中样发作（MELAS综合征）患者脑活检以探讨其病理变化及发病机制。方法收集海军总医院确诊的3例MELAS综合征患者脑活检组织石蜡标本，行AMA免疫组化染色。结果3例ME[AS综合征患者脑组织AMA免疫组化染色光镜观察发现病变脑组织及蛛网膜下腔小血管异常增生，血管壁薄厚不均，可见到大量浓染的棕褐色沉积物；神经元细胞中也可见到大量浓染的棕褐色沉积物。结论MELAS综合征患者AMA免疫组化染色的主要病理特点是病变部位血管异常增生，提示病变部位血管平滑肌、内皮细胞及神经细胞内大量异常线粒体堆积，与电镜下发现大量异常线粒体堆积对线粒体脑肌病的诊断有同样价值。

Objective To investigate the pathological changes and pathogenesis of the MELAS syndrome （mitochondrial encephalopathy lactic acidosis strok-like episodes ） by using the method of immunohistochemical staining in the brain biopsy specimens with anti-mitochondrial antibody （AMA）. Methods We performed immunohistochemical staining in 3 confirmed MELAS patients＇ paraffin-imbed brain biopsy specimens. Results Small vessel proliferation and the uneven thickness of the wall were found in the 3 MELAS patients. A lot of brown deposits was shown in the wall of small vessels and also noted in neurons. Conclusions The main pathological change in the MELAS brain biopsy immunohistochemical staining with AMA was the small vessel proliferation, indicating that abnormal mitochondria accumulated in the vascular smooth muscle, endothelial cell and neurons of the lesion sites. This finding was consistent with the electron microscopic discovery and valuable for the diagnosis of MELAS.