Li L, Duan X J, Sun Y, Lu Y, Xu H Y, Wang Q Z, Wang H Y
Department of Pathology, Fuwai Hospital, Chinese Academy of Medical Sciences, Beijing 100037, China.
Zhonghua Bing Li Xue Za Zhi. 2018 Feb 8;47(2):105-109. doi: 10.3760/cma.j.issn.0529-5807.2018.02.005.
To evaluate the sensitivity and specificity of immunohistochemistry (IHC) in the classification of cardiac amyloidosis on endomyocardial biopsy (EMB) and heart allograft. Twenty cardiac tissues from 19 patients at Fuwai Hospital from January, 1990 to April, 2017 with histopathologic features of amyloidosis and Congo red staining positivity were included. IHC was performed with monoclonal antibodies against AA amyloid and polyclonal antibodies against transthyretin (ATTR), λ-light chain (AL-λ), κ-light chain (AL-κ), ApoAⅠ, ApoAⅡ, ApoA Ⅳ and β(2)-microglobin. The extent of interstitial staining was evaluated by light microscopy, and three patterns were recognized; these included diffuse pericellular pattern, discrete pericellular pattern, and nodular pattern. Two patterns of vascular deposition were also noted, including arterial pattern and venous pattern. Endocardial involvement was also assessed and recorded. Nineteen cases were divided into three groups according to the pattern of proteins expression in specimens. The first group (5 cases) only showed single protein expression on EMB. The second group (6 cases) showed more than one protein expression, but one of them was intensely stained or any staining of any protein together with ApoA Ⅳ co-staining. The third group (8 cases) also showed more than one protein expression and all of them had intense staining. Amyloid deposits were successfully subtyped as AL-λ, ATTR, AL-κ and ApoAⅠby IHC in the former two groups with the sensitivity of 11/19. In the third group, amyloid deposits could not be subtyped by immunohistochemistry due to their poor specificity. The pericellular pattern tended to favor AL over ATTR amyloidosis and vascular deposition tended to favor ATTR. Amyloid deposits can be reliably subtyped in diagnostic cardiac specimens using IHC. The co-deposition of chaperon proteins, the distribution of amyloid proteins and clinical features are also auxiliary to subtype cardiac amyloidosis.
评估免疫组织化学（IHC）在经心内膜心肌活检（EMB）及心脏移植中对心脏淀粉样变性进行分类的敏感性和特异性。纳入1990年1月至2017年4月在阜外医院的19例患者的20份心脏组织，这些组织具有淀粉样变性的组织病理学特征且刚果红染色呈阳性。采用抗AA淀粉样蛋白单克隆抗体以及抗转甲状腺素蛋白（ATTR）、λ轻链（AL-λ）、κ轻链（AL-κ）、载脂蛋白AⅠ、载脂蛋白AⅡ、载脂蛋白AⅣ和β2微球蛋白的多克隆抗体进行免疫组织化学检测。通过光学显微镜评估间质染色程度，识别出三种模式；包括弥漫性细胞周围模式、离散性细胞周围模式和结节状模式。还注意到两种血管沉积模式，即动脉模式和静脉模式。对心内膜受累情况也进行了评估和记录。根据标本中蛋白质表达模式将19例病例分为三组。第一组（5例）在EMB上仅显示单一蛋白质表达。第二组（6例）显示一种以上蛋白质表达，但其中一种染色强烈，或任何蛋白质染色与载脂蛋白AⅣ共染色。第三组（8例）也显示一种以上蛋白质表达且所有蛋白质染色均强烈。在前两组中，通过免疫组织化学成功将淀粉样沉积物亚型分为AL-λ、ATTR、AL-κ和载脂蛋白AⅠ，敏感性为11/19。在第三组中，由于特异性较差，免疫组织化学无法对淀粉样沉积物进行亚型分类。细胞周围模式倾向于提示AL型而非ATTR型淀粉样变性且血管沉积倾向于提示ATTR型。使用免疫组织化学可在诊断性心脏标本中可靠地对淀粉样沉积物进行亚型分类。伴侣蛋白的共沉积、淀粉样蛋白的分布及临床特征也有助于心脏淀粉样变性的亚型分类。
