Department of Pathology and Laboratory Medicine, University of Florida, Box 100275, 1600 SW Archer Rd, Gainesville, FL 32610-0275, USA.
Arch Pathol Lab Med. 2010 Feb;134(2):256-63. doi: 10.5858/134.2.256.
Full activation and involvement of the complement pathway follows acute myocardial infarction. Complement fragment C4d is a stable, covalently bound marker of complement activation. Troponin T is specific for cardiomyocytes.
To determine the specificity of C4d, C9, and troponin T immunoreactivity in necrotic myocytes and to establish whether they can be used to delineate acute myocardial infarction.
Twenty-six autopsy cases with a total of 54 myocardium areas of infarction were reviewed retrospectively. Immunohistochemistry for C4d, C9, and troponin T was used on paraffin sections of formalin-fixed tissue. Controls consisted of 5 cases without evidence of infarction, and histologically normal myocardium functioned as an internal control.
C4d and C9 antibodies reacted strongly and diffusely with necrotic myocytes in all samples of infarctions for up to 2 days (19 of 19; 100%). Adjacent histologically normal myocytes were nonreactive, resulting in a clear delineation between damaged and viable myocardium. Reactivity declined with increased duration and was absent in scars. Troponin T showed loss of staining in preinflammatory lesions (8 of 13; 62%); however, nonspecific patchy loss of staining was present in negative controls and in viable myocardium. Immunostains provided new diagnoses in 2 cases, including evidence of reinfarction and a newly diagnosed acute myocardial infarction.
C4d and C9 have comparable reactivity and specificity for necrotic myocytes. C4d and C9 staining of necrotic myocytes is apparent before the influx of inflammatory cells, demonstrating utility in early myocardial infarction. Patchy loss of Troponin T in some cases of histologically normal myocardium limited its usefulness as a sole marker of infarction.
补体途径在急性心肌梗死后完全激活和参与。补体片段 C4d 是补体激活的稳定、共价结合标志物。肌钙蛋白 T 是心肌细胞的特异性标志物。
确定 C4d、C9 和肌钙蛋白 T 在坏死心肌细胞中的特异性，并确定它们是否可用于描绘急性心肌梗死。
回顾性分析了 26 例尸检病例，共 54 个心肌梗死区。使用石蜡切片对福尔马林固定组织进行 C4d、C9 和肌钙蛋白 T 的免疫组织化学染色。对照组包括 5 例无梗死证据的病例，组织学正常的心肌作为内部对照。
C4d 和 C9 抗体在所有梗死样本中均强烈且弥漫地与坏死心肌细胞反应，直至 2 天（19/19；100%）。相邻组织学正常的心肌细胞无反应，从而清晰地区分受损和存活的心肌。随着时间的延长，反应性下降，瘢痕中无反应。肌钙蛋白 T 在炎症前病变中出现染色丢失（13/19；68%）；然而，在阴性对照和存活心肌中存在非特异性斑片状染色丢失。免疫染色在 2 例中提供了新的诊断，包括再梗死和新诊断的急性心肌梗死的证据。
C4d 和 C9 对坏死心肌细胞具有相似的反应性和特异性。在炎症细胞浸润之前，坏死心肌细胞的 C4d 和 C9 染色明显，表明在早期心肌梗死后具有实用性。在一些组织学正常的心肌中，肌钙蛋白 T 的斑片状丢失限制了其作为梗死唯一标志物的用途。
