冠状动脉斑块中炎性细胞和平滑肌细胞的定量及其与斑块稳定性的关系

Morphometric study of inflammatory cells and smooth muscle cells in coronary plaques and their relation with plaque stability

目的 探讨稳定及不稳定斑块中巨噬细胞、Ｔ淋巴细胞及平滑肌细胞数量的差异及其与斑块稳定性的关系。方法 将急性心肌梗死死亡病例的尸检冠状动脉完整剥离后固定、脱钙、连续取材并常规切片及ＨＥ染色，按有无脂质中心及其大小将斑块分为稳定斑块（ 斑块无或仅有较小的脂质中心） 及不稳定斑块（ 脂质中心超过斑块的４０ ％ ）。选取２ 种斑块各１６３ 个，用ＣＤ６８ 、肌动蛋白、ＵＣＨＬ－ １ 抗体分别对巨噬细胞、平滑肌细胞、Ｔ淋巴细胞进行免疫组化染色，并通过计算机图像分析系统对２ 种斑块纤维帽中的３ 种细胞进行定量。结果 不稳定斑块纤维帽中巨噬细胞及Ｔ淋巴细胞的面积百分比分别为８９．６％ 和３２．５％ ，稳定斑块分别为１８．３％ 和７．２ ％ ，差异均具有显著性（ Ｐ＜０．０１） 。而平滑肌细胞在稳定斑块纤维帽中的面积百分比明显大于不稳定斑块，分别为６８．４ ％ 和２１ ．８％ ，差异具有显著性（Ｐ＜ ０．０５） 。结论 稳定斑块与不稳定斑块不仅脂质中心大小不同，其纤维帽中炎细胞和平滑肌细胞的数量也不同，粥样坏死中心越大，其表面纤维帽中的巨噬细胞、Ｔ淋巴细胞就越多，而平滑肌细胞则越少。脂质中心大小和纤维帽中炎细胞数量是决定斑块稳定性的主要因素。

Objective To compare the content of inflammatory cells and smooth muscle cells in stable and unstable coronary plaques in order to clarify the role of these cells in the vulnerability of plaques. Methods Hearts from 12 postmortem acute myocardial infarction cases were studied. The epicardial coronary arteries were dissected en bloc, fixed, decalcified, cut at 4 mm intervals and routinely processed for HE sections. 163 stable plaques (with no or only little lipid core) and 163 unstable plaques (with lipid core size >40% of plaque area) were studied immunohistochemically using monoclonal antibodies specific for macrophages (CD68), T lymphocytes (UCHL 1) and smooth muscle cells (actin). Computor aided planimetry was used to measure the positive area of different cells. Results The content of macrophage and T lymphocytes in unstable plaques were significantly higher than that in stable plaques ( P <0.05). Conclusions Stable plaques and unstable plaques not only had different lipid core size but also had different inflammatory cell and smooth muscle cell content. The larger the lipid core and the more macrophages and T lymphocytes in the fibrous cap, the more unstable the plaque. The lipid core and inflammatory cells (including macrophages and T lymphocytes) are the two major determinants of the vulnerability of coronary plaques.