Kühl U, Noutsias M, Schultheiss H P
Benjamin Franklin Department of Cardiology, University of Berlin. Germany.
Eur Heart J. 1995 Dec;16 Suppl O:100-6. doi: 10.1093/eurheartj/16.suppl_o.100.
The aetiology of dilated cardiomyopathy is unknown by definition. Viral myocarditis is often viewed as an early stage in the progression of the disease leading to cardiomyopathy and heart failure in humans. The chronic inflammatory process is manifested histologically as a sparse, diffuse lymphocytic infiltration of the myocardium, classified as borderline or ongoing myocarditis according to the Dallas classification. Because of limitations of light microscopy, chronic myocarditis remains an enigmatic condition to diagnose and to treat. In contrast to routine histological staining procedures, immunohistochemical methods enable better identification and quantification of infiltrating cells and also provide further evidence that the activated immunological process within the myocardium is ongoing. In 176 patients with clinically suspected dilated cardiomyopathy, borderline myocarditis was diagnosed in only 14 cases (8%) histologically. However, using immunohistological analysis of endomyocardial biopsies, pathologically increased lymphocytic infiltration was revealed in 67 biopsy specimens (38%), and activated lymphocytes or activated macrophages in all analysed inflamed cardiac tissues. All positive biopsies showed an activated vascular endothelium, demonstrated by the enhanced expression of different adhesion molecules. Various cytokines were locally released from activated inflammatory cells. This may cause a cytokine-rich micro-environment which could be responsible for the enhanced expression of adhesion molecules and thereby contribute to the inflammatory traffic of immune cells into inflamed myocardial areas. These observations underline the hypothesis that the immune process is still active in a group of patients with clinically suspected dilated cardiomyopathy, causing progression of the disease.
根据定义，扩张型心肌病的病因尚不清楚。病毒性心肌炎通常被视为导致人类心肌病和心力衰竭疾病进展的早期阶段。慢性炎症过程在组织学上表现为心肌稀疏、弥漫性淋巴细胞浸润，根据达拉斯分类法可归类为临界性或持续性心肌炎。由于光学显微镜的局限性，慢性心肌炎仍然是一种难以诊断和治疗的疾病。与常规组织学染色程序不同，免疫组织化学方法能够更好地识别和定量浸润细胞，还能进一步证明心肌内激活的免疫过程仍在进行。在176例临床疑似扩张型心肌病患者中，经组织学检查仅14例（8%）诊断为临界性心肌炎。然而，通过对心内膜活检进行免疫组织学分析，在67份活检标本（38%）中发现病理性淋巴细胞浸润增加，并且在所有分析的炎症心肌组织中均发现激活的淋巴细胞或激活的巨噬细胞。所有阳性活检均显示血管内皮激活，表现为不同黏附分子的表达增强。各种细胞因子从激活的炎症细胞中局部释放。这可能导致富含细胞因子的微环境，这可能是黏附分子表达增强的原因，从而有助于免疫细胞向炎症心肌区域的炎性迁移。这些观察结果强调了这样一种假设，即免疫过程在一组临床疑似扩张型心肌病患者中仍然活跃，导致疾病进展。
