Arbustini E, Merlini G, Gavazzi A, Grasso M, Diegoli M, Fasani R, Bellotti V, Marinone G, Morbini P, Dal Bello B
Department of Pathology, Istituto de Ricovero e Cura a Carattere Scientifico (IRCCS), Policlinico San Matteô-Universita de Pavia, Italy.
Am Heart J. 1995 Sep;130(3 Pt 1):528-36. doi: 10.1016/0002-8703(95)90362-3.
The objective of this study was to investigate the spectrum of morphologic features in myocardial biopsy specimens from patients with cardiac immunocyte-derived (AL) amyloidosis. Cardiac involvement is the most important predictor of survival in AL amyloidosis. Myocardial biopsy remains the method of choice for diagnosing cardiac amyloidosis when noninvasive studies give equivocal results. Histologic, immunohistochemical, ultrastructural, and morphometric studies were made on myocardial biopsy specimens from 11 patients in whom the diagnosis of AL amyloidosis was based on the demonstration of a monoclonal immunoglobulinopathy and of amyloid deposits in tissues. Histopathologic study showed amyloid in 10 of the 11 biopsies. In one biopsy (Congo red negative), the diagnosis was made by ultrastructural identification of amyloid fibrils. In all patients, the deposits formed perimyocytic layers that measured up to 18 microns in thickness. These layers formed along the basement membranes, which were partially preserved in 5 patients and unrecognizable in 6. Interstitial nodular deposits were also present in 5 patients. Immunohistochemical studies for the characterization of the proteins in the amyloid deposits were diagnostic in 1 patient and confirmatory in 10. Nodular deposits, thick perimyocytic layers of amyloid and small myocyte diameters were associated with shorter survival of the patients. Small-vessel involvement and myofilament loss occurred in all patients. In conclusion, myocardial biopsy serves to (1) establish the diagnosis of cardiac amyloidosis; (2) characterize immunohistochemically the proteins in the amyloid fibrils and (3) assess the degree of myocyte damage and atrophy.
本研究的目的是调查心脏免疫细胞衍生（AL）淀粉样变性患者心肌活检标本的形态学特征谱。心脏受累是AL淀粉样变性患者生存的最重要预测指标。当无创检查结果不明确时，心肌活检仍是诊断心脏淀粉样变性的首选方法。对11例患者的心肌活检标本进行了组织学、免疫组织化学、超微结构和形态计量学研究，这些患者的AL淀粉样变性诊断基于单克隆免疫球蛋白病的证实和组织中淀粉样沉积物的发现。组织病理学研究显示，11例活检中有10例存在淀粉样物质。在1例活检（刚果红阴性）中，通过淀粉样原纤维的超微结构鉴定做出诊断。在所有患者中，沉积物形成了厚度达18微米的心肌细胞周围层。这些层沿着基底膜形成，5例患者的基底膜部分保留，6例患者的基底膜无法识别。5例患者还存在间质结节状沉积物。对淀粉样沉积物中蛋白质进行表征的免疫组织化学研究对1例患者具有诊断意义，对10例患者具有确认意义。结节状沉积物、厚的心肌细胞周围淀粉样层和小的心肌细胞直径与患者较短的生存期相关。所有患者均出现小血管受累和肌丝丢失。总之，心肌活检有助于（1）确立心脏淀粉样变性的诊断；（2）通过免疫组织化学表征淀粉样原纤维中的蛋白质；（3）评估心肌细胞损伤和萎缩的程度。
