Wilisch A, Schultz A, Greiner A, Kirchner T, Müller-Hermelink H K, Marx A
Institut für Pathologie, Universität Würzburg.
Verh Dtsch Ges Pathol. 1996;80:261-6.
Autoantibodies against striated muscle proteins, particularly titin, characteristically distinguish thymoma-associated from non-paraneoplastic myasthenia gravis (MG) patients. However, the stimulus for this autoimmunity remains enigmatic since whole titin is not detectable in these tumors. Since Neurofilaments (NF) contain titin epitopes, MG-associated thymomas were investigated for NF expression using immunohistochemistry and Western blotting.
In thymomas with cortical differentiation many of the neoplastic epithelial cells expressed medium molecular weight NF at the protein level. In sharp contrast, in medullary and mixed thymomas and in normal thymuses immunoreactivity with anti-NF antibodies was rare.
The overexpression of NFs with titin epitopes by neoplastic cells in an inappropriate cortical environment may be the basis for the autosensitization of developing T-cells against titin in MG-associated cortical type thymomas.
抗横纹肌蛋白，特别是肌联蛋白的自身抗体，是胸腺瘤相关重症肌无力（MG）患者区别于非副肿瘤性MG患者的特征性标志。然而，由于在这些肿瘤中无法检测到完整的肌联蛋白，这种自身免疫的刺激因素仍然成谜。由于神经丝（NF）含有肌联蛋白表位，因此采用免疫组织化学和蛋白质印迹法对MG相关胸腺瘤的NF表达情况进行了研究。
在具有皮质分化的胸腺瘤中，许多肿瘤上皮细胞在蛋白质水平表达中等分子量的NF。与之形成鲜明对比的是，在髓质型和混合型胸腺瘤以及正常胸腺中，抗NF抗体的免疫反应性很罕见。
在不适当的皮质环境中，肿瘤细胞过度表达具有肌联蛋白表位的NF，可能是MG相关皮质型胸腺瘤中发育中的T细胞针对肌联蛋白发生自身致敏的基础。
