Vital C, Lagueny A, Mercie P, Viallard J-F, Delabrousse-Mayoux J-P, Vital A
Centre National de la Recherche Scientifique, Bordeaux Institute of Neurosciences, UMR 5227, Bordeaux, France.
Clin Neuropathol. 2010 Mar-Apr;29(2):59-64. doi: 10.5414/npp29059.
Most cases of familial amyloid polyneuropathy are identified by molecular genetic analysis of the transthyretin (TTR) gene. However, it is not uncommon to find unexpected amyloid deposits marked by the anti-TTR serum in the endoneurium of aged patients. Light chain amyloid deposits may also be found in the endoneurium. During these past 5 years, we studied the muscle and nerve biopsies from 6 patients which revealed amyloid deposits. There were 2 patients with an idiopathic polyneuropathy and 4 with monoclonal gammopathy (MG).
In each case, specimens from the superficial peroneal nerve and peroneus brevis muscle were taken by the same cutaneous incision.
Amyloid deposits were visible in the endoneurium of 2 cases and only on muscle specimens in 3 other cases, 1 with a MG and 2 with an idiopathic polyneuropathy. Amyloid deposits were strongly stained with the anti-TTR serum in the muscle specimens of the 2 idiopathic cases, mainly located in vessel walls. In one patient with polyneuropathy and MG, a small endoneurial amyloid deposit surprisingly revealed to be immunostained by the anti-TTR serum. In another case, a small amyloid deposit in close relationship with a macrophage was only visible in the endoneurium by electron microscopy.
Amyloid deposits were only visible on muscle fragments in 3 cases and were strongly marked by the anti-TTR serum in 2 of them, indicating their familial origin. Combining muscle and nerve biopsy raises the number of cases with visible amyloid deposits.
大多数家族性淀粉样多神经病病例是通过转甲状腺素蛋白（TTR）基因的分子遗传学分析来确诊的。然而，在老年患者的神经内膜中发现以抗TTR血清标记的意外淀粉样沉积物并不罕见。在神经内膜中也可能发现轻链淀粉样沉积物。在过去5年中，我们研究了6例患者的肌肉和神经活检，结果显示有淀粉样沉积物。其中2例为特发性多神经病患者，4例为单克隆丙种球蛋白病（MG）患者。
在每例患者中，通过相同的皮肤切口获取腓浅神经和腓骨短肌的标本。
2例患者的神经内膜可见淀粉样沉积物，另外3例仅在肌肉标本中可见，其中1例为MG患者，2例为特发性多神经病患者。在2例特发性病例的肌肉标本中，淀粉样沉积物被抗TTR血清强烈染色，主要位于血管壁。在1例患有多神经病和MG的患者中，一个小的神经内膜淀粉样沉积物令人惊讶地被抗TTR血清免疫染色。在另一例中，与巨噬细胞密切相关的一个小淀粉样沉积物仅在神经内膜的电子显微镜下可见。
3例患者仅在肌肉碎片上可见淀粉样沉积物，其中2例被抗TTR血清强烈标记，表明其家族性起源。联合肌肉和神经活检增加了可见淀粉样沉积物的病例数。
