Moorhouse D F, Fox R I, Powell H C
Department of Pathology (Neuropathology), University of California, San Diego.
Acta Neuropathol. 1992;84(5):484-94. doi: 10.1007/BF00304467.
An 85-year-old man with a 2-year history of progressive lower limb weakness and paresthesia was found to have an IgG kappa monoclonal gammopathy of undetermined significance (mgus). Clinical and electrophysiological studies revealed a severe distal bilateral symmetrical polyneuropathy. A sural nerve biopsy showed extensive nerve fibre loss with the deposition of large amounts of amorphous material throughout the endoneurium. Electron microscopy showed the deposits to be composed of microtubular structures which were located diffusely throughout the endoneurium. The deposits were also located within the lumina of the vasa nervorum, some of which were undergoing disintegration and rupture with release of the proteinaceous material into the endoneurium. The regions of the nerve in which they appeared most numerous showed more severe nerve fibre damage than other areas. These microtubular structures were also observed in disintegrating vessels and adjacent endoneurium. On immunohistochemistry they stained with antibody to IgG. Identical deposits were found in the dermis in which there was a leucocytoclastic vasculitis. Located in linear arrays within the axons of myelinated and unmyelinated fibres were highly organised tubular structures resembling immunotactoids. Identification of immunotactoid-like structures within the nerve is unique and may be another mechanism by which monoclonal proteins can induce nerve fibre injury.
一名85岁男性，有2年进行性下肢无力和感觉异常病史，被发现患有意义未明的IgG κ单克隆丙种球蛋白病（MGUS）。临床和电生理研究显示为严重的双侧远端对称性多发性神经病。腓肠神经活检显示广泛的神经纤维丢失，大量无定形物质沉积于整个神经内膜。电子显微镜显示沉积物由微管结构组成，这些结构弥漫分布于整个神经内膜。沉积物也位于神经血管腔隙内，其中一些正在崩解和破裂，蛋白质物质释放到神经内膜中。沉积物出现最多的神经区域比其他区域显示出更严重的神经纤维损伤。在崩解的血管和相邻的神经内膜中也观察到这些微管结构。免疫组织化学显示它们与IgG抗体染色。在真皮中发现了相同的沉积物，其中存在白细胞破碎性血管炎。在有髓和无髓纤维的轴突内呈线性排列的是高度组织化的管状结构，类似于免疫触须样结构。在神经内鉴定出免疫触须样结构是独特的，可能是单克隆蛋白诱导神经纤维损伤的另一种机制。
