质谱分析显示非突变载脂蛋白 A1 腰骶神经根丛淀粉样变瘤。
Mass spectrometry analysis reveals non-mutated apolipoprotein A1 lumbosacral radiculoplexus amyloidoma.
机构信息
Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905, USA.
出版信息
Muscle Nerve. 2012 Nov;46(5):817-22. doi: 10.1002/mus.23415.
INTRODUCTION
In rare instances, amyloidosis presents as a focal, macroscopic lesion involving peripheral neural tissues (amyloidoma). In all known reported cases, peripheral nerve amyloidomas have had immunoglobulin light-chain fibril composition and occurred in the context of paraproteinemia.
METHODS
A 46-year-old man presented with progressive insidious-onset right lumbosacral radiculoplexus neuropathy without paraproteinemia. MRI-targeted fascicular nerve biopsy was performed on an enlarged sciatic nerve after earlier distal fibular nerve biopsy was nondiagnostic. Laser dissected mass spectroscopy of the discovered amyloid protein was performed after immunohistochemistry failed to identify the specific amyloid protein. Complete gene sequencing of apolipoprotein A1 (ApoA1) was performed.
RESULTS
Only wild-type ApoA1 amyloid was found in the congophilic component in the nerve.
CONCLUSIONS
This case highlights the utility of MRI-guided fascicular nerve biopsy combined with laser-dissected mass spectrometric analysis. Importantly, the case expands the known causes of amyloidomas to include wild-type ApoA1.
简介
在极少数情况下，淀粉样变性表现为涉及周围神经组织（淀粉样瘤）的局灶性、大体积病变。在所有已知的报告病例中，周围神经淀粉样瘤具有免疫球蛋白轻链原纤维组成，并发生在副蛋白血症的背景下。
方法
一名 46 岁男性出现进行性隐匿性右侧腰骶神经根丛神经病，无副蛋白血症。在先前的腓骨神经活检无诊断意义后，对增大的坐骨神经进行 MRI 靶向束状神经活检。免疫组化未能鉴定出特定的淀粉样蛋白后，对发现的淀粉样蛋白进行激光解析质谱分析。载脂蛋白 A1（ApoA1）的完整基因测序。
结果
在神经中的亲刚果红成分中仅发现野生型 ApoA1 淀粉样蛋白。
结论
本病例强调了 MRI 引导的束状神经活检结合激光解析质谱分析的实用性。重要的是，该病例将淀粉样瘤的已知病因扩展到包括野生型 ApoA1。
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