Suarez G A, Kelly J J
Department of Neurology, Tufts-New England Medical Center, Boston, MA.
Neurology. 1993 Jul;43(7):1304-8. doi: 10.1212/wnl.43.7.1304.
We evaluated the clinical characteristics and electromyographic features of 39 patients with monoclonal gammopathy of undetermined significance (MGUS) and neuropathy. Twenty-three patients had a monoclonal IgM protein, 13 had an IgG, and three had an IgA. In 15 patients of the IgM group, the M protein reacted with myelin-associated glycoprotein (MAG). Comparing IgM-MGUS and IgG-MGUS neuropathies, we found the following differences: (1) There was a statistically significant higher frequency of sensory loss in the IgM group. (2) Nine attributes of nerve conduction abnormality were statistically worse in the IgM group, with slowing of conduction velocities and prolonged distal latencies. (3) The frequency of monoclonal IgM was overrepresented in the MGUS neuropathy group. In general, the clinical and electrophysiologic features of the IgM-MGUS MAG-reactive group were not significantly different than the MAG-nonreactive group. Our cases are similar to those previously reported and suggest that monoclonal IgM-MGUS should be separated conceptually from monoclonal IgG neuropathies.
我们评估了39例意义未明的单克隆丙种球蛋白病（MGUS）合并神经病变患者的临床特征和肌电图特征。23例患者有单克隆IgM蛋白，13例有IgG，3例有IgA。在IgM组的15例患者中，M蛋白与髓鞘相关糖蛋白（MAG）发生反应。比较IgM-MGUS和IgG-MGUS神经病变，我们发现以下差异：（1）IgM组感觉丧失的频率在统计学上显著更高。（2）IgM组神经传导异常的九个指标在统计学上更差，包括传导速度减慢和远端潜伏期延长。（3）单克隆IgM在MGUS神经病变组中的频率过高。总体而言，IgM-MGUS MAG反应组的临床和电生理特征与MAG无反应组无显著差异。我们的病例与先前报道的病例相似，提示单克隆IgM-MGUS应在概念上与单克隆IgG神经病变区分开来。
