Garces-Sanchez Mercedes, Dyck Peter J, Kyle Robert A, Zeldenrust Steven, Wu Yanhong, Ladha Shafeeq S, Klein Christopher J
Peripheral Nerve Research Laboratory, Mayo Clinic, Rochester, MN 55905, USA.
Muscle Nerve. 2008 Apr;37(4):490-5. doi: 10.1002/mus.20955.
We have examined whether antibodies to myelin-associated glycoprotein (anti-MAG) influence neuropathy occurrence and phenotype in primary (AL IgM) amyloidosis. Anti-MAG and the cross-reacted sulfoglucuronyl paragloboside antibodies (SGPG) were studied in 46 patients with IgM amyloidosis (21 with polyneuropathy), and 21 matched IgM MGUS (monoclonal gammopathies of undetermined significance) controls without neuropathy. We assessed the occurrence, phenotype of neuropathy, and attributes of nerve conduction and their relation to antibody activity. Twenty of 46 patients with IgM amyloidosis (7 with and 13 without polyneuropathy) had elevation of anti-MAG or SGPG by enzyme-linked immunosorbent assay (ELISA). Two of the polyneuropathy patients with IgM amyloidosis had antibodies to MAG based on Western blot (WB) positivity. One of these patients, with the highest anti-MAG titer, had a painful sensory ataxia, with prominent demyelination, and amyloid deposition in sural nerve. The other anti-MAG WB-positive amyloid patient had an axonal neuropathy and dysautonomia. Low levels of anti-MAG antibodies were found in 12 of 21 IgM MGUS controls without neuropathy (mean follow-up, 11 years). We conclude that finding serum anti-MAG antibodies does not exclude the diagnosis of primary amyloidosis. They do not appear to affect the occurrence or expression of polyneuropathy, except possibly in occasional cases with WB positivity.
我们研究了抗髓鞘相关糖蛋白抗体（抗-MAG）是否会影响原发性（AL IgM）淀粉样变性中神经病变的发生和表型。对46例IgM淀粉样变性患者（21例患有多发性神经病）和21例匹配的无神经病的IgM意义未明的单克隆丙种球蛋白病（MGUS）对照进行了抗-MAG和交叉反应的磺基葡糖醛酸副球蛋白抗体（SGPG）研究。我们评估了神经病变的发生、表型、神经传导特性及其与抗体活性的关系。46例IgM淀粉样变性患者中有20例（7例患有和13例未患有多发性神经病）通过酶联免疫吸附测定（ELISA）检测出抗-MAG或SGPG升高。基于蛋白质印迹（WB）阳性，2例IgM淀粉样变性的多发性神经病患者有抗MAG抗体。其中1例抗-MAG滴度最高的患者患有疼痛性感觉性共济失调，有明显的脱髓鞘，腓肠神经有淀粉样沉积。另1例WB阳性的淀粉样变性抗-MAG患者患有轴索性神经病和自主神经功能障碍。21例无神经病的IgM MGUS对照中有12例发现抗-MAG抗体水平较低（平均随访11年）。我们得出结论，血清中发现抗-MAG抗体并不能排除原发性淀粉样变性诊断。它们似乎不影响多发性神经病的发生或表现，可能除了偶尔WB阳性的病例。
