Department of Neurology, Tokyo Metropolitan Neurological Hospital, 2-6-1, Musashidai, Fuchu, Tokyo, 183-0042, Japan.
Department of Neurological Science, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan.
Neurol Sci. 2017 Dec;38(12):2165-2169. doi: 10.1007/s10072-017-3133-0. Epub 2017 Oct 4.
Previous case reports and studies have shown that anti-myelin-associated glycoprotein (MAG) antibody can be detected in patients with polyneuropathy without any detectable M-protein. Nevertheless, the frequency of and related factors have not yet been adequately investigated. The objectives of this study are to examine the prevalence of anti-MAG antibody in patients with demyelinating neuropathy without M-protein and to determine their clinical characteristics. From January, 2004, to September, 2016, consecutive patients with chronic demyelinating neuropathy were recruited. Anti-MAG antibody presence was tested at the first evaluation. We determined the prevalence of anti-MAG antibody without M-protein among included patients and evaluated the clinical characteristics. A total of 44 patients were included in the present study (12 women; median age at first visit 60 years [interquartile range 47-67 years]; median duration between onset and first visit 9 months [3-26 months]). M-protein was found in eight patients (18%) at the first evaluation. Anti-MAG antibody was present in 2 of remaining 36 (5.6 [95% confidence interval 0-13.0] %) patients without M-protein. Patients with anti-MAG antibody exhibited slowly progressive and distal dominant neuropathy with elevated serum IgM levels and refractory to immunotherapy. There were no differences in clinical features between patients having anti-MAG antibody without M-protein, and those with M-protein. One patient with the anti-MAG antibody showed a delayed appearance of M-protein during a 4-year follow-up after diagnosis. The prevalence of the anti-MAG antibody in chronic demyelinating neuropathy without any detectable M-protein was 5.6%. Anti-MAG antibody may be detectable earlier than M-protein.
先前的病例报告和研究表明，在没有任何可检测到 M 蛋白的多发性神经病患者中，可以检测到抗髓鞘相关糖蛋白（MAG）抗体。然而，其频率和相关因素尚未得到充分研究。本研究的目的是检查无 M 蛋白脱髓鞘神经病患者中抗 MAG 抗体的患病率，并确定其临床特征。从 2004 年 1 月至 2016 年 9 月，连续招募了患有慢性脱髓鞘神经病的患者。在首次评估时检测抗 MAG 抗体的存在。我们确定了纳入患者中无 M 蛋白的抗 MAG 抗体的患病率，并评估了其临床特征。本研究共纳入 44 例患者（12 例女性；首次就诊时的中位年龄为 60 岁[四分位距 47-67 岁]；发病至首次就诊的中位时间为 9 个月[3-26 个月]）。在首次评估时，8 例患者（18%）发现 M 蛋白。在其余 36 例（5.6[95%置信区间 0-13.0]%）无 M 蛋白的患者中，有 2 例存在抗 MAG 抗体。抗 MAG 抗体阳性患者表现为进展缓慢、以远端为主的神经病，血清 IgM 水平升高，对免疫治疗无反应。无 M 蛋白的抗 MAG 抗体患者与 M 蛋白患者在临床特征上无差异。在诊断后 4 年的随访中，1 例抗 MAG 抗体患者的 M 蛋白出现延迟。在无任何可检测到的 M 蛋白的慢性脱髓鞘神经病中，抗 MAG 抗体的患病率为 5.6%。抗 MAG 抗体可能比 M 蛋白更早出现。
