Chronic demyelinating neuropathy with anti-myelin-associated glycoprotein antibody without any detectable M-protein
- 213 Downloads
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.
KeywordsMyelin-associated glycoprotein Anti-MAG antibody Chronic inflammatory demyelinating polyradiculoneuropathy M-protein
Compliance with ethical standards
This study was approved by the institutional ethics committee.
Conflict of interest
The authors declare that they have no conflict of interest.
- 1.Ellie E, Vital A, Steck A, Boiron JM, Vital C, Julien J (1996) Neuropathy associated with “benign” anti-myelin-associated glycoprotein IgM gammopathy: clinical, immunological, neurophysiological pathological findings and response to treatment in 33 cases. J Neurol 243:34–43CrossRefPubMedGoogle Scholar
- 3.Lunn MP, Nobile-Orazio E (2012) Immunotherapy for IgM anti-myelin-associated glycoprotein paraprotein-associated peripheral neuropathies. Cochrane Database Syst Rev:CD002827Google Scholar
- 5.European Federation of Neurological Societies/Peripheral Nerve Society Guideline on management of paraproteinemic demyelinating neuropathies (2010) Report of a Joint Task Force of the European Federation of Neurological Societies and the Peripheral Nerve Society—first revision. J Peripher Nerv Syst 15:185–195CrossRefGoogle Scholar