Clinical and laboratory features of anti-MAG neuropathy without monoclonal gammopathy

Sci Rep. 2019 Apr 16;9(1):6155. doi: 10.1038/s41598-019-42545-8.


Antibodies against myelin-associated glycoprotein (MAG) almost invariably appear in the context of an IgM monoclonal gammopathy associated neuropathy. Very few cases of anti-MAG neuropathy lacking IgM-monoclonal gammopathy have been reported. We investigated the presence of anti-MAG antibodies in 69 patients fulfilling diagnostic criteria for CIDP. Anti-MAG antibodies were tested by ELISA and confirmed by immunohistochemistry. We identified four (5.8%) anti-MAG positive patients without detectable IgM-monoclonal gammopathy. In two of them, IgM-monoclonal gammopathy was detected at 3 and 4-year follow-up coinciding with an increase in anti-MAG antibodies titers. In conclusion, anti-MAG antibody testing should be considered in chronic demyelinating neuropathies, even if IgM-monoclonal gammopathy is not detectable.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Autoantibodies / immunology*
  • Female
  • Humans
  • Immunoglobulin M / immunology*
  • Male
  • Middle Aged
  • Myelin-Associated Glycoprotein / immunology*
  • Paraproteinemias / diagnosis
  • Paraproteinemias / immunology*
  • Polyradiculoneuropathy, Chronic Inflammatory Demyelinating / diagnosis
  • Polyradiculoneuropathy, Chronic Inflammatory Demyelinating / immunology*


  • Autoantibodies
  • Immunoglobulin M
  • MAG protein, human
  • Myelin-Associated Glycoprotein