Polyneuropathies associated with IgM monoclonal gammopathies

Arch Neurol. 1988 Dec;45(12):1355-9. doi: 10.1001/archneur.1988.00520360073015.


We studied ten patients with IgM monoclonal gammopathies. Five had M proteins that reacted with myelin-associated glycoprotein (MAG) and five had no recognizable antinerve activity. The neuropathy in the MAG-reactive patients was homogeneous by clinical and laboratory analysis, while the neuropathy in the MAG-nonreactive patients varied considerably. Both groups responded well to immunosuppressive therapy, which lowered the concentration of the serum M protein. The homogeneity of the MAG-reactive patients and their response to sustained lowering of the M protein levels support the concept that the IgM M protein directly damages nerve fibers and is the proximate cause of the polyneuropathy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Female
  • Humans
  • Immunoglobulin M* / analysis
  • Leukemia, Lymphocytic, Chronic, B-Cell / complications
  • Male
  • Middle Aged
  • Myelin Proteins / immunology
  • Myelin-Associated Glycoprotein
  • Paraproteinemias / complications*
  • Paraproteinemias / physiopathology
  • Paraproteinemias / therapy
  • Peripheral Nervous System Diseases / complications*
  • Peripheral Nervous System Diseases / physiopathology
  • Peripheral Nervous System Diseases / therapy


  • Immunoglobulin M
  • Myelin Proteins
  • Myelin-Associated Glycoprotein