Are Neurological Complications of Monoclonal Gammopathy of Undetermined Significance Underestimated?

Oncotarget. 2017 Jan 17;8(3):5081-5091. doi: 10.18632/oncotarget.13861.

Abstract

Objectives: Monoclonal gammopathy of undetermined significance (MGUS) is a premalignancy preceding multiple myeloma (MM) or related disorders. Neurological symptoms caused by the monoclonal immunoglobulins or free light-chains are often associated with a high morbidity. We analyzed the prevalence of neuropathy, clinical features and the long-term outcome in 223 patients (pts.) with MGUS.

Patients and methods: Between 1/2005 and 3/2015, 223 adult pts. with MGUS were identified in our database.

Results: In36/223 pts. (16%) a neuropathy was diagnosed (MGUS associated neuropathy, MGUS-N). 20 pts. (55%) had a distal symmetric axonal neuropathy, 10 pts. (28%) had a chronic inflammatory demyelinating polyneuropathy and 6 pts (17%) a distal acquired demyelinating symmetric polyneuropathy. In MGUS-NN (without neuropathy) and in MGUS-N, progression to smoldering MM, MM or Waldenstrom's macroglobulinemia (WM) occurred in 17% of the pts. The Immunoglobulin subtype was predominantly IgG in MGUS-NN and IgM in MGUS-N and ≥5.5% plasma cells in the bone-marrow predicted progression to MM and AL-amyloidosis in MGUS-NN and to WM in MGUS-N (p<0.05).

Conclusion: Due to the substantial prevalence of neuropathies, MGUS pts. should be monitored carefully and referred to a specialized center if neurological symptoms occur.

Keywords: MGUS; MGUS associated neuropathy; monoclonal gammopathy of undetermined significance; multiple myeloma.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Disease Progression
  • Female
  • Humans
  • Immunoglobulin G / metabolism
  • Immunoglobulin M / metabolism
  • Male
  • Middle Aged
  • Monoclonal Gammopathy of Undetermined Significance / complications*
  • Monoclonal Gammopathy of Undetermined Significance / immunology
  • Nervous System Diseases / classification*
  • Nervous System Diseases / epidemiology*
  • Nervous System Diseases / immunology
  • Prevalence
  • Retrospective Studies
  • Survival Analysis

Substances

  • Immunoglobulin G
  • Immunoglobulin M