title: Characterization of monoclonal gammopathy in patients with amyotrophic lateral sclerosis.
abstract: BACKGROUND
  Recently, new guidelines for the monitoring and the risk evaluation of monoclonal gammopathy with undetermined significance (MGUS) became available and the light chain MGUS subtype was defined.
  
  
  OBJECTIVE
  To characterize the type, risk and diagnostic implications of MGUS in patients with amyotrophic lateral sclerosis.
  
  
  METHODS
  We screened 97 consecutive patients with ALS and 97 age- and gender-matched controls for MGUS by serum electrophoresis and immunofixation and compared the characteristics of MGUS with population-based data.
  
  
  RESULTS
  MGUS was identified in 8.2% of ALS patients and 6.2% of controls (mean age: 62.5 years both). Seven of eight ALS patients with MGUS had 'low-risk MGUS'. M-protein was moderately increased in one ALS patient. The immunoglobulin distribution in ALS patients with MGUS was IgG kappa (n = 2), IgM lambda (n = 1) and light chains of lambda type (n = 3). No differences in demographic and clinical parameters were found between patients with and without MGUS.
  
  
  CONCLUSIONS
  The percentage of patients with MGUS is increased in ALS, but the immunoglobulin distribution is similar to that reported in the general population. MGUS in ALS mostly represents 'low-risk MGUS'; therefore, unnecessary diagnostic procedures should be avoided in ALS patients.
authors: Department of Internal Medicine IV, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany.
authors: H-H
authors: HH
authors: Wolf
authors: Department of Neurology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany.
authors: A
authors: A
authors: Posa
authors: Department of Neurology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany.
authors: S
authors: S
authors: Panitz
authors: Department of Neurology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany.
authors: M
authors: M
authors: Kornhuber
authors: Department of Neurology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany.
authors: F
authors: F
authors: Hanisch
mesh_terms: D000328:Adult; D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000150:complications*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008998:Monoclonal Gammopathy of Undetermined Significance / Q000453:epidemiology*
keywords: amyotrophic lateral sclerosis; light chain MGUS; low-risk MGUS; monoclonal gammopathy; motor neurone disease