title: Comparison of monoclonal gammopathy of undetermined significance-associated neuropathy and chronic inflammatory demyelinating polyneuropathy patients.
abstract: OBJECTIVE
  There are varying reports on whether monoclonal gammopathy of undetermined significance-associated neuropathy (MGUSN) patients are distinguishable from those with chronic inflammatory demyelinating polyneuropathy (CIDP) and whether specific MGUSN subclasses are associated with specific clinical phenotypes.
  
  
  METHODS
  We performed a retrospective chart review of MGUSN (n = 56) and CIDP (n = 67) patients. Data extracted included: demographics, neurological examination, and nerve conduction studies (NCS) at baseline and last visit. Clinical status was rated as 0 = worse, 1 = unchanged, 2 = stabilized after a declining course, or 3 = improved. The electrophysiology data were rated as 0 = worse, 1 = stable, or 2 = improved. Statistical analyses were performed using JMP (version 9.0.2 for Macintosh, from SAS).
  
  
  RESULTS
  Seventy percent were males, aged 68.1 ± 12.6 years with neuropathy for 9.8 ± 6.8 years and follow-up of 4.0 ± 3.2 years. CIDP patients had more severe neuropathy, and were more likely to receive treatment and to respond. The clinical neuropathy status remained unchanged in 52.8 % of the MGUSN and 24.2 % of the CIDP patients, and stabilized in 7.6 % of MGUSN and 30.3 % of CIDP patients. IgM-MGUSN patients did not differ from other immunoglobulin subclasses in response to treatment. The clinical severity and the number of abnormal NCS parameters were greater in the demyelinating MGUSN in comparison to the axonal group.
  
  
  CONCLUSIONS
  MGUSN patients have less severe neuropathy than CIDP patients, but among the MGUSN patients the severity is greater in the demyelinating and the IgM groups. MGUSN patients may do well without treatment and exposure to potential adverse effects.
authors.affiliation: Department of Medicine (Neurology), King Saud University, Riyadh, Saudi Arabia.
authors.forename: Nuha M
authors.initials: NM
authors.lastname: Alkhawajah
authors.forename: Samantha K
authors.initials: SK
authors.lastname: Dunnigan
authors.forename: Vera
authors.initials: V
authors.lastname: Bril
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood; D008297:Male; D008875:Middle Aged; D008998:Monoclonal Gammopathy of Undetermined Significance / Q000175:diagnosis*; D009431:Neural Conduction; D009460:Neurologic Examination; D020277:Polyradiculoneuropathy, Chronic Inflammatory Demyelinating / Q000175:diagnosis*; D012189:Retrospective Studies
chemical_list: D007075:Immunoglobulin M