title: Association between IgM response to IgG damaged by glyoxidation and disease activity in rheumatoid arthritis.
abstract: OBJECTIVE
  To determine the association of serum IgG advanced glycation endproducts (AGE) and IgM anti-IgG-AGE antibodies with clinical measurements of rheumatoid arthritis (RA) disease activity.
  
  
  METHODS
  The study group consisted of 62 patients with RA and 16 control patients with osteoarthritis. Patient derived variables included perceived disease activity (10 cm visual analog scale, VAS) and Health Assessment Questionnaire (HAQ) results. Clinical measures of RA activity consisted of tender and swollen joint counts and a physician evaluation of disease activity (by VAS) as well as history of nodules, bone erosions, Sjogren's syndrome, and vasculitis documented by chart review. Patient sera were evaluated for glucose, glycosylated hemoglobin, and presence of RF, IgG-AGE and IgM anti-IgG-AGE. The nitroblue tetrazolium colorimetric and aminophenyl boronic acid methods were used for measurement of IgG-AGE, along with an ELISA for measurement of IgM anti-IgG-AGE.
  
  
  RESULTS
  Significant correlations were found between the presence of IgM anti-IgG-AGE and clinical measurements of swollen joint count and physician VAS.
  
  
  CONCLUSIONS
  IgM anti-IgG-AGE appears to be associated with clinical measurements of RA activity and represents a new marker of more active disease in RA.
authors.affiliation: Department of Medicine, The McGill University Health Centre, and The Montreal General Hospital Research Institute, Quebec, Canada.
authors.forename: M D
authors.initials: MD
authors.lastname: Lucey
authors.forename: M M
authors.initials: MM
authors.lastname: Newkirk
authors.forename: C
authors.initials: C
authors.lastname: Neville
authors.forename: K
authors.initials: K
authors.lastname: Lepage
authors.forename: P R
authors.initials: PR
authors.lastname: Fortin
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000276:immunology* / Q000503:physiopathology; D001786:Blood Glucose / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D017127:Glycation End Products, Advanced / Q000097:blood / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology*; D007075:Immunoglobulin M / Q000097:blood / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000097:blood / Q000276:immunology / Q000503:physiopathology
chemical_list: D001786:Blood Glucose; D017127:Glycation End Products, Advanced; D007074:Immunoglobulin G; D007075:Immunoglobulin M