title: Anti-alpha-glucose-based glycan IgM antibodies predict relapse activity in multiple sclerosis after the first neurological event.
abstract: BACKGROUND
  There is no specific serum-based biomarker for the diagnosis or prognosis of relapsing-remitting multiple sclerosis (RRMS).
  
  
  OBJECTIVE
  We investigated whether levels of IgM antibodies to Glc(alpha1,4)Glc(alpha) (GAGA4) or to a panel of four glucose-based glycans could differentiate MS from other neurological diseases (OND) or predict risk of early relapse following first presentation (FP) of RRMS.
  
  
  METHODS
  Retrospective analysis of 440 sera samples of three cohorts: A) FP-RRMS (n = 44), OND (n = 44); B) FP-RRMS (n = 167), OND (n = 85); and C) FP (n = 100). Anti-GAGA4 IgM levels were measured by enzyme immunoassay in cohort-A and cohort-B. Cohort-C IgM antibodies to glucose-based glycan panel were measured by immunofluorescence.
  
  
  RESULTS
  FP-RRMS had higher levels of anti-GAGA4 IgM than OND patients (cohort-A, P = 0.01; cohort-B, P = 0.0001). Sensitivity and specificity were 27% and 97% for cohort-A; and 26% and 90% for cohort-B, respectively. In cohort-C, 58 patients experienced early relapse (<24 months), 31 had late relapse (> or =24 months), and 11 did not experience second attack during follow-up. Kaplan-Meier curves demonstrated decrease in time to next relapse for patients positive for the antibody panel (P = 0.02, log rank).
  
  
  CONCLUSIONS
  Serum anti-GAGA4 IgM discerns FP-RRMS patients from OND patients. Higher levels of serum anti-alpha-glucose IgM in FP patients predict imminent early relapse.
authors.affiliation: University of Ottawa, The Ottawa Hospital-General Campus, 501 Smyth Road, Ottawa, Ontario, Canada K1H 8L6. mfreedman@ottawahospital.on.ca
authors.forename: M S
authors.initials: MS
authors.lastname: Freedman
authors.forename: J
authors.initials: J
authors.lastname: Laks
authors.forename: N
authors.initials: N
authors.lastname: Dotan
authors.forename: R T
authors.initials: RT
authors.lastname: Altstock
authors.forename: A
authors.initials: A
authors.lastname: Dukler
authors.forename: C J M
authors.initials: CJ
authors.lastname: Sindic