title: A longitudinal study of GAD65 and ICA512 autoantibodies during the progression to type 1 diabetes in Diabetes Prevention Trial-Type 1 (DPT-1) participants.
abstract: OBJECTIVE
  We examined changes in GAD65 and ICA-512 autoantibodies (GADA and IA-2A) during progression to type 1 diabetes (T1D).
  
  
  METHODS
  Diabetes Prevention Trial-Type 1 (DPT-1) participants were assessed for changes in positivity and titers of GADA and IA-2A during the progression to T1D.
  
  
  RESULTS
  Among 99 progressors to T1D with GADA and IA-2A measurements at baseline and diagnosis (mean interval = 3.3 ± 1.5 years), GADA positivity changed little and GADA titers decreased (P < 0.01). In contrast, both IA-2A positivity and titers increased substantially (P < 0.001). Even among those positive at baseline, IA-2A titers increased from baseline to diagnosis (n = 57; P < 0.001), whereas GADA titers decreased (n = 80; P < 0.01). The same patterns of change were also evident among those positive for both autoantibodies (n = 48) at baseline.
  
  
  CONCLUSIONS
  IA-2A titers increase during the years before the diagnosis of T1D, even among those positive for IA-2A. In contrast, GADA titers tend to decline during those years.
authors.affiliation: ivision of Endocrinology, University of Miami, Miami, Florida, USA. jsosenko@med.miami.edu
authors.forename: Jay M
authors.initials: JM
authors.lastname: Sosenko
authors.forename: Jay S
authors.initials: JS
authors.lastname: Skyler
authors.forename: Jerry P
authors.initials: JP
authors.lastname: Palmer
authors.forename: Jeffrey P
authors.initials: JP
authors.lastname: Krischer
authors.forename: David
authors.initials: D
authors.lastname: Cuthbertson
authors.forename: Liping
authors.initials: L
authors.lastname: Yu
authors.forename: Desmond A
authors.initials: DA
authors.lastname: Schatz
authors.forename: Tihamer
authors.initials: T
authors.lastname: Orban
authors.forename: George
authors.initials: G
authors.lastname: Eisenbarth
mesh_terms: D000293:Adolescent; D001323:Autoantibodies / Q000097:blood / Q000276:immunology / Q000378:metabolism*; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000276:immunology*; D018450:Disease Progression; D005260:Female; D005951:Glucose Tolerance Test; D005968:Glutamate Decarboxylase / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D007515:Islets of Langerhans / Q000276:immunology; D008137:Longitudinal Studies; D008297:Male; D055815:Young Adult
chemical_list: D001323:Autoantibodies; C096322:ICA512 autoantibody; D005968:Glutamate Decarboxylase; C402565:glutamate decarboxylase 1