title: Autoantibodies in children with type 2 diabetes mellitus.
abstract: To evaluate the frequency of autoantibodies to glutamic acid decarboxylase (GAD), protein tyrosine phosphatase-like protein (IA-2), and insulin (IAA) in children with type 2 diabetes mellitus (DM), we studied 37 children and adolescents whose type 2 DM was defined by fasting and 90-min standard liquid meal-stimulated serum C-peptide levels of >0.2 and >0.5 nmol/l (0.7 and 1.5 ng/ml), respectively. Mean fasting-stimulated serum C-peptide levels were 1.1 +/- 0.10 nmol/l (3.38 +/- 0.29 ng/ml) and 1.9 +/- 0.17 nmol/l (5.79 +/- 0.50 ng/ml), respectively. Eleven out of 37 patients (29.7%) were positive for at least one autoantibody: 8.1% (n = 3) had positive GAD, 8.1% (n = 3) had positive IA-2, and 27% (n = 10) had positive IAA. Nine of the 10 IAA-positive patients were on insulin treatment at the time of testing. Three of the 10 IAA-positive patients were also positive for GAD or IA-2. Since insulin treatment can stimulate IAA, we considered this to be less informative in classifying autoimmunity in DM. Therefore, GAD and IA-2 were considered primary autoimmune markers. Four out of 37 patients (10.8%) were positive for GAD (n = 3) or IA-2 (n = 3) or both (n = 2). Thus, low (10.8%) frequency of autoimmunity in children and adolescents is consistent with their clinical classification of type 2 DM based on the presence of residual C-peptide.
authors.affiliation: Department of Pediatrics, State University of New York Health Science Center at Brooklyn, 11203, USA.
authors.forename: Vatcharapan
authors.initials: V
authors.lastname: Umpaichitra
authors.forename: Mary Ann
authors.initials: MA
authors.lastname: Banerji
authors.forename: Salvador
authors.initials: S
authors.lastname: Castells
mesh_terms: D000293:Adolescent; D001323:Autoantibodies / Q000097:blood*; D002096:C-Peptide / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy / Q000276:immunology*; D005215:Fasting; D005968:Glutamate Decarboxylase / Q000276:immunology; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D007328:Insulin / Q000627:therapeutic use; D007330:Insulin Antibodies / Q000097:blood; D008687:Metformin / Q000627:therapeutic use
chemical_list: D001323:Autoantibodies; D002096:C-Peptide; D007004:Hypoglycemic Agents; C096322:ICA512 autoantibody; D007328:Insulin; D007330:Insulin Antibodies; D008687:Metformin; D005968:Glutamate Decarboxylase