title: Anti-glutamate decarboxylase and other antibodies at the onset of childhood IDDM: a population-based study.
abstract: Sera obtained at diagnosis from 273 children (0-14 years) with insulin-dependent diabetes mellitus (IDDM) were studied to compare different autoantibody levels. The subjects comprise 75% of all incident cases in New South Wales, Australia, for a 2-year period (ascertainment > 99% complete). Antibodies against glutamate decarboxylase were measured by radioimmunoprecipitation, insulin autoantibodies (on 176 sera collected within 4 days of initiation of insulin therapy) by radioimmunoassay, thyroid peroxidase and antigliadin IgA antibodies by enzyme-linked immunoassay, and anti-endomysial IgA and islet cell antibodies by indirect immunofluorescence. Reference ranges for anti-glutamate decarboxylase and insulin autoantibodies were determined in a group of non-diabetic children. Of the sera 69% were positive for anti-glutamate decarboxylase, 65% for insulin autoantibodies, 71% for islet cell antibodies (> or = 20 Juvenile Diabetes Foundation units), 10% for anti-thyroid peroxidase, 2.6% for antigliadin and 3.0% for anti-endomysial antibodies. Islet cell antibodies and insulin autoantibodies were both negative in 13.7% of the sera, while only 5.8% were negative for all three of islet cell antibodies, insulin autoantibodies and anti-glutamate decarboxylase. There was a higher frequency of anti-glutamate decarboxylase among girls than boys (75% vs 63%, p = 0.03) and a negative correlation between the level of insulin autoantibodies and age at diagnosis (r = -0.41, p < 0.0001). A higher frequency of antithyroid peroxidase was found with increasing age (p = 0.05). Higher titres of islet cell antibodies were associated with a higher frequency of both anti-glutamate decarboxylase (p < 0.0001) and insulin autoantibodies (p = 0.003).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Ray Williams Institute for Paediatric Endocrinology, Royal Alexandra Hospital for Children, Sydney, Australia.
authors.forename: C F
authors.initials: CF
authors.lastname: Verge
authors.forename: N J
authors.initials: NJ
authors.lastname: Howard
authors.forename: M J
authors.initials: MJ
authors.lastname: Rowley
authors.forename: I R
authors.initials: IR
authors.lastname: Mackay
authors.forename: P Z
authors.initials: PZ
authors.lastname: Zimmet
authors.forename: M
authors.initials: M
authors.lastname: Egan
authors.forename: H
authors.initials: H
authors.lastname: Hulinska
authors.forename: I
authors.initials: I
authors.lastname: Hulinsky
authors.forename: R A
authors.initials: RA
authors.lastname: Silvestrini
authors.forename: S
authors.initials: S
authors.lastname: Kamath
mesh_terms: D000293:Adolescent; D001323:Autoantibodies / Q000032:analysis*; D002446:Celiac Disease / Q000175:diagnosis; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000453:epidemiology / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005968:Glutamate Decarboxylase / Q000276:immunology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007328:Insulin / Q000276:immunology*; D007453:Iodide Peroxidase / Q000276:immunology*; D007515:Islets of Langerhans / Q000276:immunology*; D008297:Male; D009517:New South Wales / Q000453:epidemiology; D011153:Population; D011863:Radioimmunoassay; D015531:Radioimmunoprecipitation Assay
chemical_list: D001323:Autoantibodies; D007328:Insulin; D007453:Iodide Peroxidase; D005968:Glutamate Decarboxylase