title: Autoantibodies to GAD and IA-2 in Saudi Arabian diabetic patients.
abstract: OBJECTIVE
  To determine the prevalence of autoantibodies in sera of Saudi diabetic patients including Type 1 and Type 2 diabetes mellitus (DM) and gestational diabetes mellitus (GDM) living in Jeddah, Saudi Arabia. Apart from data on the prevalence of islet-cell antibodies in patients in Ryhadh (Al-Attas et al. Frequency of islet cell antibodies in adult newly diagnosed diabetic patients. Ann Saudi Med 1990; 10: 369-373) immunological markers of autoimmune diabetes have not been explored in Saudi Arabians.
  
  
  METHODS
  Autoantibodies to GAD65 (GADA) and IA-2 (IA-2A) were determined using radio-immunoprecipitation assays.
  
  
  RESULTS
  In Type 1 DM patients, 54% were GADA+ and 27% were IA-2A+. A greater negative effect of disease duration was noted for IA-2A than for GADA positivity. Autoantibodies were more prevalent with younger age of onset. GADA were slightly more common in female Type 1 DM patients. In Type 2 DM, 8/99 patients were GADA+, and three of these patients with shorter disease duration were also IA-2A+. GADA, and particularly IA-2A, were associated with a younger age of onset of Type 2 DM and all the autoantibody-positive Type 2 DM patients were insulin-treated. GADA were detected in 2.2% of GDM patients, but none of these patients possessed IA-2A.
  
  
  CONCLUSIONS
  The prevalence and associations of autoantibodies in Saudi diabetic patients are very similar to those reported for diabetic patients in other ethnic groups.
authors.affiliation: Institute of Infection, Immunity and Inflammation, and Division of Immunology, School of Molecular Medical Sciences, University of Nottingham, Nottingham, UK.
authors.forename: L H
authors.initials: LH
authors.lastname: Damanhouri
authors.forename: J A
authors.initials: JA
authors.lastname: Dromey
authors.forename: M R
authors.initials: MR
authors.lastname: Christie
authors.forename: H A
authors.initials: HA
authors.lastname: Nasrat
authors.forename: M S M
authors.initials: MS
authors.lastname: Ardawi
authors.forename: R A
authors.initials: RA
authors.lastname: Robins
authors.forename: I
authors.initials: I
authors.lastname: Todd
mesh_terms: D000328:Adult; D017668:Age of Onset; D000368:Aged; D018912:Arabs; D001323:Autoantibodies / Q000097:blood*; D001327:Autoimmune Diseases / Q000208:ethnology / Q000276:immunology*; D015415:Biomarkers / Q000097:blood; D003920:Diabetes Mellitus / Q000208:ethnology / Q000276:immunology*; D003922:Diabetes Mellitus, Type 1 / Q000208:ethnology / Q000276:immunology; D003924:Diabetes Mellitus, Type 2 / Q000208:ethnology / Q000276:immunology; D016640:Diabetes, Gestational / Q000276:immunology; D005260:Female; D005968:Glutamate Decarboxylase / Q000276:immunology*; D006801:Humans; D007527:Isoenzymes / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D015995:Prevalence; D015531:Radioimmunoprecipitation Assay / Q000379:methods; D012529:Saudi Arabia / Q000453:epidemiology
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; C096322:ICA512 autoantibody; D007527:Isoenzymes; D005968:Glutamate Decarboxylase; C401141:glutamate decarboxylase 2