title: Autoimmune markers in young Malaysian patients with type 1 diabetes mellitus.
abstract: This study determined the prevalence and significance of autoantibodies to GAD65 (GAD Ab), insulin (IAA), tyrosine-like phosphatase (IA2) and islet-cell (ICA) in a group of 213 young Malaysian Type 1 diabetics, diagnosed before the age of 40 years. Venous blood was taken at fasting, and at 6 minutes post-glucagon (1 mg i.v.). IAA was detected in 47.4%, GAD Ab in 33.8%, IA2 in 8.9% and ICA in 1.4% of the subjects. When based on post-glucagon C-peptide level of 600 pmol/L, 172 (80.7%) patients had inadequate pancreatic reserve, while the remainder 41(19.3%) showed normal response. The autoantibodies, either alone or in combination, were detectable in both groups of patients; higher prevalence in those with poor or no beta-cell function (73.3% versus 46.3%, p = 0.0001). Although the prevalence of GAD Ab was highest in newly diagnosed patients (< 5 years), unlike IA2 and ICA, the marker remained detectable in 24-25% of those patients with long-standing disease. Nineteen patients could probably belong to the "latent autoimmune diabetes in adults (LADA)" subset, where pancreatic reserve was adequate but patients had detectable autoantibodies and insulin-requiring. On the other hand, 68 of the 213 patients (32%) were seronegative, but presented with near or total beta-cell destruction. Thus, as has also been suggested by others, there is indeed etiological differences between the Asian and the Caucasian Type 1 diabetics, and, there is also the possibility that other, but unknown autoantigens are involved in causing the pancreatic damage.
authors.affiliation: Division of Endocrinology, Institute for Medical Research, Jalan Pahang, 50588 Kuala Lumpur.
authors.forename: W M
authors.initials: WM
authors.lastname: Nazaimoon
authors.forename: K N
authors.initials: KN
authors.lastname: Azmi
authors.forename: R
authors.initials: R
authors.lastname: Rasat
authors.forename: I S
authors.initials: IS
authors.lastname: Ismail
authors.forename: M
authors.initials: M
authors.lastname: Singaraveloo
authors.forename: W B
authors.initials: WB
authors.lastname: Mohamad
authors.forename: R
authors.initials: R
authors.lastname: Letchuman
authors.forename: I H
authors.initials: IH
authors.lastname: Sheriff
authors.forename: I
authors.initials: I
authors.lastname: Faridah
authors.forename: B A
authors.initials: BA
authors.lastname: Khalid
mesh_terms: D000293:Adolescent; D000328:Adult; D001323:Autoantibodies / Q000032:analysis*; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000276:immunology*; D005260:Female; D005968:Glutamate Decarboxylase / Q000276:immunology; D006801:Humans; D007223:Infant; D007328:Insulin / Q000276:immunology; D007515:Islets of Langerhans / Q000276:immunology; D007527:Isoenzymes / Q000276:immunology; D008296:Malaysia; D008297:Male; D008875:Middle Aged; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1; D017027:Protein Tyrosine Phosphatases / Q000276:immunology
chemical_list: D001323:Autoantibodies; D007328:Insulin; D007527:Isoenzymes; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1; D017027:Protein Tyrosine Phosphatases; D005968:Glutamate Decarboxylase; C401141:glutamate decarboxylase 2