Genetic and immunological characteristics of Type I diabetes mellitus in an Indo-Aryan population

• Published in: Diabetologia 2000-04, Vol.43 (4), p.450-456
• Main Authors: KELLY, M. A, ALVI, N. S, CROFT, N. J, MIJOVIC, C. H, BOTTAZZO, G. F, BARNETT, A. H
• Format: Article
• Language: English
• Subjects: Adolescent; Antibodies; Autoantibodies - blood; Biological and medical sciences; Child; Child, Preschool; Diabetes; Diabetes Mellitus, Type 1 - genetics; Diabetes Mellitus, Type 1 - immunology; Diabetes. Impaired glucose tolerance; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; Etiopathogenesis. Screening. Investigations. Target tissue resistance; Female; Glutamate Decarboxylase - immunology; Haplotypes; HLA-DQ alpha-Chains; HLA-DQ Antigens - genetics; HLA-DQ beta-Chains; HLA-DR Antigens - genetics; HLA-DRB1 Chains; Hospitals; Humans; Immunology; India - ethnology; Infant; Insulin; Insulin - immunology; Islets of Langerhans - immunology; Male; Medical sciences; Pakistan - ethnology; Phosphatase; Protein Phosphatase 2; Protein Tyrosine Phosphatase, Non-Receptor Type 1; Protein Tyrosine Phosphatases - immunology; Proteins
• ISSN: 0012-186X; 1432-0428
• DOI: 10.1007/s001250051328

Our aim was to characterise the genetic and immunological features associated with Type I (insulin-dependent) diabetes mellitus in a cohort of Indo-Aryan children resident in the United Kingdom. Children with Type I diabetes (n = 53), unaffected first-degree relatives (n = 146) and unrelated healthy control children (n = 54) were typed for alleles of the HLA-DRB1, HLA-DQA1 and HLA-DQB1 genes. Islet cell antibodies and antibodies to glutamic acid decarboxylase, protein tyrosine phosphatase-2 (IA-2ic) and insulin were measured in the diabetic and control children. The DRB1*03.DQA1*05.DQB1*02 haplotype was positively associated with the disease, occurring in 78% of diabetic children compared with 22.6 % of healthy children (p(c) < 2.4 x 10(-5)). In simplex families, this haplotype was transmitted more frequently to the diabetic children than to their unaffected siblings (p < 1 x 10(-4)). The DRB1*04.DQA1* 03.DQB1*0302 haplotype was also transmitted preferentially to the diabetic probands (p < 0.025) but was not associated with disease in the case control study. Islet-related autoantibodies were detected in 89.6 % of diabetic patients compared with 11.8 % of control children (p < 1 x 10(-6)). Although protein tyrosine phosphatase-2 autoantibodies were detected more frequently among DRB1*04-positive diabetic patients compared with patients lacking this allele, the overall frequency of these autoantibodies was lower than observed in Europid diabetic subjects. This could reflect the absence of a disease association with DRB1*04 in the Indo-Aryan cohort. Type I diabetes in our Indo-Aryan cohort is similar to the disease observed in Anglo-Europeans but has important immunogenetic differences. The low frequency of protein tyrosine phosphatase-2 autoantibodies among the Indo-Aryan diabetic children could have important implications for the design of future strategies for disease prediction in this population.