Correlation of islet cell antibodies and HLA-DR phenotypes with diabetes mellitus in adults.
In a cross-sectional study, sera of 81 adult diabetic in-patients were tested for the presence of pancreatic islet cell antibodies (ICA), both IgG and complement-fixing. All patients had been well controlled initially with oral hypoglycaemic agents and therefore had been classified as having Type 2 (non-insulin-dependent) diabetes. However, 14 were subsequently classified as Type 1 (insulin-dependent) because they became insulin-dependent within 2 months of diagnosis. Ten of these patients (71%) were ICA-positive. Sixty-seven patients had been non-insulin-dependent for at least 1 year after diagnosis. Circulating ICA were present in 18 patients and 16 of these (89%) required insulin therapy. Secondary oral hypoglycaemic agent failure developed within a mean period of 3.7 years after diagnosis. In contrast, in the ICA-negative sub-group (n = 49) insulin treatment became necessary in 29 patients. Secondary oral hypoglycaemic agent failure of these patients had developed after a mean period of 8.4 years, which was significantly longer than in the ICA-positive patients (p less than 0.01). Complement-fixing-ICA were detected only in sera with an ICA-IgG titre of at least 8, and its prevalence was similar in the sub-groups tested, i.e., the Type 1 diabetic patients and the patients with secondary oral hypoglycaemic agent failure. With HLA-DR typing, a significant excess of the DR3 antigen and heterozygous DR3/DR4 phenotypes was found in ICA-positive patients with secondary oral hypoglycaemic agent failure and in the Type 1 diabetic patients, which was comparable with the frequencies reported in juvenile-onset Type 1 diabetes.
D000328:Adult; D000368:Aged; D000906:Antibodies / Q000302:isolation & purification*; D001323:Autoantibodies; D003920:Diabetes Mellitus / Q000276:immunology*; D003922:Diabetes Mellitus, Type 1 / Q000276:immunology; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy / Q000276:immunology; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D007515:Islets of Langerhans / Q000276:immunology*; D008875:Middle Aged; D010641:Phenotype
D000906:Antibodies; D001323:Autoantibodies; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II; D007004:Hypoglycemic Agents; C024211:islet cell antibody