Anti-insulin antibodies in children with type I diabetes mellitus. Genetic regulation of production and presence at diagnosis before insulin replacement.
We evaluated the production of antibodies against insulin in a genetically well-defined population. In the first study, 124 young patients with type I diabetes for longer than 6 mo were included. Anti-insulin antibodies were detected by polyethyleneglycol (PEG) precipitation after incubation of acidified, charcoal-stripped sera with 125I-labeled pork insulin and were expressed as microunits insulin bound per milliliter whole serum. For comparison, the patients were divided into six groups based on HLA DR antigens: 3/3, 3/-, 4/4, 4/-, 3/4, and -/-(-is non-DR3 or -DR4). The mean age of the patients was 14.7 +/- 0.5 yr; the duration of diabetes was 5.8 +/- 0.4 yr; and the glucose control, as measured by hemoglobin A1c was average (7.6 +/- 0.2%). There were no significant differences in any of these parameters among the patients in any of the HLA DR groups. Patients expressing DR3/3 had significantly lower insulin binding than the rest of the groups (2.5 +/- 0.4 vs. 13.6 +/- 1.4 microU/ml, P less than 0.0001). Patients with DR3/ - did not differ in insulin-binding capacity from the other groups. The type of insulin used for replacement was not correlated with the serum insulin-binding capacity. In a second study, sera from 48 children, newly diagnosed with type I diabetes, were examined for the presence of insulin binding before treatment with exogenous insulin and compared with sera from 80 children without diabetes or a family history of diabetes and from 103 unaffected HLA-identical or haploidentical siblings of a child with type I diabetes.(ABSTRACT TRUNCATED AT 250 WORDS)
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000188:drug therapy / Q000235:genetics / Q000276:immunology*; D005260:Female; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II / Q000032:analysis; D006801:Humans; D007223:Infant; D007328:Insulin / Q000627:therapeutic use; D007330:Insulin Antibodies / Q000032:analysis*; D008297:Male; D012737:Sex Factors
D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II; D007328:Insulin; D007330:Insulin Antibodies