Relationship of insulin autoantibodies to presentation and early course of IDDM in children.

Insulin antibodies have been documented before (insulin autoantibodies [IAAs]) and after (insulin antibodies) insulin administration in children with new-onset insulin-dependent diabetes mellitus (IDDM). Whereas the relationship of IAA to various factors at presentation has been studied in some detail, little is known about their relationship to events during the 1st yr after diagnosis. Furthermore, the course and factors affecting insulin-antibody response to human insulin administration in children with newly diagnosed IDDM remain poorly defined. To study these questions, we measured serum glucose, pH, bicarbonate, C-peptide, and IAA at diagnosis in 84 children between 0.5 and 18 yr of age. Basal and peak C-peptide responses to Sustacal ingestion, glycosylated hemoglobin (HbA1c), and IAA were then measured in 33 of these patients at 10 days and 1, 3, 6, and 12 mo after diagnosis. At presentation, IAAs were absent (binding below the mean + 3SD of the binding of control serums) in 51 patients (61%) and present (binding above the mean + 3SD) in 33 patients (39%). Multiple regression analysis showed a significant nonlinear relationship between IAAs and both age (P less than .005) and blood glucose (P less than .05) at onset. There was a stepwise increase in median insulin-antibody binding throughout the 1st yr. This increase was most marked during the 1st mo of insulin therapy and showed a statistically significant difference between successive measurements only during this period.(ABSTRACT TRUNCATED AT 250 WORDS)