Anti-insulin IgE in diabetics.

Anti-insulin IgE and IgG were estimated in sera of diabetic patients. Using a paper radioimmunosorbent technique, detectable titers of anti-insulin IgE were found in all insulin-treated diabetics who were non-allergic to insulin. Patients with generalized insulin allergy, and immune-type insulin-resistance had higher titers of anti-insulin IgE. Anti-insulin IgG was present in all insulin-treated patients. The titers were significantly higher in insulin-resistant diabetics. Four of the 12 cases with insulin allergy had undetectable anti-insulin IgG titers. The ratios of 125I-insulin bound by IgE and IgG were significantly higher in 11 (91%) patients with systemic insulin-allergy. It is suggested that a relative excess of anti-insulin IgE may be associated with the insulin allergic state.