title: Immunoreactivity of human insulin of recombinant DNA origin.
abstract: To evaluate possible advantages of human insulin of recombinant DNA origin (HI) in the treatment of diabetic patients, we compared cellular and humoral immunoreactivities of HI and porcine insulin (PI). Anti-insulin IgE bound equal amounts of 125I-HI and 125I-PI. There was no difference between HI- and PI-stimulated lymphocyte transformation indices. The binding of 125I-HI with circulating anti-insulin IgG was lower compared with 125I-PI binding (12.1 +/- 1% versus 15.4 +/- 1.5%, P less than 0.001) in 60 insulin-treated cases. Thirteen sera were selected for high antibody titers and analyzed in detail. In the competitive inhibition assays, a 50% displacement of 125I-PI required a fourfold higher concentration of HI than PI. Although total insulin binding capacities were almost equal, 63 +/- 11 nM/L for PI and 60 +/- 12 nM/L for HI, the high-affinity antibodies had significantly reduced avidity for HI compared with PI. These differences in avidities suggest that HI may be useful in treatment of immune-type insulin resistance.
mesh_terms: D000293:Adolescent; D000818:Animals; D000937:Antigen-Antibody Reactions; D004274:DNA, Recombinant; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D007328:Insulin / Q000276:immunology*; D008213:Lymphocyte Activation; D008875:Middle Aged; D013552:Swine
chemical_list: D004274:DNA, Recombinant; D007074:Immunoglobulin G; D007328:Insulin; D007073:Immunoglobulin E