Specific IgE antibody response to human insulin in diabetic subjects

Treatment with heterologous insulin preparations induce insulin antibody formation in most of the patients. A hundred of diabetic individuals in treatment with human insulin (HI) for at least 6 months at the time of the study and without any clinical immunological reaction, were selected in order to study the development of specific IgE antibodies against HI by in vivo and in vitro methods. Serologic specific IgE antibodies to HI were measured by RAST (Pharmacia) and 5 RAST-positive subjects were found. The specificity of these results were confirmed in 4 of the 5 subjects by RAST-inhibition. Thus, the prevalence of specific serologic IgE to HI in our study was 4% (1.1%-9.9%, p < 0.05). Only two of the RAST-positive subjects had cutaneous reactivity to HI by intradermal technique and one of the RAST-negative subjects presented also insulin skin reactivity. HI skin reactivity was found in 3% (0.6%-8.5%, p < 0.05) of the 100 diabetic subjects. These results differ from others obtained with heterologous insulins.