Antigenicity of desamido-insulin and monocomponent insulin

No consensus about the antigenicity of monocomponent insulin has yet been reached. We have therefore administered different insulin preparations to rabbits and rats to determine IgG and IgE antibody production. The preparations used were porcine monocomponent insulin, conventional bovine and porcine insulin powders, porcine b-component and synthesized porcine mono-desamido-insulin and hexa-desamido-insulin. In rabbits, porcine b-component was the most antigenic preparation, followed by conventional bovine and porcine insulins. No antibody production was observed with the other preparations. In rats the 60 h passive cutaneous anaphylaxis test showed virtually no insulin IgE antibody production in response to porcine monocomponent insulin. However, if porcine b-component or porcine hexa-desamido-insulin was employed both for sensitisation and as the challenging antigen, positive skin reactions were observed with demonstration of insulin IgE antibodies. Our results confirm the low antigenicity of the pharmaceutical preparation of porcine monocomponent insulin and suggest that porcine hexa-desamido-insulin and porcine b-component administration may result in the production of reagin-type antibodies.