The production and characteristics of anti-insulin, anti-A-component and anti-proinsulin antibodies in patients treated with monocomponent or conventional insulin.

Highly purified pork monocomponent insulin produced less anti-insulin antibody than conventional insulins in diabetic patients. The smaller amount of anti-insulin antibody produced by MC insulin bound pork insulin more strongly than beef insulin in both displacement and direct binding studies of 125I-insulin. On the contrary, anti-insulin antibody which was produced by conventional insulins (beef insulin or mixture of pork and beef insulin) bound beef insulin more strongly. No significant anti-a-component and anti-proinsulin antibodies were detected in diabetics treated with highly purified monocomponent pork insulin about two years, compared to significant production of these antibodies in diabetics treated with conventional insulins. These results suggest that the species difference of the insulin molecule itself plays a significant role for the production of anti-insulin antibody, as the impurities do, in insulin-treated diabetic patients. The production of anti-insulin and anti-a-component antibodies decreased clearly after switching to highly purified monocomponent from conventional insulin. No effect of the switching on insulin requirement was found; however, better control of diabetes was accomplished in relation to the level of fasting blood sugar.