In 50 per cent of a beef insulin-treated diabetic population immediate whealing to beef insulin was found. Only 6.2 per cent showed a similar response to pork insulin.
The plasma of patients with immediate whealing to beef insulin binds beef insulin in preference to pork insulin.
No difference in in vitro binding titer was found between groups exhibiting immediate whealing responses to insulin and those showing no such reaction. It has been confirmed by radioimmunoelectrophoretic and chromatographic procedures that the insulin IgG antibody complex can be fractionated into gamma1 and gamma2 components. The gammaj component was found to be relatively more clearly differentiated by radioimmunoelectrophoresis in the majority of patients with dermal responsiveness. The possible significance of these findings is discussed, and it is proposed that the whealing response described may rest on an antibody of some sort, although we were unable to incriminate either the insulin binding or the P.K. reaginic types in the serum.
An IgM insulin binding antibody was detected in four patients, three of whom were having acute local reactions at the site of insulin injection and two of whom had been receiving insulin for approximately four weeks.