INSULIN ANTIBODY FORMATION

Abstract

ABSTRACT Sixty-three patients with diabetes mellitus were treated with a porcine or a bovine insulin preparation, either in solution or in a crystal suspension of protamine-insulin. The amounts of circulating insulin-binding antibodies were periodically determined for up to 3 years. Forty-nine patients developed antibodies during the first 6 to 9 months of treatment. Taking into account the length of insulin treatment and the age of the patients, the amounts of antibodies developed were compared for groups treated with the different insulin preparations. Of the patients treated with insulin in a neutral solution, those who had received bovine insulin developed significantly more antibodies than those treated with porcine insulin. Patients treated with porcine insulin in a neutral solution developed only traces of antibodies. The mean titre was significantly less than for patients treated with porcine insulin in an acid solution or as protamine-insulin. Treatment with porcine protamine-insulin resulted in significantly less antibody formation, provided the patients had received porcine insulin in a neutral solution before the treatment with protamineinsulin. It was shown that as a rule, patients developed antibodies with the same avidity for porcine and bovine insulin, although a few patients treated with porcine or bovine insulin developed antibodies with greatest avidity for bovine insulin.