A prospective study of the immunogenicity of porcine insulin in HLA-typed new insulin-treated diabetics.

Fifty-four diabetics were started on insulin therapy with highly purified porcine insulin (Velosulin, Insulatard, Mixtard) and treated for at least 1 yr with blood samples drawn at regular intervals for insulin antibody determinations. In 43 patients the insulin antibody response was correlated with HLA A, B, and DR antigens. Approximately half of the patients formed insulin antibodies within 6 months of treatment, and this incidence remained constant for up till 2 yr. In those patients who developed insulin antibodies a plateau of 12% insulin binding capacity was reached after 9-12 months which remained constant for up till 2 yr. Formation of antibodies to proinsulin and pancreatic polypeptide proved completely avoidable, and no local reactions at the injection sites were observed. There was indication of a positive association between HLA DR4 tissue types and the tendency to immune response to injected insulin (p = 0.07).