Abstract
The induction of insulin antibodies and the development of an insulin allergy were observed in a male diabetic patient treated with insulin during α-IFN therapy of renal cell carcinoma. Diabetes and renal cell carcinoma were diagnosed at the same time. The patient was treated with biosynthetic human insulin and nephrectomy was performed. Four months later, antineoplastic chemotherapy was started (α-IFN, vinblastin). Six weeks after initiation of α-IFN injections, the patient reported signs of insulin allergy. Significant titers of insulin antibodies of both the IgG and IgE subclasses were found in the serum at that time and during follow-up, but not before the treatment with α-IFN. None of the other autoantibodies investigated were positive.