Anti-insulin antibodies (IAs) in patients with insulin-treated diabetes, though common, correlate poorly with glycemic control, insulin requirement, and insulin resistance. We are hereby reporting the clinical course and challenges in the management of a 70-year-old man who had severe insulin resistance as evidenced by recurrent diabetic ketoacidosis and poor glycemic control despite treatment with >9 U of insulin/kg body weight per day. He was found to have anti-IAs and responded clinically to plasmapheresis and immunosuppression with mycophenolate mofetil and prednisolone. Improved glycemic control correlated well with falling titers of antibodies. This case emphasizes that clinicians should be alert to the possibility of insulin resistance due to anti-IAs and the role of immunosuppression and plasmapheresis in such cases.
Keywords: Diabetic ketoacidosis; Insulin antibodies; Insulin resistance; Plasmapheresis.