Type B insulin resistance developing during interferon-alpha therapy.

Objective: To report a rare case of diabetes caused by type B insulin resistance due to development of insulin receptor autoantibodies during treatment of hepatitis C with interferon-alpha and ribavirin.

Methods: Clinical and laboratory findings in the case are presented. The literature on type B insulin resistance and interferon-induced autoimmunity is reviewed.

Results: A 55-year-old African American man with hepatitis C was treated with interferon and ribavirin. Eight months later, he presented with rapid onset of hyperglycemia, profound weakness, and weight loss. Severe hyperglycemia persisted despite insulin infusion rates as high as 125 U/h. The presence of insulin receptor autoantibodies was confirmed by immunoprecipitation of recombinant human insulin receptor with patient serum. Assays for autoantibodies to islet cell antigens and glutamic acid decarboxylase were negative. The interferon and ribavirin were discontinued. His insulin requirement spontaneously declined to low levels over a 6-month period. Two years after discharge of the patient, insulin receptor autoantibodies could no longer be demonstrated in his serum. He remains euglycemic and is no longer taking insulin.

Conclusion: This case demonstrates that type B insulin resistance can occur as a complication of interferon-alpha therapy. To our knowledge, this is the first reported case in the United States of type B insulin resistance with development of insulin receptor autoantibodies during treatment with interferon-alpha.