The effects of liraglutide on both hypereosinophilic insulin allergy and the characteristics of anti-insulin antibodies in type 2 diabetes mellitus: a case report

BACKGROUND Liraglutide is one of the glucagon-like peptide-1 analogs; there are only a few reports of liraglutide being used for the treatment of insulin allergy. Furthermore, anti-insulin immunoglobulin G antibodies are occasionally detected in patients with diabetes. Hence, we report a case in which switching to liraglutide therapy ameliorated both the symptoms of insulin allergy with hypereosinophilia and the characteristics of insulin antibodies in a patient with type 2 diabetes mellitus. CASE PRESENTATION We present the case of a 70-year-old Japanese man with type 2 diabetes who developed insulin allergy with hypereosinophilia. Anti-insulin antibodies, high glycated hemoglobin levels (approximately 12 %), and high serum insulin levels were detected. Because a change in his insulin treatment was inefficient, treatment with liraglutide to protect residual insulin secretion was started, resulting in improvements in his insulin allergy, serum glycated hemoglobin, insulin, and eosinophil levels. Scatchard plots revealed decreased binding capacity and increased affinity constant for high affinity sites of anti-insulin antibodies. CONCLUSIONS Liraglutide might be useful for treating insulin allergy and anti-insulin antibodies in patients with type 2 diabetes.