Endocrine Abstracts

Introduction: Insulin antibodies, developed in patients treated with exogenous insulin, might affect glycemic control due to their tendency to bind and/or release insulin in an unpredictable fashion. It is reported to be caused by immunoglobulin G-derived insulin antibodies. Insulin antibodies induced by exogenous insulin in diabetic patients is associated with hypersensitivity reactions, glycemic variability mainly with insulin resistance/ hyperglycemia or hypoglycemia. We reported a case of Type 1 diabetes mellitus (T1DM) who developed exogenous insulin antibody syndrome (EIAS) to insulin analogues during follow-up.

Case presentation: A 20 year-old female patient diagnosed as TIDM three months before, had been using insulin aspart and glargine for three months. She weighed 42 kg. Her blood glucose levels were under control and her HbA1c level decreased from 13.9% to 8.6% in two months. Although she followed her diet and increased daily activity, her need for insulin aspart increased (3 U at each meal to 9-12 U), insulin glargine (7 U/d to 16 U/d) in a month. Her blood sugar levels still remained high (fasting plasma glucose were around 200 mg/dl and posprandial glucose levels were around 300 mg/dl). Her insulin regimen was transitioned to insulin detemir and glulisine but, her glucose control could not be achived despite using 2 U/kg of insulin. In suspicion of developing antibodies against insulin analogues, insuline glulisine was changed to regular insulin. Also, the patient’s anti-insulin antibody levels were found to be increased than that at the time of diagnosis [30.93→44.62 IU/ml (0-20 IU/ml)]. After this treament regimen, her glucose levels were controlled in doses 0.95 U/kg (8 U regular insulin at each meal and 20 U/d detemir).

Conclusion: The majority of EIAS is reported in patients with type 2 DM and is very uncommon in patients with TIDM. Insulin analogues are known to have lower immunogenicity than animal/human insulin; accordingly, replacement with an insulin analogue is suggested to be an effective treatment of EIAS. However, a recent study by Hattori et al., found that glargine and aspart were more antigenic than other insulin analogues. Recommended other regimens include glucocorticoids, immunsuppresants and plasmapheresis. Glucocorticoids may induce or worsen ketoacidosis in patient with TIDM. Interestingly, changing insulin regimen to human regular insulin is sufficient to achieve glucose control for our patient.