Scarlett is a basic trainee with an interest in Haematology.
A Case of Clopidogrel-Induced Insulin Antibody Syndrome in a NZ European Woman
Case: Mrs X is a 76 year old New Zealand European woman. She presented to the Emergency Department with reduced level of consciousness and a blood sugar of 1.6 mmol/L. She had no history of diabetes or exposure to exogenous insulin. The blood sugar only transiently increased with intravenous dextrose. Initial investigations demonstrated an elevated C-peptide and insulin of 4669 pmol/L and 6945pmol/L respectively. The sulphonylurea screen was negative. Cross sectional imaging failed to show evidence of an insulinoma. Her polyethylene glycol test confirmed the presence of insulin antibodies. Discussion: Autoimmune insulin syndromes are rare in non-Asian populations1. Half of non-Asian patients who develop these have been exposed to predisposing drugs1,2. This includes sulfahydryl containing drugs such as clopidogrel which Mrs X had been taking for three months3,4. The hallmark of the condition is post-prandial hypoglycaemia due to dissociation of antibodies from insulin several hours after they first bind1,2. The condition typically regresses within 3-6 months of cessation of the causative drug1. In the interim it is treated with low glycaemic index diets. Immunosuppression may be required.
References: 1.Censi S, Mian C and Betterle C. Insulin autoimmune syndrome: from diagnosis to clinical management. Annals of Translational Medicine. 2018 Sep; 6(17):335. 2.Cappellani D, Macchia E, Falorni A, Marcehtti P. Insulin Autoimmune Syndrome (Hirata Disease): A Comprehensive Review Fifty Years After Its Frist Description. Diabetes, Metabolic Syndrome and Obesity: Targets and Therapy.2020 Apr; 13: 963-978 3.Rajpal A. Kassem L, Moscoso-Cordero M, Arafah B. Clopidogrel-Induced Insulin Autoimmune Syndrome: A Newly Recognized Cause of Hypoglycaemia in a Patient without Diabetes. Jounral of the Endocrine Society. 2017 Sep 1; 1(9): 1217-1223. 4.Calder G, Ward G, Sachithanadan, MacIssac R. Insulin Autoimmune Syndrome: A Case of Clopidogrel-Induced Autoimmune Hypoglycaemia. The Journal of Clinical Endocrinology & Metabolism. 2020 Mar 17; 105 (4): 996-999.