Abstract 176: Relapse of insulin autoimmune syndrome associated with monoclonal gammopathy of undetermined significance precipitated by alpha-lipoic acid

Objective/Background: We describe an unusual case of relapsing autoimmune hypoglycaemia, associated with monoclonal gammopathy of Undetermined Significance precipitated by alpha lipoid acid, in a 66 -year-old non-diabetic lady who was not exposed to exogenous insulin before. Method: 66-year-old lady non-diabetic who was not exposed to exogenous insulin before, started experiencing recurrent attacks of sweating, tiredness, uneasiness and increased hunger, while she was on a supplement which contained alpha-lipoic acid in 2016. She had taken it for few months after which her symptoms started. On investigation, she was found to have low glucose levels of 70 mg/dl. A 72-h fast test was normal, her serum insulin levels were found to be more than 1000 mU, and insulin autoantibodies were positive, at 27 KU/ml. Recently, she was on a medication containing alpha lipoic acid for a few weeks, after which she had relapse of symptoms. Her blood investigations this time showed sugars were as low as 41 mg/dl. Her serum insulin was >1000 mU/ml), The antibody titre was 81 KU/ml more than what was found 6 years back Both the times, she was investigated thoroughly with endoscopic ultrasound, CT abdomen, Exendin PET for structural lesions and it was negative. Result: The exceedingly high insulin and insulin antibodies both the times and negative preliminary imaging studies led to the consideration of an immunological syndrome. Accordingly, a diagnosis of Relapsing Insulin Autoimmune Syndrome was made. In 2016, she was put on steroids for 2-3 weeks, which were tapered due to gastrointestinal problems. From then, she was managed with small frequent meals. She had symptoms persisting for about one and half years, after which she was asymptomatic for about 6 years. With relapse of symptoms recently, while she was on medication containing alpha lipoic acid which she was taking for few weeks, the patient was advised to take frequent, small meals. Inspite of that, she continued to have these symptoms. Finally, she was started on steroids 20 mg/day, thus achieving good control of her symptoms and she is having stable sugar levels for the past two weeks. Conclusion: We present an unusual case where potentially life- threatening relapsing hypoglycaemia due to IAS associated with MGUS, precipitated by alpha lipoid acid was successfully managed with steroids and short frequent meals. We conclude that these treatment modalities effectively manage severe, refractory IAS.