Recurrent Hypoglycaemia due to Insulin Autoimmune Disease (Hirata Disease) Associated with Monoclonal Gammopathy of Unknown Significance.

Hirata disease is a rare disease characterised by recurrent episodes of hypoglycaemia due to anti-insulin antibody. In most of these cases causative agents were sulfhydryl containing compounds like Penicillamine, Glutathione, and Methimazole. The presentation of disease closely mimics insulinoma. We report 52 years female patient presenting with recurrent episodes of hypoglycaemia due to anti-insulin antibody. On evaluation, underlying cause of antibody was found to be monoclonal gammopathy of unknown significance (MGUS).