THU390 Case Report On Hirata Syndrome: A Rare Cause Of Hypoglycemia

Disclosure: M. Pranala: None. V. Kuttiyil Oommen: None. V. Sanker: None. S. Vallabhaneni: None. K. Ajith: None. A. Thomas: None. Introduction: Hirata's disease, also known as insulin autoimmune syndrome (IAS), is a rare cause of hypoglycemia that is characterized by episodes of spontaneous hypoglycemia and insulin autoantibodies in patients who have not received exogenous insulin. IAS has been associated with rheumatoid arthritis and Graves' disease in 96% of Japanese IAS patients, and it has also been associated with other autoimmune disorders like Graves' disease. Case History: We report a case of 73-year-old male presented with the complaints of episodes of profuse sweating, palpitation and numbness over his head. Patient was initially treated symptomatically and since the symptoms were not resolving further evaluation was done. Two hourly GRBS, c- peptide, insulin levels and serum cortisol of our patient was monitored. Patient had extremely high serum insulin levels. Serum insulin antibodies level was also high (>300 U/ml). CT abdomen ruled out pancreatic pathology. It has been speculated that hypoglycemia occurring in IAS is due to dissociation of insulin from its antibodies in the post absorptive state. Our patient was diagnosed with IAS based on the criteria of Hirata. The age at onset, sex, and duration of hypoglycemic attacks, outcome or treatment, medication taken prior to the onset of IAS and background disease were all taken into consideration. In our patient, hypoglycemia occurred spontaneously in the post-absorptive state 4–6 hours after meal rather than after a 72-hour fast test. Extremely high levels of insulin (>200 µIU/mL) and Serum insulin antibodies found to be >30 U/ml were constructive in the diagnosis of IAS. The patient improved on dietary management alone consisting of frequent small meals. Conclusion: In order to facilitate early recognition and prevent unnecessary investigations, this could be the most significant syndrome in the differential diagnosis of endogenous hyper-insulinemic hypoglycemia (EHH). In such patients with a high index of suspicion, insulin autoantibodies should be examined. IAA prevents insulin to bind its receptor in the postprandial phase, possibly resulting in mild hyperglycemia; thereafter, insulin is released from the complexes irrespective of blood glucose concentrations, thus inducing hypoglycemia Presentation: Thursday, June 15, 2023