SAT-LB93 Rapid Reduction of Insulin Requirement in a Hyperglycemic Patient Treated for Hemophagocytic Lymphohistiocytosis

Background: Hemophagocytic lymphohistiocytosis (HLH) is life-threatening disorder of immune dysregulation involving macrophage and T-cell activation resulting in massive cytokine release causing multi-organ dysfunction. Similar release of cytokine products from fat tissue is associated with obesity-related insulin resistance. Our case presentation is an example of HLH and insulin resistance, two conditions with overlapping pathophysiology, occurring simultaneously. Clinical Presentation: A 17-year-old male, with no history of hyperglycemia, underwent renal transplant due dysplastic kidneys. He received 500mg IV methylprednisolone during surgery followed by a prednisone taper starting at 70mg daily. Serum glucoses post-transplant ranged from 97 to 129 mg/dL. Three weeks post-transplant he was admitted for fever and dehydration. BMI on admission was the 85(th) percentile. Serum glucose was 371 mg/dL without ketosis. He started on insulin therapy, requiring 60 units per day (0.8 units/kg). It was suspected his new-onset diabetes was due to his immunosuppressant regimen (prednisone 50mg daily, tacrolimus) and/or acute illness. With persistent fevers and negative infectious workup, there was concern for HLH. The diagnosed was confirmed with ferritin level of 65,962 ng/mL (27-265), hemoglobin 6.5 gm/dL, platelets 88,000, triglycerides 765 mg/dL, soluble IL-2 receptor 2,717 u/mL (45 - 1,105). For HLH treatment, he received methylprednisolone 800 mg daily x 3 doses. During this time his insulin requirements increased to 188 units per day (3.6 units/kg). He was transitioned to dexamethasone 20mg daily. His insulin requirements increased over the next 72 hours to 388 units per day (5.2 units/kg). He was found to be positive for Ehrlichiosis, a known precipitant of HLH. Doxycycline therapy was initiated for a 14 day course. One week into his doxycycline course his ferritin had decreased to 999 ng/mL. He remained on dexamethasone 20 mg daily but developed severe hypoglycemia to 29 mg/dL with altered mental status. All insulin therapy was held. Fasting glucoses over the next 4 days ranged from 94-154 mg/dL and post-prandial glucoses 116-288 mg/dL. He discharged home with only short acting insulin for glucoses above 250 mg/dL, which he did not require. Case Lessons: Cytokine release from macrophages is implicated in the pathology of both HLH and insulin resistance associated with obesity. Glucocorticoids used to treat HLH can also exacerbate insulin resistance. Providers should be aware of the risk of hyperglycemia and large insulin requirements in patients with HLH, and the potential for rapid reduction of insulin needs as HLH is successfully treated.