Introduction: Tacrolimus is effective immunosuppressant in posttransplant patients. It inhibits calcineurin and prevents T cell activation. Post-transplantation diabetes mellitus (PTDM) is a well-established adverse effect of tacrolimus. We report the rare occurrences of DKA and hyperosmolar hyperglycemia syndrome respectively in 2 patients on tacrolimus after renal transplants.

Description Case 1: A 25 year old obese (BMI 37.7 kg/m2) black female with no history of DM received a live donor kidney transplant. She was on mycophenolate 720 mg po bid, tacrolimus 7 mg po bid, and prednisone 5 mg daily. Eleven weeks after transplant she presented with polyuria and polydipsia and was admitted for DKA. Labs revealed glucose 1000 mg/dL (74-106) , HCO3 7.0 meq/L (21-32) , beta-hydroxybutyric acid 8.4 mg/dL (0.2 - 2.8) , tacrolimus trough levels 19.6 ng/mL (4.1 - 10.7) . Her A1c was 10.6% compared to 5.3% pre-transplant. Case 2: A 50 year old obese (BMI 35.6 kg/m2) black female with no prior history of DM received a cadaveric kidney transplant due to ESRD. Patient was on mycophenolate 360 mg bid, and tacrolimus 8 mg bid. She was admitted to hospital for HHS 9 weeks later. Labs revealed a glucose 940 mg/dL, serum osmolality 341 msom/kg (275-295) , HCO3 22 mmol/L, tacrolimus trough levels 12.1 ng/mL. Her A1c was 8.7% compared to 5.3% pre-transplant.

Discussion: Our 2 patients with no history of DM developed hyperglycemic emergencies within 3 months of receiving kidney transplants and initiating tacrolimus. Both responded well to IV fluids and insulin and were transitioned to SQ insulin by discharge. Risk factors for post-transplant de novo DKA and HHS common to both patients were African American ethnicity, high BMI, and tacrolimus treatment with elevated trough levels. Tacrolimus inhibits insulin secretion and is linked to increased rates of PTDM, which is often reversible with tacrolimus dosage reduction. Both of our patients were prescribed tacrolimus at reduced dosage and were scheduled for outpatient Endocrine clinic evaluation to determine whether they should continue insulin treatment.

Disclosure

S. Gupta: None. D. Lovre: Other Relationship; AstraZeneca, Bayer AG, Novo Nordisk. R. Galagan: None.

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