SAT239 Deceased Donor Parathyroid Allotransplant For Sever Refractory Iatrogenic Hypoparathyroidism

Disclosure: K.M. Devon: None. A. Zahedi: None. A. Madani: None. J.D. Pasternak: None. B. Saravana-Bawan: None. A. Humar: None. T. Kathryn: None. While Halstead experimented with dog parathyroid transplantation, the first reported human parathyroid allotransplant appeared in the Annals of Surgery in 1911. Efforts of varying success in restoring calcium homeostasis in patients with refractory hypoparathyroidism after thyroidectomy have included parathyroid transplantation(tx), mainly in immunosuppressed kidney transplant recipients, using cryopreserved, cultured, or hypercellular tissues. Recently, cases of living-donor parathyroid allotransplants have been reported. We present a 46 year-old woman who developed hypoparathyroidism following total thyroidectomy 9 years prior. Treatment included two years of continuous teriparatide via CAD pump. Complications of portacath sepsis and pulmonary emboli, required intensive care. At the time of transplantation, our patient was taking elemental calcium 16 grams daily, magnesium 12 grams daily, calcitriol 8 ug daily, hydroochlorothiazide 25 mg twice daily, and nonetheless requiring biweekly intravenous calcium for symptoms and Calcium levels of 1.6 mmol/l (2.2-2.6 mmol/L). PTH ranged between 0.6- 1.2 pmol/l with poor quality of life. A medically suitable neurologically deceased donor was identified through the provincial organ donation organization. Her cumulative cPRA was 98% (Class I-95%/II-81%). Virtual crossmatch only positive for DQ2 specificity with weak positive B-cell flow crossmatch. Four healthy parathyroids were retrieved. The tissue was minced and placed into pockets in the recipient’s right brachioradialis muscle, under local anaesthesia with sedation. Ischemic time was 2.5 hours. She was induced with basiliximab and received tacrolimus, mycophenolate, and prednisone as immunotherapy. Evidence of biochemical parathyroid function was present post-tx day 9, and she was weaned off all calcium homeostatic medications by day 35, remaining asymptomatic at 7 months at the time of writing, with no calcium infusions. Self-reported quality of life is significantly improved. PTH 0.8-2.8 pmol/L and Calcium 2.06-2.37 mmol/l. To our knowledge this is the first successful fresh normal tissue deceased donor parathyroid transplant in a non-transplant recipient in North America. One study suggests that despite immunosuppression risks, 14 percent of patients would entertain parathyroid allotransplantation. We are currently recruiting additional patients with the aim of demonstrating that deceased donor parathyroid allotransplant using fresh tissue and immunosuppression is a novel viable and curative approach to treat permanent severe hypoparathyroidism. Presentation: Saturday, June 17, 2023