Parathyroid allotransplantation for severe post-surgical hypoparathyroidism: a Brazilian experience

This study presents the cases of two women who developed severe permanent hypoparathyroidism after neck surgery for papillary thyroid cancer and underwent parathyroid allotransplantation. Despite taking high doses of calcium and calcitriol supplements, the patients experienced persistent hypocalcemic symptoms. Fresh parathyroid tissue was removed and prepared from two patients with hyperparathyroidism secondary to end-stage kidney disease and was implanted in the non-dominant forearm of the recipients. Donors and recipients were ABO-compatible, and immunological screening was performed only in Case 2 (HLA typing, panel reactive antibody, and crossmatch tests). A short-term immunosuppressive regimen was adopted, consisting of 3 days of methylprednisolone followed by 7 days of prednisone. In Case 1, oral supplementation decreased to half of the initial dose 1 month after transplantation and to one-fifth at the end of a 12-month follow-up period. In Case 2, intravenous calcium was discontinued 1-week post-transplantation, with no need for its use during the 12-month follow-up period. Serum parathyroid hormone levels did not increase and remained undetectable in both cases. In contrast, serum calcium levels increased significantly, and both patients experienced relief from hypocalcemic symptoms. Parathyroid allotransplantation can be an effective and safe treatment for PH and should be considered in severe cases. Nevertheless, formal recommendations depend on additional studies and validated protocols.