title: Parathyroid responsiveness during hypocalcemia after total parathyroidectomy and autotransplantation in patients with renal hyperparathyroidism.
abstract: BACKGROUND
  Hyperparathyroidism is a frequent complication of chronic kidney disease (CKD). Total parathyroidectomy (PTX) with parathyroid tissue autotransplantation (AT) is a treatment option in those individuals that do not respond to clinical management.
  
  
  OBJECTIVE
  To evaluate grafted parathyroid tissue response during induced hypocalcemia among CKD patients who underwent total PTX with AT.
  
  
  METHODS
  Eighteen patients with renal hyperparathyroidism were submitted to total PTX with parathyroid AT selected by stereomicroscopy between April and October 2008. Eleven (eight with successful kidney transplantation, 2 in peritoneal dialysis and 1 in hemodialysis) were clinically stable and eligible for testing. Hypocalcemia was induced using sodium bicarbonate infusion in 5 healthy controls and in patients 6-12 months after surgery.
  
  
  RESULTS
  Among controls, hypocalcemia elicited a major rise in intact PTH (iPTH) levels 4 minutes after bicarbonate infusion. In patients, a significant decrease in ionized calcium concentration was observed [from 1.17 ± 0.12 to 1.09 ± 0.11 mean (± SE) mmol/L] in the 4th minute (p < 0.001) illustrating the nadir point. In the 10thminute, ionized calcium did not show a statistical increase compared to the 4th minute (p = 0.451). The iPTH levels ranged from 34.8 ± 18.6 to 34.1 ± 18.8 pg/mL (similar values between base line and 4thminute p = 0.087) and did not change in the 10th minute (33.3 ± 19,6 pg/ mL p = 0.693).
  
  
  CONCLUSIONS
  Among CKD patients tested 6-12 months after surgery, grafted parathyroid tissue revealed a blunted secretory capacity during bicarbonate induced hypocalcemia with no changes in iPTH levels.
authors.affiliation: Universidade Federal de São Paulo, Brazil.
authors.forename: Patricia
authors.initials: P
authors.lastname: Dreyer
authors.affiliation: Universidade Federal de São Paulo, Brazil.
authors.forename: Monique Nakayama
authors.initials: MN
authors.lastname: Ohe
authors.affiliation: Universidade Federal de São Paulo, Brazil.
authors.forename: Livia Marcela Dos
authors.initials: LM
authors.lastname: Santos
authors.affiliation: Universidade Federal de São Paulo, Brazil.
authors.forename: Ilda Sizue
authors.initials: IS
authors.lastname: Kunii
authors.affiliation: Universidade Federal de São Paulo, Brazil.
authors.forename: Rodrigo Oliveira
authors.initials: RO
authors.lastname: Santos
authors.affiliation: Universidade Federal de São Paulo, Brazil.
authors.forename: Aluizio Barbosa de
authors.initials: AB
authors.lastname: Carvalho
authors.affiliation: Universidade Federal de São Paulo, Brazil.
authors.forename: Jose Gilberto Henriques
authors.initials: JG
authors.lastname: Vieira
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000209:etiology / Q000601:surgery*; D006996:Hypocalcemia / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010280:Parathyroid Glands / Q000637:transplantation*; D010281:Parathyroid Hormone / Q000378:metabolism*; D016105:Parathyroidectomy / Q000379:methods; D051436:Renal Insufficiency, Chronic / Q000150:complications; D014182:Transplantation, Autologous
chemical_list: D010281:Parathyroid Hormone