BACKGROUND: Chronic uremia is responsible for secondary hyperparathyroidism (HPT II). Parathyroid secretion usually tends to normalize after kidney transplantation (KT), but the parameters of the reversibility of HPT II remain poorly defined, particularly the intrinsic mechanisms underlying the improvement of parathyroid function. METHODS: The kinetic functional parameters of the ionized calcium (iCa)/parathormone (PTH) relationship curve were studied in 11 patients with mild to moderate HPT II one and six months after successful KT. Hypercalcemia and hypocalcemia were induced, respectively, by CaCl2 and Na2-ethylenediaminetetraacetic acid (Na2-EDTA) infusions. RESULTS: The mean glomerular filtration rate remained stable during follow-up. Basal PTH decreased from 195 +/- 54 pg/ml before KT to 70 +/- 12 pg/ml six months later (P < 0. 005). During the tests, mean PTH levels decreased significantly between the two measured times for all iCa levels, indicating an improved parathyroid function. An analysis of the kinetic parameters of the curves showed significant decreases of the mean maximal and minimal PTH levels, respectively, from 340 +/- 91 to 220 +/- 30 pg/ml (P = 0.03) and from 25 +/- 6 to 15 +/- 5 pg/ml (P = 0.005). On the other hand, no change was noted in the parathyroid-cell calcium-sensitivity parameters (slope, set point) assessed using two different approaches, either the entire curve or the limited calcium-mediated suppression curve. CONCLUSION: Improvement of the parathyroid function between the first and sixth months post-KT seems mainly attributable to a reduction of the parathyroid functional mass.
BACKGROUND:Chronic uremia is responsible for secondary hyperparathyroidism (HPT II). Parathyroid secretion usually tends to normalize after kidney transplantation (KT), but the parameters of the reversibility of HPT II remain poorly defined, particularly the intrinsic mechanisms underlying the improvement of parathyroid function. METHODS: The kinetic functional parameters of the ionizedcalcium (iCa)/parathormone (PTH) relationship curve were studied in 11 patients with mild to moderate HPT II one and six months after successful KT. Hypercalcemia and hypocalcemia were induced, respectively, by CaCl2 and Na2-ethylenediaminetetraacetic acid (Na2-EDTA) infusions. RESULTS: The mean glomerular filtration rate remained stable during follow-up. Basal PTH decreased from 195 +/- 54 pg/ml before KT to 70 +/- 12 pg/ml six months later (P < 0. 005). During the tests, mean PTH levels decreased significantly between the two measured times for all iCa levels, indicating an improved parathyroid function. An analysis of the kinetic parameters of the curves showed significant decreases of the mean maximal and minimal PTH levels, respectively, from 340 +/- 91 to 220 +/- 30 pg/ml (P = 0.03) and from 25 +/- 6 to 15 +/- 5 pg/ml (P = 0.005). On the other hand, no change was noted in the parathyroid-cell calcium-sensitivity parameters (slope, set point) assessed using two different approaches, either the entire curve or the limited calcium-mediated suppression curve. CONCLUSION: Improvement of the parathyroid function between the first and sixth months post-KT seems mainly attributable to a reduction of the parathyroid functional mass.
Authors: Catherine Madorin; Randall P Owen; William D Fraser; Phillip K Pellitteri; Brian Radbill; Alessandra Rinaldo; Raja R Seethala; Ashok R Shaha; Carl E Silver; Matthew Y Suh; Barrie Weinstein; Alfio Ferlito Journal: Eur Arch Otorhinolaryngol Date: 2011-11-20 Impact factor: 2.503
Authors: Irene Lou; David Foley; Scott K Odorico; Glen Leverson; David F Schneider; Rebecca Sippel; Herbert Chen Journal: Ann Surg Date: 2015-10 Impact factor: 12.969