Messa P, Sindici C, Cannella G, Miotti V, Risaliti A, Gropuzzo M, Di Loreto P L, Bresadola F, Mioni G
Nephrology, Dialysis and Transplantation Unit, Tissue Typing Laboratory, Ospedale S. Maria della, Martino, Genova, Italy.
Kidney Int. 1998 Nov;54(5):1704-13. doi: 10.1046/j.1523-1755.1998.00142.x.
The persistence of secondary hyperparathyroidism after renal transplantation is frequent and often complicated by overt hypercalcemia. Recent investigations have shown an effect of the different vitamin D receptor (VDR) genotypes on parathyroid hormone (PTH) secretion in both primary and secondary hyperparathyroidism. The aims of this study were (i) to assess whether persistent secondary hyperparathyroidism after renal transplantation is characterized by any change in calcium-controlled PTH secretion, and (ii) whether different VDR allelic distributions might play any role on this setting.
Eighty-one cadaveric renal transplantation recipients, followed-up for at least 12 months, were checked for PTH, other primary metabolic and clinical variables, and VDR B/b alleles (BsmI). In 22 of these the following parameters were evaluated: (a) kinetics parameters of the Ca-PTH relation curve; (b) vertebral mineral density; (c) calcitriol serum levels; (d) PTH-related peptide serum levels; and (e) urinary hydroxyproline.
According to the stabilised PTH levels (reached by the third month), the patients were divided in two groups: group A (N = 40, PTH < 80 pg/ml) and group B (N = 41, PTH > 80 pg/ml). Group B differed from group A in that patients had higher PTH levels at the time of transplantation, were older in age, and spent more time on dialysis. Group B had increased maximal and minimal PTH levels, and higher set-point levels than Group A. The patients with the BB pattern of VDR genotype were characterized by the lowest PTH levels both at time of transplantation and after stabilization, and lower set point values than patients with Bb and bb patterns.
Our study suggests that (i) the severity of pre-existing secondary hyperparathyroidism is the main factor determining its persistence after renal transplantation, (ii) persistent secondary hyperparathyroidism is characterized by an autonomous pattern of PTH secretion, (iii) the VDR BB genotype seems to be related to lower PTH levels.
肾移植后继发性甲状旁腺功能亢进持续存在的情况很常见，且常并发明显的高钙血症。最近的研究表明，不同的维生素D受体（VDR）基因型在原发性和继发性甲状旁腺功能亢进中对甲状旁腺激素（PTH）分泌均有影响。本研究的目的是：（i）评估肾移植后继发性甲状旁腺功能亢进持续存在是否以钙控制的PTH分泌的任何变化为特征，以及（ii）不同的VDR等位基因分布是否可能在此情况下发挥任何作用。
对81名尸体肾移植受者进行至少12个月的随访，检查其PTH、其他主要代谢和临床变量以及VDR B/b等位基因（BsmI）。其中22名受者评估了以下参数：（a）钙 - PTH关系曲线的动力学参数；（b）椎体骨密度；（c）骨化三醇血清水平；（d）PTH相关肽血清水平；以及（e）尿羟脯氨酸。
根据稳定的PTH水平（第三个月时达到），患者分为两组：A组（N = 40，PTH < 80 pg/ml）和B组（N = 41，PTH > 80 pg/ml）。B组与A组的不同之处在于，B组患者在移植时PTH水平较高、年龄较大且透析时间较长。B组的最大和最小PTH水平升高，设定点水平高于A组。VDR基因型为BB模式的患者在移植时和稳定后PTH水平最低，设定点值低于Bb和bb模式的患者。
我们的研究表明：（i）移植前存在的继发性甲状旁腺功能亢进的严重程度是决定其肾移植后持续存在的主要因素；（ii）持续性继发性甲状旁腺功能亢进的特征是PTH分泌自主模式；（iii）VDR BB基因型似乎与较低的PTH水平相关。
