Viganò G, Gotti E, Comberti E, Giangrande A, Trevisan R, Remuzzi G
Istituto di Ricerche Farmacologiche 'Mario Negri' Bergamo, Italy.
Nephrol Dial Transplant. 1989;4(11):971-4. doi: 10.1093/ndt/4.11.971.
Patients with chronic renal failure suffer from secondary hyperparathyroidism and have greatly increased blood concentrations of intact parathyroid hormone (PTH) and PTH fragments. Thus PTH has been regarded in the last few years as a uraemic toxin possibly responsible for many clinical manifestations of the uraemic syndrome including a tendency to prolonged bleeding. Since PTH inhibits platelet aggregation 'in vitro', the possibility that hyperparathyroidism of uraemia plays a role in the pathogenesis of uraemic bleeding has been considered. Clinical data to support this possibility is not available so far. In this study we have correlated the skin bleeding time, the best clinical marker of uraemic bleeding tendency, with serum concentrations of intact PTH or PTH fragments in 40 patients with chronic renal failure undergoing chronic haemodialysis. Since the skin bleeding time is known to be influenced by packed cell volume (PCV), we also considered two distinct groups of uraemic patients on the basis of their PCV values. The results indicated that bleeding time does not correlate with serum concentrations of intact PTH or PTH fragments. Also, no correlation has been found between PTH values and blood concentrations of calcium, phosphorus, magnesium and hydroxyproline. It is concluded that elevated PTH values in renal-failure patients do not contribute to uraemic platelet defect, as reflected by the skin bleeding time.
慢性肾衰竭患者会患继发性甲状旁腺功能亢进，其血液中完整甲状旁腺激素（PTH）和PTH片段的浓度会大幅升高。因此，在过去几年中，PTH被视为一种尿毒症毒素，可能是尿毒症综合征许多临床表现的病因，包括出血倾向延长。由于PTH在“体外”抑制血小板聚集，因此人们认为尿毒症的甲状旁腺功能亢进在尿毒症出血的发病机制中起作用。目前尚无支持这一可能性的临床数据。在本研究中，我们将皮肤出血时间（尿毒症出血倾向的最佳临床指标）与40例接受慢性血液透析的慢性肾衰竭患者的血清完整PTH或PTH片段浓度进行了关联。由于已知皮肤出血时间受血细胞比容（PCV）影响，我们还根据PCV值将尿毒症患者分为两个不同的组。结果表明，出血时间与血清完整PTH或PTH片段浓度无关。此外，未发现PTH值与血液中钙、磷、镁和羟脯氨酸浓度之间存在相关性。结论是，肾衰竭患者PTH值升高不会导致以皮肤出血时间为反映的尿毒症血小板缺陷。
