Falkiewicz K, Bidzińska B, Demissie M, Boratyńska M, Zmonarski S C, Tworowska K, Klinger M, Milewicz A, Patrzałek D
Department of Nephrology and Transplantation Medicine, Wrocław Medical University, Wrocław, Poland.
Transplant Proc. 2005 Mar;37(2):1023-5. doi: 10.1016/j.transproceed.2005.01.048.
Secondary hyperparathyroidism and immunosuppressive treatments are the most important pathogenetic factors for bone disease after kidney transplantation. The aim of study was to compare the influence of vitamin D receptor (VDR) genotype on the PTH level and bone mineral density (BMD) in 67 patients, including 45 immunosuppressed with cyclosporine (CsA) and 22 with tacrolimus (Tac) versus 147 healthy volunteers. Two VDR polymorphisms: BsmI and FokI were assayed with RFLP-PCR. Scantibodies were utilized to evaluate 1-84 PTH. BMD was measured by DEXA. Hormone levels were measured on the third day and sixth month after transplantation. BMD was examined at the third and ninth month. The distribution of FokI genotype differed, but the BsmI genotypes did not differ between the transplant patients and the control group. All transplanted patients showed an elevated tPTH at the first examination. The highest PTH values, which were observed in bb genotype, significantly decreased after the transplant procedure. Patients with the FF genotype who were treated with CsA showed higher levels of tPTH than those with the Ff genotype. At 6 months, a decrease in tPTH occurred in both the CsA and the Tac patients. A low BMD at the third month was more frequent among patients of the BB genotype treated with CsA. The Z-score remained low at the third month and at the ninth month. In conclusion, kidney graft recipients show overrepresentation of the Ff genotype. Our preliminary data suggest that the bb genotype exhibits a protective effect on bone loss after renal transplantation.
继发性甲状旁腺功能亢进和免疫抑制治疗是肾移植后骨病最重要的致病因素。本研究的目的是比较维生素D受体（VDR）基因型对67例患者甲状旁腺激素（PTH）水平和骨密度（BMD）的影响，其中45例接受环孢素（CsA）免疫抑制治疗，22例接受他克莫司（Tac）免疫抑制治疗，另有147名健康志愿者作为对照。采用限制性片段长度多态性聚合酶链反应（RFLP-PCR）检测VDR基因的两个多态性位点：BsmI和FokI。使用抗体检测1-84 PTH。采用双能X线吸收法（DEXA）测量骨密度。在移植后第三天和第六个月测量激素水平。在移植后第三个月和第九个月检查骨密度。FokI基因型的分布存在差异，但移植患者和对照组之间BsmI基因型无差异。所有移植患者在首次检查时均显示总PTH升高。在bb基因型患者中观察到的最高PTH值在移植手术后显著下降。接受CsA治疗的FF基因型患者的总PTH水平高于Ff基因型患者。在6个月时，CsA组和Tac组患者的总PTH均下降。接受CsA治疗的BB基因型患者在第三个月时骨密度低的情况更为常见。在第三个月和第九个月时Z评分均较低。总之，肾移植受者中Ff基因型的比例过高。我们的初步数据表明，bb基因型对肾移植后骨质流失具有保护作用。
