Ozel L, Ata P, Ozel M S, Toros A B, Kara M, Unal E, Canbakan M, Erdogrul G, Aktas G E, Titiz M I
Department of 1st General Surgery and Transplantation, Haydarpasa Numune Training and Research Hospital, İstanbul, Turkey.
Transplant Proc. 2011 Apr;43(3):858-62. doi: 10.1016/j.transproceed.2011.02.075.
Rapid loss of vertebral or hip mineral density after renal transplantation is a major complication which occurs within 6-12 months. The aim of this study was to evaluate risk factors contributing to bone disease in the early stage after renal transplantation and the effect of vitamin D receptor (VDR) gene polymorphisms.
We prospectively followed for up to 12 months 44 patients (29 men and 15 women) with end-stage renal disease who underwent kidney transplantation. All patients received prednisone with either cyclosporine (CsA)/mycophenolate mofetil (MMF) or tacrolimus (Tac)/MMF therapy. Spine, hip, and whole body bone mineral density (BMD) was measured at 12 months after transplantation. According to World Health Organization recommendations, our patients were categorized as normal, osteopenic, or osteoporotic BMD levels. VDR alleles were genotyped as BB, Bb, or bb by polymerase chain reactions based on polymorphism at the Bsm I restriction site.
Forty-six percent of patients were normal, 43% osteopenic, and 11% osteoporotic. Significant risk factors for osteoporosis among renal transplant recipients were younger age and pretransplant high intact parathyroid hormone (iPTH) levels. (P values .045 and .027, respectively). According to polymorphic group categorization, posttransplant serum Ca was significantly higher in patients with BB or Bb genotype than in those with bb genotype (P = .012). Although there was no statistical significance regarding iPTH levels, it was higher among Bb+BB than the bb genotype group. Also, first-year BMD analysis after transplantation according to Bsm I polymorphism showed significant differences in femur BMD levels according to the dual classification of polymorphism (P < .05). The BMD levels in the bb group was higher than in the Bb+BB group.
Although high pretransplant iPTH levels and younger age enhanced posttransplant bone loss, functionally different alleles of the VDR gene may modulate bone turnover during the first year after renal transplantation.
肾移植后椎体或髋部骨矿物质密度迅速下降是一种主要并发症，发生在6 - 12个月内。本研究的目的是评估肾移植术后早期导致骨病的危险因素以及维生素D受体（VDR）基因多态性的影响。
我们对44例接受肾移植的终末期肾病患者（29例男性和15例女性）进行了长达12个月的前瞻性随访。所有患者均接受泼尼松联合环孢素（CsA）/霉酚酸酯（MMF）或他克莫司（Tac）/MMF治疗。在移植后12个月测量脊柱、髋部和全身骨矿物质密度（BMD）。根据世界卫生组织的建议，将我们的患者分为BMD水平正常、骨量减少或骨质疏松。基于Bsm I限制性位点的多态性，通过聚合酶链反应将VDR等位基因基因分型为BB、Bb或bb。
46%的患者BMD正常，43%骨量减少，11%骨质疏松。肾移植受者骨质疏松的显著危险因素是年龄较小和移植前高血清完整甲状旁腺激素（iPTH）水平。（P值分别为0.045和0.027）。根据多态性分组分类，BB或Bb基因型患者移植后血清钙显著高于bb基因型患者（P = 0.012）。虽然iPTH水平无统计学意义，但Bb + BB组高于bb基因型组。此外，根据Bsm I多态性进行的移植后第一年BMD分析显示，根据多态性的双重分类，股骨BMD水平存在显著差异（P < 0.05）。bb组的BMD水平高于Bb + BB组。
虽然移植前高iPTH水平和年轻会加重移植后骨丢失，但VDR基因功能不同的等位基因可能在肾移植后的第一年调节骨转换。
