Jarava C, Armas J R, Palma A
Servicios de Nefrología y Anatomía Patológica, Hospital Universitario Virgen Macarena, Sevilla.
Nefrologia. 2000 Jul-Aug;20(4):362-72.
The spectrum of bone disease in uremic patients on hemodialysis has changed in the last years. Undecalcified bone biopsy with histomorphometric measurements and tetracycline labelling remains the gold standard for diagnosis of the different forms of renal osteodystrophy. But because of its invasive nature and complicated laboratory processing a number of non-invasive biochemical parameters have been proposed. The aim of our study was to determine the prevalence of the different forms of renal osteodystrophy in our patients in hemodialysis. Moreover we analyse the correlation between several biochemical parameters and the histological findings and evaluate their diagnostic and predictive value. Transiliac bone biopsies were performed in seventy three uremic patients (31 males) on chronic hemodialysis and static and dynamic parameters were measured. Serum levels of intact parathyroid hormone (iPTH), osteocalcin (OC), total alkaline phosphatase (FAT) and bone alkaline phosphatase (FAO) were determined. High-bone remodelling (50 pts, 68.5%) predominates over low-bone remodelling (23 pts, 31.5%). The distribution of the different types of bone disease was: Mild hyperparathyroidism 8 pts, Osteitis fibrosa 37 pts, Mixed lesions 5 pts, Adynamic bone disease 21 pts and Osteomalacia 2 pts. Six of our 73 patients were diabetics and they had adynamic bone disease (4 pts), osteomalacia (1 pt) and osteitis fibrosa (1 pt). Patients older than 50 years presented lower cellular activity (osteoblast surface, ObS/BS) and lower bone formation rate (BFR/BS). iPTH showed different correlation with these parameters of bone formation in patients above and below 50 years old suggesting that older patients need higher levels of PTH to obtain a determined level of bone formation. iPTH, OC, FAT and FAO correlated with the majority of histomorphometric indices of bone formation and resorption, though the best correlations were those with iPTH. The diagnostic and predictive value of these bone markers is better with high-bone remodelling. Serum levels of FAT > 300 U/l, OC > 150 ng/ml, FAO > 40 ng/ml and iPTH > 200 pg/ml showed a positive predictive value of 1 (with a specificity of 1, but sensibility below 0.78 except for iPTH that is 0.95) in the diagnosis of high-bone remodelling. After an analysis with ROC curves the cut-off value to differentiate high from low-bone remodelling was obtained. iPTH level > 200 pg/ml combined with one of the other markers (FAT > 150 U/l, FAO > 30 ng/ml or OC > 100 ng/ml) are predictive of high-bone remodelling, while values below those figures are predictive of low-bone remodelling.
在过去几年中，接受血液透析的尿毒症患者的骨病谱发生了变化。采用组织形态计量学测量和四环素标记的未脱钙骨活检仍是诊断不同形式肾性骨营养不良的金标准。但由于其具有侵入性且实验室处理复杂，人们提出了一些非侵入性生化参数。我们研究的目的是确定我们血液透析患者中不同形式肾性骨营养不良的患病率。此外，我们分析了几种生化参数与组织学结果之间的相关性，并评估了它们的诊断和预测价值。对73例接受慢性血液透析的尿毒症患者（31例男性）进行了经髂骨活检，并测量了静态和动态参数。测定了血清完整甲状旁腺激素（iPTH）、骨钙素（OC）、总碱性磷酸酶（FAT）和骨碱性磷酸酶（FAO）水平。高骨重塑（50例，68.5%）比低骨重塑（23例，31.5%）更为常见。不同类型骨病的分布情况为：轻度甲状旁腺功能亢进8例，纤维性骨炎37例，混合性病变5例，骨代谢低下21例，骨软化2例。我们的73例患者中有6例为糖尿病患者，他们患有骨代谢低下（4例）、骨软化（1例）和纤维性骨炎（1例）。年龄大于50岁的患者表现出较低的细胞活性（成骨细胞表面，ObS/BS）和较低的骨形成率（BFR/BS）。iPTH在50岁以上和以下的患者中与这些骨形成参数显示出不同的相关性，这表明老年患者需要更高水平的PTH才能获得一定水平的骨形成。iPTH、OC、FAT和FAO与大多数骨形成和吸收的组织形态计量学指标相关，尽管与iPTH的相关性最佳。这些骨标志物在高骨重塑时的诊断和预测价值更好。血清FAT>300 U/l、OC>150 ng/ml、FAO>40 ng/ml和iPTH>200 pg/ml在诊断高骨重塑时的阳性预测值为1（特异性为1，但敏感性低于0.78，iPTH除外，其敏感性为0.95）。通过ROC曲线分析后，获得了区分高骨重塑和低骨重塑的临界值。iPTH水平>200 pg/ml与其他标志物之一（FAT>150 U/l、FAO>30 ng/ml或OC>100 ng/ml）结合可预测高骨重塑，而低于这些数值则可预测低骨重塑。
