Rojas González Andrés Marcelo, Opazo Valenzuela Marcela, Muñoz Navarro Sergio
Universidad de la Frontera, Temuco, Chile. Universidad San Sebastián, Chile. Address: Seminario s/n, Puerto Montt, Chile. Email:
Hospital Puerto Montt, Chile.
Medwave. 2014 Sep 3;14(8):e6014. doi: 10.5867/medwave.2014.08.6014.
High turnover renal osteodystrophy (HTRO) is a highly prevalent complication in patients with chronic kidney disease and mineral bone disease (CKD-MBD), causing pain and significant fracture-associated morbidity and mortality. The diagnostic gold standard test is bone biopsy but there are other, more widely available screening tests such as 1-84 intact parathormone (1-84 iPTH) and nonspecific markers such as total alkaline phosphatase (tALP).
To determine the diagnostic value (ROC curve, predictive values and likelihood ratios) of 1-84 iPTH and tALP for HTRO screening.
A diagnostic accuracy study was performed on a sample of CKD-MDB patients, grouping them according to bone biopsy results and analyzing the results of the diagnostic tests as descriptive variables.
The study group comprised 188 patients with CKD-MDB, 36 of which had biopsy-confirmed HTRO (19.15%). The average age was 50.2 years in the biopsy group, and 53.4 years in the non-biopsy group (p=0.2385), most were male (63.8%) and diabetic (80.5%). The mean time in dialysis was 5.02 years in the biopsy group, and 2.61 years for the non-biopsy group (p<0.001). The mean Kt/V was 1.44 in the biopsy group, and 1.40 in the non-biopsy group (p=0.5354). The mean tALP was 398.02 IU/L in the group with HTRO versus 141.76 IU/L in the group without HTRO (p<0.001). The best cut-off value for tALP was 300-350 IU/L with a near 80% post-test probability, but also with a 15-20% probability for HTRO if the test is negative. The mean 1-84 iPTH was 1248.01 pg/ml in the group with HTRO versus 350.76 pg/ml in the group without HTRO (p<0.001). The 1-84 iPTH cut-off reference value of 300 pg/ml was associated with a post-test probability of 30% for HTRO diagnosis and had a lower overall performance. The best cut-off value for iPTH 1-84 was 600 pg/ml with a post-test probability for HTRO of 70% if positive and less than 5% if the test results are negative.
Both markers show good correlation with bone biopsy findings. tALP elevation detects presence of HTRO in selected patients but does not rule it out. tALP does not perform as well as 1-84 iPTH as a screening test for HTRO.
高转换型肾性骨营养不良（HTRO）是慢性肾脏病和矿物质骨病（CKD-MBD）患者中一种非常普遍的并发症，会导致疼痛以及与骨折相关的显著发病率和死亡率。诊断的金标准检测是骨活检，但还有其他更广泛可用的筛查检测，如1-84全段甲状旁腺激素（1-84 iPTH）以及非特异性标志物，如总碱性磷酸酶（tALP）。
确定1-84 iPTH和tALP用于HTRO筛查的诊断价值（ROC曲线、预测值和似然比）。
对一组CKD-MDB患者进行诊断准确性研究，根据骨活检结果对他们进行分组，并将诊断检测结果作为描述性变量进行分析。
研究组包括188例CKD-MDB患者，其中36例经活检确诊为HTRO（19.15%）。活检组的平均年龄为50.2岁，非活检组为53.4岁（p = 0.2385），大多数为男性（63.8%）且患有糖尿病（80.5%）。活检组的平均透析时间为5.02年，非活检组为2.61年（p<0.001）。活检组的平均Kt/V为1.44，非活检组为1.40（p = 0.5354）。HTRO组的平均tALP为398.02 IU/L，无HTRO组为141.76 IU/L（p<0.001）。tALP的最佳截断值为300 - 350 IU/L，检测后概率接近80%，但如果检测结果为阴性，HTRO的概率也有15 - 20%。HTRO组的平均1-84 iPTH为1248.01 pg/ml，无HTRO组为350.76 pg/ml（p<0.001）。300 pg/ml的1-84 iPTH截断参考值与HTRO诊断的检测后概率为30%相关，总体表现较低。1-84 iPTH的最佳截断值为600 pg/ml，检测结果为阳性时HTRO的检测后概率为70%，检测结果为阴性时小于5%。
两种标志物均与骨活检结果显示出良好的相关性。tALP升高可在部分患者中检测到HTRO的存在，但不能排除。作为HTRO的筛查检测，tALP的表现不如1-84 iPTH。
