Sokoll L J, Drew H, Udelsman R
Departments of Pathology and Surgery, Johns Hopkins Medical Institutions, Baltimore, MD 21287, USA.
Clin Chem. 2000 Oct;46(10):1662-8.
Immunoassays for parathyroid hormone (PTH), with short incubation times and results available in <15 min, have allowed intraoperative monitoring of the success of parathyroid surgery. The purpose of this study was to evaluate the analytical performance of a rapid PTH assay and its clinical performance in a series of 200 patients.
PTH was measured with a modified immunochemiluminometric assay with a 7-min incubation time (QuiCk-IntraOperative(TM) Intact PTH assay). The rapid assay was compared with results in a central laboratory (immunoradiometric assay) in 44 EDTA-plasma specimens. The rapid assay was used intraoperatively in 200 consecutive cases with specimens analyzed before and 5-10 min after resection of the hypersecreting parathyroid gland(s).
Intraassay imprecision was 12% at 28 ng/L and 11% at 278 ng/L. Regression analysis of results of the rapid PTH assay and the IRMA PTH assay in 44 parathyroidectomy patients yielded y = 1.26x - 12 ng/L, S:(y|x) = 26.3 ng/L, r = 0.984, and in 40 of 44 patients with values <200 ng/L, y = 1.02x + 1.9, S:(y|x) = 13.9, r = 0.947. In the 195 cases using intraoperative PTH testing with complete results and defined clinical outcomes, the overall accuracy of the assay in predicting surgical success was 88% using the criterion of a 50% decrease at 5-10 min and 97% including the subset of patients with delayed decreases of PTH.
The rapid PTH assay had excellent analytical performance and excellent agreement with the PTH immunoradiometric assay and predicted the success of parathyroid surgery in this large series of consecutive patients.
甲状旁腺激素（PTH）免疫测定法孵育时间短，15分钟内即可获得结果，已可用于甲状旁腺手术成功与否的术中监测。本研究的目的是评估一种快速PTH测定法的分析性能及其在200例患者中的临床性能。
采用改良的免疫化学发光测定法测定PTH，孵育时间为7分钟（QuiCk-IntraOperative™全段甲状旁腺激素测定法）。将该快速测定法与中心实验室（免疫放射测定法）对44份乙二胺四乙酸（EDTA）血浆标本的检测结果进行比较。该快速测定法在200例连续病例的手术中使用，在切除分泌过多甲状旁腺之前和之后5-10分钟对标本进行分析。
批内不精密度在28 ng/L时为12%，在278 ng/L时为11%。对44例甲状旁腺切除术患者的快速PTH测定法和免疫放射测定法（IRMA）PTH测定法结果进行回归分析，得出y = 1.26x - 12 ng/L，S:(y|x) = 26.3 ng/L，r = 0.984；在44例PTH值<200 ng/L的患者中，40例的结果为y = 1.02x + 1.9，S:(y|x) = 13.9，r = 0.947。在195例术中使用PTH检测且结果完整、临床结局明确的病例中，按照5-10分钟时降低50%的标准，该测定法预测手术成功的总体准确率为88%；若将PTH降低延迟的患者子集包括在内，则准确率为97%。
快速PTH测定法具有出色的分析性能，与PTH免疫放射测定法一致性良好，且在这一大系列连续患者中预测了甲状旁腺手术的成功。
