Laboratory of Genetic, Endocrine and Metabolic Diseases, Department of Laboratory Medicine, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands.
Clin Chem. 2010 Oct;56(10):1570-9. doi: 10.1373/clinchem.2010.149187. Epub 2010 Aug 25.
Hepcidin is an iron-regulatory peptide hormone that consists of 3 isoforms: bioactive hepcidin-25, and inactive hepcidin-22 and hepcidin-20. Hepcidin is instrumental in the diagnosis and monitoring of iron metabolism disorders, but reliable methods for its quantification in serum are sparse, as is knowledge of their relative analytical strengths and clinical utility.
We developed a competitive (c)-ELISA and an immunocapture TOF mass-spectrometry (IC-TOF-MS) assay. Exploiting these 2 methods and our previously described weak cation exchange (WCX)-TOF-MS assay, we measured serum hepcidin concentrations in 186 patients with various disorders of iron metabolism and in 23 healthy controls.
We found that (a) the relative differences in median hepcidin concentrations in various diseases to be similar, although the absolute concentrations measured with c-ELISA and WCX-TOF-MS differed; (b) hepcidin isoforms contributed to differences in hepcidin concentrations between methods, which were most prominent in patients with chronic kidney disease; and (c) hepcidin concentrations measured by both the c-ELISA and IC-TOF-MS correlated with ferritin concentrations <60 μg/L, and were suitable for distinguishing between iron deficiency anemia (IDA) and the combination of IDA and anemia of chronic disease.
c-ELISA is the method of choice for the large-scale quantification of serum hepcidin concentrations, because of its low limit of detection, low cost, and high-throughput. Because of its specificity for bioactive hepcidin-25, WCX-TOF-MS can be regarded as a valuable special-purpose assay for disorders with variable concentrations of hepcidin isoforms, such as chronic kidney disease.
铁调素是一种由 3 种同工型组成的铁调节肽激素：生物活性的铁调素-25、无活性的铁调素-22 和铁调素-20。铁调素在铁代谢紊乱的诊断和监测中起着重要作用，但血清中铁调素的定量方法可靠，其相对分析优势和临床应用也知之甚少。
我们开发了一种竞争（c）-ELISA 和免疫捕获飞行时间质谱（IC-TOF-MS）检测法。利用这两种方法和我们之前描述的弱阳离子交换（WCX）-TOF-MS 检测法，我们测量了 186 例各种铁代谢紊乱患者和 23 例健康对照者的血清铁调素浓度。
我们发现：（a）尽管 c-ELISA 和 WCX-TOF-MS 检测法的绝对浓度不同，但各种疾病的铁调素浓度中位数的相对差异相似；（b）铁调素同工型导致了不同检测法之间铁调素浓度的差异，在慢性肾脏病患者中最为明显；（c）c-ELISA 和 IC-TOF-MS 检测的铁调素浓度与铁蛋白浓度<60μg/L 相关，适合区分缺铁性贫血（IDA）和 IDA 与慢性病性贫血的联合。
c-ELISA 因其低检测限、低成本和高通量而成为血清铁调素浓度大规模定量的首选方法。由于其对生物活性铁调素-25 的特异性，WCX-TOF-MS 可视为一种用于铁调素同工型浓度变化的疾病的有价值的专用检测法，如慢性肾脏病。
