Popovici Théodora, Moreira Baptiste, Schlageter Marie-Hélène, Bories Phuong-Nhi
Department of Clinical Chemistry, Hôpital Cochin, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France.
Department of Cellular Biology, Hôpital Saint-Louis, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France.
Clin Biochem. 2014 Jan;47(1-2):87-91. doi: 10.1016/j.clinbiochem.2013.10.029. Epub 2013 Nov 5.
Chromogranin A (CgA) is the best-characterized biological marker common to neuroendocrine tumours and is therefore recommended for their diagnosis. The measurement of serum CgA is of great importance for reaching an early diagnosis and thus reducing the delay before treatment is instigated. The Kryptor CgA assay is the first fully automated assay available. The aim of this study was to evaluate its analytical performance.
The imprecision and linearity of the Kryptor CgA assay were evaluated. This assay was compared with the Cis Bio CgA RIA assay in 78 serum samples. Its clinical utility was assessed in serum from 229 patients.
The study performed on imprecision of Kryptor measurements showed intra- and inter-run CVs ≤ 5%. The study of linearity showed a satisfactory recovery rate for CgA concentrations up to 1200 μg/L. The Kryptor and RIA assays agreed well on the basis of the cut-off values provided by the two manufacturers. The Bland and Altman plot of the values obtained (range: 20-5560 μg/L) provided a mean difference of -10.1 μg/L (SD: 116). The clinical sensitivities of Kryptor CgA for diagnosis of pheochromocytoma and paraganglioma (n 20) and gastroenteropancreatic NETs (n 17) were respectively 100 and 94%.
The Kryptor assay for CgA shows reliable analytical and clinical characteristics and allows a fast delivery of results.
嗜铬粒蛋白A（CgA）是神经内分泌肿瘤最具特征性的常见生物标志物，因此推荐用于其诊断。血清CgA的检测对于早期诊断从而减少开始治疗前的延迟至关重要。Kryptor CgA检测是首个可用的全自动检测方法。本研究的目的是评估其分析性能。
评估Kryptor CgA检测的不精密度和线性。将该检测方法与Cis Bio CgA RIA检测方法在78份血清样本中进行比较。在229例患者的血清中评估其临床实用性。
关于Kryptor测量不精密度的研究显示批内和批间变异系数≤5%。线性研究表明，对于高达1200μg/L的CgA浓度，回收率令人满意。根据两家制造商提供的临界值，Kryptor和RIA检测结果一致性良好。所获得值（范围：20 - 5560μg/L）的Bland和Altman图显示平均差异为 - 10.1μg/L（标准差：116）。Kryptor CgA诊断嗜铬细胞瘤和副神经节瘤（n = 20）以及胃肠胰神经内分泌肿瘤（n = 17）的临床敏感性分别为100%和94%。
Kryptor CgA检测显示出可靠的分析和临床特征，并能快速出具结果。
