Silén A, Wiklund B, Andersson E L, Nilsson S
AB IDL ImmunoDevelopLab, Borlänge, Sweden.
Scand J Clin Lab Invest. 1995 Apr;55(2):153-61. doi: 10.3109/00365519509089608.
Cytokeratins 8 and 18 are most frequently co-expressed in simple epithelia and carcinomas. Fragments of these cytokeratins are released into the systemic circulation where they can be quantified and utilized as tumour markers. The present paper reports on a solid-phase sandwich monoclonal immunoassay, considered "epithelial tissue-specific", which recognizes fragments of human cytokeratins 8 and 18 of different sizes (10-50 kD). The evaluated ELISA and IRMA assays exhibited a detection limit of 0.1 microgram 1-1 and characteristically demonstrated a within-assay coefficient of variation (CV) of 1-4% and a between-assay CV of 3-5%. The long-term (300 days) repeatability of lyophilized samples tested in the assay was estimated to have a less than 10% CV. Of apparently healthy individuals, 95% were found to have serum concentrations of less than 0.95 micrograms 1-1. A highly significant difference was found between apparently healthy individuals and pancreatic cancer patients. Patients with metastatic disease showed a sensitivity of 93% and those with local disease 83%, at 95% specificity. This TPAcyk assay revealed good correlation (0.98) with the TPS assay detecting the specific M3 epitope of the tissue polypeptide antigen. The correlation with the long established polyclonal assay of tissue polypeptide antigen (TPA) was estimated to be 0.9.
细胞角蛋白8和18最常共同表达于单层上皮和癌组织中。这些细胞角蛋白的片段会释放到体循环中，在那里它们可以被定量并用作肿瘤标志物。本文报道了一种被认为是“上皮组织特异性”的固相夹心单克隆免疫测定法，该方法可识别不同大小（10 - 50 kD）的人细胞角蛋白8和18的片段。所评估的ELISA和IRMA测定法的检测限为0.1微克/升，批内变异系数（CV）为1 - 4%，批间CV为3 - 5%。在该测定法中测试的冻干样品的长期（300天）重复性估计CV小于10%。在明显健康的个体中，发现95%的人血清浓度低于0.95微克/升。在明显健康的个体和胰腺癌患者之间发现了高度显著的差异。在95%的特异性下，转移性疾病患者的敏感性为93%，局部疾病患者为83%。这种TPAcyk测定法与检测组织多肽抗原特异性M3表位的TPS测定法显示出良好的相关性（0.98）。与长期建立的组织多肽抗原（TPA）多克隆测定法的相关性估计为0.9。
