Baseler M W, Maxim P E, Veltri R W
Cancer. 1987 May 15;59(10):1727-31. doi: 10.1002/1097-0142(19870515)59:10<1727::aid-cncr2820591009>3.0.co;2-n.
A double antibody enzyme-linked immunosorbent assay (ELISA) was developed to quantitate circulating immune complexed IgA (IgA IC) in human serum. The serum panel for this study consisted of normal blood donors, benign surgery (BS), head and neck cancer (HN), nasopharyngeal carcinoma (NPC), lung cancer (LC), and colon cancer (CC) patients. Immune complexes (IC) were isolated from these sera by precipitation with 3.5% polyethylene glycol (PEG), washed and then redissolved in 0.1 M phosphate-buffered saline pH 7.2. The amount of IgA IC present were then quantified using the double antibody IgA ELISA. This assay was found to be both sensitive (26.0 ng/ml) and reproducible (intra-assay coefficient of variation 4.0%). The mean IgA IC for each cancer group tested (HN = 11.38 +/- 12.54 micrograms/ml; NPC = 13.36 +/- 17.56 micrograms/ml; LC = 17.39 +/- 13.04 micrograms/ml; CC = 26.50 +/- 4.60 micrograms/ml) were significantly elevated (P = 0.001) over both the normals (5.12 +/- 4.09 micrograms/ml) and the benign surgery controls (5.92 +/- 5.04 micrograms/ml). In addition to providing a new tumor marker the presence of high levels of IgA IC in cancer patients could provide a source of tumor-specific antibody as well as antigen and provide reagents to study immune regulation in cancer patients.
开发了一种双抗体酶联免疫吸附测定法（ELISA）来定量人血清中循环免疫复合物IgA（IgA IC）。本研究的血清样本包括正常献血者、良性手术患者（BS）、头颈癌（HN）、鼻咽癌（NPC）、肺癌（LC）和结肠癌（CC）患者。通过用3.5%聚乙二醇（PEG）沉淀从这些血清中分离免疫复合物（IC），洗涤后再溶解于0.1M pH 7.2的磷酸盐缓冲盐水中。然后使用双抗体IgA ELISA定量存在的IgA IC量。发现该测定法既灵敏（26.0 ng/ml）又可重复（批内变异系数为4.0%）。所测试的每个癌症组的平均IgA IC（HN = 11.38 +/- 12.54微克/毫升；NPC = 13.36 +/- 17.56微克/毫升；LC = 17.39 +/- 13.04微克/毫升；CC = 26.50 +/- 4.60微克/毫升）均显著高于正常组（5.12 +/- 4.09微克/毫升）和良性手术对照组（5.92 +/- 5.04微克/毫升）（P = 0.001）。除了提供一种新的肿瘤标志物外，癌症患者中高水平IgA IC的存在还可以提供肿瘤特异性抗体以及抗原的来源，并提供研究癌症患者免疫调节的试剂。
