Koper N P, Thomas C M, Massuger L F, Segers M F, Olthaar A J, Verbeek A L
Department of Obstetrics and Gynaecology, University of Nijmegen, The Netherlands.
Clin Chem Lab Med. 1998 Jan;36(1):23-8. doi: 10.1515/CCLM.1998.005.
Currently no available immunoassay system offers complete protection against spuriously elevated or lowered results due to interference by Human Anti-Mouse Antibodies (HAMA). Although routine use of chromatography procedures is not an acceptable option because of the extra cost and workload involved, such a procedure would be highly desirable to ensure accurate immunoassay results. The present report describes a relatively simple affinity chromatography procedure using a HiTrap Protein G column to isolate immunoglobulin G (IgG) HAMA, followed by a HiTrap N-hydroxy-succinimide (NHS)-activated column coupled to goat-anti human immunoglobulin M (IgM) to bind IgM HAMA. To examine the usefulness of this purification procedure we determined CA 125 in forty serum samples prior to and following chromatography. Pre- and post-injection samples were obtained from 20 patients injected with 1 mg of 111In-labelled murine OC 125 F(ab')2 fragments in an immunoscintigraphy study. It is shown that this analytical procedure provides a technique to determine the extent and the nature of the existing HAMA interference in samples of patients after in vivo use of monoclonal antibodies for diagnostic or therapeutic purposes. The procedure can also contribute to the clarification of clinically discordant CA 125 results. Finally, the availability of such a procedure in the clinical laboratory provides an opportunity to test the robustness of newly developed immunoassay systems towards HAMA interference.
目前，由于人抗鼠抗体（HAMA）的干扰，没有一种现有的免疫分析系统能够完全防止结果出现假性升高或降低。尽管由于涉及额外的成本和工作量，常规使用色谱法不是一个可接受的选择，但这样的程序对于确保免疫分析结果的准确性将是非常理想的。本报告描述了一种相对简单的亲和色谱法，该方法使用HiTrap Protein G柱分离免疫球蛋白G（IgG）HAMA，随后使用与山羊抗人免疫球蛋白M（IgM）偶联的HiTrap N-羟基琥珀酰亚胺（NHS）活化柱结合IgM HAMA。为了检验这种纯化程序的实用性，我们在色谱分离前后测定了40份血清样本中的CA 125。注射前和注射后的样本取自20名在免疫闪烁显像研究中注射了1 mg 111In标记的鼠源OC 125 F(ab')2片段的患者。结果表明，这种分析程序提供了一种技术，可用于确定在体内使用单克隆抗体进行诊断或治疗后患者样本中现有HAMA干扰的程度和性质。该程序还有助于澄清临床上不一致的CA 125结果。最后，临床实验室中具备这样一种程序提供了一个机会，可用于测试新开发的免疫分析系统对HAMA干扰的稳健性。
