Wang Hui, Bi Xiaohui, Xu Lei, Li Yirong
1 Department of Laboratory Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
2 Department of Laboratory Medicine, Zhongnan Hospital, Wuhan University, Wuhan, China.
Ann Clin Biochem. 2017 Jan;54(1):55-59. doi: 10.1177/0004563216636646. Epub 2016 Sep 28.
Background Rheumatoid factor causes positive interference in multiple immunoassays. Recently, negative interference has also been found in immunoassays in the presence of rheumatoid factor. The chemiluminescent microparticle immunoassay is widely used to determine serum alpha-fetoprotein. However, it is not clear whether the presence of rheumatoid factor in the serum causes interference in the chemiluminescent microparticle immunoassay of alpha-fetoprotein. Methods Serum alpha-fetoprotein was determined using the ARCHITECT alpha-fetoprotein assay. The estimation of alpha-fetoprotein recovery was carried out in samples prepared by diluting high-concentration alpha-fetoprotein serum with rheumatoid factor-positive or rheumatoid factor-negative serum. Paramagnetic microparticles coated with hepatitis B surface antigen-anti-HBs complexes were used to remove rheumatoid factor from the serum. Results The average recovery of alpha-fetoprotein was 88.4% and 93.8% in the rheumatoid factor-positive and rheumatoid factor-negative serum samples, respectively. The recovery of alpha-fetoprotein was significantly lower in the rheumatoid factor-positive serum samples than in the rheumatoid factor-negative serum samples. In two of five rheumatoid factor-positive samples, a large difference was found (9.8%) between the average alpha-fetoprotein recoveries in the serially diluted and initial recoveries. Fourteen rheumatoid factor-positive serum samples were pretreated with hepatitis B surface antigen-anti-HBs complex-coated paramagnetic microparticles. The alpha-fetoprotein concentrations measured in the pretreated samples increased significantly. Conclusions It was concluded that the alpha-fetoprotein chemiluminescent microparticle immunoassay is susceptible to interference by rheumatoid factor, leading to significantly lower results. Eliminating the incidence of negative interference from rheumatoid factor should be an important goal for immunoassay providers. In the meantime, laboratorians must remain alert to the negative interference by rheumatoid factor, and in some cases, pretreat rheumatoid factor-positive samples with blocking or absorbing reagents.
背景 类风湿因子在多种免疫测定中会引起正干扰。最近，在存在类风湿因子的免疫测定中也发现了负干扰。化学发光微粒子免疫测定法被广泛用于测定血清甲胎蛋白。然而，血清中类风湿因子的存在是否会对甲胎蛋白的化学发光微粒子免疫测定产生干扰尚不清楚。方法 使用ARCHITECT甲胎蛋白测定法测定血清甲胎蛋白。通过用类风湿因子阳性或类风湿因子阴性血清稀释高浓度甲胎蛋白血清制备的样本中进行甲胎蛋白回收率的估算。使用包被有乙肝表面抗原-抗-HBs复合物的顺磁性微粒子从血清中去除类风湿因子。结果 类风湿因子阳性和类风湿因子阴性血清样本中甲胎蛋白的平均回收率分别为88.4%和93.8%。类风湿因子阳性血清样本中甲胎蛋白的回收率显著低于类风湿因子阴性血清样本。在五个类风湿因子阳性样本中的两个样本中，连续稀释后的平均甲胎蛋白回收率与初始回收率之间存在较大差异（9.8%）。对14个类风湿因子阳性血清样本用包被有乙肝表面抗原-抗-HBs复合物的顺磁性微粒子进行预处理。预处理样本中测得的甲胎蛋白浓度显著增加。结论 得出结论，甲胎蛋白化学发光微粒子免疫测定易受类风湿因子干扰，导致结果显著降低。消除类风湿因子产生的负干扰发生率应是免疫测定供应商的一个重要目标。同时，实验室人员必须对类风湿因子的负干扰保持警惕，在某些情况下，用封闭或吸附试剂对类风湿因子阳性样本进行预处理。
