Metzger Jochen, von Landenberg Philipp, Kehrel Marcus, Buhl Alexander, Lackner Karl J, Luppa Peter B
Institute of Clinical Chemistry and Pathobiochemistry, Klinikum Rechts der Isar der TU München, München, Germany.
Clin Chem. 2007 Jun;53(6):1137-43. doi: 10.1373/clinchem.2006.079632. Epub 2007 Apr 13.
For the laboratory diagnosis of the antiphospholipid syndrome (APS) we developed a biosensor with the ability to distinguish between disease-relevant anti-beta2-glycoprotein I (beta2GPI) autoantibodies (anti-beta2GPI) and pathogen-specific beta2GPI cross-reactive antibodies that occur transiently during infections.
We used a surface plasmon resonance (SPR) biosensor device. For the detection of anti-beta2GPI in serum samples, affinity-purified human beta2GPI was covalently attached to a functionalized n-alkanethiol self-assembling monolayer on the biosensor chip. After verifying the specificity of the biosensor system with a panel of monoclonal antibodies to beta2GPI, we analyzed sera from healthy donors and patients suffering from APS, systemic lupus erythematosus (SLE), syphilis, or parvovirus B19 infections. The SPR results were compared with beta2GPI-specific ELISA.
Using the SPR biosensor, we recorded antigen binding curves with response levels in the range of 50-500, resonance units (RU) for anti-beta2GPI ELISA-positive APS patient sera. The amplitudes of the antiphospholipid antibody (APL) responses in the biosensor correlated with the overall IgG and IgM anti-beta2GPI ELISA titers with a correlation coefficient of 0.87. Moreover, we observed immunoglobulin isotype-specific association and dissociation profiles for APL binding of different APS patient sera to the biosensor-immobilized beta2GPI. In contrast to APS patient samples, no significant anti-beta2GPI binding (response levels <35 RU) was observed in samples from healthy individuals or from patients suffering from SLE, syphilis, or parvovirus B19 infection.
The SPR biosensor system enables specific detection of APS-associated beta2GPI-reactive APL and differentiation from beta2GPI cross-reactive antibodies that occur frequently during acute infections. The established association/dissociation plot for anti-beta2GPI responses in APS patient sera gives additional information regarding the influence of anti-beta2GPI IgG and IgM isotype distribution.
为实现抗磷脂综合征（APS）的实验室诊断，我们研发了一种生物传感器，它能够区分与疾病相关的抗β2糖蛋白I（β2GPI）自身抗体（抗β2GPI）和在感染期间短暂出现的病原体特异性β2GPI交叉反应抗体。
我们使用了表面等离子体共振（SPR）生物传感器设备。为检测血清样本中的抗β2GPI，将亲和纯化的人β2GPI共价连接到生物传感器芯片上功能化的正烷硫醇自组装单分子层上。在用一组β2GPI单克隆抗体验证生物传感器系统的特异性后，我们分析了健康供体以及患有APS、系统性红斑狼疮（SLE）、梅毒或细小病毒B19感染的患者的血清。将SPR结果与β2GPI特异性酶联免疫吸附测定（ELISA）结果进行比较。
使用SPR生物传感器，我们记录了抗β2GPI ELISA阳性的APS患者血清的抗原结合曲线，响应水平在50 - 500共振单位（RU）范围内。生物传感器中抗磷脂抗体（APL）反应的幅度与总的IgG和IgM抗β2GPI ELISA滴度相关，相关系数为0.87。此外，我们观察到不同APS患者血清的APL与生物传感器固定的β2GPI结合的免疫球蛋白同种型特异性结合和解离曲线。与APS患者样本不同，在健康个体或患有SLE、梅毒或细小病毒B19感染的患者样本中未观察到明显的抗β2GPI结合（响应水平<35 RU）。
SPR生物传感器系统能够特异性检测与APS相关的β2GPI反应性APL，并与急性感染期间频繁出现的β2GPI交叉反应抗体相区分。所建立的APS患者血清中抗β2GPI反应的结合/解离图提供了关于抗β2GPI IgG和IgM同种型分布影响的额外信息。
