Petersen Eskild, Borobio Maria Victoria, Guy Edward, Liesenfeld Oliver, Meroni Valeria, Naessens Anne, Spranzi Emma, Thulliez Philippe
WHO/FAO International Centre for Research and Reference on Toxoplasmosis, Statens Serum Institut, Artillerivej 5, DK-2300 Copenhagen S, Denmark.
J Clin Microbiol. 2005 Apr;43(4):1570-4. doi: 10.1128/JCM.43.4.1570-1574.2005.
The LIAISON system is a fully automated system based on chemiluminescence and antigen bound to magnetic microparticles. The system allows fast and precise measurement of Toxoplasma-specific immunoglobulin G (IgG) and IgM antibody levels and measurement of the IgG avidity index even at low levels of Toxoplasma-specific IgG antibodies in a single step without manual interference. Seven European centers participated in a multicenter evaluation of the LIAISON system. The sensitivity and specificity of the LIAISON system compared to the Sabin-Feldman dye test were 99.3 and 96.8%, respectively. In a comparison of the LIAISON Toxoplasma-specific IgM assay with an immunosorbent agglutination assay, the LIAISON assay had a sensitivity of 96.7% and a specificity of 95.4%. The LIAISON IgG assay showed agreements of 91, 100, and 100% with the AXSYM IgG (Abbott), VIDAS IgG (bioMerieux), and Platelia IgG (Bio-Rad) assays, respectively. The LIAISON IgM assay showed agreements of 95% with the AXSYM IgM and Platelia IgM assays, 96% with the ISAGA IgM assay (bioMerieux), and 97% with the VIDAS IgM assay. The coefficient of correlation between the LIAISON system and the VIDAS Toxoplasma-specific IgG avidity index was 0.81. By use of the Toxoplasma-specific IgG avidity index assay with specific IgM-positive samples, the diagnosis of infection with Toxoplasma gondii in early pregnancy has been improved significantly. The LIAISON avidity assay is a valuable assay for the exclusion of recently acquired infection with T. gondii (less than 4 months) in pregnant women, and it decreases significantly the necessity for follow-up testing.
LIAISON系统是一个基于化学发光和与磁性微粒结合的抗原的全自动系统。该系统能够在无需人工干预的情况下，一步快速、精确地检测弓形虫特异性免疫球蛋白G（IgG）和IgM抗体水平，甚至在弓形虫特异性IgG抗体水平较低时也能检测IgG亲和力指数。七个欧洲中心参与了LIAISON系统的多中心评估。与Sabin-Feldman染料试验相比，LIAISON系统的灵敏度和特异性分别为99.3%和96.8%。在将LIAISON弓形虫特异性IgM检测法与免疫吸附凝集试验进行比较时，LIAISON检测法的灵敏度为96.7%，特异性为95.4%。LIAISON IgG检测法与AXSYM IgG（雅培公司）、VIDAS IgG（生物梅里埃公司）和Platelia IgG（伯乐公司）检测法的一致性分别为91%、100%和100%。LIAISON IgM检测法与AXSYM IgM和Platelia IgM检测法的一致性为95%，与ISAGA IgM检测法（生物梅里埃公司）的一致性为96%，与VIDAS IgM检测法的一致性为97%。LIAISON系统与VIDAS弓形虫特异性IgG亲和力指数之间的相关系数为0.81。通过对特异性IgM阳性样本使用弓形虫特异性IgG亲和力指数检测法，显著改善了早孕期间弓形虫感染的诊断。LIAISON亲和力检测法对于排除孕妇近期（少于4个月）获得的弓形虫感染是一种有价值的检测方法，并且显著降低了后续检测的必要性。
