Khammari I, Saghrouni F, Bougmiza I, Gheith S, Ben Abdejlil J, Yaacoub A, Boukadida J, Babba H, Ben Saïd M
Laboratoire de parasitologie-mycologie, CHU Farhat Hached, rue Mohamed Karoui, 4000 Sousse, Tunisie.
Pathol Biol (Paris). 2012 Jun;60(3):160-5. doi: 10.1016/j.patbio.2011.02.003. Epub 2011 Nov 10.
The serological tests commonly used for the diagnosis of toxoplasmosis raise the problem of the interpretation of the borderline immunoglobulin G (IgG) levels and discordant results between various tests.
The purpose of our study was to evaluate the contribution of the immunoblotting in the detection of specific IgG in acquired toxoplasmosis of immunocompetent patients especially when levels are equivocal or discordant in enzyme-linked immunosorbent assay (Elisa) and indirect fluorescent antigen test (IFAT).
[corrected] We tested three groups of sera. The first included 87 positive sera, the second 33 negative sera, and the last one 29 equivocal sera.
Results obtained with the first and the second group of sera led us to identify the bands 30kDa and 32kDa as markers of the toxoplasmic infection. The simultaneous presence of both bands showed a sensitivity of 91.5%, a specificity of 96.9%, a VPP of 98.7%, a VPN of 74.4% and a Youden's index of 0.88. Our findings suggest that the presence of these two bands is a reliable criterion for the confirmation of the presence of anti-toxoplasmic IgG in the corresponding serum. The immunoblot allowed us to ascertain serological status of 27 (93.1%) patients from the third group in which results were discrepant or equivocal in Elisa and/or in IFAT.
Immunoblot is a useful serological test for detection of very low or equivocal titers.
常用于诊断弓形虫病的血清学检测引发了临界免疫球蛋白G（IgG）水平的解读问题以及不同检测结果不一致的问题。
我们研究的目的是评估免疫印迹法在检测免疫功能正常患者获得性弓形虫病特异性IgG中的作用，尤其是当酶联免疫吸附测定（ELISA）和间接荧光抗原试验（IFAT）结果不明确或不一致时。
我们检测了三组血清。第一组包括87份阳性血清，第二组33份阴性血清，最后一组29份临界血清。
第一组和第二组血清的检测结果使我们确定30kDa和32kDa条带为弓形虫感染的标志物。两条带同时出现时，灵敏度为91.5%，特异性为96.9%，阳性预测值为98.7%，阴性预测值为74.4%，约登指数为0.88。我们的研究结果表明，这两条带的存在是确认相应血清中抗弓形虫IgG存在的可靠标准。免疫印迹法使我们能够确定第三组中27例（93.1%）患者的血清学状态，这些患者在ELISA和/或IFAT中的结果不一致或不明确。
免疫印迹法是检测极低或临界滴度的有用血清学检测方法。
