Saraei M, Shojaee S, Esmaeli Ar, Jahani-Hashemi H, Keshavarz H
Dept. of Medical Parasitology and Mycology, School of Medicine, Qazvin University of Medical Sciences, Qazvin, Iran.
Iran J Parasitol. 2010 Dec;5(4):55-62.
The IFA test is one of the most usual methods for detecting anti-Toxoplasma antibodies, although it has not any unique standardization. It seems that the microscopic judgment of results is an important confounder in IFA test. Therefore, we conducted the present study to clarify the role of microscopic observer, and other confounders on the test.
Eighty sera were collected from patients suspicious to toxoplasmosis for detection IgG anti-T. gondii by this test. Samples were examined against different series of antigens, IgG anti-human conjugates, and observers.
There were no significant differences between the two series of antigens and conjugates. For the observers groups the kappa coefficient of the test results in the experts group (0.97, 0.94-1.00) were significantly higher than the less experienced observers (0.77, 0.68-0.87).
We recommend the IFA test to be performed only in reference laboratories and by laboratory technicians that have enough experience for this test. Otherwise, we suggest the substitution of this test with other tests like ELISA for the diagnosis and epidemiological studies.
间接荧光抗体试验（IFA）是检测抗弓形虫抗体最常用的方法之一，尽管该方法没有统一的标准化流程。结果的显微镜判断似乎是IFA试验中的一个重要干扰因素。因此，我们开展了本研究以阐明显微镜观察者及其他干扰因素在该试验中的作用。
收集了80份疑似弓形虫病患者的血清，通过该试验检测抗弓形虫IgG抗体。针对不同系列的抗原、抗人IgG结合物和观察者对样本进行检测。
两个系列的抗原和结合物之间没有显著差异。对于观察者组，专家组检测结果的kappa系数（0.97，0.94 - 1.00）显著高于经验较少的观察者（0.77，0.68 - 0.87）。
我们建议仅在参考实验室由对此试验有足够经验的实验室技术人员进行IFA试验。否则，我们建议在诊断和流行病学研究中用ELISA等其他试验替代该试验。
