Estimation of the avidity of immunoglobulin G for routine diagnosis of chronic Toxoplasma gondii infection in pregnant women
Estimation of the avidity of immunoglobulin G for routine diagnosis of chronic Toxoplasma gondii infection in pregnant women
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DOI：
10.1007/bf01584360
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发表时间：
1998-01-01
影响因子：
4.5
通讯作者：
Peyron, F
中科院分区：
文献类型：
--
作者：
Cozon, GJN;Ferrandiz, J;Peyron, F
目前的血清学方法很难区分孕妇的急性和慢性弓形虫病，特别是当弓形虫免疫球蛋白G(Ig G)和免疫球蛋白M(Ig M)抗体同时存在时。在目前的研究中，评估了一种区分高亲和力抗体和低亲和力抗体的简单测试，高亲和力抗体通常存在于慢性感染中，低亲和力抗体通常出现在急性感染中。用一种商用的酶免疫测定法对血清中的弓形虫抗体进行了评估，但用6M尿素清洗了一个重复的井，以破坏低亲和力的复合体。结果以抵抗尿素洗脱的抗体百分比表示。用标准方法分别测定了309例慢性或急性感染孕妇血清中弓形虫抗体的亲和力。~gt；35%的耐洗脱抗体的值总是与慢性感染有关，完全可以排除最近(<；3个月)的感染事件。35%的值需要在四周后重复检测以确认患者的状态，因为慢性弓形虫病患者的一部分人长期保持低亲和力抗体。这种廉价、简单的方法可以为明显的慢性感染者提供保证，并避免在这些情况下进行重复检测。
Present serological methods differentiate poorly between acute and chronic toxoplasmosis in pregnant women, particularly when immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies to Toxoplasma gondii are present simultaneously. In the present study, a simple test for discriminating between high-avidity antibodies, which are usually present in chronic infections, and low-avidity antibodies, typical of acute infection, was evaluated. Sera were evaluated for Toxoplasma gondii antibodies using a commercial enzyme immunoassay, but a duplicate well was washed in 6M urea to disrupt low-avidity complexes. Results are expressed as the percentage of antibodies resisting elution by urea. Equivocal sera (n = 493) containing both IgG and IgM Toxoplasma gondii antibodies from 309 pregnant women whose status as chronically or acutely infected had been independently determined using standard methods were evaluated for antibody avidity. A value of > 35% elution-resistant antibodies was always associated with chronic infection and could absolutely exclude a recent (< 3 months) infectious incident. Values of < 35% require repeat testing four weeks later to confirm the patient's status, since a proportion of individuals with chronic toxoplasmosis maintain low-avidity antibodies over long periods. This inexpensive, simple method can provide reassurance to clearly chronically infected individuals and avoids the need for repeated testing in these cases.