Universidade Federal de Goiás, Goiânia, GO, Brazil.
Rev Bras Ginecol Obstet. 2021 Dec;43(12):887-893. doi: 10.1055/s-0041-1740272. Epub 2021 Dec 21.
The purpose of the present study is to standardize and evaluate the use of the immunoglobulin G (IgG) antibody avidity test on blood samples from newborns collected on filter paper to perform the heel test aiming at its implementation in ongoing programs.
Blood samples from newborns were collected on filter paper simultaneously with the heel prick test. All samples were subjected to immunoglobulin M IgM and IgG enzyme-linked immunosorbent assays (ELISA). Peripheral blood was collected again in the traditional way and on filter paper from newborns with high IgG levels (3). Three types of techniques were performed, the standard for measuring IgG in serum, adapted for filter paper and the technique of IgG avidity in serum and on filter paper. The results of the avidity test were classified according to the Rahbari protocol.
Among the 177 samples, 17 were collected in duplicate from the same child, 1 of peripheral blood and 1 on filter paper. In this analysis, 1 (5.88%) of the 17 samples collected in duplicate also exhibited low IgG avidity, suggesting congenital infection. In addition, the results obtained from serum and filter paper were in agreement, that is, 16 (94.12%) samples presented high avidity, with 100% agreement between the results obtained from serum and from filter paper.
The results of the present study indicate that the avidity test may be another valuable method for the diagnosis of congenital toxoplasmosis in newborns.
本研究旨在规范和评估在滤纸采集的新生儿血样上进行 IgG 抗体亲和力检测的方法，以应用于足跟血筛查，并将其纳入现行项目。
同时在滤纸和足跟采血处采集新生儿血样。所有样本均进行 IgM 和 IgG 酶联免疫吸附试验（ELISA）检测。对 IgG 水平较高（³3）的新生儿，采用传统方法和滤纸再次采集外周血。采用 3 种技术，即血清 IgG 标准测量法、滤纸适配测量法和血清及滤纸 IgG 亲和力测量法。根据 Rahbari 方案对亲和力试验结果进行分类。
在 177 份样本中，有 17 份来自同一名儿童的重复样本，其中 1 份来自外周血，1 份来自滤纸。在这项分析中，17 份重复样本中有 1 份（5.88%）也表现出 IgG 亲和力较低，提示先天性感染。此外，血清和滤纸的结果一致，即 16 份（94.12%）样本具有高亲和力，血清和滤纸的结果完全一致。
本研究结果表明，亲和力试验可能是诊断新生儿先天性弓形虫病的另一种有价值的方法。
