Tuomanen E I, Powell K R
J Pediatr. 1980 Aug;97(2):238-43. doi: 10.1016/s0022-3476(80)80481-1.
The early diagnosis of congenital infection frequently depends on the ability to distinguish between infant IgM and maternal IgG antibodies. Staphylococcal protein A, which specifically binds IgG, removed maternal IgG from the serum of newborn infants. Residual IgM antibodies to CMV, rubella, toxoplasmosis, and syphilis were then identified by routine serologic techniques. Persistence of greater than or equal to 25% of the original antibody titer following SPA adsorption distinguished the sera of infants with congenital infection from those of healthy infants. No false negative results were encountered. Specificity of the serologic results of SPA-treated infant sera correlated with IgM-specific identification of the causative agent. Potentially false positive titers were identified by concurrent elevation of IgA or rheumatoid factor. Adsorption of cord or neonatal serum with SPA facilitates accurate serologic diagnosis of congenital infection.
先天性感染的早期诊断常常依赖于区分婴儿IgM和母体IgG抗体的能力。葡萄球菌A蛋白能特异性结合IgG，可从新生儿血清中去除母体IgG。然后通过常规血清学技术鉴定针对巨细胞病毒、风疹、弓形虫病和梅毒的残留IgM抗体。经葡萄球菌A蛋白吸附后，原始抗体滴度持续存在大于或等于25%，可将先天性感染婴儿的血清与健康婴儿的血清区分开来。未出现假阴性结果。经葡萄球菌A蛋白处理的婴儿血清的血清学结果特异性与致病原的IgM特异性鉴定相关。通过IgA或类风湿因子同时升高可识别潜在的假阳性滴度。用葡萄球菌A蛋白吸附脐带血或新生儿血清有助于对先天性感染进行准确的血清学诊断。
