Wallon M, Dunn D, Slimani D, Girault V, Gay-Andrieu F, Peyron F
Service de Parasitologie, Hôpital de la Croix-Rousse, Lyon, France.
Eur J Pediatr. 1999 Aug;158(8):645-9. doi: 10.1007/s004310051168.
Recommendations vary on the best combination of tests to use for the diagnosis of subclinical congenital toxoplasmosis at birth. The diagnostic accuracy of IgM and IgA tests was assessed in the context of routine clinical practice on 233 newborns with congenital toxoplasmosis and 661 healthy controls. IgM/IgA sensibility and specificity were compared in cord and postnatal samples. Both tests were considerably more specific in neonatal blood (IgM: 98%; IgA: 100%) than in cordblood (IgM: 85%; IgA: 88%). Sensitivity for IgM and IgA was not significantly different in neonatal blood (61% and 60%, respectively) and cord blood (67% and 54%, respectively). Combining IgM and IgA increased the overall sensitivity to 73% without any significant loss in specificity (98%). The influence of the date of maternal infection on the sensitivity and negative predictive value was also clearly demonstrated.
Because of their relatively low cost compared to more sophisticated methods, IgM and IgA tests should remain the main method for the routine diagnosis of congenital toxoplasmosis although follow up is essential to identify the Ca. 25% of infected children who are missed at birth on the basis of these tests.
关于出生时用于诊断亚临床先天性弓形虫病的最佳检测组合，建议各不相同。在常规临床实践中，对233例先天性弓形虫病新生儿和661例健康对照进行了IgM和IgA检测的诊断准确性评估。比较了脐带血和出生后样本中IgM/IgA的敏感性和特异性。两种检测在新生儿血液中的特异性均显著高于脐带血（IgM：98%；IgA：100%）（IgM：85%；IgA：88%）。IgM和IgA在新生儿血液中的敏感性（分别为61%和60%）和脐带血中的敏感性（分别为67%和54%）无显著差异。联合使用IgM和IgA可将总体敏感性提高至73%，而特异性无显著损失（98%）。还清楚地证明了母亲感染日期对敏感性和阴性预测值的影响。
与更复杂的方法相比，由于IgM和IgA检测成本相对较低，它们应仍然是先天性弓形虫病常规诊断的主要方法，尽管随访对于识别约25%在出生时基于这些检测被漏诊的感染儿童至关重要。
