Serology using rROP2 antigen in the diagnostic of toxoplasmosis in pregnant women Sorologia utilizando o antígeno recombinante ROP2 no diagnóstico da toxoplasmose em mulheres grávidas

• Published in: Revista do Instituto de Medicina Tropical de São Paulo
• Main Authors: Miriam de Souza Macre, Márcio Pires, Luciana Regina Meireles, Sérgio O. Angel, Heitor Franco de Andrade Jr.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Universidade de São Paulo (USP) 2009
• Subjects: Toxoplasmosis; Pregnancy; Serology; Recombinant proteins; Avidity; Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Aguda; Arctic
• Online Access: https://doi.org/10.1590/S0036-46652009000500009; https://doaj.org/article/8b104732570344dea82ce895d7bcf275

Toxoplasma gondii causes severe fetal disease during acute infection in pregnant women, thus demanding early diagnosis for effective treatment and fetus preservation. Fetal tests are inefficient and risky, and diagnosis is based on maternal IgM serology, which had weak screening ability due to increased sensitivity, with alternative IgG avidity tests. Here, we performed ELISA and avidity assays using a recombinant T. gondii antigen, rROP2, in samples from 160 pregnant women screened from a large public hospital who were referred due to positive IgM assays. IgG serology and avidity assays were compared using whole T. gondii extract or rROP2. ELISA IgG detection with rROP2 showed good agreement with assays performed with T. gondii extract, but rROP2 IgG avidity assays were unrelated to whole extract antigen IgG avidity, regardless of the chaotrope used. These data show that avidity maturation is specific to individual antigen prevalence and immune response during infection. ELISA rROP2 IgG assays may be an alternative serological test for the diagnosis of toxoplasmosis during pregnancy, although our data do not support their use in avidity assays. A toxoplasmose causa grave doença fetal durante a infecção aguda da gestante, assim demanda diagnóstico precoce para tratamento efetivo e preservação fetal. Os testes fetais são de baixa eficiência e o diagnóstico é baseado na sorologia para IgM materna, que tem fraca capacidade de triagem devido a sensibilidade crescente dos testes, sendo uma alternativa os testes de avidez de IgG. Apresentamos aqui um ELISA e ensaio de avidez de IgG usando antígeno recombinante de T. gondii, rROP2, em amostras de 162 gestantes triadas para um grande hospital público por uma sorologia positiva para IgM. O ELISA IgG e o ensaio de avidez de IgG foram comparados usando o antígeno rROP2 ou extrato total de T. gondii. O ELISA usando rROP2 mostrou excelente concordância com os ensaios usando extrato de T. gondii, mas nos ensaios de avidez usando rROP2, os valores encontrados não se ...