Use of an Immunoglobulin G Avidity Assay Based on Recombinant Antigens for Diagnosis of Primary<i>Toxoplasma gondii</i>Infection during Pregnancy

Beghetto, Elisa; Buffolano, Wilma; Spadoni, Andrea; Pezzo, Mariassunta Del; Cristina, Manlio Di; Minenkova, Olga; Petersen, Eskild; Felici, Franco; Gargano, Nicola

doi:10.1128/jcm.41.12.5414-5418.2003

Cited by 80 publications

(50 citation statements)

References 26 publications

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“…Moreover, many recombinant proteins from T. gondii have been synthesized and tested for sensitivity and specificity in IgG ELISAs (194). Some of them displayed an interesting avidity response pattern, allowing a better performance than crude antigens for discriminating between chronic and acute infections, but their interest to clinical practice remains to be confirmed with larger series (28,257).…”

Section: Serologic Techniques and Interpretation (I) A Wide Range Ofmentioning

confidence: 99%

Epidemiology of and Diagnostic Strategies for Toxoplasmosis

2012

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SUMMARY The apicomplexan parasite Toxoplasma gondii was discovered a little over 100 years ago, but knowledge of its biological life cycle and its medical importance has grown in the last 40 years. This obligate intracellular parasite was identified early as a pathogen responsible for congenital infection, but its clinical expression and the importance of reactivations of infections in immunocompromised patients were recognized later, in the era of organ transplantation and HIV infection. Recent knowledge of host cell-parasite interactions and of parasite virulence has brought new insights into the comprehension of the pathophysiology of infection. In this review, we focus on epidemiological and diagnostic aspects, putting them in perspective with current knowledge of parasite genotypes. In particular, we provide critical information on diagnostic methods according to the patient's background and discuss the implementation of screening tools for congenital toxoplasmosis according to health policies.

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Section: Serologic Techniques and Interpretation (I) A Wide Range Ofmentioning

confidence: 99%

Epidemiology of and Diagnostic Strategies for Toxoplasmosis

2012

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“…Several previous studies have found that recombinant antigens improve the serological diagnosis of T. gondii infections in adults with acquired infection (1,4,20,23,28,33,40). However, no studies so far have described the use of recombinant antigens for the diagnosis of congenital toxoplasmosis in newborns.…”

Section: Discussionmentioning

confidence: 99%

“…Immunodominant regions of T. gondii proteins have previously been identified (2)(3)(4)(5)9). The immunoreactivity of seven distinct fragments of T. gondii, the MIC2, MIC3, MIC4, M2AP, AMA1, and SAG1 proteins, expressed as GST fusion products, was assessed with sera from infants with congenital T. gondii infection.…”

Section: Discussionmentioning

confidence: 99%

Use of Recombinant Antigens for Early Postnatal Diagnosis of Congenital Toxoplasmosis

Buffolano

Beghetto²,

Pezzo

et al. 2005

J Clin Microbiol

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The main objective of this work was to improve the early serologic diagnosis of toxoplasmosis in children at risk of congenital infection by using recombinant antigens. Serum samples from 104 infants born to mothers with primary Toxoplasma gondii infection acquired during pregnancy, of which 35 were congenitally infected and 22 had clinical silent toxoplasmosis at birth, were included. Immunoglobulin M (IgM), IgG, and IgG subtype antibodies against epitopes carried by fragments of T. gondii MIC2, MIC3, MIC4, M2AP, AMA1, and SAG1 gene products were measured by performing parallel enzyme immunoassays (Rec-ELISAs). Recombinant antigens preferentially reacted with IgG antibodies from infected infants compared to uninfected subjects (P < 0.0001), indicating that sera from infected children recognized a more diverse repertoire of antigens than sera transferred over the placenta from the mothers. Using two serial samples collected within 3 months of life, it was possible to demonstrate a neosynthesis of specific anti-MIC2 and anti-SAG1 immunoglobulin G, mainly of the IgG2 subtype, in 13 out of 20 infants with congenital toxoplasmosis. IgM antibodies in 97% of infected infants reacted with at least one of the recombinant antigens, confirming the diagnosis of congenital infection as soon as 2 months after birth (P < 0.0001). The use of recombinant antigens is effective in distinguishing T. gondii-infected from uninfected infants and shows that assays based on recombinant antigens improve the diagnosis of newborns with congenital toxoplasmosis.

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“…Several studies have reported that the avidity of antibody IgG is a good index of the time of the infection, defining if the acute infection has occurred in the past few months despite conflicting results between tests (BARBERI et al, 2001). Recombinant antigens were frequently tested in serology for toxoplasmosis (SUZUKI et al, 2001), usually with adequate but weak screening results compared to whole extracts in ELISA ( VAN GELDER et al, 1993 (BEGHETTO et al, 2003). Most of these studies were performed on selected sera panels defined by other tests, which could interfere in efficacy determination.…”

Section: Introductionmentioning

confidence: 99%

Serology using rROP2 antigen in the diagnostic of toxoplasmosis in pregnant women

Macre¹,

Pires²,

Meireles³

et al. 2009

Rev. Inst. Med. trop. S. Paulo

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SUMMARYToxoplasma 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.

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Use of an Immunoglobulin G Avidity Assay Based on Recombinant Antigens for Diagnosis of PrimaryToxoplasma gondiiInfection during Pregnancy

Cited by 80 publications

References 26 publications

Epidemiology of and Diagnostic Strategies for Toxoplasmosis

Epidemiology of and Diagnostic Strategies for Toxoplasmosis

Use of Recombinant Antigens for Early Postnatal Diagnosis of Congenital Toxoplasmosis

Serology using rROP2 antigen in the diagnostic of toxoplasmosis in pregnant women

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