A switch towards Th2 during serological rebound in children with congenital toxoplasmosis

Kahi, Sandrine; Cozon, G.; Pinon, J. M.; Greenland, Timothy; Wallon, Martine; Kurdi, M Al; Ferrandiz, Josette; Peyron, François

doi:10.1046/j.1365-2249.1999.01019.x

Cited by 12 publications

(13 citation statements)

References 26 publications

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“…The low risk of rebound during treatment, and the signi®cant increase after therapy discontinuation is in favour of a role played by parasite reactivation. This hypothesis is supported by ®ndings of studies performed in our laboratory which indicated the presence of circulating speci®c IgG antibody secreting cells [8] and the switch toward Th2 observed in children with recent IgG rebound [9], as well as by the presence of Toxoplasma IgE antibodies in 50% of the cases in two studies [9,13]. However, the absence of a signi®cant risk of active ocular lesions in the long-term in children who had a rebound compared to those with no rebound, the absence of any noticeable eect of an additional course of treatment on duration of the rebound and ophthalmological outcome, and the fact that some rebounds occurred during treatment or long after therapy discontinuation are in favour of other mechanisms.…”

Section: Discussionmentioning

confidence: 56%

Serological rebound in congenital toxoplasmosis: long-term follow-up of 133 children

et al. 2001

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Section: Discussionmentioning

confidence: 56%

Serological rebound in congenital toxoplasmosis: long-term follow-up of 133 children

et al. 2001

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“…In newborn children, reduced production of T. gondii-specific IgG antibodies has been observed during treatment during the first year of life (8,29). A generally reduced antibody response to pathogens could be due to either pregnancy or the drug (13).…”

Section: Discussionmentioning

confidence: 99%

Spiramycin Treatment of Toxoplasma gondii Infection in Pregnant Women Impairs the Production and the Avidity Maturation of T. gondii -Specific Immunoglobulin G Antibodies

Meroni

Genco

Tinelli

et al. 2009

Clin Vaccine Immunol

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The aim of the study was to evaluate the influence of treatment with spiramycin on the increase of immunoglobulin G (IgG) titers and IgG avidity indexes (AI) in pregnant women with seroconversion from the beginning of therapy until delivery and after delivery. This group was compared with adult patients with recently acquired untreated toxoplasmosis. One hundred four samples from 32 pregnant women with seroconversion for toxoplasmosis and/or very low IgG AI were followed from the beginning of therapy with spiramycin until delivery. Twenty-nine women were further followed some months after delivery and interruption of therapy. Thirty-eight samples from 16 untreated, nonpregnant patients were evaluated as the control group. The Toxoplasma gondii-specific IgG antibody and the T. gondii-specific IgG AI were significantly delayed in pregnant women receiving therapy compared to nonpregnant, untreated controls, and the findings were consistent with the results of assays from two different manufacturers. The T. gondii-specific IgG AI increased in pregnant women after they gave birth. Avidity maturation is delayed during pregnancy and treatment, and low-avidity antibodies in pregnant women within 3 to 4 months cannot be taken as a sign of infection.After infection, the specific immunoglobulin G (IgG) antibody response matures by the selection of clones of B cells producing antibodies with increasingly higher avidities against a specific antigen from the invading microorganism. In Toxoplasma gondii infections, specific IgM may be present for a long time (14-17), and measurement of the T. gondii-specific IgG avidity index (AI) is the best method to determine the time of infection (24) and is a further development of the differential agglutination assay (3,27).The original method developed by Hedman et al. (4, 5) used serial dilutions tested in enzyme immunoassays with and without 6 M urea, but automated assays calculate the IgG AI from two single measurements with and without urea (22). This introduces uncertainty, although experiments with only two serum sample dilutions showed excellent agreement with IgG AI measurements obtained with four serial serum sample dilutions (9).A persistent, low IgG AI poses a diagnostic problem, at least in some pregnant women receiving treatment during pregnancy (21).The observation that Toxoplasma gondii-specific IgG maturation is delayed in treated pregnant women compared to nontreated, nonpregnant individuals has been reported in two previous studies, which found significantly delayed IgG maturation in treated individuals (13, 26).The maturation of the IgG response varies between individuals and may take months in pregnant, treated women, for whom one study found that a low IgG AI persisted up to 9 months postinfection (20). In a study of T. gondii-infected pregnant women identified prospectively through prenatal screening, one study found that 2 out of 73 women had IgG AI above 0.2 before 20 weeks of gestation, but many continued to have low IgG AI even a year after infection. It is ass...

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“…Incubation times for optimal cellular responses and cytokine detection in supernatants had previously been determined by kinetic assays. 18 On day 7, culture supernatants were collected from each tube and stored at −20°C until required for cytokine determination.…”

Section: Patientsmentioning

confidence: 99%

Systemic T Cell Response to Toxoplasma gondii Antigen in Patients with Ocular Toxoplasmosis

et al. 2006

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A switch towards Th2 during serological rebound in children with congenital toxoplasmosis

Cited by 12 publications

References 26 publications

Serological rebound in congenital toxoplasmosis: long-term follow-up of 133 children

Serological rebound in congenital toxoplasmosis: long-term follow-up of 133 children

Spiramycin Treatment of Toxoplasma gondii Infection in Pregnant Women Impairs the Production and the Avidity Maturation of T. gondii -Specific Immunoglobulin G Antibodies

Systemic T Cell Response to Toxoplasma gondii Antigen in Patients with Ocular Toxoplasmosis

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