Serological diagnosis of toxoplasmosis: usefulness of IgA detection and IgG avidity determination in a patient with a persistent IgM antibody response to Toxoplasma gondii

Bertozzi, Luciana C.; Suzuki, Lisandra Akemi; Rossi, Claudio

doi:10.1590/s0036-46651999000300008

Cited by 28 publications

(21 citation statements)

References 12 publications

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“…In most cases, the indeterminate patients were negative in our IgM-GIPL ELISA but positive in the commercial IgM tests (IFA and capture ELISA). While the use of low-affinity IgG as being indicative of acute infection with T. gondii is a matter of debate (13,15), different studies indicate that, consistent with our findings, high-avidity IgG antibodies are good indicators of an infection that was acquired in the past (3,4,5,13).…”

Section: Discussionsupporting

confidence: 85%

Immunoglobulin M (IgM)-Glycoinositolphospholipid Enzyme-Linked Immunosorbent Assay: an Immunoenzymatic Assay for Discrimination between Patients with Acute Toxoplasmosis and Those with Persistent Parasite-Specific IgM Antibodies

et al. 2002

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In the present study we developed an enzyme-linked immunosorbent assay (ELISA) to measure immunoglobulin M (IgM) specific for glycoinositolphospholipids (GIPL) derived from tachyzoite membrane (IgM-GIPL ELISA). The sensitivity and specificity of the assay were compared with those of commercially available Toxoplasma-specific IgM serological tests, namely, immunofluorescence assay (IFA) with fixed tachyzoites and capture ELISA employing tachyzoite extracts. Our results show that all patients with acute toxoplasmosis, as determined by clinical data and conventional serological tests, were also positive by the IgM-GIPL ELISA. Interestingly, many patients that were classified as indeterminate, who had IgG with high avidity but positive results in the IgM-specific IFA and capture ELISA, were negative by the IgM-GIPL ELISA. Finally, we tested the sera from patients with rheumatoid arthritis and various parasitic infections and found no evidence of false positives in the IgM-GIPL ELISA.

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Section: Discussionsupporting

confidence: 85%

Immunoglobulin M (IgM)-Glycoinositolphospholipid Enzyme-Linked Immunosorbent Assay: an Immunoenzymatic Assay for Discrimination between Patients with Acute Toxoplasmosis and Those with Persistent Parasite-Specific IgM Antibodies

et al. 2002

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“…19 More recently, the capture principle has been applied for the detection of other immunoglobulin isotypes such as IgE 20,21 and IgA. 22,23 The binding of a representative part of the total IgE and subsequent detection of anti-P. brasiliensis IgE reflects the relative amount of specific versus total IgE, and not the absolute concentration of specific IgE as measured by indirect ELISA. An increase in the relative amount of specific IgE seemed to be a more sensitive parameter than an increase in the absolute concentration of specific IgE in serum measured by indirect ELISA.…”

Section: Resultsmentioning

confidence: 99%

Capture enzyme-linked immunosorbent assay to detect specific immunoglobulin E in sera of patients with paracoccidioidomycosis.

Mamoni¹,

Rossi²,

Camargo³

et al. 2001

The American Journal of Tropical Medicine and Hygiene

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Abstract. Paracoccidioidomycosis (PCM) is the most frequent systemic mycosis in South America. The disease is characterized by a polyclonal activation of B cells, resulting in hyperimmunoglobulinemia. The production of immunoglobulin (Ig) E in deep mycosis has been related to the severity of the disease. However, the detection of specific IgE in sera of patients is difficult because of the competition with the IgG. We compared a capture and an indirect enzyme-linked immunosorbent assay (ELISA) technique to detect Paracoccidioides brasiliensis IgE. We found that the capture ELISA presented higher performance and lower background values than the indirect assay, resulting in a significant quantitative discrimination between sera from patients with the 2 major clinical forms of PCM. Patients with the juvenile form presented significantly higher levels of P. brasiliensis IgE, as compared with patients with the adult form. The capture ELISA was used in the follow-up of patients receiving treatment, showing that the levels of specific IgE decreased as the patient's clinical conditions improved.

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“…However, kinetic studies revealed that in most cases the decline in the reactivity of IgA antibodies detected by the Platelia test was slower than for IgM antibodies detected by ELISA. Bertozzi et al [8] reported the detection of speci®c IgA antibodies by the ETI-TOXOK-A kit in sequential sera from a patient exhibiting signi®cant levels of T. gondii-speci®c IgM antibodies for 7 years after the onset of the clinical symptoms of toxoplasmosis. Although shorter persistence of speci®c IgA antibodies was observed, signi®-cant levels (.…”

Section: Discussionmentioning

confidence: 99%

Evaluation of serological markers for the immunodiagnosis of acute acquired toxoplasmosis

Suzuki¹,

Rocha

Rossi³

2001

Journal of Medical Microbiology

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The detection of speci®c IgM antibodies has been the most frequently used serological marker for diagnosing recent toxoplasmosis. However, the persistence of speci®c IgM antibodies in some patients and the use of tests with a low speci®city have complicated the interpretation of serological results when toxoplasmosis is suspected. The purpose of the present study was to determine the value of newer serological techniques in the diagnosis of acute acquired toxoplasmosis. Sixty-four sera, 31 from patients with Toxoplasma gondii infection and 33 from patients with latent infection, were tested. Anti-T. gondii IgA was measured by two antibody capture ELISA tests (Platelia 1 Toxo IgA and ETI-TOXOK A) and an automated direct ELISA (IMx 1 Toxo IgA); all three assays detected antibody levels compatible with a recent infection in sera from all 31 patients with acute toxoplasmosis. However, signi®cant levels of IgA were also detected with high frequency by all three assays in sera from patients with latent infection. IgE antibodies detected by IgE immunosorbent agglutination assay (ISAGA) were present in 26 (84%) of 31 patients with acute toxoplasmosis and in sera from two subjects with latent infection taken >1 year after the beginning of the clinical symptoms of infection. Thirty (97%) of 31 patients with a recent T. gondii infection and 15 (45%) of 33 subjects with latent infection had an AC/HS pattern compatible with acute toxoplasmosis. The avidity of T. gondii IgG was evaluated by two methods. One method was based on the titration of each serum sample and calculation of the titres, in the absence and presence of urea, in relation to a de®ned cut-off value. In the other method, a single serum dilution was used and the absorbances of the reactions in the presence and absence of urea were compared. The titration method was more sensitive for diagnosing recent primary infection; all 31 sera from patients with acute toxoplasmosis had avidity indices compatible with acute toxoplasmosis by the titration method, whereas with the single dilution method, sera from four patients had equivocal results. In the 33 individuals with latent infection, similar results were obtained with the two avidity methods; only one serum sample had a non-compatible avidity value with the titration method. The results obtained in the present study show that the current serological markers used for diagnosing acute acquired toxoplasmosis have signi®cant limitations. The data suggest that determination of the avidity of T. gondii-speci®c IgG by the titration method in patients with detectable IgM antibodies de®nes most accurately the stage of infection by T. gondii.

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Serological diagnosis of toxoplasmosis: usefulness of IgA detection and IgG avidity determination in a patient with a persistent IgM antibody response to Toxoplasma gondii

Cited by 28 publications

References 12 publications

Immunoglobulin M (IgM)-Glycoinositolphospholipid Enzyme-Linked Immunosorbent Assay: an Immunoenzymatic Assay for Discrimination between Patients with Acute Toxoplasmosis and Those with Persistent Parasite-Specific IgM Antibodies

Immunoglobulin M (IgM)-Glycoinositolphospholipid Enzyme-Linked Immunosorbent Assay: an Immunoenzymatic Assay for Discrimination between Patients with Acute Toxoplasmosis and Those with Persistent Parasite-Specific IgM Antibodies

Capture enzyme-linked immunosorbent assay to detect specific immunoglobulin E in sera of patients with paracoccidioidomycosis.

Evaluation of serological markers for the immunodiagnosis of acute acquired toxoplasmosis

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