Immunoglobulin-A detection and the investigation of clinical toxoplasmosis

Patel, Bindya; Young, Yvonne; Duffy, Kim; Tanner, R. P.; Johnson, Julie; Holliman, R. E.

doi:10.1099/00222615-38-4-286

Cited by 27 publications

(16 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The methods used for IgA detection include ISAGA-A and EIA-A. However, recent reports on the comparative sensitivities of EIA-A and ISAGA-A are discordant (10,13,25,26). In our hands, better results were achieved with ISAGA-A than with EIA-A.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Strategy for Diagnosis of Congenital Toxoplasmosis: Evaluation of Methods Comparing Mothers and Newborns and Standard Methods for Postnatal Detection of Immunoglobulin G, M, and A Antibodies

et al. 2001

Self Cite

View full text Add to dashboard Cite

In a study involving 14 laboratories supported by the European Community Biomed 2 program, we evaluated immunologic methods for the postnatal diagnosis of congenital toxoplasmosis (CT). Among babies born to mothers who seroconverted to positivity for toxoplasmosis during pregnancy, we analyzed 55 babies with CT on the basis of persistent anti-Toxoplasma immunoglobulin G (IgG) at 1 year of life and 50 control babies without anti-Toxoplasma IgG at 1 year of life in the absence of curative treatment with pyrimethaminesulfonamides. We tested in-house methods such as the enzyme-linked immunofiltration assay (ELIFA) or Immunoblotting (IB) for the detection of IgG or IgM; these methods allowed comparison of the immunologic profiles of the mothers and the infants. We compared ELIFA and IB with a commercial enzyme immunoassay (EIA) or in-house immunosorbent agglutination assay (ISAGA) for the detection of IgM or IgA. The performances of combinations of methods were also assessed. A cumulative sensitivity of 98% during a 1-year follow-up was obtained with the ELIFA plus ISAGA combination. Only one case of CT was missed by the ELIFA plus ISAGA combination, whereas three cases were missed by the IB plus ISAGA combination, even though 48% of patients with CT were treated with pyrimethamine-sulfonamides, which are known to inhibit antibody neosynthesis. A similar performance was obtained with either ELIFA or IB in combination with EIA. The difference in performance between ELIFA plus ISAGA and IB plus ISAGA was not statistically significant (P ‫؍‬ 0.31), and we conclude that both combinations of tests can be used for the diagnosis of CT in newborns.

show abstract

Section: Discussionmentioning

confidence: 99%

“…The contribution of IgA detection to the early diagnosis of CT has been show in many studies (2,6,13,25,27). The methods used for IgA detection include ISAGA-A and EIA-A.…”

Section: Discussionmentioning

confidence: 99%

Strategy for Diagnosis of Congenital Toxoplasmosis: Evaluation of Methods Comparing Mothers and Newborns and Standard Methods for Postnatal Detection of Immunoglobulin G, M, and A Antibodies

et al. 2001

Self Cite

View full text Add to dashboard Cite

show abstract

“…IgA test results seem to be less sensitive than IgM test results but give a higher specificity and PPV for the diagnosis of acute infection (13,33,34). Moreover, IgA detection is important for the diagnosis of congenital toxoplasmosis and could also be useful in immunocompromised patients in the case of reactivation (8,19,21,27,33). In our study, we obtained very good sensitivity and specificity of IgA test results (90.9 and 95.2%, respectively).…”

Section: Discussionmentioning

confidence: 99%

Multiplexed Anti-Toxoplasma IgG, IgM, and IgA Assay on Plasmonic Gold Chips: towards Making Mass Screening Possible with Dye Test Precision

Pomarès

Gonfrier

et al. 2016

J Clin Microbiol

View full text Add to dashboard Cite

Toxoplasmosis is an infection caused by the protozoan parasite Toxoplasma gondii that can lead to severe sequelae in the fetus during pregnancy. Definitive serologic diagnosis of the infection during gestation is made mostly by detecting T. gondii-specific antibodies, including IgG and IgM, individually in a single serum sample by using commercially available kits. The IgA test is used by some laboratories as an additional marker of acute infection. Most of the commercial tests have failed to reach 100% correlation with the reference method, the Sabin-Feldman dye test for the detection of Toxoplasma IgG antibodies. For Toxoplasma IgM and IgA antibodies, there is no reference method and their evaluation is done by comparing the results of one assay to those of another. There is a need for multiplexed assay platforms, as the serological diagnosis of T. gondii infection does not rely on the detection of a single Ig subtype. Here we describe the development of a plasmonic gold chip with vast fluorescence enhancement in the near-infrared region for simultaneous detection of IgG, IgM, and IgA antibodies against T. gondii in an ϳ1-l serum or whole-blood sample. When 168 samples were tested on this platform, IgG antibody detection sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were all 100%. IgM antibody detection achieved 97.6% sensitivity and 96.9% specificity with a 90.9% PPV and a 99.2% NPV. Thus, the nanoscience-based plasmonic gold platform enables a high-performance, low-cost, multiplexed assay requiring ultrasmall blood volumes, paving the way for the implementation of universal screening for toxoplasmosis infection during gestation.

show abstract

“…Outros autores referem, também, que em menos de 3% a 6% dos casos de encefalite toxoplásmica não se detectam evidências de infecção pregressa 8,12,17 . Em contraste, o valor diagnóstico das imunoglobulinas IgA, importantes marcadores de toxoplasmose aguda e congênita, na reativação da toxoplasmose cerebral não é bem estabelecido, com alguns estudos mostrando resultados conflitantes 13,14,16 . Não encontramos correlação entre sua positividade no soro e o diagnóstico de neurotoxoplasmose, comportando-se como os anticorpos IgM na reativação da toxoplasmose cerebral.…”

Section: Métodounclassified

“…A pesquisa de imunoglobulinas IgA no soro, um marcador de infecção aguda, apresenta resultados conflitantes em pacientes com neurotoxoplasmose e sua demonstração na saliva não se mostrou útil para diferenciação entre infecção recente e crônica [13][14][15] . Os achados liquóricos são inespecíficos e o encontro de anticorpos no líquor deve ser interpretado com cautela, pois a sua presença pode significar apenas transferência passiva do soro para o SNC 11,16 . Na maioria dos casos, portanto, o diagnóstico da neurotoxoplasmose é presuntivo, baseado nos achados de TC ou de RM e na presença de anticorpos IgG específicos no soro, uma vez que em apenas 3% -6% dos casos de reativação não se detecta tais anticorpos 12,17,18 .…”

unclassified

Detecção de imunoglobulinas IgG, IgM e IgA anti-Toxoplasma gondii no soro, líquor e saliva de pacientes com síndrome da imunodeficiência adquirida e neurotoxoplasmose

Borges

Figueiredo

2004

Arq. Neuro-Psiquiatr.

View full text Add to dashboard Cite

RESUMO -Estudamos 55 pacientes com sindrome da imunodeficiência adquirida (SIDA) e neurotoxoplasmose (grupo 1); 37 pacientes com SIDA e comprometimento neurológico por outra etiologia (grupo 2) e 18 indivíduos anti-HIV negativos com manifestações neurológicas (grupo 3), pesquisando IgG, IgA e IgM anti-Toxoplasma gondii, no soro, líquor e saliva, utilizando teste ELISA, para fins diagnósticos. O valor preditivo negativo do teste para o encontro de IgG no soro foi 100% e no líquor, 92,4%. Não houve diferença entre os três grupos quanto aos anticorpos IgA neste material. Para IgA, no líquor, o teste alcançou 72,7% de especificidade (p<0,05). Na saliva, apenas o encontro de IgG mostrou correlação com o diagnóstico de neurotoxoplasmose. Enfatizamos que a ausência de anticorpos IgG anti-T. gondii no soro e líquor depõe fortemente contra o diagnóstico de neurotoxoplasmose e que imunoglobulinas IgA específicas no líquor e IgG na saliva podem representar dois marcadores auxiliares para o diagnóstico diferencial da encefalite toxoplásmica na SIDA.PALAVRAS-CHAVE: SIDA, neurotoxoplasmose, anticorpos, soro, líquor, saliva. Detection of anti-Toxoplasma gondii IgG, IgM and IgA immunoglobulins in the serum, cerebrospinal fluid and saliva of patients with acquired immunodeficiency syndrome and neurotoxoplasmosisABSTRACT -We studied 55 patients with acquired immunodeficiency syndrome (AIDS) and neurotoxoplasmosis (group 1), 37 patients with AIDS and neurological involvement due to another etiology (group 2) and 18 anti-HIV-negative individuals with neurological manifestations, by searching for anti-T. gondii IgG, IgA and IgM immunoglobulins in serum, cerebrospinal fluid (CSF)and saliva, using ELISA. The negative predictive value of the test for IgG in serum was 100% and in CSF, 92.4%. There was no difference among the three groups studied regarding IgA in serum. For IgA, in CSF the test reached 72.7% specificity (p<0.05). In saliva, only the detection of IgG was found to be correlated with a diagnosis of neurotoxoplasmosis. We emphasize that the absence of anti-T. gondii IgG antibodies in serum and CSF strongly indicates the absence of a diagnosis of neurotoxoplasmosis and that specific IgA immunoglobulins in CSF and IgG in saliva may represent two auxiliary markers for the differential diagnosis of toxoplasmic encephalitis in AIDS.KEY WORDS: AIDS, neurotoxoplasmosis, antibodies, serum, cerebrospinal fluid, saliva.A neurotoxoplasmose permanece como uma das principais causas de encefalite focal em pacientes com síndrome da imunodeficiência adquirida (SIDA). A doença resulta, na maioria dos casos, de reativação de infecção latente, com prevalência de 3% a 50%, de acordo com a área geográfica, e apresenta elevada morbi-mortalidade, se não reconhecida e tratada precocemente [1][2][3] . O risco estimado de reativação a nível de sistema nervoso central (SNC) de pacientes com SIDA e infecção crônica varia de 12% a 47% 4,5 . O diagnóstico precoce da neurotoxoplasmose, nestes casos, tem sido limitado por falta de métodos propedêuticos não...

show abstract

Immunoglobulin-A detection and the investigation of clinical toxoplasmosis

Cited by 27 publications

References 11 publications

Strategy for Diagnosis of Congenital Toxoplasmosis: Evaluation of Methods Comparing Mothers and Newborns and Standard Methods for Postnatal Detection of Immunoglobulin G, M, and A Antibodies

Strategy for Diagnosis of Congenital Toxoplasmosis: Evaluation of Methods Comparing Mothers and Newborns and Standard Methods for Postnatal Detection of Immunoglobulin G, M, and A Antibodies

Multiplexed Anti-Toxoplasma IgG, IgM, and IgA Assay on Plasmonic Gold Chips: towards Making Mass Screening Possible with Dye Test Precision

Detecção de imunoglobulinas IgG, IgM e IgA anti-Toxoplasma gondii no soro, líquor e saliva de pacientes com síndrome da imunodeficiência adquirida e neurotoxoplasmose

Contact Info

Product

Resources

About