Anti-Toxoplasma gondii secretory IgA in tears of patients with ocular toxoplasmosis: immunodiagnostic validation by ELISA
Mem. Inst. Oswaldo Cruz
; 104(6): 818-822, Sept. 2009. graf, tab
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em En
| LILACS
| ID: lil-529552
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BR1.1
ABSTRACT
Toxoplasma gondii causes posterior uveitis and the specific diagnosis is based on clinical criteria. The presence of anti-T. gondii secretory IgA (sIgA) antibodies in patients' tears has been reported and an association was found between ocular toxoplasmosis and the anti-T. gondii sIgA isotype in Brazilian patients. The purpose of this study was to provide an objective validation of the published ELISA test for determining the presence of anti-T. gondii sIgA in the tears of individuals with ocular toxoplasmosis. Tears from 156 patients with active posterior uveitis were analysed; 82 of them presented characteristics of ocular toxoplasmosis (standard lesion) and 74 patients presented uveitis due to other aetiologies. Cases of active posterior uveitis were considered standard when a new inflammatory focus satellite to old retinochoroidal scars was observed. The determination of anti-T. gondii sIgA was made using an ELISA test with crude tachyzoite antigenic extracts. Tears were collected without previous stimulation. Detection of sIgA showed 65.9 percent sensitivity (95 percent CI = 54.5-74.4), 71.6 percent specificity (95 percent CI = 59.8-81.2), a positive predictive value of 72 percent (95 percent CI = 60.3-81.5) and a negative predictive value of 65.4 percent (95 percent CI = 54.0-75.4). sIgA reactivity was higher in the tears of patients with active posterior uveitis due to T. gondii (p < 0.05). The test is useful for differentiating active posterior uveitis due to toxoplasmosis from uveitis caused by other diseases.
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Índice:
LILACS
Assunto principal:
Lágrimas
/
Toxoplasma
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Imunoglobulina A Secretora
/
Ensaio de Imunoadsorção Enzimática
/
Uveíte Posterior
/
Toxoplasmose Ocular
Tipo de estudo:
Diagnostic_studies
/
Prognostic_studies
Limite:
Adolescent
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Adult
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Child
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Female
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Humans
/
Male
Idioma:
En
Revista:
Mem. Inst. Oswaldo Cruz
Assunto da revista:
MEDICINA TROPICAL
/
PARASITOLOGIA
Ano de publicação:
2009
Tipo de documento:
Article