Evaluation of a Duplex ELISA assay for diagnosis, prognosis and treatment monitoring of Chagas disease patients.

KA GOMEZ; S LONGHI; S BRANDARIZ; L NIBORSKI; S LAFON; H MUJICA; A LUQUETTI; A SCHIJMAN; MJ LEVIN

Buenos Aires

Congreso; First French-Argentine Immunology Congress; 2010

Sociedad Argentina de Inmunologia (SAI)

In indeterminate and chronic forms of Chagas disease, current diagnosis is based on the presence of antibodies in the serum using at least two serological assays. However, more rapid tests for diagnosis, disease progression and treatment monitoring. Accordingly, the aim of this work was to investigate the potential usefulness of T. cruzi whole lysate, recombinant protein JL7, and peptides P013, R13, JL18, JL19, P0â and TcHSP70 as serological markers for human Chagas disease. In this study, we analyzed 228 serum samples from Chagas disease patients classified into four groups according to clinical and conventional serological parameters, and 114 from non chagasic patients including other infectious or autoimmune diseases. We defined the diagnostic sensitivity, specificity, Kappa index, positive predictive value (PPV) and receiver-operating characteristics (ROC) curve of tested substances measured by ELISA. The highest values of diagnostic parameters were achieved for the combined use of T. cruzi lysate and JL7, showing a sensitivity of 99.6% and specificity of 100% with a Kappa index of 0.99. By  using  the ROC curve to find restricted cut-off values, we observed that the PPV of T. cruzi lysate/JL7 to discriminate between indeterminate and severe Chagas disease was 70.6%, with a sensitivity of 44.4% and a specificity of 82.2%. In addition, JL7 might provide a good marker for monitoring drug treatment efficacy, since 58,3% (7/12 patients) presented a regression in specific antibody levels to this antigen after 24 months after treatment with benznidazole.