Dados do Trabalho

Título

Western Blot as a Diagnostic Tool for Chagas Disease Using Chimeric Recombinant Proteins

Introdução

Chronic Chagas disease (CD), caused by the protozoan Trypanosoma cruzi, is a neglected tropical disease affecting approximately seven million people worldwide. Given the complexity of laboratory diagnostics, there is a critical need for reliable confirmatory tests, particularly for cases with inconclusive results. Western blot (WB) assays are widely used as confirmatory tools for various infectious diseases; however, the discontinuation of the only WB assay for CD has created a significant gap in the diagnostic process. This study investigates the potential of using chimeric recombinant proteins to detect anti-T. cruzi antibodies using WB as a diagnostic platform.

Objetivo (s)

This study aims to evaluate the diagnostic performance of chimeric T. cruzi antigens (IBMP-8.1, IBMP-8.2, IBMP-8.3, and IBMP-8.4) using WB for detecting anti-T. cruzi antibodies in a phase II study.

Material e Métodos

This study was conducted following approval from the Gonçalo Moniz Institute IRB (CAAE 67809417.0.0000.0040). A total of 96 T. cruzi-positive and 104 T. cruzi negative-samples were analyzed using WB assays incorporating the chimeric proteins. Relative band intensities (RBI) were quantified using Image J and statistically analyzed with GraphPad Prism 9.5.1. The established thresholds for were defined according to area under the curve (AUC) values, with positive results exceeding 1.00.

Resultados e Conclusão

Although all four T. cruzi chimeric antigens were successfully expressed and purified, only IBMP-8.1 and IBMP-8.2 were evaluated in this study. Among the 96 T. cruzi-positive samples, IBMP-8.1 and IBMP-8.2 failed to detect 20 and 26 cases, respectively, resulting in sensitivities of 87.1% and 80.3%. For the 104 T. cruzi-negative samples, IBMP-8.1 correctly identified 100, achieving a specificity of 96.4%, while IBMP-8.2 accurately classified 95, yielding a specificity of 86.5%. The AUC was 0.95 for IBMP-8.1 and 0.89 for IBMP-8.2. Statistical analysis revealed significant differences in RBI between positive and negative samples for both antigens (p < 0.0001).

Palavras Chave

Trypanosoma cruzi; chimeric recombinant antigens; Western blot; immunodiagnostic