The Trypomastigote Small Surface Antigen from Trypanosoma cruzi improves treatment evaluation and diagnosis in pediatric Chagas disease.
Balouz, V., Melli, L. J., Volcovich, R., Moscatelli, G., Moroni, S., Gonzalez, N., Ballering, G., Bisio, M., Ciocchini, A., Buscaglia, C. A. and Altcheh, J.
Instituto de Investigaciones Biotecnologicas-Instituto Tecnologico de Chascomus (IIB-INTECh), Universidad Nacional de San Martin (UNSAM) and Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Buenos Aires, Argentina.
Servicio de Parasitologia-Chagas, Hospital de Ninos 'Dr Ricardo Gutierrez', Buenos Aires, Argentina.
Instituto de Investigaciones Biotecnologicas-Instituto Tecnologico de Chascomus (IIB-INTECh), Universidad Nacional de San Martin (UNSAM) and Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Buenos Aires, Argentina. cbuscaglia89@gmail.com.
Chagas disease is caused by the protozoan parasite Trypanosoma cruzi. Assessment of parasitological cure upon treatment with available drugs relies on achieving consistent negative results in conventional parasitological and serological tests, which may take years to assess. Here, we evaluated the use of a recombinant T. cruzi antigen termed TSSA as an early serological marker of drug efficacy in T. cruzi-infected children. A cohort of 78 pediatric patients born to T. cruzi-infected mothers was included in this study. Solely 39 of them were infected with T. cruzi, and were immediately treated with trypanocidal drugs. Serological responses against TSSA were evaluated in infected and non-infected populations during the follow-up period using an in-house ELISA test, and compared to conventional serological methods. Anti-TSSA antibody titers decreased significantly faster than anti-whole parasite antibodies detected by conventional serology in both T. cruzi-infected patients undergoing effective treatment and in those not infected. This differential kinetics allowed a significant reduction in the required follow-up periods to evaluate therapeutic responses or to rule out maternal-fetal transmission, respectively. Finally, we present the case of a congenitally-infected patient with atypical course, in which TSSA provided an early marker for T. cruzi infection. In conclusion, we showed that TSSA was efficacious both for rapid assessment of treatment efficiency and for early negative diagnosis in infants at risk of congenital T. cruzi infection. Based upon these findings we propose the inclusion of TSSA for refining the post-therapeutic cure criterion and other diagnostic needs in pediatric Chagas disease.
Journal of Clinical Microbiology : en prensa (2017)