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The efficacy of treatment with nifurtimox and/or benznidazole among adults with chronic Chagas disease with no previous electrocardiographic disturbances was evaluated over a mean follow-up of 21 years, by means of conventional serology, xenodiagnosis, clinical examination, electrocardiograms and chest X-ray. One hundred and eleven patients, between 17 and 46 years old, were studied: 54 underwent treatment (nifurtimox 27, benznidazole 27) and 57 remained untreated (control group). Xenodiagnosis was performed on 65% of them: 36/38 of the treated and 9/34 of the untreated patients had previous positive xenodiagnosis. Post-treatment, 133 xenodiagnoses were performed on 41 patients, all resulting negative. In the control group, 29 xenodiagnoses were performed on 14 patients; 2 resulted positive. Sera stored during the follow-up were simultaneously analyzed through conventional serology tests (IHA; DA-2ME; IIF). The serological evolution in the treated group was: a) 37% underwent negative seroconversion (nifurtimox 11, benznidazole 9); b) 27.8% decreased titers (nifurtimox 9, benznidazole 6), 9 showed inconclusive final serology (nifurtimox 7, benznidazole 2); c) 35.2% remained positive with constant titers (nifurtimox 7; benznidazole 12). The control group conserved the initial antibody levels during the follow-up. In the clinical evolution, 2/54 (3.7%) of the treated and 9/57 (15.8%) of the untreated patients showed electrocardiographic disturbances attributable to Chagas myocardiopathy, with a statistically relevant difference (p

The aim of this work was to compare the evolution of chronic chagasic untreated patients (UTPs) with that of benznidazole or nifurtimox-treated patients (TPs). A longitudinal study from a low endemic area (Santa Fe city, Argentina) was performed during an average period of 14 years. Serological and parasitological analyses with clinical exams, ECG and X-chest ray were carried out. At the onset, 19/198 infected patients showed chagasic cardiomyopathy (CrChM) while 179 were asymptomatic. In this latter group the frequency of CrChM during the follow-up was lower in TPs compared with UTPs (3.2% vs 7%). Within the CrChM group, 2/5 TPs showed aggravated myopathy whereas this happened in 9/14 UTPs. Comparing the clinical evolution of all patients, 5.9% of TPs and 13% of UTPs had unfavourable evolution, but the difference is not statistically relevant. Serological titers were assessed by IIF. Titers equal to or lower than 1/64 were obtained in 86% of the TPs, but only in 38% of UTPs. The differences were statistically significant (geometric mean: 49.36 vs. 98.2). Antiparasitic assessment of the drugs (xenodiagnosis) proved to be effective. The low sensitivity in chronic chagasic patients must be born in mind. Despite treated patients showed a better clinical evolution and lower antibody levels than untreated ones, it is necessary to carry on doing research in order to improve therapeutic guidelines, according to the risk/benefit equation and based on scientific and ethical principles. Para comparar a evolução dos infectados chagásicos crônicos não tratados (UTPs) e tratados (TPs) com nifurtimox ou benznidazol, fez-se um estudo longitudinal numa área de baixa endemicidade (cidade de Santa Fe, Argentina), com média de seguimento de 14 anos. Em cada controle foram feitas análises sorológicas e parasitológicas, exames clínicos, eletrocardiográficos e radiológicos. No inicio, 19/198 infectados apresentaram miocardiopatia chagásica crônica (MChCr), enquanto 179 eram assintomáticos. A frequência de MChCr no seguimento destes últimos foi 3,2% para os tratados e 7% para os não tratados. Dos pacientes com MChCr no início, 2/5 dos tratados e 9/14 dos não tratados agravaram sua miocardiopatia. Comparando a evolução clínica dos infectados, 5,9% dos tratados e 13% dos não tratados tiveram evolução desfavorável, mas esta diferença não é estatisticamente significativa. Na avaliação sorológica por IFI, 86% dos TPs e só 38% dos UTPs apresentaram títulos menores ou iguais a 1/64. As diferenças são estatisticamente significativas (média geométrica: 49,36 vs 98,2). Os xenodiagnósticos seriados realizados, demonstraram efetividade das drogas (considerar a baixa sensibilidade deste método na etapa crônica). Os pacientes tratados mostraram melhor evolução clínica e mais baixos níveis de anticorpos do que os não tratados. É preciso continuar as investigações para estabelecer pautas terapêuticas mais claras sobre a relação risco-benefício, sustentadas nos princípios científicos e éticos.

The direct agglutination technique for chagasic infection diagnosis is easy to perform and inexpensive. It has good sensitivity and specificity when used in conjunction with other serological and/or parasitological techniques. It has been replaced with other reactions with faster results and easiness to read (i.e. immunoenzymatic assay (ELISA) and indirect hemagglutination). Currently it is difficult to obtain commercial kits. In the present paper we present a series of cases that show the usefulness of the direct agglutination test to early determine acute and/or congenital infection and to differentiate acute from chronic infections.

We investigated the relationship between potentially pathogenic antibodies against a Trypanosoma cruzi ribosomal protein (P2β) and the evolution of Chagas disease and the effect of trypanocidal treatment on these variables. Seventy-eight patients with chronic Chagas disease who were followed-up for more than 20 years were divided into three groups: 30 asymptomatic persons undergoing specific treatment (group A), 37 asymptomatic persons not undergoing specific treatment (group B), and 11 patients with chronic chagasic cardiomyopathy (CCC) who were not treated. Five patients in group B showed evolution to myocardial abnormalities. Among persons with CCC, six showed no changes; the remaining persons showed progression of cardiac involvement. Levels of antibodies to P2β in persons in group A decreased from their initial values. This finding was not observed in persons in groups B and C. Comparisons at the end of the follow-up showed lower amounts of antibodies to P2β in groups A and C. These findings support the benefits of specific treatment during chronic infection. Fil: Fabbro, Diana Lucrecia. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Centro de Invest.sobre Endemias Nacionales; Argentina Fil: Olivera, Veronica Soledad. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Centro de Invest.sobre Endemias Nacionales; Argentina Fil: Bizai, María Laura. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Centro de Invest.sobre Endemias Nacionales; Argentina Fil: Denner, Susana. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Centro de Invest.sobre Endemias Nacionales; Argentina Fil: Diez, Cristina Noemí. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Centro de Invest.sobre Endemias Nacionales; Argentina Fil: Marcipar, Iván Sergio. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Centro de Invest.sobre Endemias Nacionales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina Fil: Streiger, Mirtha. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Centro de Invest.sobre Endemias Nacionales; Argentina Fil: Arias, Enrique. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Centro de Invest.sobre Endemias Nacionales; Argentina Fil: del Barco, Mónica. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Centro de Invest.sobre Endemias Nacionales; Argentina Fil: Mendicino, Diego. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Centro de Invest.sobre Endemias Nacionales; Argentina Fil: Bottasso, Oscar Adelmo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Centro de Invest.sobre Endemias Nacionales; Argentina

La proteína flagelar F29 es una proteína ligadora de calcio del Trypanosoma cruzi. En el presente trabajo se realizó un estudio transversal en sueros de pacientes con infección crónica por T. cruzi tratados con nifurtimox (Nx) o benznidazol (Bz) y no tratados, para evaluar el antígeno F29 como marcador de eficacia terapéutica. Se utilizó un ensayo inmuno-enzimático con la proteína recombinante F29 (ELISA F29) y se analizó su relación con la serología convencional (SC) y la evolución parasitológica y clínica en esos pacientes. Se estudiaron 118 sueros de pacientes que formaban parte de una cohorte, de los cuales se disponía de información retrospectiva, serológica, parasitológica y clínica.Los pacientes se dividieron en 3 grupos: A) 30 tratados negativizaron SC post-tratamiento; B) 34 tratados permanecieron con SC reactiva; C) 54 no tratados. Las muestras de suero se procesaron a doble ciego en forma simultánea mediante serología convencional (hemoaglutinación indirecta, aglutinación directa e inmunofluorescencia indirecta) y ELISA F29. El test ELISA F29 resultó no reactivo en: 100% del grupo A, 82,4% del grupo B y 13% del grupo C. Los infectados con alteraciones electrocar-diográficas compatibles con miocardiopatía chagásica crónica (n = 11) fueron reactivos al ELISA F29. Los pacientes en quienes los estudios parasitológicos (xenodiagnóstico y/o strout) fueron (+) presentaron elevada reactividad al ELISA F29. La correlación entre ELISA F29 y SC en los pacientes tratados con SC no reactiva (grupo A) y no tratados (grupo C), fue significativa (p < 0,05). En cambio, en pacientes tratados que mantuvieron la SC reactiva (grupo B) el test de ELISA F29 fue reactivo sólo en 17,6%. Estos resultados sugieren que el test ELISA F29, rápido y sencillo, podría ser útil para monitorear cambios post-tratamiento tripanocida.