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1. New regimens of benznidazole monotherapy and in combination with fosravuconazole for treatment of Chagas disease (BENDITA): a phase 2, double-blind, randomised trial

Author

Arteaga, Roger, de la Barra, Anabelle, Camacho Borja, Jhonny, Martinez, Ivana, Fernandes, Jayme, Garcia, Lineth, Lozano, Daniel, Palacios, Alejandro, Schijman, Alejandro, Pinazo, Maria Jesus, Pinto, Jimmy, Rojas, Gimena, Estevao, Igor, Ortega-Rodriguez, Uriel, Mendes, Maria Tays, Schuck, Edgar, Hata, Katsura, Maki, Noritsugu, Asada, Makoto, Torrico, Faustino, Gascón, Joaquim, Barreira, Fabiana, Blum, Bethania, Almeida, Igor C, Alonso-Vega, Cristina, Barboza, Tayná, Bilbe, Graeme, Correia, Erika, Garcia, Wilson, Ortiz, Lourdes, Parrado, Rudy, Ramirez, Juan Carlos, Ribeiro, Isabela, Strub-Wourgaft, Nathalie, Vaillant, Michel, and Sosa-Estani, Sergio

Published
2021
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2. Treatment of adult chronic indeterminate Chagas disease with benznidazole and three E1224 dosing regimens: a proof-of-concept, randomised, placebo-controlled trial

Author

Santina, Glaucia, Blum, Bethania, Correia, Erika, Garcia-Bournisen, Facundo, Vaillant, Michel, Morales, Jimena Ramos, Pinto Rocha, Jimy Jose, Rojas Delgadillo, Gimena, Magne Anzoleaga, Helmut Ramon, Mendoza, Nilce, Quechover, Roxana Challapa, Caballero, Maria Yurly Escobar, Lozano Beltran, Daniel Franz, Zalabar, Albert Mendoza, Rojas Panozo, Lizeth, Palacios Lopez, Alejandro, Torrico Terceros, Dunia, Fernandez Galvez, Violeta Alejandra, Cardozo, Letty, Cuellar, Gabriela, Vasco Arenas, Rudy Nelson, Gonzales, Isabel, Hoyos Delfin, Carlos Florencio, Garcia, Lineth, Parrado, Rudy, de la Barra, Anabelle, Montano, Nair, Villarroel, Sandro, Duffy, Tomas, Bisio, Margarita, Ramirez, Juan Carlos, Duncanson, Fred, Everson, Michael, Daniels, Antonia, Asada, Makoto, Cox, Eugene, Wesche, David, Diderichsen, Paul Matthias, Marques, Alexandre F, Izquierdo, Luis, Sender, Silvia Sanz, Reverter, Joan Carlos, Morales, Manuel, Jimenez, Wladimiro, Torrico, Faustino, Gascon, Joaquim, Ortiz, Lourdes, Alonso-Vega, Cristina, Pinazo, María-Jesús, Schijman, Alejandro, Almeida, Igor C, Alves, Fabiana, Strub-Wourgaft, Nathalie, and Ribeiro, Isabela

Published
2018
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3. Genetic polymorphism of Trypanosoma cruzi bloodstream populations in adult chronic indeterminate Chagas disease patients from the E1224 clinical trial

Author

Ramírez, Juan Carlos, primary, Acevedo, Gonzalo Raúl, additional, Torres, Carolina, additional, Parrado, Rudy, additional, De La Barra, Anabelle, additional, Villarroel, Sandro, additional, García, Lineth, additional, Gascon, Joaquim, additional, Ortiz, Lourdes, additional, Torrico, Faustino, additional, Ribeiro, Isabela, additional, and Schijman, Alejandro Gabriel, additional

Published
2021
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4. New regimens of benznidazole monotherapy and in combination with fosravuconazole for treatment of Chagas disease (BENDITA): a phase 2, double-blind, randomised trial

Author

Torrico, Faustino, primary, Gascón, Joaquim, additional, Barreira, Fabiana, additional, Blum, Bethania, additional, Almeida, Igor C, additional, Alonso-Vega, Cristina, additional, Barboza, Tayná, additional, Bilbe, Graeme, additional, Correia, Erika, additional, Garcia, Wilson, additional, Ortiz, Lourdes, additional, Parrado, Rudy, additional, Ramirez, Juan Carlos, additional, Ribeiro, Isabela, additional, Strub-Wourgaft, Nathalie, additional, Vaillant, Michel, additional, Sosa-Estani, Sergio, additional, Arteaga, Roger, additional, de la Barra, Anabelle, additional, Camacho Borja, Jhonny, additional, Martinez, Ivana, additional, Fernandes, Jayme, additional, Garcia, Lineth, additional, Lozano, Daniel, additional, Palacios, Alejandro, additional, Schijman, Alejandro, additional, Pinazo, Maria Jesus, additional, Pinto, Jimmy, additional, Rojas, Gimena, additional, Estevao, Igor, additional, Ortega-Rodriguez, Uriel, additional, Mendes, Maria Tays, additional, Schuck, Edgar, additional, Hata, Katsura, additional, Maki, Noritsugu, additional, and Asada, Makoto, additional

Published
2021
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5. Genetic polymorphism of Trypanosoma cruzi bloodstream populations in adult chronic indeterminate Chagas disease patients from the E1224 clinical trial.

Author

Ramírez, Juan Carlos, Acevedo, Gonzalo Raúl, Torres, Carolina, Parrado, Rudy, Barra, Anabelle De La, Villarroel, Sandro, García, Lineth, Gascon, Joaquim, Ortiz, Lourdes, Torrico, Faustino, Ribeiro, Isabela, Schijman, Alejandro Gabriel, and De La Barra, Anabelle

Subjects
TRYPANOSOMA cruzi, GENETIC polymorphisms, SATELLITE DNA, CLINICAL trials, CHAGAS' disease, GENETIC variation, GENE amplification, GENETIC distance, PROTOZOA, RESEARCH, RESEARCH methodology, EVALUATION research, COMPARATIVE studies, TRYPANOSOMIASIS, RESEARCH funding
Abstract

Background: The role that the genetic diversity of natural Trypanosoma cruzi populations plays in response to trypanocidal treatment of chronic Chagas disease (CD) patients remains to be understood. We analysed the genetic polymorphisms of parasite bloodstream populations infecting chronic CD patients enrolled in the E1224 clinical trial.Methods: A total of 506 baseline and post-treatment follow-up samples from 188 patients were analysed. T. cruzi satellite DNA (satDNA) was amplified and sequenced using cruzi1/cruzi2 primers, and samples with TcI/III, TcII, TcIV or hybrid satDNA sequences were identified. Minicircle signatures were obtained after kinetoplast DNA amplification using 121/122 primers and restriction enzyme digestion. Genetic distances between baseline and post-treatment minicircle signatures were estimated using the Jaccard coefficient.Results: At baseline, 74.3% TcII, 17.9% hybrid and 7.8% TcI/III satDNA sequences were found, whereas at the end of follow-up the distribution was 55.2% TcII, 35.2% hybrid and 9.5% TcI/III. The placebo arm was the treatment group with the highest variation of satDNA sequences between baseline and post-treatment follow-up. Genetic distances between baseline and post-treatment minicircle signatures were similar among all treatment arms. No association between minicircle signature variability and satDNA type distribution was found.Conclusions: Genetic variability of T. cruzi bloodstream populations during post-treatment follow-up did not differ from that observed during chronic infection in the absence of treatment, suggesting that there were no selection events of E1224-resistant parasite populations. This is the first report documenting the genetic polymorphism of natural T. cruzi populations in chronic patients in the context of clinical trials with trypanocidal drugs. [ABSTRACT FROM AUTHOR]

Published
2022
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9. Leishmaniasis in Chapare, Bolivia

Author

Rojas, Ernesto, Parrado, Rudy, Delgado, Raul, Reithinger, Richard, and Garcia, Ana L.

Subjects
Company distribution practices, Leishmaniasis -- Risk factors, Leishmaniasis -- Distribution, Leishmaniasis -- Drug therapy, Leishmaniasis -- Research, Disease transmission -- Control, Disease transmission -- Research
Abstract

To the Editor: In Bolivia, most cases of leishmaniasis are caused by Leishmania (Viannia) braziliensis (1). The parasite is transmitted zoonotically by several sandfly species and, when transmitted to humans, [...]

Published
2009

10. Sequence analysis of the 3’-untranslated region of HSP70 (type I) genes in the genus Leishmania: its usefulness as a molecular marker for species identification

Author

Requena Jose M, Chicharro Carmen, García Lineth, Parrado Rudy, Puerta Concepción J, and Cañavate Carmen

Subjects
Leishmania, HSP70, 3’UTR, Sequence analysis, Microsatellites, Phylogenetic analysis, Infectious and parasitic diseases, RC109-216
Abstract

Abstract Background The Leishmaniases are a group of clinically diverse diseases caused by parasites of the genus Leishmania. To distinguish between species is crucial for correct diagnosis and prognosis as well as for treatment decisions. Recently, sequencing of the HSP70 coding region has been applied in phylogenetic studies and for identifying of Leishmania species with excellent results. Methods In the present study, we analyzed the 3’-untranslated region (UTR) of Leishmania HSP70-type I gene from 24 strains representing eleven Leishmania species in the belief that this non-coding region would have a better discriminatory capacity for species typing than coding regions. Results It was observed that there was a remarkable degree of sequence conservation in this region, even between species of the subgenus Leishmania and Viannia. In addition, the presence of many microsatellites was a common feature of the 3´-UTR of HSP70-I genes in the Leishmania genus. Finally, we constructed dendrograms based on global sequence alignments of the analyzed Leishmania species and strains, the results indicated that this particular region of HSP70 genes might be useful for species (or species complex) typing, improving for particular species the discrimination capacity of phylogenetic trees based on HSP70 coding sequences. Given the large size variation of the analyzed region between the Leishmania and Viannia subgenera, direct visualization of the PCR amplification product would allow discrimination between subgenera, and a HaeIII-PCR-RFLP analysis might be used for differentiating some species within each subgenera. Conclusions Sequence and phylogenetic analyses indicated that this region, which is readily amplified using a single pair of primers from both Old and New World Leishmania species, might be useful as a molecular marker for species discrimination.

Published
2012
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11. Usefulness of Serial Blood Sampling and PCR Replicates for Treatment Monitoring of Patients with Chronic Chagas Disease

Author

Parrado, Rudy, primary, Ramirez, Juan Carlos, additional, de la Barra, Anabelle, additional, Alonso-Vega, Cristina, additional, Juiz, Natalia, additional, Ortiz, Lourdes, additional, Illanes, Daniel, additional, Torrico, Faustino, additional, Gascon, Joaquim, additional, Alves, Fabiana, additional, Flevaud, Laurence, additional, Garcia, Lineth, additional, Schijman, Alejandro G., additional, and Ribeiro, Isabela, additional

Published
2019
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12. First external quality assurance program for bloodstream Real-Time PCR monitoring of treatment response in clinical trials of Chagas disease

Author

Ramírez, Juan C., Parrado, Rudy, Sulleiro Igual, Elena, de la Barra, Anabelle, Rodríguez, Marcelo, Villarroel, Sandro, Irazu, Lucía, Alonso-Vega, Cristina, Alves, Fabiana, Curto, María A., García, Lineth, Ortiz, Lourdes, Torrico, Faustino, Gascon, Joaquim, Flevaud, Laurence, Molina Romero, Israel, Ribeiro, Isabela, Schijman, Alejandro G., Universitat Autònoma de Barcelona, and Universitat de Barcelona

Subjects
0301 basic medicine, Chagas disease, Posaconazole, Molecular biology, lcsh:Medicine, Artificial Gene Amplification and Extension, Satellite DNA, Ravuconazole, Polymerase Chain Reaction, Biochemistry, Geographical locations, purl.org/becyt/ford/1 [https], 0302 clinical medicine, Malaltia de Chagas, Medicine and Health Sciences, lcsh:Science, Protozoans, Trypanosoma Cruzi, Multidisciplinary, External quality assurance, Eukaryota, Trypanocidal Agents, Clinical Laboratory Sciences, 3. Good health, Nucleic acids, Clinical Laboratories, Nitroimidazoles, Benznidazole, CIENCIAS NATURALES Y EXACTAS, Research Article, medicine.drug, Trypanosoma, Bolivia, medicine.medical_specialty, Drug Research and Development, Forms of DNA, Otras Ciencias Biológicas, Concordance, 030231 tropical medicine, 030106 microbiology, Real-Time Polymerase Chain Reaction, Research and Analysis Methods, Ciencias Biológicas, 03 medical and health sciences, Diagnostic Medicine, Internal medicine, parasitic diseases, Parasitic Diseases, Genetics, medicine, Humans, Chagas Disease, Clinical Trials, purl.org/becyt/ford/1.6 [https], Molecular Biology Techniques, Molecular Biology, Monitoring, Physiologic, Biologia molecular, Pharmacology, proficiency testing, business.industry, lcsh:R, Organisms, Biology and Life Sciences, DNA, Triazoles, South America, Molecular diagnostics, medicine.disease, Parasitic Protozoans, Clinical trial, Chagas' disease, Immunology, lcsh:Q, Real-Time PCR, Clinical Medicine, People and places, business, Quality assurance
Abstract

Real-Time PCR (qPCR) testing is recommended as both a diagnostic and outcome measurement of etiological treatment in clinical practice and clinical trials of Chagas disease (CD), but no external quality assurance (EQA) program provides performance assessment of the assays in use. We implemented an EQA system to evaluate the performance of molecular biology laboratories involved in qPCR based follow-up in clinical trials of CD. An EQA program was devised for three clinical trials of CD: the E1224 (NCT01489228), a pro-drug of ravuconazole; the Sampling Study (NCT01678599), that used benznidazole, both conducted in Bolivia; and the CHAGASAZOL (NCT01162967), that tested posaconazole, conducted in Spain. Four proficiency testing panels containing negative controls and seronegative blood samples spiked with 1, 10 and 100 parasite equivalents (par. eq.)/mL of four Trypanosoma cruzi stocks, were sent from the Core Lab in Argentina to the participating laboratories located in Bolivia and Spain. Panels were analyzed simultaneously, blinded to sample allocation, at 4-month intervals. In addition, 302 random blood samples from both trials carried out in Bolivia were sent to Core Lab for retesting analysis. The analysis of proficiency testing panels gave 100% of accordance (within laboratory agreement) and concordance (between laboratory agreement) for all T. cruzi stocks at 100 par. eq./mL; whereas their values ranged from 71 to 100% and from 62 to 100% at 1 and 10 par. eq./mL, respectively, depending on the T. cruzi stock. The results obtained after twelve months of preparation confirmed the stability of blood samples in guanidine-EDTA buffer. No significant differences were found between qPCR results from Bolivian laboratory and Core Lab for retested clinical samples. This EQA program for qPCR analysis of CD patient samples may significantly contribute to ensuring the quality of laboratory data generated in clinical trials and molecular diagnostics laboratories of CD. Fil: Ramirez Gomez, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina Fil: Parrado, Rudy. Universidad Mayor de San Simon; Bolivia Fil: Sulleiro, Elena. Universitat Autònoma de Barcelona; España Fil: De La Barra, Anabelle. Universidad Mayor de San Simon; Bolivia Fil: Rodríguez, Marcelo. Dirección Nacional de Institutos de Investigación. Administración Nacional de Laboratorios e Institutos de Salud. Instituto Nacional de Enfermedades Infecciosas; Argentina Fil: Villarroel, Sandro. Universidad Mayor de San Simon; Bolivia Fil: Irazu, Lucía. Dirección Nacional de Institutos de Investigación. Administración Nacional de Laboratorios e Institutos de Salud. Instituto Nacional de Enfermedades Infecciosas; Argentina Fil: Alonso Vega, Cristina. Drugs for Neglected Diseases initiative; Suiza Fil: Alves, Fabiana. Drugs for Neglected Diseases initiative; Suiza Fil: Curto, Maria de Los Angeles. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina Fil: García, Lineth. Universidad Mayor de San Simon; Bolivia Fil: Ortiz, Lourdes. Universidad Autonoma Juan Misael Saracho; Bolivia Fil: Torrico, Faustino. Fundacion CEADES; Bolivia Fil: Gascón, Joaquim. Universidad de Barcelona; España Fil: Flevaud, Laurence. Medecins Sans Frontières Operational Center Barcelona-Athens; España Fil: Molina, Israel. Universitat Autònoma de Barcelona; España Fil: Ribeiro, Isabela. Drugs for Neglected Diseases initiative; Suiza Fil: Schijman, Alejandro Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina

Published
2017

13. Real Time PCR for the Evaluation of Treatment Response in Clinical Trials of Adult Chronic Chagas Disease: Usefulness of Serial Blood Sampling and qPCR Replicates

Author

Parrado, Rudy, primary, Ramirez, Juan Carlos, additional, de la Barra, Anabelle, additional, Alonso-Vega, Cristina, additional, Juiz, Natalia, additional, Ortiz, Lourdes, additional, Illanes, Daniel, additional, Torrico, Faustino, additional, Gascon, Joaquim, additional, Alves, Fabiana, additional, Flevaud, Laurence, additional, Garcia, Lineth, additional, Schijman, Alejandro G., additional, and Ribeiro, Isabela, additional

Published
2018
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14. Treatment of adult chronic indeterminate Chagas disease with benznidazole and three E1224 dosing regimens: a proof-of-concept, randomised, placebo-controlled trial

Author

Torrico, Faustino, primary, Gascon, Joaquim, additional, Ortiz, Lourdes, additional, Alonso-Vega, Cristina, additional, Pinazo, María-Jesús, additional, Schijman, Alejandro, additional, Almeida, Igor C, additional, Alves, Fabiana, additional, Strub-Wourgaft, Nathalie, additional, Ribeiro, Isabela, additional, Santina, Glaucia, additional, Blum, Bethania, additional, Correia, Erika, additional, Garcia-Bournisen, Facundo, additional, Vaillant, Michel, additional, Morales, Jimena Ramos, additional, Pinto Rocha, Jimy Jose, additional, Rojas Delgadillo, Gimena, additional, Magne Anzoleaga, Helmut Ramon, additional, Mendoza, Nilce, additional, Quechover, Roxana Challapa, additional, Caballero, Maria Yurly Escobar, additional, Lozano Beltran, Daniel Franz, additional, Zalabar, Albert Mendoza, additional, Rojas Panozo, Lizeth, additional, Palacios Lopez, Alejandro, additional, Torrico Terceros, Dunia, additional, Fernandez Galvez, Violeta Alejandra, additional, Cardozo, Letty, additional, Cuellar, Gabriela, additional, Vasco Arenas, Rudy Nelson, additional, Gonzales, Isabel, additional, Hoyos Delfin, Carlos Florencio, additional, Garcia, Lineth, additional, Parrado, Rudy, additional, de la Barra, Anabelle, additional, Montano, Nair, additional, Villarroel, Sandro, additional, Duffy, Tomas, additional, Bisio, Margarita, additional, Ramirez, Juan Carlos, additional, Duncanson, Fred, additional, Everson, Michael, additional, Daniels, Antonia, additional, Asada, Makoto, additional, Cox, Eugene, additional, Wesche, David, additional, Diderichsen, Paul Matthias, additional, Marques, Alexandre F, additional, Izquierdo, Luis, additional, Sender, Silvia Sanz, additional, Reverter, Joan Carlos, additional, Morales, Manuel, additional, and Jimenez, Wladimiro, additional

Published
2018
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15. First external quality assurance program for bloodstream Real-Time PCR monitoring of treatment response in clinical trials of Chagas disease

Author

Ramírez, Juan C., primary, Parrado, Rudy, additional, Sulleiro, Elena, additional, de la Barra, Anabelle, additional, Rodríguez, Marcelo, additional, Villarroel, Sandro, additional, Irazu, Lucía, additional, Alonso-Vega, Cristina, additional, Alves, Fabiana, additional, Curto, María A., additional, García, Lineth, additional, Ortiz, Lourdes, additional, Torrico, Faustino, additional, Gascón, Joaquim, additional, Flevaud, Laurence, additional, Molina, Israel, additional, Ribeiro, Isabela, additional, and Schijman, Alejandro G., additional

Published
2017
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16. Analytical Validation of Quantitative Real-Time PCR Methods for Quantification of Trypanosoma cruzi DNA in Blood Samples from Chagas Disease Patients

Author

Ramírez, Juan Carlos, primary, Cura, Carolina Inés, additional, da Cruz Moreira, Otacilio, additional, Lages-Silva, Eliane, additional, Juiz, Natalia, additional, Velázquez, Elsa, additional, Ramírez, Juan David, additional, Alberti, Anahí, additional, Pavia, Paula, additional, Flores-Chávez, María Delmans, additional, Muñoz-Calderón, Arturo, additional, Pérez-Morales, Deyanira, additional, Santalla, José, additional, Marcos da Matta Guedes, Paulo, additional, Peneau, Julie, additional, Marcet, Paula, additional, Padilla, Carlos, additional, Cruz-Robles, David, additional, Valencia, Edward, additional, Crisante, Gladys Elena, additional, Greif, Gonzalo, additional, Zulantay, Inés, additional, Costales, Jaime Alfredo, additional, Alvarez-Martínez, Miriam, additional, Martínez, Norma Edith, additional, Villarroel, Rodrigo, additional, Villarroel, Sandro, additional, Sánchez, Zunilda, additional, Bisio, Margarita, additional, Parrado, Rudy, additional, Maria da Cunha Galvão, Lúcia, additional, Jácome da Câmara, Antonia Cláudia, additional, Espinoza, Bertha, additional, Alarcón de Noya, Belkisyole, additional, Puerta, Concepción, additional, Riarte, Adelina, additional, Diosque, Patricio, additional, Sosa-Estani, Sergio, additional, Guhl, Felipe, additional, Ribeiro, Isabela, additional, Aznar, Christine, additional, Britto, Constança, additional, Yadón, Zaida Estela, additional, and Schijman, Alejandro G., additional

Published
2015
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17. Congenital infection with Trypanosoma cruzi primes cord blood Vd2 T cells to proliferate in response to isopentenyl pyrophosphate

Author

Hermann Emmanuel, Flores Amilcar, Berthe Aurlie, Alonso-Vega Cristina, Truyens Carine, Carlier Yves, Parrado Rudy, and Torrico Faustino

Subjects
chemistry.chemical_compound, chemistry, Cord blood, Immunology, Isopentenyl pyrophosphate, Immunology and Allergy, Biology, Non-peptidic antigen, Trypanosoma cruzi, biology.organism_classification, Virology
Published
2013

19. Analytical Performance of a Multiplex Real-Time PCR Assay Using TaqMan Probes for Quantification of Trypanosoma cruzi Satellite DNA in Blood Samples

Author

Duffy, Tomas, primary, Cura, Carolina I., additional, Ramirez, Juan C., additional, Abate, Teresa, additional, Cayo, Nelly M., additional, Parrado, Rudy, additional, Bello, Zoraida Diaz, additional, Velazquez, Elsa, additional, Muñoz-Calderon, Arturo, additional, Juiz, Natalia A., additional, Basile, Joaquín, additional, Garcia, Lineth, additional, Riarte, Adelina, additional, Nasser, Julio R., additional, Ocampo, Susana B., additional, Yadon, Zaida E., additional, Torrico, Faustino, additional, de Noya, Belkisyole Alarcón, additional, Ribeiro, Isabela, additional, and Schijman, Alejandro G., additional

Published
2013
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27. Analytical Validation of Quantitative Real-Time PCR Methods for Quantification of Trypanosoma cruziDNA in Blood Samples from Chagas Disease Patients

Author

Ramírez, Juan Carlos, Cura, Carolina Inés, da Cruz Moreira, Otacilio, Lages-Silva, Eliane, Juiz, Natalia, Velázquez, Elsa, Ramírez, Juan David, Alberti, Anahí, Pavia, Paula, Flores-Chávez, María Delmans, Muñoz-Calderón, Arturo, Pérez-Morales, Deyanira, Santalla, José, Marcos da Matta Guedes, Paulo, Peneau, Julie, Marcet, Paula, Padilla, Carlos, Cruz-Robles, David, Valencia, Edward, Crisante, Gladys Elena, Greif, Gonzalo, Zulantay, Inés, Costales, Jaime Alfredo, Alvarez-Martínez, Miriam, Martínez, Norma Edith, Villarroel, Rodrigo, Villarroel, Sandro, Sánchez, Zunilda, Bisio, Margarita, Parrado, Rudy, Maria da Cunha Galvão, Lúcia, Jácome da Câmara, Antonia Cláudia, Espinoza, Bertha, Alarcón de Noya, Belkisyole, Puerta, Concepción, Riarte, Adelina, Diosque, Patricio, Sosa-Estani, Sergio, Guhl, Felipe, Ribeiro, Isabela, Aznar, Christine, Britto, Constança, Yadón, Zaida Estela, and Schijman, Alejandro G.

Abstract

An international study was performed by 26 experienced PCR laboratories from 14 countries to assess the performance of duplex quantitative real-time PCR (qPCR) strategies on the basis of TaqMan probes for detection and quantification of parasitic loads in peripheral blood samples from Chagas disease patients. Two methods were studied: Satellite DNA (SatDNA) qPCR and kinetoplastid DNA (kDNA) qPCR. Both methods included an internal amplification control. Reportable range, analytical sensitivity, limits of detection and quantification, and precision were estimated according to international guidelines. In addition, inclusivity and exclusivity were estimated with DNA from stocks representing the different Trypanosoma cruzidiscrete typing units and Trypanosoma rangeliand Leishmaniaspp. Both methods were challenged against 156 blood samples provided by the participant laboratories, including samples from acute and chronic patients with varied clinical findings, infected by oral route or vectorial transmission. kDNA qPCR showed better analytical sensitivity than SatDNA qPCR with limits of detection of 0.23 and 0.70 parasite equivalents/mL, respectively. Analyses of clinical samples revealed a high concordance in terms of sensitivity and parasitic loads determined by both SatDNA and kDNA qPCRs. This effort is a major step toward international validation of qPCR methods for the quantification of T. cruziDNA in human blood samples, aiming to provide an accurate surrogate biomarker for diagnosis and treatment monitoring for patients with Chagas disease.

Published
2015
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28. Killer cell immunoglobulin-like receptor expression induction on neonatal CD8+ T cells in vitro and following congenital infection with Trypanosoma cruzi.

Author

Hermann, Emmanuel, Berthe, Aurélie, Truyens, Carine, Alonso-Vega, Cristina, Parrado, Rudy, Torrico, Faustino, Carlier, Yves, and Braud, Véronique M.

Subjects
MAJOR histocompatibility complex, KILLER cells, T cells, INTERLEUKIN-2, CORD blood, TRYPANOSOMA cruzi, IMMUNE response
Abstract

Major histocompatibility complex (MHC) class I-specific inhibitory natural killer receptors (iNKRs) are expressed by subsets of T cells but the mechanisms inducing their expression are poorly understood, particularly for killer-cell immunoglobulin-like receptors (KIRs). The iNKRs are virtually absent from the surface of cord blood T cells but we found that KIR expression could be induced upon interleukin-2 stimulation in vitro. In addition, KIR expression was enhanced after treatment with 5-aza-2′-deoxycytidine, suggesting a role for DNA methylation. In vivo induction of KIR expression on cord blood T cells was also observed during a human congenital infection with Trypanosoma cruzi which triggers activation of fetal CD8+ T cells. These KIR+ T cells had an effector and effector/memory phenotype suggesting that KIR expression was consecutive to the antigenic stimulation; however, KIR was not preferentially found on parasite-specific CD8+ T cells secreting interferon-γ upon in vitro restimulation with live T. cruzi. These findings show that KIR expression is likely regulated by epigenetic mechanisms that occur during the maturation process of cord blood T cells. Our data provide a molecular basis for the appearance of KIRs on T cells with age and they have implications for T-cell homeostasis and the regulation of T-cell-mediated immune responses. [ABSTRACT FROM AUTHOR]

Published
2010
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30. Usefulness of Serial Blood Sampling and PCR Replicates for Treatment Monitoring of Patients with Chronic Chagas Disease

Author

Parrado, Rudy, Ramirez, Juan Carlos, de la Barra, Anabelle, Alonso-Vega, Cristina, Juiz, Natalia, Ortiz, Lourdes, Illanes, Daniel, Torrico, Faustino, Gascon, Joaquim, Alves, Fabiana, Flevaud, Laurence, Garcia, Lineth, Schijman, Alejandro G., and Ribeiro, Isabela

Abstract

This work evaluated a serial blood sampling procedure to enhance the sensitivity of duplex real-time quantitative PCR (qPCR) for baseline detection and quantification of parasitic loads and posttreatment identification of failure in the context of clinical trials for treatment of chronic Chagas disease, namely, DNDi-CH-E1224-001 (ClinicalTrials.gov registration no. NCT01489228) and the MSF-DNDi PCR Sampling Optimization Study (NCT01678599).

Published
2018
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32. [Estimation of the parasitemia in Trypanosoma cruzi human infection: high parasitemias are associated with severe and fatal congenital Chagas disease].

Author

Torrico MC, Solano M, Guzmán JM, Parrado R, Suarez E, Alonzo-Vega C, Truyens C, Carlier Y, and Torrico F

Subjects
Animals, Birth Weight, Bolivia epidemiology, Chagas Disease diagnosis, Female, Hematocrit instrumentation, Hematocrit methods, Humans, Infant, Newborn, Male, Mice, Sensitivity and Specificity, Umbilical Cord, Chagas Disease congenital, Chagas Disease parasitology, Parasite Egg Count methods, Parasitemia mortality, Trypanosoma cruzi isolation & purification
Abstract

The aim of this study was to validate the method of microhematocrit tube, as a rapid method to estimate the parasitemia in blood and to associate the parasites concentration with the morbidity and mortality of new born children with congenital Chagas diseases. Our results were determined experimentally and shown that the detection limit of the microhematocrit tube method is 40 parasites/ml when at least one of the four observed tubes is positive. Besides, it was also established that when the four examined tubes are positive the parasitemia in blood reaches more than 100 parasites/ml. It is important to highlight the modification made by our laboratory in the microscopic observation of the microhematocrit tubes with respect to the methodology used by previous investigators. A positive association exists between a high number of parasites in blood and the morbi-mortality of the newly born children with congenital chagas. The results of positive association between the parasitic load and the morbility and mortality could constitute an argument to understand the possible role of the parasite in the pathology of the disease.

Published
2005

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