Banca de DEFESA: JÉSSICA SPÍNOLA SILVA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : JÉSSICA SPÍNOLA SILVA
DATE: 12/05/2022
TIME: 13:30
LOCAL: Plataforma Google Meet
TITLE:

EVALUATION OF THE PERFORMANCE OF A SEROLOGICAL METHOD BY FLOW CYTOMETRY FOR THE GENOTYPE-SPECIFIC DIAGNOSIS OF CHAGAS DISEASE

KEY WORDS:

Universal diagnosis; genotype-specific diagnosis; Chagas disease; DTU; TcI, TcVI, TcII.

PAGES: 58
BIG AREA: Ciências da Saúde
AREA: Farmácia
SUMMARY:

Trypanosoma cruzi was subdivided into six distinct genetic groups, called Discrete Typing Units (DTUs), from TcI to TcVI. The genetic variability of T. cruzi can influence the biological characteristics of the parasite, the epidemiology and clinical features of Chagas disease (DCh). Furthermore, individuals infected with different T. cruzi genotypes may present a distinct therapeutic response to the treatment of DCh. Therefore, the development of new methods for the genotype-specific diagnosis of DCh is of great importance for clinical, epidemiological and post-therapeutic monitoring studies. Some molecular methods used for this proposal have limitations, such as: the need for previous isolation of the parasite from the blood by low-sensitivity techniques (blood culture and xenodiagnosis) that can select T. cruzi DTUs, in addition to the need to use multiple targets of the parasite's genome for the correct identification of the genetic groups that infect the host. The serological methods developed for the genotype-specific diagnosis of DCh were not able to recognize all T. cruzi DTUs present in samples of individuals from different geographic regions. In this sense, the technique of investigation of anti-amastigote (A), trypomastigote (T) and epimastigote (E) antibodies of T. cruzi by flow cytometry (Chagas-Flow ATE) for the diagnosis of DCh was standardized. Initially, Chagas-Flow ATE was developed for the genotype-specific diagnosis of experimental infection by T. cruzi, showing a good performance to discriminate the different DTUs of the parasite that infect mice. Therefore, continuing these studies, the objective of this project was to evaluate the performance of Chagas-Flow ATE in the universal and genotype-specific diagnosis of DCh, using human serum samples. 102 sera from patients with Chagas disease (CH) in the chronic phase, infected with TcI, TcVI or TcII of T. cruzi DTUs, using the Chagas-Flow ATE, were evaluated. The results showed that this new methodology showed excellent accuracy (100%) in the universal diagnosis of DCh, being able to segregate all serum samples from CH patients from those not infected with T. cruzi (NI), using certain sets of attributes (target antigens, serum dilutions and cut-off points). Furthermore, analysis by decision trees, using selected sets of attributes, indicated an excellent performance of Chagas-Flow ATE in the genotype-specific diagnosis of DCh, with an accuracy of 92% and 97% to discriminate infections by “TcI vs TcVI vs TcII” and “TcI vs TcII”, respectively. The data obtained suggest the use of Chagas-Flow ATE in the universal and genotype-specific diagnosis of DCh. Thus, through this new method, it will be possible to interfere with the T.cruzi genotypes that infect the patient, having a practical impact on the epidemiological surveillance of this disease, in the clinic and in the post-therapeutic monitoring of individuals with Chagas disease.

BANKING MEMBERS:
Presidente - 1699263 - MELINA DE BARROS PINHEIRO INACIO
Externo ao Programa - 1066935 - VINICIUS SILVA BELO
Externo ao Programa - 1676450 - GUSTAVO MACHADO ROCHA
Externa à Instituição - MARIA DAS GRACAS CARVALHO - UFMG
Externa à Instituição - LEILISMARA SOUSA NOGUEIRA - UFLA
Externa à Instituição - GLAUCIA DINIZ ALESSIO - FIOCRUZ