Banca de DEFESA: BÁRBARA ARAUJO FIDELLIS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : BÁRBARA ARAUJO FIDELLIS
DATE: 29/08/2024
TIME: 14:00
LOCAL: https://meet.google.com/kxz-jucr-mdt
TITLE:

The use of α-Gal epitope in the serological diagnosis of chronic Trypanosoma cruzi
infection

KEY WORDS:

Chagas disease. VLP. Serology. Benznidazole.

PAGES: 70
BIG AREA: Ciências Biológicas
AREA: Parasitologia
SUBÁREA: Protozoologia de Parasitos
SPECIALTY: Protozoologia Parasitária Humana
SUMMARY:

The diagnosis of chronic Trypanosoma cruzi infection is based on the detection of anti-T. cruzi IgG
antibodies produced by infected individuals, typically using protein antigens. However, the use of
carbohydrate antigens present on the surface of the parasite has shown great potential for this purpose. In
this context, this work aimed to evaluate the performance of Qβ(α-Gal) 540 in the serological diagnosis of
chronic T. cruzi infection, as well as to assess the production of anti-α-Gal IgG antibodies in individuals
treated with benznidazole. A total of 118 samples from individuals with reactive and 46 with non-reactive
serology for T. cruzi were tested against antigens obtained from the total extract of epimastigote forms of
the parasite and Qβ(α-Gal)540, as well as 81 samples from 22 patients who underwent etiological
treatment with benznidazole. The results showed a significant difference between the groups of individuals
with reactive and non-reactive serology for both antigens, and none of the negative individuals’ samples showed reactivity against the Qβ(α-Gal) 540 antigen, demonstrating 100% specificity and positive predictive value. Regarding sensitivity, the total antigen achieved 55.08%, while Qβ(α-Gal) 540 presented 88.98%. The

other parameters analyzed also indicated better results for the Qβ(α-Gal) 540 antigen, with a negative
predictive value and accuracy of 77.97% and 92.07%, respectively. The production of anti-α-Gal IgG
antibodies before and after treatment using Qβ(α-Gal) 540 as antigen showed no significant difference when
compared to the production of anti-T.cruzi IgG using the epimastigote antigen. In this way, Qβ(α-Gal)540
becomes a potential antigenic alternative in the diagnosis of chronic T. cruzi infection, reinforcing the need
for further studies to explore its application more broadly to populations from other geographic regions.

COMMITTEE MEMBERS:
Externo à Instituição - ALEXANDRE FERREIRA MARQUES
Presidente - 2611909 - CARLOS RAMON DO NASCIMENTO BRITO
Interno - 1752367 - PAULO MARCOS DA MATTA GUEDES