Banca de DEFESA: WÉSLEI ALMEIDA COSTA ARAÚJO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : WÉSLEI ALMEIDA COSTA ARAÚJO
DATE: 20/02/2024
TIME: 15:00
LOCAL: Faculdade de Farmácia
TITLE:

Diagnostic evaluation of Strongyloides stercoralis infection in asthmatic individuals using recombinant antigens

KEY WORDS:

Strongyloides stercoralis. Asthma. Antigens. Glucocorticoids.

PAGES: 60
BIG AREA: Ciências Biológicas
AREA: Parasitologia
SUBÁREA: Helmintologia de Parasitos
SPECIALTY: Helmintologia Humana
SUMMARY:

Strongyloides stercoralis is the main etiological agent of human strongyloidiasis, a neglected disease with wide worldwide distribution. The infection is generally chronic and asymptomatic. However, in immunocompromised individuals using systemic glucocorticoids, such as individuals with severe asthma, S. stercoralis infection can progress to severe forms, hyperinfection and/or dissemination, with a low therapeutic response and a high lethality rate. Currently, the definitive diagnosis of S. stercoralis infection is made by searching for larvae in feces. However, this parasite releases few larvae and intermittently, which makes it necessary to examine several fecal samples. The objective of this study is to analyze the frequency of S. stercoralis infection in asthmatic individuals treated in the Asthma and Allergic Rhinitis Control Program (ProAR) in Bahia/Brazil, through parasitological and immunological diagnosis, using crude and recombinant antigens. A total of 500 asthmatics treated at ProAR were included in the study. The diagnosis of strongyloidiasis was made using three parasitological methods: spontaneous sedimentation (SE), Baermann-Moraes (BM) and, Agar Plate Culture (CPA). Serological diagnosis was preformed by IgG4 and IgE –ELISA using crude membrane antigen. Samples from individuals diagnosed positively by parasitological and /or immunological methods (n=66) were reevaluated through ELISA(s) using recombinant antigens (NIE and SsIR). Of the individuals studied, 21.2 (106/500) and 78.8% (394/500) were male and female, respectively. Around 42 (210/500) and 58% (290/500) of the individuals had mild/moderate or severe asthma, respectively, with 43.6% (218/500) being diagnosed in childhood. A frequency of enteroparasites was 8.6% (43/500) The most prevalent pathogenic parasite was S. stercoralis, 2.2% (11/500). The sensitivities of ELISA(s) for detection of IgG4 and IgE anti-S. stercoralis, using membrane antigen were 91.7% and 91.2%, respectively, and the specificities were 95.7% and 95.4%, respectively. Sera from individuals positive for S. stercoralis, diagnosed in this study, by finding larvae in feces and/or detection of IgG and IgE anti-S. stercoralis (n=66) were reevaluated through IgG-ELISA, using the recombinant antigens, NIE and SsIR, demonstrating sensitivities and specificities of 91.2, 85.3% and 95.4 and 90.9%, respectively. Immunoblotting confirmed the positivity of 39.4% (26/66) of reevaluated samples, revealing immunoreactivity bands of 30 to 90 KDa. Regarding the use of corticosteroids, 36.2% (181/500) reported having taken one or more cycles of oral corticosteroids for 3 or more days in 1 year and 8.4% (42/500) one or more cycles of injectable corticosteroids in 6 months. Among the 66 individuals who were positive (detection of larvae in feces for anti-S. stercoralis antibodies), 63.6% (42/66) used corticosteroids. The most, 60.6% (40/66) via inhalation, 30 .3% (20/66) via orally and 9.1% (6/66) via injection. The association observed between corticosteroid therapy and strongyloidiasis was not statistically significant (p = 0.768, 0.798, 0.351 and 1.0, respectively). The present study demonstrates that the agreement between the methods used was poor, encouraging new studies to develop an effective and reproducible test for the diagnosis of S. stercoralis infection. Furthermore, the study did not demonstrate a correlation between S. stercoralis infection and the use of glucocorticoids.

COMMITTEE MEMBERS:
Presidente - 2178405 - NECI MATOS SOARES
Externa ao Programa - 3163149 - CARINA CARVALHO DOS SANTOS - UFBAExterno à Instituição - ALVARO AUGUSTO SOUZA DA CRUZ FILHO