Oliveira, Edward José de

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Cadernos Espinosanos (E-Journal)

Rev. Inst. Med. trop. S. Paulo48(2):64, March-April, 2006*This thesis is available at the Library of the Instituto de Medicina Tropical de São PauloSUMMARY OF THESIS*OLIVEIRA, Edward José de - Desenvolvimento de um método sorológico para o diagnóstico laboratorial da esquistossomose mansoni baseadoem peptídeos sintéticos. São Paulo, 2005. (Tese de Doutorado - Faculdade de Ciências Farmacêuticas da Universidade de São Paulo).DEVELOPMENT OF A SEROLOGIC METHOD FOR LABORATORY DIAGNOSIS OF THESCHISTOSOMIASIS MANSONI BASED ON SYNTHETIC PEPTIDESBased on algorithms of hidrophilicity and flexibility, obtained bythe use of the ProtScale software, disposable at the site http://au.expasy.org/cgi-bin/protscale.pl, seven potentially antigenic peptideswere selected from different Schistosoma mansoni proteins: cathepsinB (Sm31), heat shock protein (SmHSP-70), cathodic circulating antigen(CCA) and the polypeptidic sequence of the open reading frame (ORF)of the ET-03 clone. The peptides were produced by chemical synthesisand denominated as P1, P2, P3, P4, P5, P6 and P7. These wereindependently tested against two pools of human sera, one positiveand one negative for schistosomiasis. The peptides P1, P2, P3, P6 andP7, that presented better reactivity when assayed by animmunoenzymatic method, were chosen to be used as antigen for thestandardization of an ELISA method, by utilizing Costar 3590 microplates, and it was called Peptide-ELISA (Pp-ELISA). This method wasevaluated on 192 serum samples, divided in four groups: (A) 23 samplesfrom patients with acute schistosomiasis and positive for S. mansonieggs in fecal examination, who were living in a Brazilian Northeaststate; (B) 30 samples from patients with chronic schistosomiasis andpositive for S. mansoni eggs, who were living in a Brazilian Northstate; (C) 39 samples from individuals with other parasite infection,but no schistosomiasis, living in a Brazilian North state; (D) 100samples from clinically healthy individuals who presented negativeresults for coproparasitologic method, living in Campinas, São PauloState. The serological data obtained by Pp-ELISA were comparativelyanalyzed with the results obtained by other immunodiagnostic methods:immunofluorescence test for detection of IgM antibodies against gutassociated antigens (IgM-IFT); ELISA for detection of IgM antibodiesagainst gut associated polysaccharide antigens (IgM-ELISA) or fordetection of IgG antibodies against worm crude antigens (IgG-ELISA).The sensitivity of Pp-ELISA was of 86.6%, considering asschistosomiasis patients only the ones who presented S. mansoni eggsin stool examination, and 79.3%, when a serological criterion was usedfor definition of schistosomiasis patients, with positive results for bothIgM-IFT and IgM-ELISA. The specificity of the Pp-ELISA wasrespectively 94.2% or 94.7%, considering as control group, withoutschistosomiasis, S. mansoni egg negative individuals in stoolexamination or serologically negative individuals by both tests, IgM-IFT and IgM-ELISA. The positive predictive value for Pp-ELISA was85.2%, while for the other serologic methods varied from 63.4% to78.6%. The negative predictive value for Pp-ELISA was as a rule 3%lower than the indices obtained for other serologic methods. When theresults of Pp-ELISA were compared with the ones obtained by otherserologic methods, better concordance was demonstrated with IgM-ELISA (Kappa indice = 0.75). The reactivity indices for detection ofIgG and IgM antibodies were significantly higher (p < 0.05) in acute(group A) than chronic schistosomiasis patients (group B). In this studythe Pp-ELISA presented a good performance (Diagnostic efficacy =81.0%), however further studies should be necessary for the evaluationof its applicability on seroepidemiologic surveys.Edward José de OliveiraDepartamento de Análises ClínicasFaculdade de Ciências FarmacêuticasUniversidade de São Paulo,Cj. das Químicas Bloco 17Av. Prof. Lineu Prestes, 580Caixa Postal 6608305315-970 São Paulo, SP, Brazil

Development of a serologic method for laboratory diagnosis of the schistosomiasis mansoni based on synthetic peptides

Scientific Electronic Library Online - Brazil

Desenvolvimento de um método sorológico para o diagnóstico laboratorial da esquistossomose mansoni baseado em peptídeos sintéticos

https://www.revistas.usp.br/rimtsp/article/download/30986/32870

Desenvolvimento de um método sorológico para o diagnóstico laboratorial da esquistossomose mansoni baseado em peptídeos sintéticos

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Cadernos Espinosanos (E-Journal)

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