Standardization of serological tests in Chagas' disease: immunoenzimatic test for screening of blood bank donnors

• Autor(a) principal: Ferreira, A. Walter
• Data de Publicação: 1991
• Outros Autores: Belem, Zila R., Moura, M. Emilia G., Camargo, M. E.
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Revista do Instituto de Medicina Tropical de São Paulo
• Texto Completo: https://www.revistas.usp.br/rimtsp/article/view/28803
• topic: Teste imunoenzimático; Doença de Chagas; Doadores de Sangue

In the serological diagnosis of Chagas disease large divergences may be found even between laboratories with experience, as a consequence of different criteria for the standardization of the tests. To standardize a immunoenzimatic test developed primarily for screening blood donors, serum panels were carefully chosen so as to best represent chagasic and non-chagasic populations. Produced for the highest sensibility and stability, the new reagent (bioELISA cruzi, Biolab Diagnóstica S/A, Brasil), was tested in serum from 1648 patients 219 with Chagas disease and 104 with other diseases, plus a comparison with well standardized immunofluorescence and hemagglutination tests in 1325 sera. In the immunoenzimatic assays, the cut off was indicated by the absorbance value of a chagasic serum showing a minimal reactivity. ELISA sensibility was 0,9954 and specificity 0,9969, as conegativity. False positive results were absent with sera from sifilis, toxoplasmosis, mononucleosis and high titered sera for antistreptolysin 0 antibodies. However they were seen in 5 to 15 cases of tegu-mentar leishmaniosis, 1 of 12 Kala-azar 1 of 15 reumatoid arthritis and 1 of 12 sistemic lupus erythematosus. The high sensibility in chagasics and high specificity in the general population indicate the confiability of the imunoenzimatic assay for screening blood donors and even to confirm a clinical diagnosis of Chagas' disease.