REACAO DE IMUNOFLUORESCENCIA INDIRETA PARA O DIAGNOSTICO SOROLOGICO DA BLASTOMICOSE SUL AMERICANA. PADRONIZACAO DA REACAO E COMPARACAO DOS RESULTADOS COM A REACAO DE FIXACAO DO COMPLEMENTO

Abstract

An indirect fluorescent antibody test (IFA) for the serologic diagnosis of South American blastomycosis (SAB) was standardized. As antigen the authors used the cell walls of cerebriform forms of Paracoccidioides brasiliensis remaining in the sediment, after the preparation of the polysaccharide antigen for Fava Netto's complement fixation test (CFT) for SAB. IFA was applied to 50 sera from patients with SAB, CFT positive, and to 50 sera from patients in whom deep mycoses were excluded, CFT negative (control group). IFA was negative in the control group and positive in sera from patients with SAB. There was significant statistical correlation (p < 0.001) between titers of the two tests. IFA was also tested with 9 eluates obtained from blood smears on filter paper from patients with SAB; sera from the same blood samples were simultaneously tested and both tests gave similar results. The simplicity of the proposed method, its sensitivity and the fact that it may be done on eluates from blood smears on filter paper make it applicable to large populational surveys.