Detecção de antígeno circulante nas candidemias: diagnóstico de candidemia em pacientes de UTI pela detecção da molécula de 65 kDa de Candida albicans através da técnica de ELISA de inibição

• Autor(a) principal: Berzaghi, Rodrigo [UNIFESP]
• Data de Publicação: 2009
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UNIFESP
• dARK ID: ark:/48912/00130000002g9
• Texto Completo: http://repositorio.unifesp.br/handle/11600/9320
• topic: Detecção de antígenos; 65 kDa; ELISA de inibição; Candidemia; Ensaio de imunoadsorção enzimática; Candidíase

Nosocomial candidiasis is a major concern in tertiary care hospitals worldwide. This infection generally occurs in patients with degenerative and neoplastic diseases and is considered the fourth most frequent cause of bloodstream infections. Diagnosis of candidemia or hematogenous candidiasis has been problematic because clinical signs and symptoms are nonspecific, leading to delays in diagnosis and, consequently, in appropriate antifungal therapy. We developed an inhibition ELISA for detection of a 65 kDa-antigen in an experimental model of candidemia and for diagnosis of patients in ICUs with suspected candidemia. An anti-65 kDa monoclonal antibody was tested for detection of the 65 kDa antigen produced by C. albicans, C. tropicalis, and C. parapsilosis in murine candidemia models. The 65 kDa-antigen was detected in sera at concentrations ranging from 0.012 to 3.25 μg/ml. A total of 20 human patients with candidemia were then evaluated with the inhibition ELISA using sequential sera. Sixteen (80%) patients had the 65 kDa-antigen in concentrations ranging from 0.07 to 5.0 μg/ml. Sequential sera from patients with candidemia presented 3 different patterns of antigenemia of the 65 kDa molecule; 1- total clearance of antigenemia; 2-initial clearance and relapse of antigenemia; and 3- partial clearance of antigenemia. Our results indicate detection of the 65 kDa protein may be a valuable tool in the diagnosis of candidemia by C. albicans, C. tropicalis, and C. parapsilosis. We also evaluated a possible biological role of the molecule of 65 kDa from C. albicans. The tests showed that the protein of 65 kDa is bound to fibronectin from extracellular matrix, and a possible role of the adhesion of the fungus in the host.