Expressão dos receptores FC de imunoglobulina A em fagócitos do sangue de pacientes com bacteremia. / Expression of immunoglobulin a FC receptors on blood phagocytes of patients with gram-negative bacteremia.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2001

RESUMO

The expression and function of FcaRI (CD89) were analyzed on blood monocytes and neutrophils of patients with gram-positive and gram-negative bacteremia. Eighteen patients with gram-positive bacteremia, sixteen patients with gram-negative bacteremia and twenty healthy individuals were studied. CD89 expression were analyzed by flow cytometry using specific stained antibodies. Analysis of the surface iodinated CD89 molecules by SDS-PAGE and of the CD89 g-associated chain by immunoblotting also were performed. A marked increase in expression of the a and g subunits of the FcaRI were found on both types of cells in patients with gram-negative bacteremia, but not in patients with gram-positive bacteremia. This increase was independent of serum IgA levels. FcaRI Mr was lower on cells from gram negative patients than on cells from controls (50-65 kDa vs 55-75 kDa) despite of similar 32 kDa backbone, indicating altered glycosylation. Increased levels of FcaRI on blood phagocytes correlated with enhanced serum IL-6 levels, but not with IFN-g or TNF-a levels. The CD89 g-associated chain was phosphorylated on neutrophils, suggesting an engagement of CD89 during gram negative sepsis.

ASSUNTO(S)

bacteremia/imunologia receptores fc/análise imonoglobulinas/análise fagócitos/imunologia sepsis citometeria de fluxo/métodos iga fc receptor iga/análise

ACESSO AO ARTIGO

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