RESUMEN
Polymorphonuclear leukocytes (PMLs) play a key role in host defense, and phagocyte dysfunction has been associated with increased susceptibility to infections in patients with thermal injury. Intercellular adhesion molecule-1 (ICAM-1) plays a role in leukocyte accumulation and extravasation. Therefore, the aim of the present study was to assess the PMLs expression of opsonin receptors: Fc gamma RIII, CR1 and CR3; opsonophagocytosis of PMLs and plasma soluble ICAM-1. Flow cytometric analysis (FCM) was used to study PMLs expression of IgG Fc-receptor III (Fc gamma RIII) as well as the complement receptors CR1 (receptor for C3b) and CR3 (receptor for C3bi) in 23 patients with large burns. Analysis of PML complement- and immunoglobulin-mediated phagocytosis of Candida albicans were performed in parallel using the phagocytic index. Plasma sICAM-1 was determined using ELISA. This study revealed a significant increase, with variable degrees, in CR1 and CR3-dependent fluorescence, complement-mediated phagocytosis of C. albicans and plasma sIGAM-1 that started at day 2 and remained for about 20 days before normalization. In contrast, Fc gamma RIII-dependent fluorescence and Ig-mediated phagocytosis were significantly decreased versus the control values. These results demonstrate significant changes of PMLs opsonin receptors expression and opsonophagocytosis documenting systemic activator of PMLs after large burns. In addition, elevation of plasma sICAM-1 may enhance the harmful effect of neutrophil activation through leukocyte accumulation and extravasation through endothelial damage in skin and in lung.
Asunto(s)
Quemaduras/inmunología , Molécula 1 de Adhesión Intercelular/sangre , Neutrófilos/inmunología , Proteínas Opsoninas/inmunología , Fagocitosis , Receptores de Complemento/análisis , Receptores de IgG/análisis , Receptores Inmunológicos/análisis , Adolescente , Adulto , Anciano , Candida albicans , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
In this study we have determined the frequency of beta S haplotypes in a Brazilian sickle cell disease population from Sao Paulo, Brazil, by analyzing sequence variations in the immediate 5' flanking and second intervening sequence (IVSII) regions of the gamma globin genes. This association between sequence differences and beta s haplotype backgrounds was determined by screening genomic DNA samples using dot blot analysis of polymerase chain reaction products. We studied 148 beta s chromosomes, and found that haplotype 20 (CAR or Bantu) significantly predominated in this population. This is in agreement with the findings of the historical Portuguese Atlantic slave trade from Africa to South America.