Assessment of certain neutrophil receptors, opsonophagocytosis and soluble intercellular adhesion molecule-1 (ICAM-1) following thermal injury

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: Fcγ 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 (Fcγ 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, Fcγ 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.