Dynamics of monocyte surface receptors after burns: a pilot study

Previous studies suggested that monocytes may play a vital role in infection and sepsis following burn injury. The aim of this study was to determine whether burn injury had any effect on the levels of expression of monocyte cell-surface receptors at different phases post burn injury. Ten adult burn victims with burns of >25% of the total body surface area were included in this study. Blood samples were collected on the first, third and seventh day post burn injury. The peripheral blood mononuclear cells were extracted, with or without lipopolysaccharide stimulation. The monocyte phenotypes of CD14, CD16, HLA-DR, CD163, TLR2 and TLR4 were characterized by flow cytometry. Six healthy volunteers were recruited as controls. The percentage of expressed CD14+ monocytes increased during the first day, and then decreased on the third and seventh day after burn injury. The percentages of CD14+ cells expressing CD16 and HLA-DR decreased on the first day, followed by an increase on the third and seventh day post burn. In comparison, the percentage of CD14+ monocytes expressing TLR2 and TLR4 was higher on the first day in burn patients than that of control participants, followed by no change on the third and seventh day post burn injury. There was no significant difference in the percentages of CD14+ expressing CD163 between the two groups. This study showed that the expression of the specific receptors on the surface of monocyte is affected by burn injury. The changes in the expression levels of these receptors may contribute to burn-induced infection susceptibility.