Immune responses in relation to the type and time of thermal injury: an experimental study

Thermal injuries are followed by a complex immune response, but the relationship between the severity of burn injury and the time exposure to the thermal injury on the extent of the immune response is still not known.

This study focuses on characterising the effect of temperature and time exposure on the post-burn immune response.

We used 120 C57BL/6 male mice divided equally in 5 burn groups and one sham operated group (groups A-E and sham). Ten mice per group were sacrificed at 24 and 48 h after burn injury and whole blood was collected; specimens of liver, lung, spleen, kidney and bowel were excised. Apoptosis and TREM-1 expression on circulating blood cells were measured. Splenocytes were isolated and stimulated for cytokine production; the rate of apoptosis of splenocytes was also measured.

Production of IL-17 from splenocytes of mice group D was enhanced. Considerable effects were shown on the apoptosis of circulating lymphocytes and of spleen cells. The apoptotic rates varied between groups and also evolved after 24 and 48 h. To examine the origin of this differential response, quantitative bacterial cultures of liver, lung and kidney were made but no differences were observed compared with sham-operated animals.

This study was based on an experimental murine model.

There is a unique response for each type of injury depending on the temperature of the thermal source and the exposure time.