Soluble CD163: A novel biomarker for the susceptibility to sepsis in severe burn injuries

Abstract

Objective: Soluble CD163 (sCD163) has been previously shown to play a role in inflammatory and infectious diseases. This study, for the first time, investigates the characteristics and potential values of sCD163 in burn patients. A first look is taken on the changes of sCD163 levels in burn patients by comparing predefined subgroups at single time points.

Materials and methods: Serum samples of 18 patients with burn injuries were collected for biochemical analysis at the time of admission and in a chronological sequence of 12, 24, 48 and 120 h after the injury and were matched to clinical parameters. Statistical analysis was performed using the Mann-Whitney test, Wilcoxon signed rank and Pearson bivariate correlation.

Results: Patients with sepsis showed a significant increase of sCD163 levels. sCD163 was correlated with leukocytes (P=0.035) over the time course of 120 h. Patients characterized by a burn size exceeding 25% of the total body surface area (TBSA) showed a significant increase of sCD163 between 12 and 48 h after burn injury (P=0.038).

Conclusions: The first view on the characteristics of sCD163 in the serum of burn patients points out that sCD163 seems to be an early indicator for the susceptibility to sepsis. Furthermore, the changes in sCD163 serum levels within the first hours after burn trauma have great potential for early prediction of organ failure after burn injury.

Keywords: Inflammation; immune response; organ failure; sepsis; serum marker.

Figure 1

Serum levels of sCD163 (L) in patients with burn trauma in relation to the total body surface area (TBSA) burned group A (white boxes) TBSA <25% (n=8) in comparison with group B (grey boxes) TBSA of 25% or more (n=10)

Figure 2

Serum levels of sCD163 (L) in patients with burn trauma in relation to the abbreviated burn severity index (ABSI) group A ABSI <10 (n=11) in comparison with group B ABSI of 10 or more (n=7). Statistical significant differences between groups (Mann-Whitney test) and time points (Wilcoxon signed rank) are labelled under specification of the level of significance

Figure 3

Serum levels of sCD163 (L) in patients with burn trauma in relation to the initial measured level of IL-6 group A initial IL-6 <100 pg/ml (n=9) in comparison with group B initial IL-6 of 100 pg/ml or more (n=9). Statistical significant differences between groups (Mann-Whitney test) and time points (Wilcoxon signed rank) are labelled under specification of the level of significance

Figure 4

Regression plot between serum level of soluble CD163 and leukocyte count in patients with burn trauma. The Positive linear regression describes a relationship between the tested variables (P=0.035, r=0.25)

Figure 5

Serum levels of sCD163 (L) in patients with burn trauma in relation to sepsis. Group A burn patients without diagnose of a sepsis (n=12) in comparison with group B patients with sepsis (n=6). Statistical significant differences between groups (Mann-Whitney test) and time points (Wilcoxon signed rank) are labelled under specification of the level of significance

Figure 6

Serum levels of sCD163 (L) in patients with burn trauma in relation to the peak of the SOFA score within the first 120 h after the burn injury. Group A burn patients with a SOFA score (n=10) from 0 to 10 points in comparison with group B patients with a SOFA score of 11 points or more (n=8). Statistical significant differences between groups (Mann-Whitney test) and time points (Wilcoxon signed rank) are labelled under specification of the level of significance