Reduced local inflammatory reactivity in septic patients compared with healthy controls

Introduction

The aim of this study was to access the local inflammatory reactivity by measurement of the cytokine response after catheter insertion into subcutaneous adipose tissue (SAT) of patients with severe sepsis compared with healthy volunteers.

Methods

Eight healthy volunteers and 10 patients with severe sepsis were included. One 18-gauge open-flow microperfusion double-lumen catheter was inserted into SAT of the abdominal wall and perfused with an isotonic solution at a flow rate of 1 μl/min. Blood samples and probe effluent samples from interstitial fluid of SAT were withdrawn in two hourly intervals for a period of 8 hours and retrospectively analysed using a Multiplex ELISA system for IL-1β, IL-6, IL-8 and TNFα.

Results

Concentrations of IL-1β, IL-6 and IL-8 were substantially higher in SAT (13.3 (11.2; 31.0); 1,934 (1,650; 2,730); 917 (656; 2,672) pg/ml; median (25th; 75th percentile)) than in serum (0.8 (0.6; 1.3); 49.2 (3.8; 67.6); 36.1 (6.3; 89.1) pg/ml) for both groups, whereas TNFα concentrations were similar in serum and SAT (Figure 1). Serum concentrations of all cytokines remained stable over time. However, a significant increase was observed for IL-1β and IL-8 in SAT in both groups. This increase was significantly in septic patients vs healthy controls.

Figure 1

Conclusion

Insertion of a catheter into subcutaneous adipose tissue promotes a local inflammatory response in both healthy individuals and critically ill patients. The attenuated response in patients with severe sepsis might be caused by reduced inflammatory reactivity in this group.