Research paperExercise-induced cytokine changes in antigen stimulated whole-blood cultures compared to serum

- Intraindividually, exercise-induced systemic cytokine changes are different from sWBC.
- The cytokine output in a sWBC is a measure of leukocyte function.
- A sWBC offers a more sensitive insight into the cytokine response to exercise.
- Serum measurements reflect net changes with respect to both production and clearance.
- It is proposed to use both approaches synergistically.

Strenuous exercise is followed by an elevation of many cytokines with inflammation regulating properties. Since most cytokines act at pico- or nanomolar concentrations many investigations failed to detect their concentrations in vivo. Hence, the aim of this study was to evaluate the significance of cytokine measurements (IL-1β, TNF-α, IL-1ra, IL-6, CCL2 and CXCL8) in a stimulated whole-blood culture (sWBC) compared to serum with respect to their exercise-induced kinetics and detection rates. 40 male volunteers (age: 25,5 ± 4,3 years, BMI: 24,00 ± 2,24, VO2peak: 46,9 ± 4,1 mL/kg × min) performed 60 min of intensive bicycle exercise (80% VO2peak). Blood samples were taken before and for up to 24 h after exercise. All cytokines were determined by a multiplex ELISA. There were weak to moderate correlations between cytokines in sWBC and serum. While exercise did not affect pro-inflammatory cytokines in serum, in sWBC only IL-1β was increased 1.2-fold at 3 h (p < 0,05). All other cytokines increased both in sWBC and serum. The detection rate was superior in sWBC vs serum for most cytokines. Exercise-induced cytokine kinetics in sWBC do not reflect systemic changes. Both approaches provide a synergistic insight into inflammatory processes on the cytokine level.