Background: The cytokine network remarkably influences homeostasis. There is not a complex analysis describing physiological values of soluble cytokines in healthy individuals.
Methods: Authors used the ELISA method to detect soluble cytokines and costimulatory molecules simultaneously in the plasma of 30 blood donors.
Results: Data are shown as (a range of concentrations; median) IL-2 (0-74.48 pg/mL; 0), IL-4 (0-65.18 pg/mL; 0), IL-5 (0-86.69 pg/mL; 0), IL-6 (0-73.17 pg/mL; 0), IL-8 (0-74.8 pg/mL; 0), IL-10 (0-12.6 pg/mL; 0), IL-13 (0-3.9 pg/mL; 0), sCD40L (0-3.5 ng/mL; 0), and TNF-alpha (0-67.6; 0). For the IL-6 receptor, the concentration was 75.89 +/- 35.83 ng/mL (average +/- SD), sCD23 28.9 +/- 15.22 ng/mL, and TGFbeta1 14.98 +/- 12.39 ng/mL. A special approach was taken for the analysis of values, which had median 0. A model for the probability of detectable level's occurrence for each interleukin was formulated with intervals of confidence.
Conclusion: These results provide reference values for cytokine levels in the plasma of healthy individuals.