Longitudinal course of LPS-induced IL8-production for the fatigued and non-fatigued group. Whole blood samples obtained from participants assigned to the fatigued group (black circles, n = 53) and non-fatigued group (white squares, n = 388) were stimulated for 24 h with 1 ng/mL LPS and IL-8 levels in the culture supernatant were quantified. Samples were collected before deployment (T0), and 1 month (T1) and 6 months (T2) after return from deployment. The amount of LPS-induced IL-8 production did not change over time and there were no significant differences between the fatigued and non-fatigued group (time: F(1.90, 934.51): 1.87, P = 0.157; group: F(1,439): 0.36, P = 0.551; time x group: F(1.90, 934.51): 0.10, P = 0.900). Data are presented as mean ± SEM.