Interleukin-18 (IL-18) Cytokine Serum Concentrations Correlate with Pain Scores and the Number of Analgesic Doses following Surgery

Abstract

Background/Aim: Anti- and proinflammatory cytokines and plasma high-sensitivity C-reactive protein (hsCRP) are used to assess inflammatory stress response (ISR) following surgery. However, the serum IL-18 (interleukin-18) cytokine values versus numeric rating scale (NRS) pain score and number of analgesic doses (NAD) postoperatively are unknown. Patients and Methods: Blood levels of six interleukins (IL-18, IL-1ra, IL-6, IL-10, IL-1β, and IL-8) and hs-CRP were measured at three time points; before operation (PRE), immediately after operation (POP1), and six hours after operation (POP2) in 114 patients with cholelithiasis. Results: Following surgery, the blood levels of hs-CRP and IL-1ra, IL-6, IL-10, and IL-1β cytokines had a trend for increase (p<0.001 and p=0.014, respectively). The serum IL-18 concentrations inversely correlated to NRS and NAD during the first 24 h postoperatively. Conclusion: The correlation of IL-18 levels to NRS and NAD values supports the hypothesis that ISR and pain are related.