Free Interleukin 18 (IL-18F) Blood Levels Following Midline Laparotomy: A Prospective Randomized Study of Patients With Benign Disease and Patients With Cancer.

Abstract

Background/aim: The purpose of this work was to assess blood level correlations of free IL-18 (IL-18F) and various cytokines (CYTs), caspase-1 (Casp1), high sensitive C-reactive protein (hs-CRP), and 4-hydroxynonenal (4-HNE) in 56 patients subjected to midline laparotomy (MLa) and to investigate their link to pain scales.

Patients and methods: Blood levels of IL-18F and seven CYTs (IL-18, IL-18BP, IL-1ra, IL-6, IL-8, IL-10, IL-1β), Casp1, hs-CRP, and 4-HNE were measured and the pain surveys were reported using numerical rating scale (NRS) and the Brief Pain Inventory (BPI) scales conducted preoperatively (PRE) and postoperatively (POP).

Results: The IL-18F levels decreased at POP and the decrease between POP1 (immediately after MLa) and POP2 (24 hours after MLa) blood levels (26.5 versus 20.0) was significant (p<0.001). Moreover, the IL-18F levels at POP2 were slightly higher in patients with cancer than in patients with benign disease (21.2 versus 17.8). Interestingly, the IL-18F levels correlated to IL-18 (r=0.523, p<0.001), IL-18BP (r=-0.475, p<0.001), and 4-HNE (r=0.414, p<0.001) levels. Furthermore, the IL-18F levels correlated with BPI score values (r=-0.459, p=0.05).

Conclusion: This is the first report to demonstrate a link between increased IL-18F levels and pain scales in MLa. IL-18F levels decreased significantly after operation and correlated with IL-18, IL-18BP, and 4-HNE blood levels, and inversely correlated with BPI pain scores. These results support the applicability of acute phase response biomarkers in understanding pain in patients subjected to MLa.