Decreased serum level of IL-12 in the course of ischemia and reperfusion during abdominal aortic surgery

Ischemic-reperfusion injury (IRI) is defined as tissue damage, organ dysfunction or failure developed in the course of inflammatory response following ischemia and reperfusion (IR). Abdominal aortic aneurysm (AAA) repair required IR of distal parts of the body carries a risk of organ injury and postoperative mortality of between 4% and 12%. The aim of this study was the evaluation of IL-12 serum level during AAA repair in relation to IR. Blood samples were taken before surgery (Preop), before aortic unclamping (Pre-X(off)), 90 min after unclamping (90 min-X(off)) and 24 h after surgery (Postop) from 37 AAA patients; and before surgery (Preop), at 90 min of surgery (90 min-surg), at 180 min of surgery (180 min-surg) and 24 h after operation (stop) from ten patients scheduled for elective surgery of lumbar discopathy (SC); and once from ten healthy controls. IL-12 was measured using the ELISA technique. Preoperative IL-12 was higher in AAA (0.21 pg/ml) and SC (0.31 pg/ml) patients than in controls (0.05 pg/ml). A significant decrease in IL-12 (0.09 pg/ml) was observed at 90 min-X(off) in comparison to the preoperative value in AAA but not in the SC group. 24 h after surgery, IL-12 levels were still low in the AAA group (0.13 pg/ml), and nonsignificantly surpassed the preoperative value in the SC group (0.36 pg/ml). We conclude that operative injury was associated with increased IL-12 levels, and IR with decreased IL-12 levels. Diminished IL-12 during AAA repair might be associated with a higher risk of postoperative complications, but this needs further evaluation.