Effects of interleukin-6 and its neutralizing antibodies on peritoneal adhesion formation and wound healing

This study investigates the effects of preoperative IV administration of IL-6 and anti IL-6 on peritoneal adhesion formation and wound healing. Thirty-six male Sprague-Dawley rats (350-400 mg) were divided into three groups: control (group 1); IL-6 (group 2); and anti IL-6 (group 3). Under sterile conditions, all rats underwent a midline laparotomy. Ten cm2 of cecal serosa was abraded, the cecum further irritated with 0.1 ml of 70 per cent alcohol, and the incision closed in layers. At 3 weeks, peritoneal adhesions were graded using a score of 0 (none) to 3 (extensive, dense). Skin samples from incisional sites were examined tensiometrically (true stress and true strain), biochemically (collagen content), and histologically. Adhesion formation score was significantly increased in IL-6 group (2.78 +/- 0.44, Mean +/- SD) and decreased in anti IL-6 group (1.40 +/- 0.52) compared to control (2.00 +/- 0.50). (P < 0.03 by Kruskal Wallis test). There was no significant difference in true stress, true strain, and collagen content between the two treatment groups and controls at the 0.05 level by ANOVA. Histological analysis showed higher number of inflammatory cells and fibroblasts in IL-6 treated groups. We conclude that IL-6 plays a major role in peritoneal adhesion formation. Selective immunosuppression, using IL-6 neutralizing antibodies preoperatively, leads to a reduction of such adhesion formation without a significant effect on wound healing.