Increased proinflammatory cytokines in mesenteric fat in major surgery and Crohn disease.

BACKGROUND: Proinflammatory cytokines play an important role in abdominal surgery and are often associated with the development of postoperative ileus, especially in Crohn disease. The aim of this study was to investigate proinflammatory cytokine levels in mesenteric fat in Crohn disease and patients without Crohn disease.

METHODS: Human mesenteric tissue specimen were divided into 3 patient groups (n = 10 each): minor surgery (laparoscopic cholecystectomy), major surgery (colectomy) in patients without Crohn disease, and major surgery (colectomy) in patients with Crohn disease. Levels of interleukin 6, interleukin 1-β, and tumor necrosis factor α were determined by cytometric bead array, enzyme-linked immunosorbent assay and reverse transcription polymerase chain reaction. The Kruskal-Wallis and the Mann-Whitney U test were used to compare continuous variables. For categorical variables, the χ2 test or Fisher exact test was used.

RESULTS: In minor surgery, cytokines levels of interleukin 6, interleukin 1-β and Tumor necrosis factor α were low (ie, interleukin 6: 1 pg/mL [0-36], interleukin 1-β: 0 fg/mL [0-18], tumor necrosis factor α: 157 fg/mL [91-237]) compared with major surgery in patients with and without Crohn disease. Cytokines were significantly higher in major surgery (ie, interleukin 6: 147 pg/mL [29-347], interleukin 1-β: 660 fg/mL [0-2580], tumor necrosis factor α: 532 fg/mL [289-1647]; P = .02 and major surgery with CD (cytometric bead array: interleukin 6: 94 pg/mL [24-627], interleukin 1-β: 708 fg/mL [0-1664], tumor necrosis factor α: 733 fg/mL [209-1,354]; P < .05). Cytokine levels in major surgery with Crohn disease showed a further increase of interleukin 6 in polymerase chain reaction in comparison to major surgery in patients without Crohn disease (1.2 vs 4, P = .04).

CONCLUSION: Proinflammatory cytokines are increased in the mesenteric fat in major operations compared to minor operations, which indicates local mesenteric inflammation. In Crohn disease, levels of proinflammatory cytokines are even higher, which may put the patients at risk for postoperative ileus.