Plasma soluble interleukin-2 receptor levels during and after upper abdominal surgery

Soluble interleukin-2 (IL-2) receptor (sIL-2R) is reported to be up-regulated in inflammatory disorders. Although sIL-2R may modulate perioperative inflammatory responses, it remains unclear whether upper abdominal surgery affects plasma sIL-2R levels. We evaluated the influence of major abdominal surgery on plasma sIL-2R levels. Ten patients scheduled for upper abdominal surgery received anaesthesia with isoflurane, nitrous oxide, and epidural block. Plasma sIL-2R and IL-6 levels were determined at pre-anaesthesia, 0, 2, and 4 hours during surgery, and on postoperative days 1 (POD1) and 3 (POD3). The plasma levels of sIL-2R decreased significantly and achieved their minimum value at 4 hours (677.0 +/- 125.3 pg/ml, P < 0.01 compared to pre-anaesthesia value; 924.5 +/- 178.8 pg/ml, 95% confidence interval = 122.2-550.4). The plasma sIL-2R levels increased on POD1 (1336.5 +/- 174.0 pg/ml) and POD3 (1629.0 +/- 262.8 pg/ml), and reached a level significantly higher than the baseline (P < 0.05 and P < 0.001, 95% confidence interval = 93.4-730.6 and 402.8-1006.2, respectively). The plasma sIL-2R levels on POD3 significantly correlated with the peak IL-6 levels (r = 0.67, P < 0.05). The plasma sIL-2R levels on POD3 correlated with the amount of intraoperative bleeding (r = 0.66, P < 0.05). In conclusion, we found that major abdominal surgery induces characteristic changes in plasma soluble IL-2 receptor levels.