Circulating interleukin 6 as a useful marker for predicting postoperative complications.

We examined postoperative serial changes in the levels of serum interleukin 6 (IL-6), serum acute phase reactants (APRs) and plasma neutrophil elastase (NE) in patients with various cancers and reviewed these changes in patients who did, and did not, show postoperative complications. Serum IL-6 level was elevated after surgery, peaking on the first postoperative day. Elevation of serum APRs and plasma NE levels also followed. There was a significant correlation between the serum peak level of IL-6 and those of APRs and NE (P less than 0.01). Moreover, there was a significant difference in the serum IL-6 level in patients with and without complications. The relationship between the serum IL-6 greater than 400 pg/ml and the incidence of postoperative complications was also marked. These results suggest that circulating IL-6 is a clinically useful marker for the earliest detection and prediction of postoperative complications.