Detection of neopterin, interleukin-6 and acute-phase proteins as parameters of potential monocyte activation in preoperative patients.

Monocytes play a key role in the immune response to trauma and infection. Is monocyte function already altered before surgery in terms of cell activation? On admission, serum neopterin was at or above 9 nmol/l in 50.2% and serum IL-6 was detectable (> 4 pg/ml) in 10.5% of 227 patients electively undergoing major abdominal surgery. Mean values of CRP (0.8 vs. 3.6), alpha-1-antitrypsin (267 vs. 376), albumin (4.0 vs. 3.5), prealbumin (27.0 vs. 17.9, all at p < 0.01) were significantly different in patients with or without monocyte activation (neopterin > 9 nmol/l and IL-6 > 4 pg/ml). There was a significant correlation between neopterin and the acute phase proteins (all at p < 0.01). The data reflect a "primed" state at least of some parts of the immune system in a subgroup of preoperative patients potentially affecting their response to surgical trauma and bacterial contamination.