Reduced serum cholinesterase activity indicates splenic modulation of the sterile inflammation

Abstract

BackgroundSterile inflammation is an immediate and well-coordinated immune response to surgical injury. The cholinergic system plays a pivotal role in the inflammatory response. Induced inflammation stimulates the vagus nerve, which in turn activates anti-inflammatory nonneuronal processes. Serum cholinesterase (butyrylcholinesterase [BChE]) is an enzyme that hydrolyzes acetylcholine. Measuring the activity of the BChE in blood might indicate the level of the nonneuronal cholinergic activity. The spleen is a major organ of the immune system playing an important role during inflammation. A functional connection of the neuroimmune reflex has thus far been described only in experimental settings. Materials and methodsIn 48 patients receiving major pancreatic surgery, BChE activity was measured by applying point-of-care-testing, in addition to standard laboratory tests. ResultsThe BChE activity decreased in patients receiving surgery. This reduction emerged much earlier than changes in C-reactive protein concentration, an inflammatory biomarker broadly used in the clinical environment. A milder reduction in the BChE activity was observed in patients subjected to surgery with splenectomy than in those with a preserved spleen. ConclusionsThe use of the point-of-care-testing system for quick bedside diagnostics and the rapid effects of inflammation on BChE levels provide a method and a marker to facilitate the early detection of systemic inflammation. Furthermore, this study provides evidence that the experimentally documented neuroimmune interaction is part of the physiological response to surgery-induced sterile inflammation. Splenic function plays an essential role in modulating the cholinergic anti-inflammatory response.