Plasma Kynurenic Acid Concentration in Patients Undergoing Cardiac Surgery: Effect of Anaesthesia

Abstract

Increases in plasma kynurenic acid (KYNA) concentration relate to the severity of inflammation. The aim of this study was to analyse changes in plasma KYNA concentration and neutrophil/lymphocyte ratio (NLR) in cardiac surgery patients. Additionally, the effect of anaesthesia was analysed. Adult cardiac surgery patients under intravenous general anaesthesia were studied. Additionally, some patients received sevoflurane (SEV) prior to cardiopulmonary bypass. Plasma KYNA concentration and NLR were measured before anaesthesia, just after surgery and on postoperative days 1, 2 and 3. Patients were assigned to two groups: patients who did not receive SEV (NonSEV group) and patients who received SEV (SEV group). Forty-three patients were studied. Twenty-four of them received SEV. KYNA increased immediately after surgery and remained elevated through postoperative day 3 in the NonSEV group, whereas it was similar to the preoperative concentration in the SEV group. NLR increased immediately after surgery in both groups, and higher values were noted in the NonSEV group than in the SEV group at postoperative days 2 and 3. Plasma KYNA concentration correlated with NLR in the NonSEV group. Cardiac surgery caused an increase in NLR. Plasma KYNA increased in the NonSEV group and correlated with NLR. Administration of SEV inhibited the increase in KYNA, most likely due to its anti-inflammatory properties.

Carotid surgery affects plasma kynurenic acid concentration: A pilot study

“…The effect of surgery on plasma KYNA concentration has been poorly documented, but it can be assumed that a significant increase in plasma proinflammatory cytokines following the surgical procedures implemented may increase the activity of IDO and enhance production of kynurenine metabolites. This hypothesis is in accordance with our previous study, which demonstrated a significant increase in plasma KYNA concentration following cardiac surgery [ 30 ]. Likewise, Forrest et al presented an increase in plasma KYNA concentration after major surgery [ 31 ].…”

Respiratory Syncytial Virus Infection Reduces Kynurenic Acid Production and Reverses Th17/Treg Balance by Modulating Indoleamine 2,3-Dioxygenase (IDO) Molecules in Plasmacytoid Dendritic Cells

“…The kynurenine pathway has been shown to modulate tryptophan metabolism and the serotonergic system and to play critical roles in the secretion of pro-inflammatory cytokines [ 27 ]. In the kynurenine metabolic pathway, tryptophan is initially oxygenated by IDO to yield kynurenine, which is subsequently transformed by kynurenine aminotransferase to kynurenic acid [ 28 ]. Our findings showed that RSV infection markedly reduced kynurenic acid concentrations in pDCs, suggesting that RSV infection can modulate inflammatory responses in pDCs by regulating the production of kynurenic acid.…”

Negative effects on newborn piglets caused by excess dietary tryptophan in the morning in sows

“…During neonatal asphyxia, the levels of KYNA rose significantly in the brain of newborn rats, whereas they fell at birth in normal newborns . In other stages, increases in plasma KYNA concentration have been reported to be correlated with inflammatory bowel disease, severe inflammation, clinical symptoms, schizophrenia and distress intolerance …”