The Impact of Different Anesthetics on the Distribution and Cytotoxic Function of NK Cell Subpopulations: An In Vitro Study.

Only some subpopulations of natural killer (NK) cells have cytotoxic functionality, and the effects of anesthetics on these subpopulations are unknown. This study aimed to evaluate the in vitro effects of various anesthetics, both alone and in combination, on the distribution and cytotoxic function of NK cells and their subpopulations. Peripheral blood mononuclear cells (PBMCs) from eight healthy volunteers were treated for 4 h in vitro with dexmedetomidine, remifentanil, lidocaine, propofol, sevoflurane, and combinations in clinically relevant concentrations or left untreated. Flow cytometry was used to quantify the percentage of sampled NK cells and evaluate their distribution (CD56 ^bright CD16 ^neg , CD56 ^bright CD16 ^dim , CD56 ^dim CD16 ^neg , CD56 ^dim CD16 ^bright , and CD56 ^neg CD16 ^bright ) and cytotoxicity (Granzyme B (GrzB) and perforin) of NK cell subpopulations. Although the percentage of total NK cells did not change following exposure to anesthesia, the most important cytotoxic subpopulation (CD56 ^dim CD16 ^bright NK cells) decreased after exposure to both propofol (-3.58%, p = 0.045) and sevoflurane (-16.10%, p = 0.008) alone, and most combinations, especially in combination with lidocaine (propofol with lidocaine (-9.66%, p = 0.002) and sevoflurane with lidocaine (-21.90%, p < 0.001)). Dexmedetomidine and remifentanil had no effect on CD56 ^dim CD16 ^bright NK cells. Furthermore, no anesthetic regimen or combination altered the expression of GrzB and perforin in NK cells or NK cell subpopulations. In short, propofol and sevoflurane suppressed the highly cytotoxic phenotype (CD56 ^dim CD16 ^bright ) of NK cells, with those exposed to sevoflurane combinations showing greater reductions. Immunosuppression was intensified with the inclusion of lidocaine in the anesthetic regimen.
Competing Interests: Tristan J. Vulcano: No conflicts of interest to report. Wayel H. Abdulahad: No conflicts of interest to report. Matijs van Meurs: No conflicts of interest to report. Rianne M. Jongman: No conflicts of interest to report. Michel M.R.F. Struys: The author has no conflicts of interest related to this manuscript. In general, his research group/department received (over the last 3 years) research grants and consultancy fees from Masimo (Irvine, CA, USA), Becton Dickinson (Eysins, Switzerland), Fresenius (Bad Homburg, Germany), Paion (Aachen, Germany), Medcaptain Europe (Andelst, The Netherlands), Baxter (Chicago, Il, USA), and HanaPharm (Seoul, Republic of Korea). He receives royalties on intellectual property from Demed Medical (Sinaai, Belgium) and Ghent University (Gent, Belgium). Dirk J. Bosch: No conflicts of interest to report.