Neutrophil extracellular traps as a promising marker of poor prognosis in operated patients with infective endocarditisarditis.

Aim. To assess the prognostic value of the formation of neutrophil extracellular traps (NETs) in blood smears of operated patients with infective endocarditis (IE).

Material and methods. We prospectively included 46 patients with verified IE and 50 patients with valvular heart disease without IE, hospitalized in a cardiac surgery hospital in 2021-2022 (Moscow), comparable by sex and age. In all patients, NETs were determined upon admission and 7 days after surgery using the MECOS-Ts2 automated microscope (Russia). Patients included in the study were prospectively followed during the in-hospital period (ME [IQR] 30,0 [21,0-41,0] days) for the primary composite endpoint (in-hospital all-cause mortality, embolic, intracardiac, infectious complications) and its individual components.

Results. Patients with IE were predominantly male (n=37, 80,4%) with a median age of 55,5 [44,0-70,0] years. The primary combined endpoint was recorded in 76,1% (n=35) of those examined with IE. The NET level after 7 days was significantly higher in patients with IE who had primary combined endpoint events than in the group of operated patients with heart defects without IE (Me [IQR] 4,4 [0,6-26,6] vs 2,9 [1,1-4,3], respectively, p<0,05). Patients with IE who died in the hospital had a significantly higher NET level compared with surviving patients with IE and the control group as at admission (9,2 [1,8-18,9] vs 4,2 [0,3-28 ,5] and 3,4 [1,76,9], respectively, p<0,05), and in dynamics (18,2 [5,2-26,6] vs 4,0 [1, 0-26,6] and 2,9 [1,1-4,3], respectively, p<0,001). The threshold value of dynamic NET ≥11,2% predicted in-hospital death with high accuracy (sensitivity 80,0%, specificity 90,0%, positive predictive value 66,7%, negative predictive value 100,0%, area under the curve 0,915, p=0,003) and the development of postoperative sepsis (sensitivity 75,0%, specificity 88,0%, positive predictive value 60,0%, negative predictive value 100,0%, area under the curve 0,884, p=0,01). The obtained cut-off values significantly predicted the death (OR 23,9 (95% CI 1,7-344,8, p=0,02)) and sepsis (OR 22,0 (95% CI 1,9-256,8, p=0,01)) in the hospital in operated patients with IE.

Conclusion. The NET level in blood smears of operated patients with IE is a new promising marker for predicting the disease complicated course. NETs ≥11,2% in operated patients with IE increase the probability of hospital mortality by 24 times and postoperative sepsis by 22 times.

1. Demin A, Kobalava Z, Skopin I, et al. Infectious endocarditis and infection of intracardiac devices in adults. Clinical guidelines 2021. Russian Journal of Cardiology. 2022; 27(10):5233. (In Russ.) doi:10.15829/1560­40712022­5233.

2. Pisaryuk A, Zamarashkina V, Safarova N, et al. Coagulation Disorders in Infective Endocarditis: Role of Pathogens, Biomarkers, Antithrombotic Therapy (Systematic Review). Rational Pharmacotherapy in Cardiology. 2022;18(3):320­31. (In Russ.) doi:10.20996/1819­6446­2022­06­14.

3. Brinkmann V, Reichard U, Goosmann C, et al. Neutrophil extracellular traps kill bacteria. Science. 2004;303(5663):1532­5. doi:10.1126/science.1092385.

4. Li R, Tablin F. A Comparative Review of Neutrophil Extracellular Traps in Sepsis. Front Vet Sci. 2018;5:291. doi:10.3389/fvets.2018.00291.

5. Papayannopoulos V. Neutrophil extracellular traps in immunity and disease. Nat Rev Immunol. 2018;18(2):134­47. doi:10.1038/nri.2017.105.

6. Habib G, Lancellotti P, Antunes M, et al.; ESC Scientific Document Group. 2015 ESC Guidelines for the management of infective endocarditis: The Task Force for the Management of Infective Endocarditis of the European Society of Cardiology (ESC). Endorsed by: European Association for Cardio-Thoracic Surgery (EACTS), the European Association of Nuclear Medicine (EANM). Eur Heart J. 2015;36(44):3075­128. doi:10.1093/eurheartj/ehv319.

7. Meyers S, Crescente M, Verhamme P, Martinod K. Staphylococcus aureus and Neutrophil Extracellular Traps: The Master Manipulator Meets Its Match in Immunothrombosis. Arterioscler Thromb Vasc Biol. 2022;42(3):261­76. doi:10.1161/ATVBAHA.121.316930.

8. Khandpur R, Carmona­Rivera C, Vivekanandan­Giri A, et al. NETs are a source of citrullinated autoantigens and stimulate inflammatory responses in rheumatoid arthritis. Sci Transl Med. 2013;5(178):178ra40. doi:10.1126/scitranslmed.3005580.

9. Schauer C, Janko C, Munoz L, et al. Aggregated neutrophil extracellular traps limit inflammation by degrading cytokines and chemokines. Nat Med. 2014;20(5):511­7. doi:10.1038/nm.3547.

10. Jung C, Yeh C, Hsu R, et al. Endocarditis pathogen promotes vegetation formation by inducing intravascular neutrophil extracellular traps through activated platelets. Circulation. 2015;131(6):571­81. doi:10.1161/CIRCULATIONAHA.114.011432.

11. Yipp B, Petri B, Salina D, et al. Infection-induced NETosis is a dynamic process involving neutrophil multitasking in vivo. Nat Med. 2012;18(9):1386­93. doi:10.1038/nm.2847.

12. Hsu C, Hsu R, Ohniwa R, et al. Neutrophil Extracellular Traps Enhance Staphylococcus Aureus Vegetation Formation through Interaction with Platelets in Infective Endocarditis. Thromb Haemost. 2019;119(5):786­96. doi:10.1055/s­0039­1678665.

13. Gur'ev A, Mosalskaia D, Lopatin A, Volkov A. Prognostic value of cellular markers in sepsis: extracellular DNA traps and platelet count relation. Berlin, 32nd Annual Congress of the European Society of Intensive Care Medicine ESICM LIVES 2019. Intensive Care Med Exp. 2019;000809:237­8. doi:10.1186/S40635­019­0265­Y.

14. Kassina D, Vasilenko I, Gur'ev A, et al. Neutrophil extracellular traps: diagnostic and prognostic value in COVID­19. Almanac of Clinical Medicine. 2020;48(S1):S43­50. (In Russ.) doi:10.18786/2072­0505­2020­48­029.

15. Zhang F, Zhang Z, Ma X. Plasma level of neutrophil extracellular traps in septic patients and its clinical significance: a prospective observational study. Zhonghua Wei Zhong Bing Ji Jiu Yi Xue. 2017;29(2):122­6. Chinese. doi:10.3760/cma.j.issn.2095­4352.2017.02.006.

16. Zuo Y, Yalavarthi S, Shi H, et al. Neutrophil extracellular traps in COVID­19. JCI Insight. 2020;5(11):e138999. doi:10.1172/jci.insight.138999.

17. Masuda S, Nakazawa D, Shida H, et al. NETosis markers: Quest for specific, objective, and quantitative markers. Clin Chim Acta. 2016;459:89­93. doi:10.1016/j.cca.2016. 05.029.

18. Kasprzycka W, Homa-Mlak I, Mlak R, Małecka-Massalska T. Direct and indirect methods of evaluating the NETosis process. J Pre Clin Clin Res. 2019;13(1):50­6. doi:10.26444/jpccr/105563.