Features of the subpopulation composition of circulating NK and NKT cells in patients with subclinical atherosclerosis of lower limb arteries

Aim. To study the features of the subpopulation composition of circulating NK and NKT cells and their diagnostic value in middle-aged patients, depending on the presence of subclinical atherosclerosis of lower limb arteries.

Methods. The study included 80 patients, 44 men (55.0%) and 36 women (45.0%), whose age was 49.0 (44.0; 56.0) years. All patients underwent duplex ultrasound scanning (DUS) of the arteries of the lower extremities. Lymphocyte immunophenotyping was performed on a Navios 6/2 flow cytometer (Beckman Coulter, USA) using reagents: CD45-PC7.0, CD16-PE, CD11b-FITC, CD4-APC, CD8-PC5.5, CD3-ECD manufactured by the company Beckman Coulter, USA.

Results. According to the results of the DUS of the arteries of the lower extremities, the patients were divided into two groups: the first group included 46 (57.5%) patients with atherosclerosis of the lower limb arteries, the second group included 34 (42.5%) patients without plaques in the arteries of the lower limbs. Patients with atherosclerosis of the lower limb arteries differed from patients with intact arteries of the lower extremities with statistically significantly higher values of circulating NK cells, and lower values of NK-CD4⁺ CD11b⁺ cells. The decrease in the number of NK-CD4⁺CD11b⁺ cells ≤16.5 cells/μl allowed to diagnose atherosclerosis of the lower limb arteries with a sensitivity of 80.0% and a specificity of 58.8%. According to logistic regression analysis, a decrease in the number of NK-CD4⁺CD11b⁺ cells ≤16.5 cells / μl was associated with a odds ratio (OR) of atherosclerosis of lower limb arteries 5.71 (95% confidence interval (CI) 1.44-22.6; p=0.013).

Conclusion. Compared with the control group, patients with atherosclerosis of the lower limb arteries differed in a statistically significantly larger number of circulating NK cells and a smaller number of NK-CD4⁺CD11b⁺ cells. The decrease in the number of NK-CD4⁺CD11b⁺ cells ≤16.5 cells/μl allowed to diagnose atherosclerotic lesions of the arteries of the lower extremities with a sensitivity of 80.0% and a specificity of 58.8%.

1. Reshetnikov O.V., Kurilovich S.A., Nikitin Yu.P. Infections, inflammation and atherosclerosis. Ateroscleros. 2019; 15(2): 78-88. doi: 10.15372/ATER20190211

2. Kumar A., Suryadevara N., Hill T.M. et al. Natural Killer T Cells: An Ecological Evolutionary Developmental Biology Perspective. Front Immunol. 2017; 8: 1858. doi: 10.3389/fimmu.2017.01858.

3. Zitti B., Bryceson Y.T. Natural killer cells in inflammation and autoimmunity. Cytokine Growth Factor Rev. 2018; 42: 37-46. doi: 10.1016/j.cytogfr.2018.08.001.

4. van Puijvelde G.H.M, Kuiper J. NKT cells in cardiovascular diseases. Eur J Pharmacol. 2017; 816: 47-57. doi: 10.1016/j.ejphar.2017.03.052.

5. Kyaw T., Tipping P., Toh B.H., Bobik A. Killer cells in atherosclerosis. Eur J Pharmacol. 2017; 816: 67-75. doi: 10.1016/j.ejphar.2017.05.009.

6. Bonaccorsi I., Spinelli D., Cantoni C. et al. Symptomatic Carotid Atherosclerotic Plaques Are Associated With Increased Infiltration of Natural Killer (NK) Cells and Higher Serum Levels of NK Activating Receptor Ligands. Front Immunol. 2019; 10: 1503. doi: 10.3389/fimmu.2019.01503.

7. Bonaccorsi I., De Pasquale C., Campana S. et al. Natural killer cells in the innate immunity network of atherosclerosis. Immunol Lett. 2015; 168(1): 51-7. doi: 10.1016/j.imlet.2015.09.006.

8. Sprynger M., Rigo F., Moonen M. et al. Focus on echovascular imaging assessment of arterial disease: complement to the ESC guidelines (PARTIM 1) in collaboration with the Working Group on Aorta and Peripheral Vascular Diseases. Eur Heart J Cardiovasc Imaging. 2018; 19 (11): 1195-1221. doi: 10.1093/ehjci/jey103.

9. Mozzini C., Roscia G., Casadei A., Cominacini L. Searching the perfect ultrasonic classification in assessing carotid artery stenosis: comparison and remarks upon the existing ultrasound criteria. J Ultrasound. 2016; 19 (2): 83-90. doi: 10.1007/s40477-016-0193-6

10. Aboyans V., Ricco J.B., Bartelink M.E.L. et al. 2017 ESC Guidelines on the Diagnosis and Treatment of Peripheral Arterial Diseases, in collaboration with the European Society for Vascular Surgery (ESVS): Document covering atherosclerotic disease of extracranial carotid and vertebral, mesenteric, renal, upper and lower extremity arteries. Endorsed by: the European Stroke Organization (ESO)The Task Force for the Diagnosis and Treatment of Peripheral Arterial Diseases of the European Society of Cardiology (ESC) and of the European Society for Vascular Surgery (ESVS). Eur Heart J. 2018; 39 (9): 763-816. doi: 10.1093/eurheartj/ehx095.

11. Aboyans V., Criqui M.H., Abraham P. et al. Measurement and interpretation of the ankle-brachial index: a scientific statement from the American Heart Association. Circulation. 2012; 126 (24): 2890-909. doi: 10.1161/CIR.0b013e318276fbcb.

12. Selathurai A., Deswaerte V., Kanellakis P. et al. Natural killer (NK) cells augment atherosclerosis by cytotoxic-dependent mechanisms. Cardiovasc Res. 2014; 102(1): 128-37. doi: 10.1093/cvr/cvu016.

13. Nour-Eldine W., Joffre J., Zibara K. et al. Genetic Depletion or Hyperresponsiveness of Natural Killer Cells Do Not Affect Atherosclerosis Development. Circ Res. 2018; 122 (1): 47-57. doi: 10.1161/CIRCRESAHA.117.311743.

14. Winkels H., Ley K. Natural Killer Cells at Ease: Atherosclerosis Is Not Affected by Genetic Depletion or Hyperactivation of Natural Killer Cells. Circ Res. 2018; 122 (1): 6-7. doi: 10.1161/CIRCRESAHA.117.312289.

15. Strassheim D., Dempsey E.C., Gerasimovskaya E. et al. Role of Inflammatory Cell Subtypes in Heart Failure. J Immunol Res. 2019; 2019: 2164017. doi: 10.1155/2019/2164017.

16. Hak Ł., Myśliwska J., Więckiewicz J. et al. NK cell compartment in patients with coronary heart disease. Immun Ageing. 2007; 4: 3. doi: 10.1186/1742-4933-4-3.

17. Jabir N.R., Firoz C.K., Ahmed F. et al. Reduction in CD16/CD56 and CD16/CD3/CD56 Natural Killer Cells in Coronary Artery Disease. Immunol Invest. 2017; 46 (5): 526-535. doi: 10.1080/08820139.2017.1306866.

18. Backteman K., Ernerudh J., Jonasson L. Natural killer (NK) cell deficit in coronary artery disease: no aberrations in phenotype but sustained reduction of NK cells is associated with low-grade inflammation. Clin Exp Immunol. 2014; 175 (1):104-12. doi: 10.1111/cei.12210.

19. Ahmad F., Hong H.S., Jäckel M. et al. High frequencies of polyfunctional CD8+ NK cells in chronic HIV-1 infection are associated with slower disease progression. J Virol. 2014; 88 (21): 12397-408. doi: 10.1128/JVI.01420-14.