SCREENING ASSESSMENT OF THE IMMUNE STATUS OF PATIENTS WITH ACUTE CORONARY SYNDROME

Full Text

SCREENING EVALUATION OF THE IMMUNE STATUS OF PATIENTS WITH ACUTE CORONARY SYNDROME

Introduction. In post-COVID syndrome, including in patients with acute coronary syndrome (ACS), various disorders of the T- and B-links of immunity and NK cells have been revealed [7]. The study of the full immune status is very expensive and therefore we began to search for options for assessment by screening methods, which include T-receptor excision circle (TREC) circular DNA molecules, kappa-deletion recombination excision circles (KREC) and studies using tetras (CD 45+, 3+, 4+, 8+ and CD 45+, 16-56+, 19+), which allow us to determine the main subpopulations of T, B and NK leukocytes, as the most common disorders in post-COVID [1]. In the current situation, the number of adults with various immunodeficiencies, including primary ones, is increasing. In the work of Sait-galina M.A. et al. [4] a statistically significant difference in the content of TREC in groups of different ages was found. In HIV infection, a significant decrease in the levels of TREC and KREC was observed during the long course of HIV infection [3]. 

In the work of M.A. Saytgalina et al. [5], it was shown that the content of TREC and KREC in the peripheral blood can be molecular markers of the severity of T- and B-lymphopenia. TREC and KREC can be considered a quantitative marker of undifferentiated T- and B-cells in the central lymphoid organs and T- and B-lymphocytes in the periphery. In 63.7% of patients who died from COVID-19, the content of TREC/KREC molecules was below age norms. TREC and CD-3,4 decreased in some patients with post-COVID syndrome [1]. Also, in the study of Zurochka A.V. et al., dysfunction of the immune defense in the T-cell link of patients with post-COVID syndrome (PCS) was shown, which is possibly due to a violation of the formation of T-cells in the thymus gland. Long-term decrease in the TREC level in the blood affects the immunity of patients and requires immunocorrective treatment. At the same time, this has not been studied before in patients with ACS and PCS, so it was relevant to study TREC and KREC and tetra (CD 45+, 3+, 4+, 8+ and CD 45+, 16-56+, 19+) in patients with ACS. The aim of the work was to determine the differences in the clinical picture and immunological status in patients with ACS and PCS, taking into account the level of TREC in the peripheral blood.

Materials and methods.
A total of 32 patients aged 40 to 65 years with acute coronary syndrome (ACS) and a history of COVID-19 6 to 18 months ago were examined. All patients underwent coronary angiography and coronary artery stenting. Conventional laboratory parameters, instrumental examination, including electrocardiography, and Doppler echocardiography were also determined.
To determine TREC levels in peripheral blood, numerical multiplex PCR was determined in parallel with the amplification of the target TREC DNA fragment and fragments of two normalization genes, HPRT and RPP30, using the TREC/KREC-AMP PS reagent kit (Pasteur Research Institute, St. Petersburg) [6]. The data obtained were compared with normal values ​​depending on age [4]. When registering the studied subpopulations of blood lymphocytes, reagents from Beckman Coulter (USA) - TetraChrome were used. To determine T-lymphocytes (phenotype CD3+CD19–), B-lymphocytes (phenotype CD3– CD19+), NK cells (phenotype CD3– CD56+ CD16+) and T-NK lymphocytes (phenotype CD3+ CD56+ CD16), monoclonal antibodies were used: CD45-FITC, CD56-RD1+CD16-PE, CD19-ECD and CD3-PC5. To register T-helpers CD3+ CD4+ and cytotoxic T-lymphocytes CD3+ CD8+, antibodies CD45-FITC, CD4-RD1, CD8-ECD and CD3-PC5 were used. The analysis of samples was studied on a Navios™ flow cytofluorimeter (Beckman Coulter, USA) [8].

Results and discussion. Of the patients with ACS and SCS, the TREC content was determined in 32 patients, of whom 28 had unstable angina and 3 had acute myocardial infarction without ST segment elevation (AMI NSTE). The patients were divided into groups depending on the TREC content: with a reduced TREC level (one group) and normal (the second group). As for KREC, it should be noted that only one patient from the study had a reduced indicator, while the rest had it within the normal range, therefore, in our work, we did not find the effect of KREC on the clinical and immunological characteristics of patients with ACS and SCS. When comparing individuals with ACS and ACS depending on the TREC content, it is necessary to record that there was a reliable difference in the content of this parameter between the compared groups (p<0.05) – Table 1. Clinical, laboratory and instrumental parameters were analyzed in patients with a reduced amount of TREC (group 1) and normal TREC content (group 2).

Table 1. Clinical characteristics of patients with ACS and post-COVID syndrome depending on the content of TREC 

indicator	TREC decreased (n=8)	TREC normal  (n=24)	Т	p
TREC	5,23±2,17	196,26±46,44	2,35	0,013
lung tissue damage according to computed tomography (CT), %
ere was no defeat (0%)	4 (50,00%)	16 (66,67%)
CT-1 (up to 25%)	3 (37,50%)	5 (20,83%)
Risk by Grace, points	107,63±6,90	92,58±5,17	1,53	0,049
number of stents installed during current hospitalization
0	4 (50%)	10 (41,67%)
1	1 (12,5%)	9 (37,5%)
2	2 (25%)	4 (16,67%)
3	0	1 (4,17%)
4	1 (12,5%)	0
Ejection fraction (Simpson), %
preserved (more than 50%)	3 (37,5%)	15 (62,5%)
intermediate (40-49%)	3 (37,5%)	6 (25%)
low  (less than 40%)	2 (25%)	3 (12,5%)

Patients in both groups did not differ in age, duration of COVID-19, or duration of hospitalization. As for lung tissue damage in COVID-19, in the first group CT-1 (up to 25%) was higher than in individuals in group 2: 37.5% of patients and 20.83%, respectively. There was also a lower absence of CT signs of COVID pneumonia: 50% in individuals with reduced TREC, while in patients with increased TREC it was 66.67%. A significant increase in the Grace risk (p <0.05) was recorded in individuals with low TREC. In the current hospitalization, attention is drawn to the higher percentage of 2 stents installed in patients with low TREC: 25% versus 16.67%, respectively. One patient from group 1 had 4 stents implanted, unlike individuals with normal TREC. Preserved EF prevailed in patients of group 2, intermediate and low EF prevailed in patients with decreased TREC (37.5 and 25%, respectively). There was a tendency for troponin to increase in patients of group 1. AMI at the time of the current hospitalization was in 1 patient among individuals with low TREC (12.5%) and in 2 patients with normal TREC (8.33%). Thus, according to the data obtained, the cohort of patients with decreased TREC was more severe in clinical terms. Table 2 presents comparative features of immune parameters depending on the TREC content.

Table 2. Comparison of T- and B-cell immunity and NK cells in patients with ACS and post-COVID syndrome depending on the number of TREC

Indicator	TREC decreased (n=8)	TREC normal (n=24)
TREС	3,83±1,85 р1-2<0,018	194,99±46,65
T-helpers (CD45+CD3+ CD4+), %	32,78±4,17 р1-2<0,003	45,62±2,04
T-helpers (CD45+CD3+ CD4+), 106 cells/l	495,28±56,69 р1-2<0,006	828,92±65,59
T-cytotoxic (CD45+CD3+ CD8+), %	38,83±3,83 р1-2<0,003	27,27±1,76
T-cytotoxic (CD45+CD3+CD8+), 106 cells/l	635,86±113,51 р1-2<0,043	479,79±34,86
Immunoregulatory index (Tx/Tc)	0,93±0,26 р1-2<0,004	1,87±0,16
T-NK lymphocytes (CD45+CD3+CD 16+CD 56+), %	6,48±1,32 р1-2<0,05	4,33±0,59

              In individuals with reduced TREC, a lower relative and absolute number of T-helpers (p<0.01) was recorded, and the immunoregulatory index was lower (p<0.01). At the same time, an increase in the relative (p<0.01) and absolute number of T-cytotoxic cells (p<0.05), as well as the percentage of T-NK lymphocytes (p<0.05) was noted in this group of patients. Also, in patients of the first group, there was a tendency to an increase in NK lymphocytes and a decrease in B lymphocytes (CD3- CD19+).
Discussion of the obtained results. The proposed assessment system allows us to identify immune system disorders in patients with ACS (patients with PCS and ACS with low TREC). Considering that the sample is not very significant yet, further research of such patients is planned, and with a larger set of patients, the reliability of the changes to which the trend has been identified so far may be added. That is, the proposed screening system works and can be proposed for widespread use. Detection of disorders using the proposed screening methods requires the development of approaches for the immunocorrection of such disorders, which are currently only being discussed in cardiology [9].
Conclusions:
1. Patients with acute coronary syndrome and PCS with reduced TREC showed a more severe clinical picture, but given that the sample is not very large yet, further study of such patients is planned and with a larger set of patients, it is possible to add reliability to the changes to which the trend has been identified so far.
2. Detection of disorders using the proposed screening methods requires the development of approaches for the immunocorrection of such disorders, which are currently only being discussed in cardiology.
The work was completed on the topic of the State assignment of the IIF UB RAS "Immunophysiological and pathophysiological mechanisms of regulation and correction of body functions" state no. registration 122020900136-4, Research Institute of Virology and Infection "VIROM" "Study of the mechanisms of formation of chronic viral infection in patients with post-COVID syndrome and dysfunction of the immune system. Development of pathogenetic approaches to effective prevention and immunocorrection of identified disorders in patients with "post-COVID syndrome" State registration No. 124031500020-4    

About the authors

Eleanor Arkadyevna Safronova

Federal State Budgetary Educational Institution of Higher Education "South-Ural State Medical University" of the Ministry of Healthcare of the Russian Federation; University of Innovation and Continuing Education of the State Research Center –Burnazyan Federal Medical Biophysical Center of Federal Medical Biological Agency, Moscow, Russia

Author for correspondence.
Email: safronovaeleonora68@gmail.com

Candidate of Medical Sciences, Associate Professor, Associate Professor of the Department of Polyclinic Therapy and Clinical Pharmacology; teacher  of the Department of Therapy 

Russian Federation, 454141 city of Chelyabinsk, Vorovskogo street, house 64; 123098, Moscow, Zhivopisnaya st., 46, building 8

liana Valentinovna Ryabova

Federal State Budgetary Educational Institution of Higher Education "South Ural State Medical University" of the Ministry of Health of the Russian Federation

Email: lianarabowa@rambler.ru

MD, Associate Professor, Professor of the Department of Life Safety, Disaster Medicine, Emergency Medicine

Russian Federation, Russian Federation, 454141 Chelyabinsk, Vorovskogo street, house 64

Herman Petrovich Sarapultsev

Institute of Immunology and Physiology of the Ural Branch of the Russian Academy of Sciences, Ekaterinburg, Russia

Email: dr.sarapultsev@yandex.ru

MD, postgraduate Institute of Immunology and Physiology of the Ural Branch of the Russian Academy of Sciences, Ekaterinburg, Russia

Russian Federation, 620078, Russian Federation, Yekaterinburg, Pervomayskaya St., 106

References

Supplementary files