Immune status comparison in patients with atrial fibrillation or flutter on the base of arterial hypertension

Abstract

Abstract Aims Atrial fibrillation (AF) and atrial flutter (AFl) take the second place between supraventricular arrhythmias and lead to severe complications such as stroke and heart failure. Mostly these arrhythmias occur on the background of arterial hypertension (AH). The inflammatory theory of arrhythmogenesis in AF and AFl has attracted researcher's attention in recent years. The aim of our work is to compare the immune status of patients with paroxysmal and persistent forms of AF and AFl in patients with AH. Material and methods The study involved 103 patients with hypertension and arrhythmias, who were divided into three main groups according to the form of AF/AFl: group 1 (n=35) – with paroxysmal form of AF, group 2 (n=38) - with persistent form of AF, group 3 (n=30) – with persistent form of AFl. For comparison, 2 control groups were formed: 4 (n=23) – patients with hypertension, but without a history of arrhythmias and 5 (n=21) – almost healthy people. The immune status of these patients was assessed by determining the level of monocytes (Mc), lymphocytes subpopulations and T-regulatory cells (T-reg) in the peripheral blood using flow cytometry. Results It was noted that the number of classical CD14++CD16- and intermediate CD14++CD16+ Mc was significantly higher in patients with persistent AF and AFl comparing with patients without arrhythmias and healthy people (p<0.005). This fraction of Mc is able to produce proinflammatory cytokines and activate the local renin-angiotensin system, thus triggering the processes of fibrosis in the myocardium. Amount of non-classical CD14+CD16++ Mc was significantly lower in the second group both quantitatively and in percentage (p<0.005). The count of T cells with natural killer (TNK) activity was higher in all groups comparing to normal value, so statistical significance was observed only in comparison with the fifth group. The highest quantity of T-reg cells was found in healthy people comparing to other groups and a strong mathematical significance was obtained in all cases (p<0.005), both comparing the values in percentage and in μl. Conclusions Patients with AF and AFl on the hypertension background comparing to hypertensive patients without arrhythmias or healthy people have an increased activity of proinflammatory subpopulation of monocytes, higher amount of T-cells with natural killer activity and reduced T-regulatory cells, whose main function is to control the immune response. Funding Acknowledgement Type of funding sources: Public Institution(s). Main funding source(s): NSC “M.D. Strazhesko Institute of Cardiology” NAMS of Ukraine