Thromboembolic syndrome is the most dangerous complication of atrial fibrillation which develops in about 8-15% of cases, thus presuming the role of persisting left-heart thrombosis in presence of anticoagulant therapy in some patients. When activated, the blood platelets express multiple copies of CD40L on their membrane. Hence, the soluble form of CD40 ligand is considered a marker of platelet activation and pathogenic processes associated with increased activity of the thrombotic system. Our aim was to study the content of CD40, soluble CD40 ligand and thrombomodulin in the patients with atrial fibrillation of non-valvular genesis receiving anticoagulant therapy, discerning those with a history of thrombotic complications, and the cases with atrial fibrillation, however, free of thrombotic complications. The study group included 22 healthy volunteers and 60 patients diagnosed with atrial fibrillation who received anticoagulant therapy, of whom 21 patients have developed thrombotic complications in the course of adequate anticoagulant therapy. Quantitative assays of CD40, soluble CD40 ligand and soluble thrombomodulin were performed by enzyme immunoassay using Core Facility “Medical Genomics”, Tomsk National Research Medical Center. Concentration of soluble CD40 ligand in both groups of the patients with atrial fibrillation significantly exceeded appropriate values in the group of healthy volunteers. CD40L content was increased in the group of patients with thrombotic complications against the group of patients without thrombotic complications. Thrombomodulin content in blood serum was decreased in the patients with thrombotic complications, as compared to both thrombosis-free patients, and to practically healthy volunteers. The study of CD40/CD40L system and thrombomodulin showed that the patients with thrombotic complications exhibited higher serum level of soluble CD40L, with a simultaneous decrease of thrombomodulin, a physiological anticoagulant. A comparative analysis of the CD40/sCD40L system showed increased concentrations of the biomarkers in females, when compared to males.

The prevalence of atrial fibrillation is high and comparable in both sexes. Such factors as differently expressed blood biomarkers in women and men may play a role in the occurrence of atrial fibrillation and the development of thrombotic complications. To study markers of inflammation and platelet activation in patients with atrial fibrillation of non-valvular origin, receiving anticoagulant therapy and having a history of thrombotic complications and patients with atrial fibrillation without thrombotic complications, depending on the gender of the patients. The study included 22 healthy volunteers and 60 patients diagnosed with atrial fibrillation receiving anticoagulant therapy, of which 21 patients developed thrombotic complications. Serum levels of α2- macroglobulin, hsC-reactive protein, fetuin A, α-1-acid glycoprotein, L-selectin, serum amyloid P, adipsin, and platelet factor 4 were studied on FLEXMAP 3D using Acute Phase diagnostic test systems Panel 3. A comparative study of the content of biomarkers demonstrated an increased concentration of C-reactive protein in men and women in both groups of patients with atrial fibrillation; decrease in fetuin A and L-selectin in the group of women with thrombosis compared with women without thrombotic complications and compared with healthy women. There were no gender differences in the concentration of fetuin A and L-selectin in the group of patients with atrial fibrillation without thrombotic complications and in healthy volunteers. The level of adipsin had no gender differences in the group of patients with atrial fibrillation with thrombosis and in healthy volunteers, however, it was significantly increased in women without thrombosis. The content of platelet factor 4 in women in both groups of patients exceeded the value of this indicator in healthy women; no gender differences were found in the groups of patients with atrial fibrillation. Low levels of fetuin A and L-selectin, with a simultaneous increase in C-reactive protein and platelet factor 4, lead to an increase of prothrombogenic potential and to a change in the balance of pro- and antiinflammatory mediators towards increased inflammation in female patients with atrial fibrillation.

Aim. To analyze the relationships between the carriage of polymorphic variants in the folate metabolism genes and the development of thrombotic complications in patients with single ventricle (SV) during surgical treatment.Material and Methods. A total of 102 children with SV were examined in the performed research. All patients underwent surgical hemodynamic correction of congenital heart disease (CHD). According to a retrospective chart review, thrombosis was diagnosed in 12.7 % of the examined patients with SV. The analysis of polymorphism in the MTR A2756G enzyme gene revealed significant differences between the groups of patients with a history of thrombosis and without it.Results. We found that the risk of developing thrombosis was associated with the carriage of homozygous genotype 2756AA of the MTR enzyme gene (OR = 11.21; 95% CI: 1.39–89.96; p = 0.023).