Evaluation of New Potential Inflammatory Markers in Patients with Nonvalvular Atrial Fibrillation.

Atrial fibrillation (AF), the most common arrhythmia in clinical practice, is associated with an increase in mortality and morbidity due to its high potential to cause stroke and systemic thromboembolism. Inflammatory mechanisms may play a role in the pathogenesis of AF and its maintenance. We aimed to evaluate a range of inflammatory markers as potentially involved in the pathophysiology of individuals with nonvalvular AF (NVAF). A total of 105 subjects were enrolled and divided into two groups: patients with NVAF (n = 55, mean age 72 ± 8 years) and a control group of individuals in sinus rhythm (n = 50, mean age 71 ± 8 years). Inflammatory-related mediators were quantified in plasma samples by using Cytometric Bead Array and Multiplex immunoassay. Subjects with NVAF presented significantly elevated values of interleukin (IL)-2, IL-4, IL-6, IL-10, tumor necrosis factor (TNF), interferon-gamma, growth differentiation factor-15, myeloperoxidase, as well as IL-4, interferon-gamma-induced protein (IP-10), monokine induced by interferon-gamma, neutrophil gelatinase-associated lipocalin, and serum amyloid A in comparison with controls. However, after multivariate regression analysis adjusting for confounding factors, only IL-6, IL-10, TNF, and IP-10 remained significantly associated with AF. We provided a basis for the study of inflammatory markers whose association with AF has not been addressed before, such as IP-10, in addition to supporting evidence about molecules that had previously been associated with the disease. We expect to contribute to the discovery of markers that can be implemented in clinical practice hereafter.

Evaluation of serum haptoglobin levels and Hp1-Hp2 polymorphism in the haptoglobin gene in patients with atrial fibrillation.

BACKGROUND: Atrial fibrillation (AF) is an arrhythmia that involves structural and electrophysiological abnormalities. Many of the AF-related clinical conditions are associated with an increase in inflammatory and oxidative factors. Haptoglobin (Hp) is an acute phase protein whose biological role is to promote clearance of free hemoglobin (Hb). In addition, for being considered an inflammatory marker, Hp represents a protective mechanism against the oxidative effects of Hb. The Hp1-Hp2 polymorphism at Hp locus can lead to three phenotypes related to structural and functional differences in the protein. The objective of this study were to evaluate Hp levels and Hp1-Hp2 polymorphism at Hp locus in patients with AF compared to a control group. METHODS AND RESULTS: This study included 65 patients with AF and 54 individuals without the arrhythmia. Biochemical parameters were determined using Vitros system, plasma levels of Hp were measured in serum samples by using ELISA method and polymorphisms were verified by PCR technique. Plasma Hp levels, as well as allelic and genotypic frequency, were not associated with AF. The levels of Hp also did not differ among the genotypes according to the applied models. CONCLUSIONS: The results suggest that Hp levels and Hp1-Hp2 polymorphism are not associated to AF.

Thrombin Generation and other hemostatic parameters in patients with atrial fibrillation in use of warfarin or rivaroxaban.

Patients with atrial fibrillation (AF) present hyperactivation of both platelets and coagulation leading to a hypercoagulable state which contributes to an increased risk of thromboembolism. Therefore, one of the main strategies for treatment of AF is prevention of these events through the use of oral anticoagulants (OAC). The aim of this study was to evaluate hemostasis as a whole in patients with non-valvular AF undergoing warfarin or rivaroxaban by thrombin generation test (TGT), in addition to monocyte-platelet aggregates (MPA), glycoprotein IIb/IIIa (GPIIb/IIIa), and platelet (PMP) and endothelium (EMP) microparticles, compared to age and sex matched controls. PT/INR for OAC use was also determined. In patients taking OAC, compared to control group, a decrease in TGT (p = 0.000 for all parameters) were observed. Patients taking warfarin showed to be more hypocoagulable, presenting lower levels of ETP (p = 0.000) and peak (p = 0.002) than patients using rivaroxaban. Patients on warfarin use with INR > 3 had also lower levels of ETP (p = 0.01) and peak (p = 0.006). A decrease in ETP (p = 0.03) and peak (p = 0.02) values was also observed in patients using rivaroxaban with PT > 21.4 s. Patients using warfarin (p = 0.000) and rivaroxaban (p = 0.000) presented lower levels of MPA in relation to control group. It was also observed in patients using warfarin, lower GPIIb/IIIa levels in relation to control group (p = 0.011). Patients taking rivaroxaban (p = 0.003) and warfarin (p = 0.001) had higher PMP levels compared to control group. There was no difference in levels of EMP between the groups (p = 0.0536). The present study reinforces the usefulness of OAC in AF, which decisively contribute to a better management of the disease preventing possible complications.

Inflammatory and Infectious Processes Serve as Links between Atrial Fibrillation and Alzheimer's Disease.

Atrial fibrillation (AF) is one of the most prevalent forms of arrhythmia that carries an increased risk of stroke which, in turn, is strongly associated with cognitive decline. The majority of dementia cases are caused by Alzheimer's disease (AD) with obscure pathogenesis. While the exact mechanisms are unknown, the role of inflammatory processes and infectious agents have recently been implicated in both AD and AF, suggesting a common link between these maladies. Here, we present the main shared pathways underlying arrhythmia and memory loss. The overlapping predictive biomarkers and emerging joint pharmacological approaches are also discussed.

Serotonin and dopamine receptors profile on peripheral immune cells from patients with temporal lobe epilepsy.

The role of inflammation and immune cells has been demonstrated in neurological diseases, including epilepsy. Leukocytes, as well as inflammatory mediators, contribute to abnormal processes that lead to a reduction in seizure threshold and synaptic reorganization. In this sense, identifying different phenotypes of circulating immune cells is essential to understanding the role of these cells in epilepsy. Immune cells can express a variety of surface markers, including neurotransmitter receptors, such as serotonin and dopamine. Alteration in these receptors expression patterns may affect the level of inflammatory mediators and the pathophysiology of epilepsy. Therefore, in the current study, we evaluated the expression of dopamine and serotonin receptors on white blood cells from patients with temporal lobe epilepsy with hippocampal sclerosis (TLE-HS). Blood samples from 17 patients with TLE-HS and 21 controls were collected. PBMC were isolated and stained ex vivo for flow cytometry. We evaluated the expression of serotonin (5-HT1A, 5-HT1B, 5-HT2, 5-HT2B, 5-HT2C, 5-HT3, 5-HT4), and dopamine receptors (D1, D2, D3, D4, and D5) on the cell surface of lymphocytes and innate immune cells (monocytes and granulocytes). Our results demonstrated that innate cells and lymphocytes from patients with TLE-HS showed high mean fluorescent intensity (MFI) for 5-HT1A, 5-HT1B, 5-HT2A, and 5-HT4 compared to controls. No difference was observed for 5-HT2B. For dopamine receptors, the expression of D1, D2, D4, and D5 receptors was higher on innate cells from patients with TLE-HS when compared to controls for the MFI. Regarding lymphocytes population, D2 expression was increased in patients with TLE-HS. In conclusion, there are alterations in the expression of serotonin and dopamine receptors on immune blood cells of patients with TLE-HS. Although the biological significance of these findings still needs to be further investigated, these changes may contribute to the understanding of TLE-HS pathophysiology.

Comparison of Inflammatory Mediators in Patients With Atrial Fibrillation Using Warfarin or Rivaroxaban.

Background: Atrial fibrillation (AF) is the most common arrhythmia associated with high risk of venous thromboembolism. Inflammatory mechanisms may be involved in the pathophysiology of AF and in the AF-related thrombogenesis, and patients with AF might benefit from the use of anticoagulants with anti-inflammatory properties. However, the evidence is still scarce, and it points out the need of trials seeking to investigate the levels of inflammatory mediators in patients with AF under different anticoagulant therapies. Therefore, this study was designed to define whether patients with AF treated either with an activated coagulation factor X (FXa) inhibitor (rivaroxaban) or with a vitamin K inhibitor (warfarin) present changes in peripheral levels of inflammatory mediators, mainly cytokines and chemokines. Methods: A total of 127 subjects were included in this study, divided into three groups: patients with non-valvular atrial fibrillation (NVAF) using warfarin (N = 42), patients with NVAF using rivaroxaban (N = 29), and controls (N = 56). Plasma levels of inflammatory mediators were quantified by immunoassays. Results: Patients with AF (both warfarin and rivaroxaban groups) presented increased levels of inflammatory cytokines in comparison with controls. The use of rivaroxaban was associated with decreased levels of inflammatory cytokines in comparison with warfarin. On the other hand, patients with AF using rivaroxaban presented increased levels of the chemokines (MCP-1 in comparison with warfarin users; MIG and IP-10 in comparison with controls). Conclusions: AF is associated with an inflammatory profile that was less pronounced in patients on rivaroxaban in comparison with warfarin users. Further studies are necessary to assess the clinical implications of our results and whether patients with AF would benefit from rivaroxaban anti-inflammatory effects.