The pathogenic role of T cells in hypertension has been documented well in recent animal studies. However, the existence of T-cell–driven inflammation in human hypertension has not been confirmed. Therefore, we undertook immunologic characterization of T cells from patients with hypertension and measured circulating levels of C-X-C chemokine receptor type 3 chemokines, which are well-known tissue-homing chemokines for T cells. We analyzed immunologic markers on T cells from patients with hypertension by multicolor flow cytometry. We then measured circulating levels of the C-X-C chemokine receptor type 3 chemokines, monokine induced by γ interferon (IFN), IFN γ–induced protein 10, and IFN-inducible T-cell α chemoattractant, in patients with hypertension and in age- and sex-matched control subjects by the cytometric bead array method. In addition, we examined histological features of IFN-inducible T-cell α chemoattractant expression from renal biopsy specimens of patients with hypertensive nephrosclerosis and control subjects. The total T-cell population from patients with hypertension showed an increased fraction of immunosenescent, proinflammatory, cytotoxic CD8 + T cells. Circulating levels of C-X-C chemokine receptor type 3 chemokines were significantly higher in patients with hypertension than in control subjects. Furthermore, immunohistochemical staining revealed increased expression of the T-cell chemokine, IFN-inducible T-cell α chemoattractant, in the proximal and distal tubules of patients with hypertensive nephrosclerosis. Immunosenescent CD8 + T cells and C-X-C chemokine receptor type 3 chemokines are increased in human hypertension, suggesting a role for T-cell–driven inflammation in hypertension. A more detailed characterization of CD8 + T cells may offer new opportunities for the prevention and treatment of human hypertension.
Background: Lipid metabolites and cytokines, including chemokines and growth factors, are the key regulators of immune cell function and differentiation, and thus, dysregulation of these regulators is associated with various human diseases. However, previous studies demonstrating a positive correlation of cytokine levels with aging may have been influenced by various environmental factors and underlying diseases. Also, data regarding cytokine profiling in the elderly are limited to a small subset of cytokines. Methods: We compared the profiles of 22 cytokines, including chemokines and growth factors, in a case-controlled study group of a gender-matched, healthy cohort of 55 patients over the age of 65 and 55 patients under the age of 45. Assessment of serum cytokine concentrations was performed using commercially-available multiplex bead-based sandwich immunoassays. Results: Soluble CD40 ligand (sCD40L) and transforming growth factor alpha (TGF-α) levels were significantly higher in the elderly patients, whereas granulocyte colony-stimulating factor (G-CSF), granulocyte-monocyte colony-stimulating factor (GM-CSF), and monocyte chemoattractant protein-1 (MCP-1) levels were significantly lower in the elderly patients. The partial correlation analysis demonstrating the correlation between cytokine levels when controlled for gender, systolic blood pressure, total cholesterol, HDL cholesterol, triglyceride, and serum creatinine levels further demonstrated that G-CSF, GM-CSF, and MCP-1 had significant negative correlations with age, whereas sCD40L and TGF-α had significant positive correlations. Conclusions: Future studies will focus on examining the significance of these age-related changes in circulating cytokines and other biological markers and their potential contribution to the development of different age-associated diseases.
Myocardial extracellular volume fraction determined with dual-energy equilibrium contrast-enhanced cardiac CT showed good agreement, with a small bias and acceptable 95% limits of agreement when compared with cardiac MR imaging, as well as excellent interobserver agreement. PurposeTo evaluate the feasibility of equilibrium contrast material–enhanced dual-energy cardiac computed tomography (CT) to determine extracellular volume fraction (ECV) in nonischemic cardiomyopathy (CMP) compared with magnetic resonance (MR) imaging.Materials and MethodsThis study was approved by the institutional review board; informed consent was obtained. Seven healthy subjects and 23 patients (six with hypertrophic CMP, nine with dilated CMP, four with amyloidosis, and four with sarcoidosis) (mean age ± standard deviation, 57.33 years ± 14.82; 19 male participants [63.3%]) were prospectively enrolled. Twelve minutes after contrast material injection (1.8 mL/kg at 3 mL/sec), dual-energy cardiac CT was performed. ECV was measured by two observers independently. Hematocrit levels were compared between healthy subjects and patients with the Mann-Whitney U test. In per-subject analysis, interobserver agreement for CT was assessed with the intraclass correlation coefficient (ICC), and intertest agreement...