Search

Expansion of CD4+CD28null T‐lymphocytes is common in chronic heart failure (CHF) patients. Its ability to produce high levels of proinflammatory cytokines is probably the key role of these cells in CHF. IL‐10 is a candidate for limiting CD4+CD28null T‐lymphocyte responses, whereas tumour necrosis factor (TNF) is the cytokine most closely involved in the loss of CD28 expression. Serum levels of TNF and IL‐10 were measured in 65 CHF patients (mean age, 65.2 ± 13.84 years). Patients with an IL‐10/TNF ratio ≥1 had significantly lower levels of CD4+CD28null T‐lymphocytes than those with a ratio <1. In vitro, IL‐10 reduced the frequency of proliferative CD4+CD28null T‐lymphocytes stimulated with anti‐CD3. Pre‐treatment with IL‐10 before anti‐CD3 stimulation was required for the cytokine to inhibit TNF production by CD4+CD28null T‐lymphocytes. In addition to the previously described effect of IL‐10 on HLA‐DR and ICAM‐1 expression, LFA‐3 protein and mRNA levels were reduced in the presence of the cytokine in monocytes. IL‐10 inhibition on CD4+CD28null T‐lymphocytes may be mediated by a reduction in HLA class II and LFA‐3 expression because blocking interactions with these costimulators has similar effects to those of IL‐10 treatment. Moreover, costimulation through CD2/LFA‐3 interaction is enough to induce proliferation and cytokine production in CD4+CD28null T‐lymphocytes. [ABSTRACT FROM AUTHOR]

High levels of inflammation play an important role in chronic heart failure (CHF). Patients with CHF have elevated levels of pro-inflammatory cytokines circulating systemically, mainly TNF and IL-6. However, there are almost no studies that relate these levels to the functional status of patients in CHF, much less to their CMV serostatus. In this study, patients with CHF (n=40; age=54.9 ± 6.3; New York Heart Association functional classification (NYHA, I-III) and healthy controls (n=40; age=53.5 ± 7.1) were analyzed. The serum concentrations of nine pro- and anti-inflammatory cytokines were measured by Luminex® xMap Technology and the basal level of mRNA expression of some immune molecules was quantified by TaqMan™ Array in CD4+ T-lymphocytes. The concentration of these cytokines in culture supernatants in response to anti-CD3 and LPS was also measured. The percentage of CD28null T-cells was determined, as well as the antibody titer against CMV. We found a higher concentration of all cytokines studied in CHF serum compared to healthy controls, as well as a direct correlation between functional status in CHF patients and levels of inflammatory cytokines. Moreover, the highest cytokine concentrations were found in patients with higher concentrations of lymphocytes lacking CD28 molecule. The cytokine production was much higher in CMV+ patients, and the production of these cytokines was found mainly in the T-lymphocytes of CMV+ patients in response to anti-CD3. Anti-CMV antibody levels were positively correlated with cytokine levels. The baseline expression of specific mRNA of the main molecules involved in the Th1 response, as well as molecules related to the CD4+CD28 null subset was higher in CMV+ patients. The cytokine concentrations are higher in CHF CMV+ patients and these concentrations are related to the production of antibodies against CMV. These high levels of cytokines are also associated with the more differentiated CD28null lymphocyte populations. All this, together with the dynamics of the pathology itself, makes CMV+ patients present a worse functional status and possibly a worse evolution of the pathology. [ABSTRACT FROM AUTHOR]

Immunosenescence in chronic heart failure (CHF) is characterized by a high frequency of differentiated T-lymphocytes, contributing to an inflammatory status and a deficient ability to generate immunocompetent responses. CMV is the best known inducer of T-lymphocyte differentiation, and is associated with the phenomenon of immunosenescence. In this study, we included 58 elderly chronic heart failure patients (ECHF), 60 healthy elderly controls (HEC), 40 young chronic heart failure patients (YCHF) and 40 healthy young controls (HYC). High differentiation of CD8+ T-lymphocytes was found in CMV-seropositive patients; however, the differentiation of CD4+ T-lymphocytes was increased in CMV-seropositive but also in CHF patients. Anti-CMV antibody titers showed positive correlation with more differentiated CD4+ and CD8+ subsets and inverse correlation with CD4/CD8 ratio. Immunosenescence found in CHF patients is mainly due to the dynamics of CMV-infection, since the differentiation of T-lymphocyte subsets is related not only to CMV-infection, but also to anti-CMV antibody titers. [ABSTRACT FROM AUTHOR]

Background Our aim was to investigate whether patients with acute coronary syndrome (ACS) display an overall T cell immunosenescence that could be contributing to worsening the stage of the disease. Methods and results We compared the immunological status of 52 ACS patients, 21 controls with absence of coronary artery disease (CAD) (C1), and 50 healthy individuals (C2). We characterized leukocyte and T lymphocyte subpopulations by flow cytometry. CAD was classified according to SYNTAX score, number of diseased coronary vessels, previous episodes of ACS and left ventricular ejection fraction (LVEF). ACS patients showed an increased number of total leukocytes, neutrophils and monocytes (p < 0.001), but a decreased number of lymphocytes (p < 0.05). ACS patients had significantly higher levels of NK cells and CD8 + T-cells (p < 0.05). ACS was associated with high differentiation in CD4 + and CD8 + T-lymphocytes. Frequencies of naïve, naïve CD31 +, EM1, and pE1 subsets were significantly reduced in ACS patients (p < 0.05), while EM3, EM4 (in CD4 +), and E (in CD8 +) subsets were increased (p < 0.05). Aging of T-lymphocyte subpopulations was associated with a worse SYNTAX score (p < 0.05), and aging of CD4 + T-lymphocytes with a larger number of affected vessels, larger number of previous ACS episodes and lower LVEF, in ACS patients (p > 0.05). Furthermore, the proliferation ability of CD4 + and CD8 + T-lymphocytes was significantly impaired in ACS patients (p < 0.05), although they had increased activation (p < 0.05). Conclusions We conclude that ACS patients show a higher degree of T-lymphocyte immunosenescence than healthy controls, which could contribute to disease impairment through a compromised adaptive immune response. [ABSTRACT FROM AUTHOR]

Abstract: Background: Chronic heart failure (CHF) is characterized by an inflammatory status with high levels of cytokines such as IL-6. We hypothesized that patients with CHF may develop immunosenescence due to inflammation and that this may be associated with a worse stage of the disease. Methods and results: We compared the immunological features of 58 elderly CHF patients (ECHF), 40 young CHF patients (YCHF), 60 healthy elderly controls (HEC) and 40 healthy young controls (HYC). We characterized leukocyte and lymphocyte subpopulations by flow cytometry, and IL-6 concentration by ELISA. The extent of CHF was classified according to functional and/or morphological criteria: New York Heart Association functional class, AHA/ACC heart failure stages, left ventricular ejection fraction, and left ventricular hypertrophy. CHF patients showed an increased number of leukocytes, neutrophils and monocytes, but a decreased number of lymphocytes. CHF patients had significantly lower levels of B-cells and CD4+ T-cells, increased NK-cells in YCHF, and increased CD8+ T-cells only in ECHF. CHF was associated with high differentiation in CD4+ and CD8+ T-lymphocyte subsets. Aging of T-lymphocyte subpopulations and high IL-6 levels were associated with a worse clinical status. IL-6 also correlated positively with the number of highly differentiated T-lymphocytes and with their accelerated aging. Conclusions: We conclude that CHF patients show a higher degree of immunosenescence than age-matched healthy controls. T-lymphocyte differentiation and IL-6 levels are increased in patients with an advanced clinical status and may contribute to disease impairment through a compromised adaptive immune response due to accelerated aging of their immune system. [Copyright &y& Elsevier]

Beyond midlife, the immune system shows aging features and its defensive capability becomes impaired, by a process known as immunosenescence that involves many changes in the innate and adaptive responses. Innate immunity seems to be better preserved globally, while the adaptive immune response exhibits profound age-dependent modifications. Elderly people display a decline in numbers of naïveT-cells in peripheral blood and lymphoid tissues, while, in contrast, their proportion of highly differentiated effector and memory T cells, such as the CD28null T-cells, increases markedly. Naïve and memory CD4C T-cells constitute a highly dynamic system with constant homeostatic and antigen-driven proliferation, influx, and loss of T-cells. Thymic activity dwindles with age and essentially ceases in the later decades of life, severely constraining the generation of new T-cells. Homeostatic control mechanisms are very effective at maintaining a large and diverse subset of naïve CD4C T-cells throughout life, but although later than in CD8CT-cell compartment, these mechanisms ultimately fail with age. [ABSTRACT FROM AUTHOR]

Beyond midlife, the immune system shows aging features and its defensive capability becomes impaired, by a process known as immunosenescence that involves many changes in the innate and adaptive responses. Innate immunity seems to be better preserved globally, while the adaptive immune response exhibits profound age-dependent modifications. Elderly people display a decline in numbers of naïve T-cells in peripheral blood and lymphoid tissues, while, in contrast, their proportion of highly differentiated effector and memory T-cells, such as the CD28null T-cells, increases markedly. Naïve and memory CD4+ T-cells constitute a highly dynamic system with constant homeostatic and antigen-driven proliferation, influx, and loss of T-cells. Thymic activity dwindles with age and essentially ceases in the later decades of life, severely constraining the generation of new T-cells. Homeostatic control mechanisms are very effective at maintaining a large and diverse subset of naïve CD4+ T-cells throughout life, but although later than in CD8+T-cell compartment, these mechanisms ultimately fail with age. [ABSTRACT FROM AUTHOR]