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Loureiro Fonseca, Ana Mafalda

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  • Haemodialysis in Diabetic Patients Modulates Inflammatory Cytokine Profile and T Cell Activation Status
    Publication . Almeida, Ana Catarina Silva; Lourenço, Olga; Fonseca, A. M.
    Diabetic nephropathy (DN) is a common complication in patients with diabetes, and most of them need renal replacement therapy such as haemodialysis (HD). These patients have a high tendency to develop infections and exhibit anomalies in the immune system. The objective of this study was to assess the expression of activation-related markers on T cells, as well as to quantify inflammatory cytokines, before and after a single HD session in DN patients. The study involved DN patients under HD treatment who signed an informed consent form. Blood samples before and after one HD session were collected, to analyse the expression of CD25, CD69 and CD71 in T cells. We also quantified IL-12p70, IL-8, IL-10, IL-1β, TNF-α and IL-6 in serum samples using the cytometric bead array technique. After the HD session, there was an increase in the CD4/CD8 ratio due to significant alterations in both subsets. The relative percentage of CD25+ cells and CD8+ CD25+ increased significantly after the HD session, while the relative percentage of CD69 T cells decreased. There was a significant decrease in the CD25 mean fluorescence intensity values for CD4+ T, as well as in the case of CD71 in T cells after the HD session. Regarding cytokine synthesis, we found a significant increase in IL-10 and IL-6 and a decrease in IL-8 after HD session. This study showed that a HD session in DN patients affects the T cell activation status in the two major subpopulations and differentially modulates the production of inflammatory cytokines.
  • Demographic, laboratory and clinical characterisation of adult portuguese asthmatic patients
    Publication . Lourenço, Olga; Fonseca, A. M.; Barata, Luis Taborda
    Asthma is a heterogeneous chronic inflammatory condition characterised by reversible airway obstruction and hyperresponsiveness associated with underlying bronchial inflammation and structural changes. It represents an increasing health problem and is a huge burden on the patients, their families and society. The aim of the study was to characterise the adult asthmatic population attending a Hospital Allergy Clinic between the years of 2003 and 2006.
  • T cells in sputum of asthmatic patients are activated independently of disease severity or control
    Publication . Lourenço, Olga; Fonseca, A. M.; Barata, Luis Taborda
    Background T cells play an important role in bronchial asthma. Although airway CD4+ T cells have been extensively studied previously, there are hardly any studies relating CD8+ T cell activation and disease symptoms. Objectives The aim of this study was to analyse the association between T cell activation in induced sputum T cells and asthma severity and control; and to evaluate T cell subpopulations in the same subgroups. Methods Fifty allergic asthmatic patients were recruited and lung function testing was performed. Airway cells were obtained by sputum induction via inhalation of hypertonic saline solution. CD3, CD4, CD8, CD28, CD25 and CD69 were studied by flow cytometry in whole induced sputum and peripheral blood cells. Results Total induced sputum T cells and CD8+ T cells had a higher relative percentage of the activation markers CD25 and CD69 in comparison with peripheral blood. In sputum, the relative percentage of CD25 was higher in CD4+ T cells when compared to CD8+ T cells and the reverse was true regarding CD69. However, neither disease severity nor control were associated with the relative percentage of CD25 or CD69 expression on T cells in sputum. Conclusions Both CD4+ and CD8+ T cells are activated in the lungs and peripheral blood of asthmatic patients. However, with the possible exception of CD69+ CD8+ T lymphocytes in the sputum, there is no association between T cell activation phenotype in the target organ and disease severity or control.
  • Functional and phenotypic characterization of CD8+CD28+ and CD28- T cells in atopic individuals sensitized to Dermatophagoides pteronyssinus
    Publication . Lourenço, Olga; Fonseca, A. M.; Paiva, Artur; Arosa, F. A.; Barata, Luís Taborda
    CD8+ T suppressor cells may play a role in immunoregulation. Recent studies have characterized this population by the lack of the CD28 molecule. These CD8+CD28 T cells differ phenotypically and functionally from CD8 + CD28 + T cells. Little is known about CD8 + CD28 cells in atopy. Our aim was to analyze the phenotype and functional properties of CD8 + CD28T cells in atopic and non-atopic individuals.