Disordered microbial communities in asthmatic airways.

Background: A rich microbial environment in infancy protects against asthma [1], [2] and infections precipitate asthma exacerbations [3]. We compared the airway microbiota at three levels in adult patients with asthma, the related condition of COPD, and controls. We also studied bronchial lavage from asthmatic children and controls.

Fluticasone induces T cell apoptosis in the bronchial wall of mild to moderate asthmatics.

Background: Cytokines which signal via the gamma chain of the interleukin (IL)-2 receptor and the interferons (IFNs) have been shown to enhance T cell survival in vitro by rescuing cells from apoptosis.

Methods: A study was undertaken to determine whether treatment with inhaled fluticasone propionate (FP; 250 microg twice daily) for 2 weeks could modulate production of IL-15 or IFN-beta and thereby affect T cell survival in bronchial tissue of 10 patients with mild/moderate asthma. Bronchial biopsy specimens were taken before and on completion of treatment.

Release of inflammatory mediators from eosinophils following a hyperosmolar stimulus.

Airway dehydration and subsequent hyperosmolarity of periciliary fluid are considered critical events in exercise-induced bronchoconstriction (EIB). It has been shown that an in vitro hyperosmolar stimulation of basophils and mast cells with mannitol can induce the release of histamine and leukotrienes. The aim of this study was to establish if a hyperosmolar challenge could trigger activation of eosinophils to release chemokines and lipid mediators.

Effect of the addition of montelukast to inhaled fluticasone propionate on airway inflammation.

The aim of the study was to investigate the effect of addition of montelukast to inhaled fluticasone propionate (FP) therapy, compared with FP therapy alone (100 microg twice a day) on airway immunopathology in individuals with mild asthma. Twenty-eight subjects received FP (100 microg twice a day) or FP (100 microg twice a day) plus montelukast (10 mg at night) for 8 weeks and were then crossed over to the alternate treatment for a further 8 weeks. Physiological measurements and bronchial biopsies were obtained at +/- 2 days before treatment and +/- 2 days at the end of each treatment period.

Effects of varying doses of fluticasone propionate on the physiology and bronchial wall immunopathology in mild-to-moderate asthma.

Objectives: Inhaled corticosteroids (ICS) are typically associated with a flat dose-response curve when traditional efficacy values are examined (eg, FEV(1)). The aim of the present study was to investigate if a dose-response relationship exists for lung function and inflammatory cell numbers in bronchial biopsy specimens.

Methods: Bronchial biopsy specimens were obtained from 36 patients randomized to receive 100 micro g, 500 microg, or 2,000 microg/d of fluticasone propionate (FP).

The cellular response associated with cervical intraepithelial neoplasia in HIV+ and HIV- subjects.

This study investigates local alterations in T-cell and macrophage subsets that occur in cervical epithelial neoplasia (CIN), in the presence and absence of human immunodeficiency virus (HIV) infection. Ectocervical biopsies from 10 women with CIN who were infected with HIV, and 10 women with CIN but no HIV infection were studied by immunocytochemistry. Significantly increased proportions of activated CD8+ T cells were seen in all CIN biopsies, and these proportions were further increased in the presence of HIV infection.

Airway dehydration: a therapeutic target in asthma?

Background: Airway dehydration triggers exercise-induced bronchoconstriction in virtually all patients with active asthma. We are not aware of any investigations of airway dehydration in patients with naturally occurring asthma exacerbations. We wish to investigate whether airway dehydration occurs in acute asthmatic patients in the emergency department, and its functional significance.

Alterations in airway inflammation and lung function during corticosteroid therapy for atopic asthma.

Introduction: Although corticosteroid therapy for asthma improves lung function and reduces airway inflammation, the relation between these two events is unclear. This article investigates associations between changes in bronchial inflammation and lung function during high-dose inhaled corticosteroid therapy for asthma.

Methods: Nine subjects with atopic asthma received high-dose inhaled fluticasone propionate (FP), 2,000 microg/d for 8 weeks.

Activated, cytotoxic CD8(+) T lymphocytes contribute to the pathology of asthma death.

This study investigates the presence of CD8(+) T lymphocytes and their possible association with viral infection in bronchi of victims of fatal asthma. Postmortem samples from the peribronchial region of the lung were obtained from seven patients who died an asthma death (AD), seven asthmatic patients who died of unrelated causes (AUC), and seven postmortem cases with no history of lung disease (control subjects). Using immunohistochemical techniques, the CD8(+) cytotoxic T-cell population in peribronchial tissue was characterized in three patient groups.

Immunity in the female lower genital tract and the impact of HIV infection.

This study investigates the distribution of immunocompetent cells in the ectocervix, and cytokine and immunoglobulin (Ig) levels in cervicovaginal secretions to determine whether they are altered in asymptomatic human immunodeficiency virus (HIV) infection. Ectocervical biopsies from 10 HIV+ and 10 presumed HIV-ve women were studied by immunocytochemistry. Levels of Igs in cervicovaginal secretions were quantified by radial immunodiffusion (RID) and cytokine levels by ELISA.

IFN-gamma but not IL-4 T cells of the asthmatic bronchial wall show increased incidence of apoptosis.

Background: Previous observations have established that IFN-gamma production is depressed in CD4+ T cells from atopic asthmatics compared with non-asthmatics.

Objective: The aim of this study was to determine if decreased IFN-gamma production could be due to a dissociation between levels of apoptosis within the T cell subsets of the asthmatic bronchial wall.

Methods: Twenty asthmatics (10 atopic and 10 non-atopic) and eight non-atopic non-asthmatics underwent bronchoscopy.

Human anergic/suppressive CD4(+)CD25(+) T cells: a highly differentiated and apoptosis-prone population.

Anergic/suppressive CD4(+)CD25(+) T cells exist in animal models but their presence has not yet been demonstrated in humans. We have identified and characterized a human CD4(+)CD25(+) T cell subset, which constitutes 7-10 % of CD4(+) T cells in peripheral blood and tonsil. These cells are a CD45RO(+)CD45RB(low) highly differentiated primed T cell population that is anergic to stimulation.

Macrophages : identification, separation, and function.

Within the human lung, macrophages can be found in the pleura, interstitium, alveoli, airways, vasculature, and walls of the bronchi and bronchiols. This distribution does not simply reflect the ubiquitous nature of these cells, as the macrophages found at these different sites show subtle distinctions in terms of cell physiology and phenotype (1). Further, animal studies have revealed functional differences between macrophages from different lung compartments (2).

The inhibition of cutaneous T cell apoptosis may prevent resolution of inflammation in atopic eczema.

Atopic eczema (AE) is characterized by the persistence of infiltrating T lymphocytes in the dermis. To test the hypothesis that dysregulation of normal T cell apoptosis may contribute to the pathogenesis and chronicity of AE we compared patients with a normal resolving immune response (Mantoux reaction (MR)) induced in healthy volunteers by cutaneous PPD injection. Significantly less T cell apoptosis was observed in lesional skin of AE patients compared with either the peak or the resolution phase of the MR (P < 0.

The anti-inflammatory profile of inhaled corticosteroids: biopsy studies in asthmatic patients.

The beneficial effects of inhaled corticosteroids in the treatment of asthma are well established. A potent topical anti-inflammatory action is assumed to underlie the therapeutic effect, given that these agents alter the number and function of a range of inflammatory cells and markers in airway biopsies. This activity profile is shown by all inhaled corticosteroids, in a variety of patient types and study designs.

Designing bronchial biopsy studies.

Bronchial biopsy provides valuable information about the inflammatory processes in lung tissue, but optimal results are only achieved if the design of intervention studies is sufficiently rigorous. The parallel-group design has merit, but the cross-over design is statistically superior, providing the wash-out period is effective. Heterogeneity of contributing pathologies in asthma patients results in large inter-patient variability which must be controlled for, for example by using strict inclusion criteria, which should ideally relate to the specific inflammatory marker being studied.

Macrophage subpopulations and macrophage-derived cytokines in sputum of atopic and nonatopic asthmatic subjects and atopic and normal control subjects.

Background: Previous studies have shown a prominent macrophage signal in the bronchial mucosa from nonatopic (intrinsic) compared with atopic (extrinsic) asthmatic subjects. This observation might have represented an expansion of a proinflammatory macrophage population or a homeostatic mechanism to decrease T(H)2-type inflammation.

Objective: The aim of the study was to investigate the numbers of macrophages and macrophage subpopulations and the expression of IL-10 and IL-12 in sputum from asthmatic and control subjects.

A phase I study of a novel potential intravaginal microbicide, PRO 2000, in healthy sexually inactive women.

Background: Although the male condom provides a reliable means of preventing HIV transmission, a broader choice of methods is required particularly in circumstances where the negotiation of condom use is difficult. Development of new products that may be effective as topical vaginal microbicides is the focus of a great deal of research activity currently. The novel agent PRO 2000, a naphthalene sulphonate derivative with in vitro activity against HIV and other sexually transmissible pathogens, is one such compound.

Phenotypic analysis of IL-10-treated macrophages using the monoclonal antibodies RFD1 and RFD7.

Suppressive or tolerogenic antigen-presenting cells (APC) might play an important role in the control of auto/hyperreactivity and the resolution of the immune response. Recent studies have provided evidence that tolerogenic APC can be induced by anergic T cells or interleukin-10 (IL-10). The aim of this study is to investigate how anergic T cells and IL-10 induce the suppressive APC phenotype and how this affects the immune response.

Fluticasone propionate-induced regulation of the balance within macrophage subpopulations.

In asthma, treatment with inhaled corticosteroids reduces chronic peribronchial inflammation and restores the balance within macrophage subpopulations. This study investigates whether corticosteroids can regulate monocyte differentiation in vitro and thereby influence the balance of functionally distinct macrophages. Graded doses of fluticasone propionate (FP) were added to cultures of normal peripheral blood monocytes in the presence or absence of IL-4.

The reproducibility of repeat measures of airway inflammation in stable atopic asthma.

Measures of airway inflammation are increasingly being used as outcome measures in asthma intervention studies. Meaningful interpretation of observed changes in bronchial mucosal cell numbers should depend, in part, on the reproducibility of repeat measures over time. We wanted to investigate the reproducibility of immunopathologic and physiologic parameters after short and long measurement intervals.

Fluticasone propionate induced alterations to lung function and the immunopathology of asthma over time.

Background: Inhaled corticosteroids are the most widely used treatment for asthma, a disease characterised by both functional and immunopathological abnormalities. This study investigated the relative effects of inhaled corticosteroids on these two features of asthma over time.

Methods: A randomised, double blind, placebo controlled, parallel group study with inhaled fluticasone propionate, (FP 2 mg daily) was conducted in 27 patients with asthma.

Dysregulation of monocyte differentiation in asthmatic subjects is reversed by IL-10.

Background: IL-10 can modulate the differentiation of normal monocytes to macrophages, increasing the proportion of maturing cells with a phenotype consistent with T cell suppressive activity. Analysis of the immunopathology in endobronchial biopsies from asthmatic subjects has revealed significantly reduced proportions of suppressive macrophage populations associated with chronic T-cell mediated inflammation.

Objective: This study investigates whether the altered homeostasis within the lung macrophage populations in asthma is reflected in aberrant differentiation of peripheral blood monocytes and whether this differentiation may be influenced by IL-10.

The role of apoptosis in the resolution of T cell-mediated cutaneous inflammation.

We have investigated cutaneous purified protein derivative-induced delayed-type hypersensitivity (DTH) responses in healthy volunteers to determine features associated with both the generation and resolution of the reaction. The clinical peak of the response occurred at day 3; however, T cell numbers were maximal on day 7. There was a preferential increase of CD4+ CD45RO+ T cells on day 7, which was largely due to proliferation, since a mean of 19% was in cycle.

Changes in CD23 expression of blood and skin in atopic eczema after Chinese herbal therapy.

Background: Aberrant expression of CD23 (low affinity IgE receptor) on cells of the monocyte/macrophage series in peripheral blood and lesional skin of patients with atopic eczema has been demonstrated. It is not known whether this abnormality results from a fundamental systemic problem of the monocytes of these patients or reflects local changes to cell populations within the skin tissues.

Objectives: This study was designed to determine whether this aberrant expression was caused by local cutaneous influences on mature cells or fundamental changes in monocyte differentiation.