Eosinophils in bronchial mucosa of asthmatics after allergen challenge: effect of anti-IgE treatment

Anti-IgE, omalizumab, inhibits the allergen response in patients with asthma. This has not been directly related to changes in inflammatory conditions. We hypothesized that anti-IgE exerts its effects by reducing airway inflammation. To that end, the effect of anti-IgE on allergen-induced inflammation in bronchial biopsies in 25 patients with asthma was investigated in a randomized, double-blind, placebo-controlled study. Allergen challenge followed by a bronchoscopy at 24 h was performed at baseline and after 12 weeks of treatment with anti-IgE or placebo. Provocative concentration that causes a 20% fall in forced expiratory volume in 1 s (PC(20)) methacholine and induced sputum was performed at baseline, 8 and 12 weeks of treatment. Changes in the early and late responses to allergen, PC(20), inflammatory cells in biopsies and sputum were assessed. Both the early and late asthmatic responses were suppressed to 15.3% and 4.7% following anti-IgE treatment as compared with placebo (P < 0.002). This was paralleled by a decrease in eosinophil counts in sputum (4-0.5%) and postallergen biopsies (15-2 cells/0.1 mm(2)) (P < 0.03). Furthermore, biopsy IgE+ cells were significantly reduced between both the groups, whereas high-affinity IgE receptor and CD4+ cells were decreased within the anti-IgE group. There were no significant differences for PC(20) methacholine. The response to inhaled allergen in asthma is diminished by anti-IgE, which in bronchial mucosa is paralleled by a reduction in eosinophils and a decline in IgE-bearing cells postallergen without changing PC(20) methacholine. This suggests that the benefits of anti-IgE in asthma may be explained by a decrease in eosinophilic inflammation and IgE-bearing cells.

Why do we not find polyps in the lungs? Bronchial mucosa as a model in the treatment of polyposis

The link between lower and upper airways has been reported since the beginning of 1800s. They share the same pseudostratified ciliated columnar epithelium lining and the concept of one airway, one disease is quite well widespread. Nasal polyposis and asthma share basically the same inflammatory process: predominant infiltration of eosinophils, mucus cell hyperplasia, edema, thickened basal membrane, polarization for Th2 cell immune response, similar pro-inflammatory mediators are increased, for example cysteinyl leukotrienes. If the lower and upper airways share a lot of common epithelial structural features so why is the edema in the nasal mucosa able to increase so much the size of the mucosa to the point of developing polyps? The article tries to underline some differences between the nasal and the bronchial mucosa that could be implicated in this aberrant change from normal mucosa to polyps. This paper creates the concept that there are no polyps with the features of nasal polyposis disease in the lower airway and through it is developed the hypothesis of the nasal polyps origin could partially lie on the difference between the upper and lower airway histology. (C) 2012 Elsevier Ltd. All rights reserved.

Distinct patterns of inflammation in the airway lumen and bronchial mucosa of children with cystic fibrosis

Studies in cystic fibrosis (CF) generally focus on inflammation present in the airway lumen. Little is known about inflammation occurring in the airway wall, the site ultimately destroyed in end-stage disease.

Aerobic conditioning and allergic pulmonary inflammation in mice. II. Effects on lung vascular and parenchymal inflammation and remodeling

Vieira RP, de Andrade VF, Duarte AC, dos Santos AB, Mauad T, Martins MA, Dolhnikoff M, Carvalho CR. Aerobic conditioning and allergic pulmonary inflammation in mice. II. Effects on lung vascular and parenchymal inflammation and remodeling. Am J Physiol Lung Cell Mol Physiol 295: L670-L679, 2008. First published August 29, 2008; doi: 10.1152/ajplung.00465.2007.-Recent evidence suggests that asthma leads to inflammation and remodeling not only in the airways but also in pulmonary vessels and parenchyma. In addition, some studies demonstrated that aerobic training decreases chronic allergic inflammation in the airways; however, its effects on the pulmonary vessels and parenchyma have not been previously evaluated. Our objective was to test the hypothesis that aerobic conditioning reduces inflammation and remodeling in pulmonary vessels and parenchyma in a model of chronic allergic lung inflammation. Balb/c mice were sensitized at days 0, 14, 28, and 42 and challenged with ovalbumin ( OVA) from day 21 to day 50. Aerobic training started on day 21 and continued until day 50. Pulmonary vessel and parenchyma inflammation and remodeling were evaluated by quantitative analysis of eosinophils and mononuclear cells and by collagen and elastin contents and smooth muscle thickness. Immunohistochemistry was performed to quantify the density of positive cells to interleukin (IL)-2, IL-4, IL-5, interferon-gamma, IL-10, monocyte chemotatic protein (MCP)-1, nuclear factor (NF)-kappa B p65, and insulin-like growth factor (IGF)-I. OVA exposure induced pulmonary blood vessels and parenchyma inflammation as well as increased expression of IL-4, IL-5, MCP-1, NF-kappa B p65, and IGF-I by inflammatory cells were reduced by aerobic conditioning. OVA exposure also induced an increase in smooth muscle thickness and elastic and collagen contents in pulmonary vessels, which were reduced by aerobic conditioning. Aerobic conditioning increased the expression of IL-10 in sensitized mice. We conclude that aerobic conditioning decreases pulmonary vascular and parenchymal inflammation and remodeling in this experimental model of chronic allergic lung inflammation in mice.

Pulmonary periarterial inflammation in fatal asthma

P>Background To date, little information has been available about pulmonary artery pathology in asthma. The pulmonary artery supplies the distal parts of the lungs and likely represents a site of immunological reaction in allergic inflammation. The objective of this study was to describe the inflammatory cell phenotype of pulmonary artery adventitial inflammation in lung tissue from patients who died of asthma. Methods We quantified the different inflammatory cell types in the periarterial region of small pulmonary arteries in lung tissue from 22 patients who died of asthma [fatal asthma (FA)] and 10 control subjects. Using immunohistochemistry and image analysis, we quantified the cell density for T lymphocytes (CD3, CD4, CD8), B lymphocytes (CD20), eosinophils, mast cells (chymase and tryptase), and neutrophils in the adventitial layer of pulmonary arteries with a diameter smaller than 500 mu m. Results Our data (median/interquartile range) demonstrated increased cell density of mast cells [FA=271.8 (148.7) cells/mm

Pulmonary cavities colonized by actinomycetes: report of six cases

Six cases of a cavitary pulmonary ball formed by Actinomycetes are reported. They were observed in the state of Bahia, Brazil. All patients complained of cough and hemoptysis and the pathological study showed bronchiectasis and small cavities in the lungs. The lesions contained micro-colonies of Actinomyces, identified by morphology, staining properties and culture in two cases (thioglycolate media). In the six patients the disease was limited to the lungs. In one patient grains were found, within micro-abscesses in the surrounding parenchyma. Probably the invasion occurred due to ulceration of bronchial mucosa that was covered by granulation tissue. The author suggests that as in nocardiosis actinomycosys may have an invasive form, a saprophytic one may and colonize pulmonary cavities.

Expression of cyclooxygenase enzymes and prostaglandin E2 receptors in inflammatory airway diseases

Dissertação para obtenção do Grau de Mestre em Genética Molecular e Biomedicina

Cystic Fibrosis, Atopy, Asthma and ABPA

The role of atopy on cystic fibrosis (CF) progression remains unclear but evidence suggests that it may influence the appearance of co-morbid conditions such as CF asthma or allergic bronchopulmonary aspergillosis (ABPA). Recognising asthma in patients with CF is not always easy but the identification of atopic markers favours the diagnosis. Physicians should be aware of this fact in order to achieve a better control of respiratory symptoms in patients with CF. Bronchial mucosa inflammation and abnormal mucus predispose to mould colonisation. These patients are at higher risk of allergic sensitisation, especially when atopic susceptibility is present. In the particular case of A. fumigatus, allergic sensitisation precedes ABPA development, which occurs in up to 10% of CF patients. Progression of lung function deterioration is most strikingly pronounced in patients with ABPA. Therefore, sensitisation with A. fumigatus should be regularly tested in patients with CF, especially those at higher risk. Recombinant allergens constitute an important advance in differentiating Aspergillus sensitisation from ABPA itself.

IL-5 and IL-5 receptor in asthma

Eosinophils, along with mast cells are key cells involved in the innate immune response against parasitic infection whereas the adaptive immune response is largely dependent on lymphocytes. In chronic parasitic disease and in chronic allergic disease, IL-5 is predominantly a T cell derived cytokine which is particularly important for the terminal differentiation, activation and survival of committed eosinophil precursors. The human IL-5 gene is located on chromosome 5 in a gene cluster that contains the evolutionary related IL-4 family of cytokine genes. The human IL-5 receptor complex is a heterodimer consisting of a unique a subunit (predominantly expressed on eosinophils) and a beta subunit which is shared between the receptors for IL-3 & GM-CSF (more widely expressed). The a subunit is required for ligand-specific binding whereas association with the beta subunit results in increased binding affinity. The alternative splicing of the alphaIL-5R gene which contains 14 exons can yield several alphaIL-5R isoforms including a membrane-anchored isoform (alphaIL-5Rm) and a soluble isoform (alphaIL-5Rs). Cytokines such as IL-5 produce specific and non-specific cellular responses through specific cell membrane receptor mediated activation of intracellular signal transduction pathways which, to a large part, regulate gene expression. The major intracellular signal transduction mechanism is activation of non-receptor associated tyrosine kinases including JAK and MAP kinases which can then transduce signals via a novel family of transcriptional factors named signal transducers and activators of transcription (STATS). JAK2, STAT1 and STAT 5 appear to be particularly important in IL-5 mediated eosinophil responses. Asthma is characterized by episodic airways obstruction, increased bronchial responsiveness, and airway inflammation. Several studies have shown an association between the number of activated T cells and eosinophils in the airways and abnormalities in FEV1, airway reactivity and clinical severity in asthma. It has now been well documented that IL-5 is highly expressed in the bronchial mucosa of atopic and intrinsic asthmatics and that the increased IL-5 mRNA present in airway tissues is predominantly T cell derived. Immunocytochemical staining of bronchial biopsy sections has confirmed that IL-5 mRNA transcripts are translated into protein in asthmatic subjects. Furthermore, the number of activated CD 4 + T cells and IL-5 mRNA positive cells are increased in asthmatic airways following antigen challenge and studies that have examined IL-5 expression in asthmatic subjects before and after steroids have shown significantly decreased expression following oral corticosteroid treatment in steroid-sensitive asthma but not in steroid resistant and chronic severe steroid dependent asthma. The link between T cell derived IL-5 and eosinophil activation in asthmatic airways is further strengthened by the demonstration that there is an increased number of alphaIL-5R mRNA positive cells in the bronchial biopsies of atopic and non-atopic asthmatic subjects and that the eosinophil is the predominant site of this increased alphaIL-5R mRNA expression. We have also shown that the subset of activated eosinophils that expressed mRNA for membrane bound alpha IL5r inversely correlated with FEV1, whereas the subset of activated eosinophils that expressed mRNA for soluble alphaIL5r directly correlated with FEV1. Hence, not only does this data suggest that the presence of eosinophils expressing alphaIL-5R mRNA contribute towards the pathogenesis of bronchial asthma, but also that the eosinophil phenotype with respect to alphaIL-5R isoform expression is of central importance. Finally, there are several animal, and more recently in vitro lung explant, models of allergen induced eosinophilia, late airway responses(LARS), and bronchial hyperresponsiveness(BHR) - all of which support a link between IL-5 and airway eosinophila and bronchial hyperresponsiveness. The most direct demonstration of T cell involvement in LARS is the finding that these physiological responses can be transferred by CD4+ but not CD8+ T cells in rats. The importance of IL-5 in animal models of allergen induced bronchial hyperresponsiveness has been further demonstrated by a number of studies which have indicated that IL-5 administration is able to induce late phase responses and BHR and that anti-IL-5 antibody can block allergen induced late phase responses and BHR. In summary, activated T lymphocytes, IL5 production and eosinophil activation are particularly important in the asthmatic response. Human studies in asthma and studies in allergic animal models have clearly emphasised the unique role of IL-5 in linking T lymphocytes and adaptive immunity, the eosinophil effector cell, and the asthma phenotype. The central role of activated lymphocytes and eosinophils in asthma would argue for the likely therapeutic success of strategies to block T cell and eosinophil activation (eg steroids). Importantly, more targeted therapies may avoid the complications associated with steroids. Such therapies could target key T cell activation proteins and cytokines by various means including blocking antibodies (eg anti-CD4, anti-CD40, anti-IL-5 etc), antisense oligonucleotides to their specific mRNAs, and/or selective inhibition of the promoter sites for these genes. Another option would be to target key eosinophil activation mechanisms including the aIL5r. As always, the risk to benefit ratio of such strategies await the results of well conducted clinical trials.

Role of eosinophilic airway inflammation in models of asthma

Eosinophils play a central role in the establishment and outcome of bronchial inflammation in asthma. Animal models of allergy are useful to answer questions related to mechanisms of allergic inflammation. We have used models of sensitized and boosted guinea pigs to investigate the nature of bronchial inflammation in allergic conditions. These animals develop marked bronchial infiltration composed mainly of CD4+ T-lymphocytes and eosinophils. Further provocation with antigen leads to degranulation of eosinophils and ulceration of the bronchial mucosa. Eosinophils are the first cells to increase in numbers in the mucosa after antigen challenge and depend on the expression of alpha 4 integrin to adhere to the vascular endothelium and transmigrate to the mucosa. Blockage of alpha4 integrin expression with specific antibody prevents not only the transmigration of eosinophils but also the development of bronchial hyperresponsiveness (BHR) to agonists in sensitized and challenged animals, clearly suggesting a role for this cell type in this altered functional state. Moreover, introduction of antibody against Major Basic Protein into the airways also prevents the development of BHR in similar model. BHR can also be suppressed by the use of FK506, an immunosuppressor that reduces in almost 100% the infiltration of eosinophils into the bronchi of allergic animals. These data support the concept that eosinophil is the most important pro-inflammatory factor in bronchial inflammation associated with allergy.

Improvement of the specificity of cancer detection by autofluorescence imaging in the tracheo-bronchial tree using backscattered violet light.

BACKGROUND: Autofluorescence bronchoscopy (AFB) is a highly sensitive tool for the detection of early bronchial cancers. However, its specificity remains limited due to primarily false positive results induced by hyperplasia, metaplasia and inflammation. We have investigated the potential of blue-violet backscattered light to eliminate false positive results during AFB in a clinical pilot study. METHODS: The diagnostic autofluorescence endoscopy (DAFE) system was equipped with a variable band pass filter in the imaging detection path. The backscattering properties of normal and abnormal bronchial mucosae were assessed by computing the contrast between the two tissue types for blue-violet wavelengths ranging between 410 and 490 nm in 12 patients undergoing routine DAFE examination. In a second study including 6 patients we used a variable long pass (LP) filter to determine the spectral design of the emission filter dedicated to the detection of this blue-violet light with the DAFE system. RESULTS: (Pre-)neoplastic mucosa showed a clear wavelength dependence of the backscattering properties of blue-violet light while the reflectivity of normal, metaplastic and hyperplastic autofluorescence positive mucosa was wavelength independent. CONCLUSIONS: Our results showed that the detection of blue-violet light has the potential to reduce the number of false positive results in AFB. In addition we determined the spectral design of the emission filter dedicated to the detection of this blue-violet light with the DAFE system.

The effects on mucociliary clearance of prednisone associated with bronchial section

OBJECTIVE: Infections have been and remain the major cause of morbidity and mortality after lung transplantation. Because mucociliary clearance plays an important role in human defense mechanisms, the influence of drugs on the mucociliary epithelium of patients undergoing lung transplantation must be examined. Prednisone is the most important corticosteroid used after lung transplantation. The aim of this study was to evaluate the effects of bronchial transection and prednisone therapy on mucociliary clearance. METHODS: A total of 120 rats were assigned to 4 groups according to surgical procedure or drug therapy: prednisone therapy (1.25 mg/kg/day); bronchial section and anastomosis + prednisone therapy (1.25 mg/kg/day); bronchial section + saline solution (2 ml/day); and saline solution (2 ml/day). After 7, 15, or 30 days, the animals were sacrificed, and the lungs were removed from the thoracic cavity. The in situ mucociliary transport velocity, ciliary beat frequency and in vitro mucus transportability were evaluated. RESULTS: Animals undergoing bronchial section surgery and anastomosis had a significant decrease in the ciliary beat frequency and mucociliary transport velocity 7 and 15 days after surgery (p<0.001). These parameters were normalized 30 days after the surgical procedure. Prednisone improved mucous transportability in the animals undergoing bronchial section and anastomosis at 15 and 30 days (p<0.05). CONCLUSION: Bronchial section and anastomosis decrease mucociliary clearance in the early postoperative period. Prednisone therapy improves mucus transportability in animals undergoing bronchial section and anastomosis.

Liposomal Lidocaine Gel For Topical Use At The Oral Mucosa: Characterization, In Vitro Assays And In Vivo Anesthetic Efficacy In Humans.

To characterize liposomal-lidocaine formulations for topical use on oral mucosa and to compare their in vitro permeation and in vivo anesthetic efficacy with commercially available lidocaine formulations. Large unilamellar liposomes (400 nm) containing lidocaine were prepared using phosphatidylcholine, cholesterol, and α-tocoferol (4:3:0.07, w:w:w) and were characterized in terms of membrane/water partition coefficient, encapsulation efficiency, size, polydispersity, zeta potential, and in vitro release. In vitro permeation across pig palatal mucosa and in vivo topical anesthetic efficacy on the palatal mucosa in healthy volunteers (double-blinded cross-over, placebo controlled study) were performed. The following formulations were tested: liposome-encapsulated 5% lidocaine (Liposome-Lido5); liposome-encapsulated 2.5% lidocaine (Liposome-Lido2.5); 5% lidocaine ointment (Xylocaina®), and eutectic mixture of lidocaine and prilocaine 2.5% (EMLA®). The Liposome-Lido5 and EMLA showed the best in vitro permeation parameters (flux and permeability coefficient) in comparison with Xylocaina and placebo groups, as well as the best in vivo topical anesthetic efficacy. We successfully developed and characterized a liposome encapsulated 5% lidocaine gel. It could be considered an option to other topical anesthetic agents for oral mucosa.

Nerve endings of filliform, fungiform and vallate papillae of dorsal tongue mucosa of White-lipped peccary (Tayassu pecari): Neurohistological observations

The neurohistologic observations were performed using the specimens prepared by Winkelmann and Schmitt silver impregnation method. The tissues were fixed in 10% formalin solution and sections of 40µm thickness were obtained by Leica Cryostat at -30ºC. The sections of dorsal mucosa of White-lipped peccary tongue showed numerous filliform and fungiform papillae, and two vallate papillae on the caudal part. The epithelial layer revealed queratinized epithelial cells and the connective tissue papillae of different sizes and shapes. Thick nerve fiber bundles are noted into the subepithelial connective tissue of the papillae. The connective tissue of fungiform and vallate papillae contained numerous sensitive nerves fibers bundles forming a complex nerve plexus.

Effects of enriched colostrum supply in intestinal mucosa morphology of newborn calves

Colostrum intake in neonatal calves is essential to obtain passive immunity and to influence metabolism, endocrine systems and the nutritional state. This study compares morphologic features of small intestine of calves fed a colostrum second meal at 12 hours of life with concentrations of immunoglobulin G (IgG) higher than 100mg mL(-1) (fresh colostrum or artificially prepared with addition of lyophilized colostrum) or smaller than 30mg mL(-1). Twenty-four Holstein calves were randomly grouped according to concentration of IgG intake at 12 hours of life: low (less than 30mg mL(-1)); high (more than 100mg mL(-1)); plus lyophilized colostrum (more than 120mg mL(-1)). Intestinal tissue samples were collected at 0, 10, 24 and 72 hours after birth to evaluate morphology in segments: duodenum; proximal, middle and distal jejunum and ileum by examined with a scanning electron microscope. Villi of all segments showed more organized and uniform morphology characteristics with age. Only the animals fed colostrum with more than 100mg mL(-1) of IgG at 24 hours after birth still showed the distal jejunum villi disoriented and more united in comparison to the other ages and groups. Intake of lyophilized colostrum affected ileum morphology along experiment period. Higher concentration of immunologic and bioactive elements supplied for longer period of time could be responsible for promoting effects on the enterocytes. Use of colostrum with high IgG concentrations, with or without addition of lyophilized colostrum, influenced the precocity of the intestinal mucosa development in newborn calves, suggesting earlier maturation of the mucosa.