Female sex hormones mediate the allergic lung reaction by regulating the release of inflammatory mediators and the expression of lung E-selectin in rats

Background: Fluctuations of estradiol and progesterone levels caused by the menstrual cycle worsen asthma symptoms. Conflicting data are reported in literature regarding pro and anti-inflammatory properties of estradiol and progesterone. Methods: Female Wistar rats were ovalbumin (OVA) sensitized 1 day after resection of the ovaries (OVx). Control group consisted of sensitized-rats with intact ovaries (Sham-OVx). Allergic challenge was performed by aerosol (OVA 1%, 15 min) two weeks later. Twenty four hours after challenge, BAL, bone marrow and total blood cells were counted. Lung tissues were used as explants, for expontaneous cytokine secretion in vitro or for immunostaining of E-selectin. Results: We observed an exacerbated cell recruitment into the lungs of OVx rats, reduced blood leukocytes counting and increased the number of bone marrow cells. Estradiol-treated OVx allergic rats reduced, and those treated with progesterone increased, respectively, the number of cells in the BAL and bone marrow. Lungs of OVx allergic rats significantly increased the E-selectin expression, an effect prevented by estradiol but not by progesterone treatment. Systemically, estradiol treatment increased the number of peripheral blood leukocytes in OVx allergic rats when compared to non treated-OVx allergic rats. Cultured-BAL cells of OVx allergic rats released elevated amounts of LTB(4) and nitrites while bone marrow cells increased the release of TNF-alpha and nitrites. Estradiol treatment of OVx allergic rats was associated with a decreased release of TNF-alpha, IL-10, LTB4 and nitrites by bone marrow cells incubates. In contrast, estradiol caused an increase in IL-10 and NO release by cultured-BAL cells. Progesterone significantly increased TNF-alpha by cultured BAL cells and bone marrow cells. Conclusions: Data presented here suggest that upon hormonal oscillations the immune sensitization might trigger an allergic lung inflammation whose phenotype is under control of estradiol. Our data could contribute to the understanding of the protective role of estradiol in some cases of asthma symptoms in fertile ans post-menopausal women clinically observed.

Amphetamine modulates cellular recruitment and airway reactivity in a rat model of allergic lung inflammation

Asthma is characterized by pulmonary cellular infiltration, vascular exudation and airway hyperresponsiveness. Several drugs that modify central nervous system (CNS) activity can modulate the course of asthma. Amphetamine (AMPH) is a highly abused drug that presents potent stimulating effects on the CNS and has been shown to induce behavioral, biochemical and immunological effects. The purpose of this study was to investigate the effects of AMPH on pulmonary cellular influx, vascular permeability and airway reactivity. AMPH effects on adhesion molecule expression, IL-10 and IL-4 release and mast cell degranulation were also studied. Male Wistar rats were sensitized with ovalbumin (OVA) plus alum via subcutaneous injection. One week later, the rats received another injection of OVA-alum (booster). Two weeks after this booster, the rats were subjected to AMPH treatment 12 h prior to the OVA airway challenge. In rats treated with AMPH, the OVA challenge reduced cell recruitment into the lung, the vascular permeability and the cellular expression of ICAM-1 and Mac-1. Additionally, elevated levels of IL-10 and IL-4 were found in samples of lung explants from allergic rats. AMPH treatment, in comparison, increased IL-10 levels but reduced those of IL-4 in the lung explants. Moreover, the tracheal responsiveness to methacholine (MCh), as well as to an in vitro OVA challenge, was reduced by AMPH treatment, and levels of PCA titers were not modified by the drug. Our findings suggest that single AMPH treatment down-regulates several parameters of lung inflammation, such as cellular migration, vascular permeability and tracheal responsiveness. These results also indicate that AMPH actions on allergic lung inflammation include endothelium-leukocyte interaction mechanisms, cytokine release and mast cell degranulation. (C) 2010 Elsevier Ireland Ltd. All rights reserved.

Immunopathology of allergic contact dermatitis

Allergic contact dermatitis is the consequence of an immune reaction mediated by T cells against low molecular weight chemicals known as haptens. It is a common condition that occurs in all races and age groups and affects the quality of life of those who present it. The immunological mechanism of this disease has been reviewed in recent decades with significant advance in its understanding. The metabolism and pathway of the haptens as well as the activation and mechanism of action of the cells responsible for both the immune reaction and its completion are discussed in this article.

Development of an animal model for allergic conjunctivitis: influence of genetic factors and allergen concentration on immune response

Purpose: Animal models of diseases are extremely important in the study of the physiopathogenesis of human diseases and for testing novel therapeutic interventions. The present study aimed to develop an animal model that simulates human allergic conjunctivitis and to study how allergic response may be influenced by the allergen dose used for immunization and by genetic factors. Methods: Sixty C57Bl/6 mice and 60 BALB/c mice were immunized with placebo, or 5 mu g or 500 mu g of allergen derived from Dermatophagoides pteronyssinus. After ocular challenge, the mice were examined in order to clinically verify the occurrence or not of conjunctivitis. Material obtained from animals was used for total and specific IgE and IgG1 dosage, for assays of Der p-specific lymphocyte proliferation and supernatant cytokine dosage, and for histopathological evaluation of conjunctiva. Results: We developed a murine model of allergic conjunctivitis induced by D. pteronyssinus. The model is similar to human disease both clinically and according to laboratory findings. In mouse, conjunctivitis was associated with a Th2 cytokine profile. However, IL-10 appeared to be involved with disease blockade. Mice of different strains have distinct immune responses, depending on the sensitization dose. Conclusions: The murine model developed is suitable for the study of immunopathogenesis and as a template for future therapies. Using BALB/c and C57BL/6 mice, we demonstrated that genetic factors play a role in determining susceptibility and resistance, as well as in establishing the allergen concentration needed to induce or to block disease development.

Allergic asthma in patients with common variable immunodeficiency

P>Background: Many patients with common variable immunodeficiency (CVID) have a clinical history suggestive of allergic respiratory disease. However, in such individuals, the prevalence of asthma and the role of atopy have not been well established. The objective of this study was to evaluate pulmonary function and identify asthma in patients with CVID. We also investigated the role of IgE as a trigger of asthma in these patients. Methods: Sixty-two patients diagnosed with CVID underwent spirometry, as well as skin prick testing and in vitro determination of serum-specific IgE levels for aeroallergens, together with bronchial provocation with histamine and allergen. Results: The most common alteration identified through spirometry was obstructive lung disease, which was observed in 29 (47.5%) of the 62 patients evaluated. Eighteen (29.0%) of the 62 patients had a clinical history suggestive of allergic asthma. By the end of the study, asthma had been diagnosed in nine (14.5%) patients and atopy had been identified in six (9.7%). In addition, allergic asthma had been diagnosed in four patients (6.5% of the sample as a whole; 22.2% of the 18 patients with a clinical history suggestive of the diagnosis). Conclusion: In this study, CVID patients testing negative for specific IgE antibodies and suspected of having allergic asthma presented a positive response to bronchial provocation tests with allergens. To our knowledge, this is the first such study. When CVID patients with a history suggestive of allergic asthma test negative on traditional tests, additional tests designed to identify allergic asthma might be conducted.

Lymphocyte proliferation testing in chromium allergic contact dermatitis

Background. Lymphocyte proliferation testing (LPT) has some advantages over patch testing to diagnose allergic contact dermatitis. It is harmless, objective and can be used in clinical situations where patch testing is not recommended. Unfortunately, significant success has only been achieved with nickel. There are few studies on chromium LPT and they were performed with different methods, leading to inconsistent results. Methods. To determine the best parameters for chromium LPT, we tested 20 patients with allergic contact dermatitis to the metal and 20 controls, using various protocols. Results. The best sensitivity and specificity ratios were achieved with 6-day cultures stimulated with a range from 7.5 x 10(-4) to 5 x 10(-3) mol/L of nonfiltered chromium chloride solutions. The sensitivity, specificity and accuracy values found within this range were 65%, 95% and 80%, respectively. Conclusion. Further investigation is necessary to achieve better sensitivity values.

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.

Different strains of mice present distinct lung tissue mechanics and extracellular matrix composition in a model of chronic allergic asthma

The impact of genetic factors on asthma is well recognized but poorly understood. We tested the hypothesis that different mouse strains present different lung tissue strip mechanics in a model of chronic allergic asthma and that these mechanical differences may be potentially related to changes of extracellular matrix composition and/or contractile elements in lung parenchyma. Oscillatory mechanics were analysed before and after acetylcholine (ACh) in C57BL/10, BALB/c, and A/J mice, subjected or not to ovalbumin sensitization and challenge. In controls, tissue elastance (E) and resistance (R), collagen and elastic fibres` content, and alpha-actin were higher in A/J compared to BALB/c mice, which, in turn, were more elevated than in C57BL/10. A similar response pattern was observed in ovalbumin-challenged animals irrespective of mouse strain. E and R augmented more in ovalbumin-challenged A/J [E: 22%, R: 18%] than C57BL/10 mice [E: 9.4%, R: 11 %] after ACh In conclusion, lung parenchyma remodelled differently yielding distinct in vitro mechanics according to mouse strain. (C) 2008 Elsevier B.V. All rights reserved.

Effects of inducible nitric oxide synthase inhibition in bronchial vascular remodeling-induced by chronic allergic pulmonary inflammation

Vascular remodeling is an important feature in asthma pathophysiology. Although investigations suggested that nitric oxide (NO) is involved in lung remodeling, little evidence established the role of inducible NO synthase (iNOS) isoform in bronchial vascular remodeling. The authors investigated if iNOS contribute to bronchial vascular remodeling induced by chronic allergic pulmonary inflammation. Guinea pigs were submitted to ovalbumin exposures with increasing doses (1 similar to 5 mg/mL) for 4 weeks. Animals received 1400W (iNOS-specific inhibitor) treatment for 4 days beginning at 7th inhalation. Seventy-two hours after the 7th inhalation, animals were anesthetized, mechanical ventilated, exhaled NO was collected, and lungs were removed and submitted to picrosirius and resorcin-fuchsin stains and to immunohistochemistry for matrix metalloproteinase-9 (MMP-9), tissue inhibitor of metalloproteinase-1 (TIMP-1), and transforming growth factor-beta (TGF-beta). Collagen and elastic fiber deposition as well as MMP-9, TIMP-1, and TGF-beta expression were increase in bronchial vascular wall in ovalbumin-exposed animals. The iNOS inhibition reduced all parameters studied. In this model, iNOS inhibition reduced the bronchial vascular extracellular remodeling, particularly controlling the collagen and elastic fibers deposition in pulmonary vessels. This effect can be associated to a reduction on TGF-beta and on metalloproteinase-9/TIMP-1 vascular expression. It reveals new therapeutic strategies and some possible mechanism related to specific iNOS inhibition to control vascular remodeling.

Oral tolerance attenuates changes in in vitro lung tissue mechanics and extracellular matrix remodeling induced by chronic allergic inflammation in guinea pigs

Oral tolerance attenuates changes in in vitro lung tissue mechanics and extracellular matrix remodeling induced by chronic allergic inflammation in guinea pigs. J Appl Physiol 104: 1778-1785, 2008. First published April 3, 2008; doi:10.1152/japplphysiol.00830.2007.-Recent studies emphasize the presence of alveolar tissue inflammation in asthma. Immunotherapy has been considered a possible therapeutic strategy for asthma, and its effect on lung tissue had not been previously investigated. Measurements of lung tissue resistance and elastance were obtained before and after both ovalbumin and acetylcholine challenges. Using morphometry, we assessed eosinophil and smooth muscle cell density, as well as collagen and elastic fiber content, in lung tissue from guinea pigs with chronic pulmonary allergic inflammation. Animals received seven inhalations of ovalbumin (1-5 mg/ml; OVA group) or saline (SAL group) during 4 wk. Oral tolerance (OT) was induced by offering ad libitum ovalbumin 2% in sterile drinking water starting with the 1st inhalation (OT1 group) or after the 4th (OT2 group). The ovalbumin-exposed animals presented an increase in baseline and in postchallenge resistance and elastance related to baseline, eosinophil density, and collagen and elastic fiber content in lung tissue compared with controls. Baseline and post-ovalbumin and acetylcholine elastance and resistance, eosinophil density, and collagen and elastic fiber content were attenuated in OT1 and OT2 groups compared with the OVA group. Our results show that inducing oral tolerance attenuates lung tissue mechanics, as well as eosinophilic inflammation and extracellular matrix remodeling induced by chronic inflammation.

Impact of lung remodelling on respiratory mechanics in a model of severe allergic inflammation

We developed a model of severe allergic inflammation and investigated the impact of airway and lung parenchyma remodelling on in vivo and in vitro respiratory mechanics. BALB/c mice were sensitized and challenged with ovalbumin in severe allergic inflammation (SA) group. The control group (C) received saline using the same protocol. Light and electron microscopy showed eosinophil and neutrophil infiltration and fibrosis in airway and lung parenchyma, mucus gland hyperplasia, and airway smooth muscle hypertrophy and hyperplasia in SA group. These morphological changes led to in vivo (resistive and viscoelastic pressures, and static elastance) and in vitro (tissue elastance and resistance) lung mechanical alterations. Airway responsiveness to methacholine was markedly enhanced in SA as compared with C group. Additionally, IL-4, IL-5, and IL-13 levels in the bronchoalveolar lavage fluid were higher in SA group. In conclusion, this model of severe allergic lung inflammation enabled us to directly assess the role of airway and lung parenchyma inflammation and remodelling on respiratory mechanics. (C) 2007 Elsevier B.V. All rights reserved.

Effects of bone marrow-derived mononuclear cells on airway and lung parenchyma remodeling in a murine model of chronic allergic inflammation

We hypothesized that bone marrow-derived mononuclear cells (BMDMC) would attenuate the remodeling process in a chronic allergic inflammation model. C57BL/6 mice were assigned to two groups. In OVA, mice were sensitized and repeatedly challenged with ovalbumin. Control mice (C) received saline under the same protocol. C and OVA were further randomized to receive BMDMC (2 x 10(6)) or saline intravenously 24 h before the first challenge. BMDMC therapy reduced eosinophil infiltration, smooth muscle-specific actin expression, subepithelial fibrosis, and myocyte hypertrophy and hyperplasia, thus causing a decrease in airway hyperresponsiveness and lung mechanical parameters. BMDMC from green fluorescent protein (GFP)-transgenic mice transplanted into GFP-negative mice yielded lower engraftment in OVA. BMDMC increased insulin-like growth factor expression, but reduced interleukin-5, transforming growth factor-beta, platelet-derived growth factor, and vascular endothelial growth factor mRNA expression. In conclusion, in the present chronic allergic inflammation model, BMDMC therapy was an effective pre-treatment protocol that potentiated airway epithelial cell repair and prevented inflammatory and remodeling processes. (C) 2010 Elsevier B.V. All rights reserved.

Repeated stress reduces mucociliary clearance in animals with chronic allergic airway inflammation

We evaluated if repeated stress modulates mucociliary clearance and inflammatory responses in airways of guinea pigs (GP) with chronic inflammation. The GP received seven exposures of ovalbumin or saline 0.9%. After 4th inhalation, animals were submitted to repeated forced swim stressor protocol (5x/week/2 weeks). After 7th inhalation, GP were anesthetized. We measured transepithelial potential difference, ciliary beat frequency, mucociliary transport, contact angle, cough transportability and serum cortisol levels. Lungs and adrenals were removed, weighed and analyzed by morphometry. Ovalbumin-exposed animals submitted to repeated stress had a reduction in mucociliary transport, and an increase on serum cortisol, adrenals weight, mucus wettability and adhesivity, positive acid mucus area and IL-4 positive cells in airway compared to non-stressed ovalbumin-exposed animals (p < 0.05). There were no effects on eosinophilic recruitment and IL-13 positive cells. Repeated stress reduces mucociliary clearance due to mucus theological-property alterations, increasing acid mucus and its wettability and adhesivity. These effects seem to be associated with IL-4 activation. (C) 2010 Elsevier B.V. All rights reserved.

Impact of obesity on airway and lung parenchyma remodeling in experimental chronic allergic asthma

The impact of obesity on the inflammatory process has been described in asthma, however little is known about the influence of diet-induced obesity on lung remodeling. For this purpose, 56 recently weaned A/J mice were randomly divided into 2 groups. In the C group, mice were fed a standard chow diet, while OB animals received isocaloric high-fat diet to reach 1.5 of the mean body weight of C. After 12 weeks, each group was further randomized to be sensitized and challenged with ovalbumin (OVA) or saline. Twenty-four hours after the last challenge, collagen fiber content in airways and lung parenchyma, the volume proportion of smooth muscle-specific actin in alveolar ducts and terminal bronchiole, and the number of eosinophils in bronchoalveolar lavage fluid were higher in OB-OVA than C-OVA. In conclusion, diet-induced obesity enhanced lung remodeling resulting in higher airway responsiveness in the present experimental chronic allergic asthma. (C) 2011 Elsevier B.V. All rights reserved.

Chronic Rhinosinusitis in Allergic Asthmatic Patients: Radiography Versus Low-Dose Computed Tomography Evaluation

Objective. Chronic rhinosinusitis (CRS) is a risk factor for asthma exacerbations and is associated with greater clinical severity. Discrepancies may exist between CRS clinical diagnosis and data from paranasal sinus (PS) X-ray or computed tomography (CT) scans. The objective was to compare PS involvement using low-dose CT and plain X-ray in allergic asthmatic patients with rhinitis. Methods. Patients underwent PS radiography in the frontal and mentonian positions and low-dose CT consisting of six to eight coronal scans performed on the central region of the sphenoidal, ethmoidal, maxillary, and frontal sinuses. Possible results for each sinus were a normal aspect or the presence of mucosal thickening, opacification, and/or air-fluid level. Results. Eighty-five (93.4%) of 91 study patients had radiological changes on radiography or CT. In only six (6.6%) were both tests normal. The maxillary was the most involved sinus by both methods. Simultaneous PS abnormalities were observed in 40.5% on X-ray and 56.7% on CT. For the frontal, ethmoidal, and sphenoidal sinuses, the proportion of normal results differed significantly between X-ray and CT: 80.2% versus 89%, 76.9% versus 63.7% and 96.7% versus 70.3%, respectively (p <.05). Agreement was over 70% for the maxillary and frontal sinuses. CT also provided a better diagnosis of air-fluid level changes than X-ray. Conclusions. Low-dose CT significantly showed larger number of normal PS results and diagnosed more severe PS lesions. As the determination of true sinus severity lesion impacts in asthma control, low-dose CT may replace PS plain X-ray and conventional CT to support better clinical decisions.