Soluble intracellular adhesion molecule 1 in bronchoalveolar lavage fluid of allergic subjects following segmental antigen challenge

Delayed asthmatic response: a new phenotype of bronchial response to allergen challenge and soluble adhesion molecules in the serum

BACKGROUND

Patients with bronchial asthma develop various types of asthmatic response to bronchial challenge with allergen, such as immediate asthmatic response, late asthmatic response, or delayed asthmatic response (DYAR), due to different immunologic mechanisms.

OBJECTIVES

To investigate the appearance and possible changes in the concentrations of soluble cell adhesion molecules during the DYAR, to explore the involvement of particular cell types in the mechanism(s) leading to DYAR, and to contribute to a fuller understanding of this clinical phenomenon.

METHODS

The DYAR recorded in 28 patients (P < .001), appearing within 26 to 32 hours, reaching maximum within 32 to 48 hours, and resolving within 56 hours after the allergen challenge, was repeated 2 to 6 weeks later. The repeated DYAR (P < .001) was supplemented with blood cell counts and measurement of serum concentrations of soluble adhesion molecules by an enzyme-linked immunoassay.

RESULTS

The prechallenge concentrations of soluble intercellular adhesion molecule 1 (sICAM-1), soluble vascular cell adhesion molecule 1 (sVCAM-1), soluble platelet endothelial cell adhesion molecule (sPECAM-1), soluble E-selectin, soluble L-selectin, soluble P-selectin, and soluble E-cadherin did not differ significantly from healthy controls. The DYAR was associated with the following changes in the serum: an increase of sICAM-1 at 6 and 12 hours and a decrease at 24 hours; an increase of sVCAM-1 at 24 and 36 hours; an increase of sPECAM-1 at 36 and 48 hours and a decrease at 56 and 72 hours; an increase of soluble E-selectin at 56 hours; an increase of soluble L-selectin at 56 and 72 hours; a decrease of soluble E-cadherin at 48 and 56 hours; and increased counts of blood leukocytes at 36, 48, and 56 hours, neutrophils at 24, 36, 48, and 56 hours, lymphocytes at 24, 36, and 48 hours, and monocytes at 6, 12, and 24 hours. The Th1/Th2 ratio in blood increased at 24, 36, 48, and 56 hours. The intracellular concentration of interferon γ, but not of interleukin 4, increased at 24, 36, 48, and 56 hours.

CONCLUSIONS

These results provide evidence of the involvement of neutrophils, Th1 lymphocytes, monocytes, platelets, and endothelial cells, upon participation of various adhesion molecules, in mechanisms(s) underlying the clinical DYAR.

Anti-inflammatory, immunomodulatory, and heme oxygenase-1 inhibitory activities of ravan napas, a formulation of uighur traditional medicine, in a rat model of allergic asthma

Ravan Napas (RN) is a traditional formula used to treat pulmonary symptoms and diseases such as coughing, breathing difficulty, and asthma in traditional Uighur medicine. The purpose of this study was to investigate the anti-inflammatory, and immuno-modulatory activity of RN in a well-characterized animal model of allergic asthma. Rats were sensitized with intraperitoneal (ip) ovalbumin (OVA) and alum, and then challenged with OVA aerosols. The asthma model rats were treated with RN; saline- and dexamethasone- (DXM-) treated rats served as normal and model controls. The bronchoalveolar lavage fluid (BALF) cellular differential and the concentrations of sICAM-1, IL-4, IL-5, TNF-α, INF-γ, and IgE in serum were measured. Lung sections underwent histological analysis. The immunohistochemistry S-P method was used to measure the expression of ICAM-1 and HO-1 in the lung. RN significantly reduced the number of inflammatory cells in BALF and lung tissues, decreased sICAM-1, IL-4, IL-5, TNF-α, and IgE in serum, and increased serum INF-γ. There was a marked suppression of ICAM-1 and HO-1 expression in the lung. Our results suggest that RN may have an anti-inflammatory and immuneregulatory effect on allergic bronchial asthma by modulating the balance between Th1/Th2 cytokines.

Increase in concentration of soluble CD86 after segmental allergen challenge in patients with allergic asthma

STUDY OBJECTIVE

To investigate the effects of segmental allergen challenge on the concentration of soluble CD86 (sCD86) in BAL fluids in patients with allergic asthma.

METHODS

BAL fluid and peripheral blood were collected at baseline, 24 h after segmental saline solution or allergen challenge by fiberoptic bronchoscopy and venepuncture, respectively, from 10 patients with allergic asthma. Total and differential cell counts in BAL fluid were performed, and sCD86 levels in both BAL fluid and serum were measured by enzyme-linked immunosorbent assay.

RESULTS

In allergic asthmatics, there was no significant increase in BAL sCD86 concentrations after saline solution challenge (median, 2.0 IU/L; 25th to 75th percentiles, 0 to 3.4) compared with baseline control subjects (median, 1.2 IU/L; 25th to 75th percentiles, 0 to 3.6 IU/mL; p = 0.735); however, sCD86 concentrations were significantly elevated after allergen challenge (median, 8.1 IU/L; 25th to 75th percentiles, 4.4 to 17.0 IU/mL; p < 0.001). The concentrations of sCD86 in BAL fluid after allergen challenge exceeded levels that could be accounted for passive transudation from the circulation, based on the magnitude of increases in BAL albumin concentrations.

CONCLUSIONS

These data indicate that allergen challenge results in a significant local accumulation of sCD86 within the airways, and that the local release of sCD86 may play a role in allergen-induced inflammatory processes in the asthmatic airways.

A single nasal allergen challenge increases induced sputum inflammatory markers in non-asthmatic subjects with seasonal allergic rhinitis: correlation with plasma interleukin-5

BACKGROUND

Seasonal allergic rhinitis (SAR) is a risk factor for asthma in affected individuals. Nasal allergic inflammation enhances bone-marrow eosinophil production, mainly via IL-5, and rhinitis patients have increased airway inflammation during the pollen season.

OBJECTIVE

To assess the impact of nasal allergy on sputum inflammatory markers.

METHODS

In an open-labelled, randomized, placebo-controlled cross-over study with 16 non-asthmatic SAR patients (median age 25 years, 56% males), the effect of a single nasal allergen challenge performed out of season on induced sputum inflammatory parameters was evaluated. SAR patients were identified by history, skin-prick test and specific IgE. All patients had normal lung function/bronchial hyper-responsiveness out of season and a negative asthma/wheezing history. Sputum cells and supernatant levels of ECP, sICAM, IL-5 and IL-10, and plasma levels of IL-5 and ECP, were measured before and 24 h after nasal allergen challenge. After a washout period of at least 4 weeks, the procedure was repeated with placebo challenge (diluent).

RESULTS

Nasal allergen challenge led to an increase in sputum ECP (pre = 60 +/- 12, post = 212 +/- 63 micro g/L, P = 0.02 vs. placebo), and sICAM (4.8 +/- 2.7 to 6.5 +/- 2.9 ng/mL, P = 0.02 vs. placebo), whereas IL-10 decreased after provocation (44 +/- 11 to 29 +/- 6 pg/mL, P = 0.06 vs. placebo). Sputum IL-5 was undetectable in all patients. The absolute number of blood and sputum eosinophils did not change significantly after allergen or placebo challenge (P > 0.07, both comparisons). Plasma levels of IL-5 increased after allergen challenge (8.7 +/- 2.9 to 14.5 +/- 3.9 pg/mL, P = 0.001), and the increase in plasma IL-5 was positively correlated with the rise in sputum ECP in a subgroup of 'responders' (n = 12, r = 0.71, P = 0.01).

CONCLUSIONS

A single nasal allergen challenge in SAR patients increased markers of allergic inflammation in the lower respiratory tract, possibly via pronounced activation of inflammatory cells through circulating immediate-type reaction cytokines like IL-5. These findings may provide additional explanatory data for the high susceptibility of SAR patients to incident asthma.

Long-term repeatability of induced sputum cells and inflammatory markers in stable, moderately severe COPD

STUDY OBJECTIVES

Neutrophilic inflammation is a major feature of COPD. Induced sputum is increasingly used to monitor inflammatory airway diseases. Although short-term repeatability of selected sputum markers has been extensively studied in several populations, data on the long-term repeatability of induced sputum markers in stable COPD are scant.

DESIGN

Sputum supernatant of 12 patients with stable COPD was analyzed on three separate occasions with 4-weekly intervals. Sputum cells and inflammatory markers interleukin (IL)-8 and soluble intercellular adhesion molecule (sICAM)-1 were measured in supernatant using enzyme-linked immunosorbent assay. Repeatability of sputum markers was expressed by intraclass correlation coefficients (Ri).

MEASUREMENTS AND RESULTS

Sputum induction was safe in all patients. None of the sputum parameters analyzed changed significantly throughout the study. The repeatability for cell differential counts in stable COPD was as follows: total cells, Ri = 0.07; neutrophils, Ri = 0.66; macrophages, Ri = 0.47; eosinophils, Ri = 0.49; and lymphocytes, Ri = 0.58. The repeatability of soluble markers was as follows: IL-8, Ri = 0.50; and sICAM, Ri = 0.58. Sputum neutrophils were negatively correlated with lung function on each separate occasion, whereas soluble markers were not correlated with sputum cells (p > 0.16, all correlations) or lung function (p > 0.24, all correlations).

CONCLUSIONS

Clinically stable, moderate COPD is associated with equally stable sputum inflammatory markers. Repeatability of induced-sputum markers of neutrophilic inflammation in stable COPD is satisfactory, even over extended periods of time. These data support the usefulness of serial monitoring of induced-sputum inflammatory markers in COPD.

Circulating adhesion molecules in sera of asthmatic children

Infiltration of cells into the lung in asthma is regulated by several expressions of cell adhesion molecules (CAMs) on cells present in the airways, and may play a role in the pathogenesis of bronchial asthma. We sought to evaluate the role of serum concentrations of the soluble forms of intercellular adhesion molecule-1 (sICAM-1), vascular cell adhesion molecule-1 (sVCAM-1), and E-selectin (sE-selectin) in the control of disease activity in acute asthma. Circulating levels of sICAM-1, sVCAM-1, and sE-selectin in sera from 15 normal control subjects and from 20 allergic asthmatic children with acute exacerbations who had returned to stable condition were determined by using commercially available enzyme-linked immunosorbent assay kits. The mean concentration of serum sICAM-1 levels was significantly higher during an acute exacerbation of asthmatic children than in those with stable asthma (19.41 +/- 10.65 ng/mL vs. 13.46 +/- 5.44 ng/mL; P < 0.001) or in control subjects (9.83 +/- 2.02 ng/mL; P < 0.001). For sVCAM-1 and sE-selectin, the mean serum concentration of sVCAM-1 was slightly higher in children during an acute exacerbation asthma than when stable. However, the differences did not reach statistical significance. The mean serum concentrations of sVCAM-1 and sE-selectin in acute asthma or stable asthma were significantly higher than in control subjects. This study provides further evidence that serum concentrations of sICAM-1, sVCAM-1, and sE-selectin are increased in acute asthma. These findings further confirm that leukocyte endothelial adhesion plays a role in inflammatory airway disease.

Effect of ozone and nitrogen dioxide on the release of proinflammatory mediators from bronchial epithelial cells of nonatopic nonasthmatic subjects and atopic asthmatic patients in vitro

BACKGROUND

Although studies have suggested that ozone (O3) and nitrogen dioxide (NO2) may play a role in the pathogenesis of asthma, the underlying mechanisms are not clear.

OBJECTIVE

We aimed to investigate the effects of O3 and NO2 on the release of IL-8, GM-CSF, RANTES, and soluble intercellular adhesion molecule 1 (sICAM-1) from human bronchial epithelial cells (HBECs) of nonatopic nonasthmatic subjects (nonasthmatic subjects) and atopic subjects with mild asthma (asthmatic subjects) in vitro.

METHODS

We cultured HBECs from bronchial biopsy specimens of nonasthmatic and asthmatic subjects; exposed these for 6 hours to air, 10 to 100 ppb O3, or 100 to 400 ppb NO2; and analyzed the release of IL-8, GM-CSF, RANTES, and sICAM-1 after 24 hours' incubation.

RESULTS

There was no significant difference between the constitutive release of IL-8, GM-CSF, and sICAM-1 from HBECs of asthmatic and nonasthmatic subjects. RANTES was detected only in HBECs derived from asthmatic subjects. Exposure of HBECs of asthmatic subjects to both 50 to 100 ppb O3 and 200 to 400 ppb NO2 significantly increased the release of IL-8, GM-CSF, RANTES, and sICAM-1 from these cells after 24 hours of incubation. However, 50 to 100 ppb O3 and 200 to 400 ppb NO2 led to a significant increase in release of only IL-8 and sICAM-1 from HBECs of nonasthmatic subjects after 24 hours' incubation. A comparison between the pollutant-induced release of mediators demonstrated that 100 ppb O3-induced release of GM-CSF and sICAM-1 was significantly greater in HBECs of asthmatic subjects (medians, 0.59 and 27.4 pg/microg cellular protein, respectively) than in HBECs of nonasthmatic subjects (medians, 0.27 and 14.4 pg/microg cellular protein, respectively; P < .02).

CONCLUSION

These results suggest that O3 and NO2 may modulate airway diseases, such as asthma, by increasing the release of inflammatory mediators from bronchial epithelial cells and that the cells of asthmatic subjects may be more susceptible to the adverse effects of these pollutants.

Intrinsic ICAM-1/LFA-1 activation mediates altered responsiveness of atopic asthmatic airway smooth muscle

Cell adhesion molecules (CAMs) have been importantly implicated in the pathobiology of the airway responses in allergic asthma, including inflammatory cell recruitment into the lungs and altered bronchial responsiveness. To elucidate the mechanism of CAM-related mediation of altered airway responsiveness in the atopic asthmatic state, the expressions and actions of intercellular adhesion molecule-1 (ICAM-1) and its counterreceptor ligand lymphocyte function-associated antigen-1 (LFA-1; i.e., CD11a/CD18) were examined in isolated rabbit airway smooth muscle (ASM) tissues and cultured human ASM cells passively sensitized with sera from atopic asthmatic patients or nonatopic nonasthmatic (control) subjects. Relative to control tissues, the atopic asthmatic sensitized ASM exhibited significantly enhanced maximal contractility to acetylcholine and attenuated relaxation responses to isoproterenol. These proasthmatic changes in agonist responsiveness were ablated by pretreating the atopic sensitized tissues with a monoclonal blocking antibody (MAb) to either ICAM-1 or CD11a, whereas a MAb directed against the related beta(2)-integrin Mac-1 had no effect. Moreover, relative to control tissues, atopic asthmatic sensitized ASM cells displayed an autologously upregulated mRNA and cell surface expression of ICAM-1, whereas constitutive expression of CD11a was unaltered. Extended studies further demonstrated that 1) the enhanced expression and release of soluble ICAM-1 by atopic sensitized ASM cells was prevented when cells were pretreated with an interleukin (IL)-5-receptor-alpha blocking antibody and 2) administration of exogenous IL-5 to naive (nonsensitized) ASM cells induced a pronounced soluble ICAM-1 release from the cells. Collectively, these observations provide new evidence demonstrating that activation of the CAM counterreceptor ligands ICAM-1 and LFA-1, both of which are endogenously expressed in ASM cells, elicits autologously upregulated IL-5 release and associated changes in ICAM-1 expression and agonist responsiveness in atopic asthmatic sensitized ASM.

Inflammation markers in the serum of salt miners

The inflammation markers alpha-1-antitrypsin (AAT), Clara cell protein (CC-16), soluble interleukin-2-receptor (IL-R) and the soluble adhesion molecule E-selectin, the intercellular adhesion molecule (ICAM-1) and the vascular adhesion molecule (VCAM-1) were determined in the serum of 195 salt-exposed miners to analyse dose-response relationships between markers and potash dust. Alpha-1-antitrypsin, Clara-cell protein, IL2-R, E-selectin and VCAM-1 were not changed by salt exposure, however the ICAM-1 level in the serum fell slightly as the salt exposure increased. This effect was strongest in the group of smokers, still visible in the group of ex-smokers, no effect was seen in non-smokers. Markers, with the exception of VCAM-1, were influenced by tobacco exposure. Since markers were not elevated in relation to salt dust exposure, the results do not support an inflammatory effect of potash dust on the respiratory system.

Bronchoalveolar lavage fluid cellularity and soluble intercellular adhesion molecule-1 in children with colds

Viral colds are an important cause of respiratory symptoms in normal children. Studies in adults suggest that inflammation in the lower respiratory tract is associated with viral colds, but there are no data regarding inflammation and viral infection in the lower airway of normal children with colds. We, therefore, studied the lower airway of two groups of children: Group I, those with active coryzal symptoms and a respiratory virus isolated from bronchoalveolar lavage fluid (BALF); and Group II: asymptomatic children who had had a clinical cold within the previous 2 weeks and no respiratory virus in BALF. Both groups were compared to age- and weight-matched normal noninfected controls, who had had no coryzal symptoms for at least 8 weeks. Viruses isolated from BALF of Group I (n = 7) were: respiratory syncytial virus (n = 2), rhinovirus (n = 3), parainfluenza I (n = 1), and echovirus 11 (n = 1). Compared to normal controls, Group I had an increased BALF lymphocyte and neutrophil differential count (P < 0.05), a concomitant depressed alveolar macrophage differential count (P < 0.05), and increased BALF concentrations of soluble intercellular adhesion molecule-1 (sICAM-1) (P < 0.05, n = 6), total protein (P < 0.05, n = 6) and albumin (P < 0.05, n = 7). Similar changes were seen in Group II (n = 22), with an increased BALF neutrophil (P < 0.05) and lymphocyte (P < 0.01) differential count, and increased concentrations of sICAM-1 (P < 0.01, n = 15), total protein (P < 0.0001, n = 9) and albumin (P = 0.05, n = 17). Our results suggest that inflammation and viral infection in the lower airway are present during active colds, and that inflammation is also present during the convalescent period.

Role of bronchoscopy in asthma research

Over the past 15 years, much has been learned about the presence of airway inflammation in asthma through the use of investigative bronchoscopy. It has become quite clear that inflammation is present even in mild asthma. In addition to the eosinophils, T-lymphocytes and a variety of cytokines have been identified to play a prominent role in asthmatic inflammation. The concept of delayed asthmatic response after allergen exposure and its relationship to cellular inflammation and airway hyper-reactivity has become more clearly established. Our understanding of asthmatic airway inflammation, however, is incomplete. As interesting as the database has been so far, investigative FB has not defined a unique profile for patients with asthma. Specifically, lavage or endobronchial biopsy has not identified parameters that help in the diagnosis, assessment of disease severity, prognosis, or likelihood to respond to specific therapies. Also, the exact relationship between parameters in lavage compared with mucosal biopsy and how these are related to airway hyper-reactivity and the clinical syndrome of asthma remains poorly understood. In this regard, it must be confessed that currently FB with lavage and biopsy in asthmatics needs to be considered as a research tool for specimen retrieval to help characterize and express inflammation. Although these techniques have contributed immensely to our understanding of asthma pathogenesis, presently these techniques do not have any practical role or clinical usefulness.

Soluble adhesion molecules and cytokines in perennial allergic rhinitis

BACKGROUND

Increasing evidence suggests adhesion molecules and cytokines in patients with inflammatory airway diseases are involved in steps of entrapment and migration of inflammatory cells. Recently, soluble forms of adhesion molecules and cytokines have been detected in the sera and other body fluids of patients with various diseases.

OBJECTIVE

Eosinophilia in nasal mucosa is characteristic of allergic rhinitis. Vascular adhesion molecules expressed on the endothelium are essential for eosinophils to move from the peripheral blood into the sites of inflammation. Herein, soluble forms of vascular adhesion molecules and eosinophil-activating cytokines are measured to investigate the significance of their appearance in the sera with eosinophil infiltration in the nasal mucosa of perennial allergic rhinitis.

METHODS

With the quantitative sandwich enzyme immunoassay technique, the sera of 36 patients of perennial allergic rhinitis and 20 nonatopic subjects were used to measure the levels of soluble intercellular adhesion molecule-1 (sICAM-1), vascular cell adhesion molecule-1 (sVCAM-1), E-selectin (endothelial leukocyte adhesion molecule-1, sELAM-1), interleukin-3 (IL-3), and interleukin-5 (IL-5).

RESULTS

No significant differences in the levels of soluble vascular adhesion molecules were noted between the two groups. Eosinophil-activating cytokines, IL-3 and IL-5, were significantly increased in the group with perennial allergic rhinitis, and were correlated with eosinophil infiltration in nasal scrapings.

CONCLUSION

Although the vascular adhesion molecules expressed on the endothelium are necessary for eosinophils to appear in allergic tissues, eosinophil-activating cytokines as IL-3 and IL-5 are likely to be essential for eosinophils to function in tissues. The elevated concentrations of IL-3 and IL-5 in allergic rhinitis may reflect the inflammatory response occurring in the T cell activation and in relation to manifestation of eosinophils.

Circulating adhesion molecules in cystic fibrosis

A marked influx of inflammatory cells occurs into the airways of patients with cystic fibrosis (CF), which may contribute to the development of lung injury. Leukocyte-endothelial adhesion molecules play a crucial role in the recruitment of inflammatory cells, and soluble forms of these molecules have been shown to increase in several inflammatory diseases. By using a capture ELISA, we determined serum levels of soluble ICAM-1 (sICAM-1), E-selectin (sE-selectin), and VCAM-1 (sVCAM-1) in patients with CF, in stable clinical conditions (n = 29, mean age: 25.8+/-1.5 yr), and healthy control subjects (n = 12, mean age: 27.6+/-1.5 yr). Clinical, spirometric, microbiological, and hematological assessments were made in all subjects. sICAM-1 and sE-selectin concentrations, but not sVCAM-1 levels were significantly increased in CF patients as compared with normal subjects (both p < 0.001). sICAM-1 levels were inversely related to FEV1 values (r = -0.519, p = 0.004) and Schwachman score (r = -0.405, p = 0.03) in CF patients. In 7 of 29 CF patients, soluble adhesion molecule levels were determined not only at the time of stable clinical conditions, but also before and after antibiotic treatment for a pulmonary exacerbation. sICAM-1 and sE-selectin levels increased in all patients at the time of the exacerbation, compared with levels at the time of stable conditions (p < 0.02 for both comparisons); antibiotic treatment induced a significant decrease of both circulating adhesion molecules (p < 0.02). The elevated serum levels of sICAM-1 and sE-selectin in CF patients, even when they are clinically stable, may reflect the marked and persistent inflammatory process in the disease.

Pharmacological modulation of cell adhesion molecules

Cell adhesion molecules mediate the contact between two cells or between cells and the extracellular matrix. They are essential for morphogenesis, organization of tissues and organs, regulation of immune cell responses and migration of inflammatory cells from the blood vessels into inflamed tissues. Many diseases have been shown to be associated with dysfunction or with overexpression of certain adhesion molecules. Increased cell adhesion molecule function and number are found in clinical disorders in which inflammation and immune cells are involved. Several possible therapeutic agents are described here which have been shown to reduce the expression and/or function of cell adhesion molecules. Anti-adhesion treatment can lead to diminished infiltration and activation of inflammatory immune cells resulting in decreased tissue injury and malfunction.

Involvement of intercellular adhesion molecule-1 in the antigen-induced infiltration of eosinophils and lymphocytes into the airways in a murine model of pulmonary inflammation

We investigated the effects of in vivo intraperitoneal treatment with the rat monoclonal antibody (mAb), YN1.7.4 (YN1) against intercellular adhesion molecule-1 (ICAM-1) on the ovalbumin (OA)-inhalation-induced infiltration of leukocytes into the airways of OA-sensitized mice. YN1 (100 to 400 microg) given over a period of 72 h dose-dependently reduced the influx of lymphocytes and eosinophils into the bronchial lumen by > 60% and > or = 70%, respectively, when compared with saline or purified rat IgG-treated controls. Alveolar macrophages (AM) in the bronchoalveolar lavage fluid (BALF) were also decreased by > 50%. Lung tissue inflammation as determined by histopathologic examination was reduced. The number of neutrophils in the blood of OA-sensitized mice 3 days after challenge was significantly increased by treatment with YN1. However, at 24 h and 72 h after OA-challenge, the numbers of eosinophils and mononuclear cells in the bone marrow were reduced by YN1 treatment. Additionally, at 72 h after OA-challenge, the numbers of bone-marrow neutrophils were depressed. BALF levels of interleukin-5 (IL-5) and of IgA were lower for YN1-treated mice than for controls. With increasing doses of YN1, the levels of anti-ICAM-1 mAb in the plasma were proportionally increased. To correlate these results with YN1 treatment, blood and BALF T cells and BALF eosinophils were examined with flow cytometry. Blood T cells from YN1-treated mice were unable to bind phycoerythrin (PE)-labeled anti-ICAM- mAb ex vivo. These results implied that ICAM-1 on these cells was bound (occupied) by YN1 administered in vivo. Dose-related decreases were observed in the percentage and mean channel fluorescence (MCF) values of ICAM-1+ BALF T cells and eosinophils. The percentages of CD11a+ or CD49d+ eosinophils were also suppressed. Our data suggest that ICAM-1 is an important molecule involved in the recruitment of leukocytes into the airways of sensitized mice after pulmonary challenge.

Skin sensitivity to allergen does not accurately predict airway response to allergen

BACKGROUND

Allergen challenge of the asthmatic airway has become widely applied in the study of allergic asthma in humans. Skin sensitivity correlates with inhaled sensitivity in some populations. Skin test titration has been proposed as a useful tool to guide the selection of initial allergen concentration.

OBJECTIVE

To determine the relationship between skin test sensitivity and inhaled reactivity to allergen.

METHODS

We examined the relationship between skin test and inhaled reactivity in 22 allergic asthmatic subjects. Methacholine bronchoprovocation was performed using a standardized tidal breathing technique. Prick skin test titrations were done using serially diluted lyophilized antigen extracts reconstituted in normal saline from 1:100,000 to 1:10. Inhaled allergen challenge was routinely performed in the morning using the same allergen employed in skin test titration.

RESULTS

There was no correlation between skin test threshold and the inhaled concentration required to produce a 20% fall in FEV1 (r = 0.07; P = .78). If subjects who manifested marked cutaneous reactivity (i.e., skin reactivity at dilutions greater than 1:10,000) were excluded from analysis, there was a significant correlation between cutaneous and inhaled reactivity (r = 0.84; P < .001).

CONCLUSION

While a correlation between skin test threshold and inhaled reactivity is present in some subjects with allergic asthma, the relationship is inconsistent.

Serum levels of specific IgE, soluble interleukin-2 receptor, and soluble intercellular adhesion molecule-1 in seasonal allergic rhinitis

BACKGROUND

There is increasing evidence that soluble interleukin-2 receptor (sIL-2R) might reflect T cell activation in vivo and soluble intercellular adhesion molecule-1 (sICAM-1) might reflect the ongoing inflammatory response in the inflamed site.

OBJECTIVE

The aim of this study was to determine the effect of antihistamine tablets and allergen-specific immunotherapy on the seasonal changes in specific IgE, sIL-2R, and sICAM-1 in the serum of patients with seasonal allergic rhinitis.

METHODS

This prospective study included 99 patients with seasonal allergic rhinitis due to Japanese cedar pollens and 27 nonatopic healthy volunteers. The patients were divided into an antihistamine-treated group and an immunotherapy group. Serum samples were collected before and during the pollen season from each patient to determine specific IgE, sIL-2R, and sICAM-1.

RESULTS

Levels of sIL-2R before the pollen season did not differ significantly among the nonatopic group, the antihistamine-treated group, and the immunotherapy group. The levels of sICAM-1 before the pollen season were significantly higher in the antihistamine-treated group and in the immunotherapy group than in the nonatopic group. Seasonal increase in specific IgE was significant in the antihistamine-treated group regardless of their clinical outcomes. In contrast, significant increase in specific IgE was observed during the pollen season in poor responders but not in good responders to immunotherapy. Serum levels of sIL-2R and sICAM-1 were significantly increased during the pollen season in poor responders of the antihistamine-treated group and the immunotherapy group. On the other hand, neither seasonal increase in sIL-2R nor sICAM-1 was significant in good responders of the antihistamine-treated group and the immunotherapy group.

CONCLUSIONS

Serum levels of sICAM-1 are higher in patients with seasonal allergic rhinitis, even outside of the pollen season when the allergen does not naturally exist. Seasonal changes in serum sICAM-1 as well as sIL-2R and specific IgE are probably objective markers to indicate the clinical efficacy of antihistamines and immunotherapy on seasonal allergic rhinitis.

Soluble intercellular adhesion molecule-1 level in sera is elevated in perennial allergic rhinitis

Soluble intercellular adhesion molecule-1 (sICAM-1) in sera was measured in some allergic disorders, but serum sICAM-1 levels in perennial allergic rhinitis remain to be determined. Our study was aimed at elucidating whether the serum sICAM-1 levels in patients with perennial allergic rhinitis are different from those in nonatopic healthy volunteers and whether immunotherapy can modulate sICAM-1 levels. Serum sICAM-1 was determined in 20 nonallergic volunteers and 137 patients with perennial allergic rhinitis by a sandwich enzyme-linked immunosorbent assay. Our study demonstrated that the level of sICAM-1 in untreated patients is significantly elevated, as compared with nonatopic subjects. Immunotherapy could decrease sICAM-1 in perennial allergic rhinitis, but this suppressive effect became apparent only after many years of immunotherapy. In patients on immunotherapy, a close correlation was observed between sICAM-1 and nasal symptom scores. To take these lines of evidence together, a decrease in sICAM-1 might be related to the working mechanism of immunotherapy, and serum sICAM-1 could be used to monitor the effect of immunotherapy.

Subthreshold hyperoxia potentiates TNF-alpha-induced ICAM-1 expression on cultured pulmonary microvascular endothelial cells

The effects of combined exposure to subthreshold hyperoxia and the inflammatory cytokine tumor necrosis factor alpha (TNF-alpha) on the expression of intercellular adhesion molecule-1 (ICAM-1) were examined in bovine lung microvascular endothelial cells (BLuEC). The expression of total ICAM-1 was not affected by 50% hyperoxia conditions alone, indicating that this level is subthreshold for BLuEC. In the presence of 5 ng/mL TNF-alpha, which has minimal influence on BLuEC alone, the amount of total ICAM-1 expression under 50% hyperoxia was higher than that in normoxic conditions (approximately 30%) throughout the culture period. The amount of soluble ICAM-1 that has been released into the culture medium increased after joint exposure to hyperoxia and TNF-alpha. These results suggest that exposure to subthreshold hyperoxia, which does not by itself cause damage to the endothelial cells or induce ICAM-1 expression, potentiates the effects of low-level TNF-alpha exposure.

BAL neutrophilia in asthmatic patients. A by-product of eosinophil recruitment?

Although neutrophil number may be increased in the airways of patients with asthma, its pathogenetic role in this disorder remains unclear. We evaluated BAL of 8 normal control subjects, 30 +/- 2 years of age, and 24 patients with mild asthma: 17 patients with allergic asthma, 24 +/- 1 years of age, and 7 patients with nonallergic asthma, 30 +/- 1 years of age. The BAL of asthmatic patients showed increased numbers of neutrophils (p < 0.01), eosinophils (p < 0.01), and ciliated epithelial cells (p < 0.05) and increased concentrations of myeloperoxidase (MPO) (p < 0.01) compared with control subjects. Positive correlations were observed between the number of BAL neutrophils and eosinophils (Rs = 0.780, p < 0.0001) and between BAL neutrophil numbers and BAL MPO levels (Rs = 0.40, p < 0.05). No correlations were found between the following: (1) BAL eosinophils or neutrophils and BAL epithelial cells (p > 0.05, each comparison); (2) BAL neutrophils or eosinophils and log Pd15 methacholine (MCh) (p > 0.05, each comparison); or (3) BAL epithelial cells or log Pd15 MCh and BAL MPO (p > 0.05, each comparison). Dividing the patient population into two groups, allergic asthmatics and nonallergic asthmatics, similar BAL neutrophil, eosinophil, and epithelial cell numbers and similar MPO levels were found (p > 0.05, each comparison). In addition, the correlations between BAL neutrophils and eosinophils showed similar significance in the two patient subgroups (p > 0.05, each comparison). These results suggest that, both in allergic and nonallergic asthma, airway recruitment and activation of neutrophils occur as does parallel eosinophil migration. However, airway neutrophils do not seem to contribute significantly to epithelial cell injury or to airway hyperresponsiveness in the steady state.

Role of the adhesion molecule ICAM-1 in asthma

Cells need to interact with one another for the inflammatory response to occur. The intercellular adhesion molecule-1 (ICAM-1), a member of the immunoglobulin supergene family, plays an important role in inflammation, and circulating ICAM-1 has been reported to be elevated in patients with some inflammatory disorders. To study the influence of asthma on circulating ICAM-1 levels, we measured concentrations of circulating ICAM-1 in patients with asthma. Fifteen patients (6 male, 9 female, mean age: 30 +/- 7 years) and 5 controls (2 male, 3 female, mean age: 25 +/- 6 years) were included in the study. Daily peak flow rates and symptom scores were monitored over a week in all patients and methacholine challenge tests were performed in 7 patients. The spirometric analysis of asthmatic patients demonstrated mean FEV1: 2.57 +/- 0.97 L (74.9 +/- 17.7% predicted), mean FEV1/FVC: 70.1 +/- 9.6%, mean bronchodilator response: 19.2 +/- 8.4%. The mean morning peak flow rate was 331.0 +/- 122.2 L/min, the mean evening peak flow rate 389.0 +/- 118.5 L/min, the mean peripheral eosinophil count 268 +/- 451/mm3, and the mean serum IgE level 327.4 +/- 238.2 IU/ml. The mean serum ICAM-1 levels of asthmatic patients and controls were 429 +/- 133 ng/ml and 405.0 +/- 81.0 ng/ml, respectively. There was no statistical difference between these levels. Furthermore, we could find no correlation between serum ICAM-1 levels and FEV1, serum IgE levels, peak flow rates, and symptom scores, or methacholine PD20 values in asthmatic patients. The results of this study suggest that serum ICAM-1 levels are not increased in asthmatic patients over controls and do not correlate with clinical asthma status.