Interleukin-5 upregulates intercellular adhesion molecule-1 gene expression in the nasal mucosa in nasal allergy but not in nonallergic rhinitis

Nasal hyperreactivity and inflammation in allergic rhinitis

The history of allergic disease goes back to 1819, when Bostock described his own 'periodical affection of the eyes and chest', which he called 'summer catarrh'. Since they thought it was produced by the effluvium of new hay, this condition was also called hay fever. Later, in 1873, Blackley established that pollen played an important role in the causation of hay fever. Nowadays, the definition of allergy is 'An untoward physiologic event mediated by a variety of different immunologic reactions'. In this review, the term allergy will be restricted to the IgE-dependent reactions. The most important clinical manifestations of IgE-dependent reactions are allergic conjunctivitis, allergic rhinitis, allergic asthma and atopic dermatitis. However, this review will be restricted to allergic rhinitis. The histopathological features of allergic inflammation involve an increase in blood flow and vascular permeability, leading to plasma exudation and the formation of oedema. In addition, a cascade of events occurs which involves a variety of inflammatory cells. These inflammatory cells migrate under the influence of chemotactic agents to the site of injury and induce the process of repair. Several types of inflammatory cells have been implicated in the pathogenesis of allergic rhinitis. After specific or nonspecific stimuli, inflammatory mediators are generated from cells normally found in the nose, such as mast cells, antigen-presenting cells and epithelial cells (primary effector cells) and from cells recruited into the nose, such as basophils, eosinophils, lymphocytes, platelets and neutrophils (secondary effector cells). This review describes the identification of each of the inflammatory cells and their mediators which play a role in the perennial allergic processes in the nose of rhinitis patients.

Inflammatory mediators and eosinophilia in atopic and non-atopic patients with nasal polyposis

Nasal polyps are characterized by eosinophilic infiltration and presence of inflammatory mediators, such as total IgE, eosinophil cationic protein (ECP) and cytokines. The role of atopy in nasal polyp pathogenesis is still unclear. Therefore, we evaluated serum IgE levels, nasal mucus concentrations of ECP and cytokines and the number of infiltrating eosinophils in nasal tissue of polyps from atopic and non-atopic patients. Samples were obtained from a randomized population of 31 patients with nasal polyposis having endonasal sinus surgery and of 13 control subjects undergone corrective surgery of the nasal septum. On the basis of medical history of allergy, positive skin-prick tests and total IgE levels, patients with polyposis were divided in atopic (n = 13) and non-atopic (n = 18) patients. We determined levels of IgE in blood, ECP and cytokines (IL-4, IL-6, IL-8, IFN-gamma and IL-2) in nasal mucus, and number of infiltrating eosinophils in nasal tissue. The concentrations of total IgE, ECP, IL-4 and IL-8 and eosinophilia were significantly higher in all patients with nasal polyps compared with controls. Inside, all patients with nasal polyposis showed lower levels of IL-6, IFN-gamma and IL-2 compared with controls. The atopic patients showed significant differences when compared with non-atopic patients for the higher concentrations of total IgE (698.80+/-322.24 vs. 279.63+/-234.11; P < 0.0001) and IL-8 (1437.2 pg/ml+/-1250.7 vs. 605.5 pg/ml+/-481.1; P < 0.015). These findings suggest that inflammation still remains the major factor in the etiology of nasal polyposis and show different levels of inflammatory mediators into atopic and non-atopic patients.

Nasal polyposis and allergy: is there a correlation?

Nasal polyposis (NP) is a chronic inflammatory disease of the nasal mucosa. The etiology and formation of NP are still not elucidated and have been debated for many years. The objective of the present study was to investigate the role of nasal allergy in the development of NP. The following aspects were analyzed: age, sex, and patient's symptoms; correlation between asthma, aspirin intolerance, and NP; serum immunoglobulin levels and eosinophilia; and concentration of interleukins 1beta, 3, and 4 in NP. Thirty-nine patients with NP were selected, 13 of them allergic and 26 non-allergic. A control group of 11 individuals was also studied. The concentrations of interleukins 1beta, 3, and 4 were measured by enzyme-linked immunosorbent assay (ELISA). There was a higher incidence of NP after the fourth decade of life and among men. We found no correlation of asthma or aspirin intolerance with the presence or absence of allergy. Serum levels of IgE and eosinophils were significantly higher in patients with allergy and NP and the concentrations of interleukins 3 and 4 were positively correlated with NP. There was no difference in interleukin 3 and 4 concentration between the non-allergic group with NP and the control group, suggesting that these interleukins do not play an important role in the etiology and formation of NP. These results suggest that the immunologic pathway involved in the etiology of NP is differentfrom the one correlated with allergy (IgE-mediated).

A risk-benefit assessment of intranasal triamcinolone acetonide in allergic rhinitis

The efficacy of intranasal triamcinolone acetonide in seasonal and allergic rhinitis has been evaluated in clinical trials and has been compared with antihistamines and other intranasal corticosteroids. Intranasal corticosteroids are either as equally effective as or more effective than comparative drugs. Intranasal corticosteroids are particularly useful as they decrease membrane permeability and inhibit both early and late phase reactions to allergens. They minimise the nasal secretory response and reduce the sensitivity of local nasal irritant receptors. A potential benefit of topical application is the flushing action of the nasal mucosa, which may reduce allergens and secretions. In addition to seasonal and perennial rhinitis, intranasal corticosteroids have additional benefits when used to reduce inflammation in the treatment of sinusitis and may help in decreasing secondary rhinovirus infections. Furthermore, suboptimal control of asthma can be avoided by treatment of allergic rhinitis with intranasal corticosteroids. In clinical trials, common adverse effects for triamcinolone acetonide include sneezing, dry, mucosa, nasal irritation, sinus discomfort, throat discomfort, epistaxis and headache. Posterior subcapsular cataract formation has not been seen with triamcinolone acetonide. Recent literature evaluating systemic absorption of intranasal corticosteroids have shown surprising results where significant absorption has occurred with intranasal budesonide and fluticasone propionate. Growth and hypothalamic pituitary axis (HPA) function studies have been reviewed, with some intranasal corticosteroids showing changes with continual use. A retrospective study in children receiving daily triamcinolone acetonide for 12 months showed no effect on height and bodyweight. Triamcinolone acetonide at standard dosages (110 or 220microg once or twice a day) does not appear to suppress adrenal gland function and is effective in relieving most symptoms of allergic rhinitis. The International Consensus Conference Proceedings on Rhinitis now currently recommends the use of intranasal corticosteroids as first line therapy, since they have been found to be well tolerated and effective with minimal adverse effects and, specifically, no cognitive impairment. The recommended maximum dose of aqueous triamcinolone acetonide in adults and children is 220microg once a day. The aerosol form may be recommended in children between 7 and 12 years old, up to 440microg once a day or in divided doses. Duration of allergy treatment is generally for the length of each allergy season. If symptoms are perennial, then a reduction of dosage is made to the lowest effective dose with monitoring every 3 months for risk and benefit assessment. Complications to watch for include bleeding, and possible septal perforation and nasal candidiasis, although these are rare.

Inhaled IL-5 increases concentrations of soluble intracellular adhesion molecule-1 in sputum from atopic asthmatic subjects

BACKGROUND

Both IL-5 and intracellular adhesion molecule-1 (ICAM-1) have been shown to play important roles in the production of allergic inflammation, including atopic asthma.

OBJECTIVE

The aim of this study was to investigate the effects of recombinant human IL-5 on changes of soluble (s) ICAM-1 concentrations in induced sputum from allergic asthmatic subjects.

METHODS

In a randomized, double-blind, placebo-controlled study design, 8 nonsmoking patients with allergic asthma and 6 nonallergic normal subjects were administered recombinant human IL-5 by nebulization, and the concentrations of sICAM-1 in induced sputum from each subject were determined before and at 2, 24, 48, and 72 hours after inhalation.

RESULTS

sICAM-1 levels in sputum within the control group did not appear to change from baseline at any time throughout the study. In allergic asthmatic subjects vehicle challenge was not able to cause any changes in sputum sICAM-1 concentrations. However, there were increases in sputum sICAM-1 concentrations after IL-5 inhalation, which increased with time to significantly greater levels than those at baseline, reaching a maximum at 48 hours and lasting no less than 72 hours. The concentrations of sICAM-1 in sputum after IL-5 challenge exceeded levels that could be accounted for by passive transudation from the circulation on the basis of the magnitude of increases in sputum albumin concentration.

CONCLUSION

Our results indicated that IL-5 inhalation was capable of inducing an elevation of sputum sICAM-1 concentration by stimulating its local release in allergic asthmatic, but not in nonallergic normal, subjects.

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.