[Role of intra cellular adhesion molecule-1 (ICAM-1) and its soluble form (sICAM) in chronic airway inflammation]

Abstract

Mucosal inflammation is the feature of both bronchial asthma and allergic rhinitis with evident of tissue eosinophilia, mast cells, eosinophils and T-lymphocytes activation. The initial phase of cell recruitment is the margination and adhesion of leucocytes to the endothelium, prior to their transendothelial migration under a directed chemotactic stimulus. This adhesion occurs through specific ligand-receptor couplets involving leucocyte-endothelial adhesion molecules. One of these cell adhesion molecules is ICAM-1, an important early marker of immune activation and response. Its ligand, leukocyte function-associated antigen one (LFA-1) is expressed on neutrophils, eosinophils and T-cells. ICAM-1 was found to be expressed on epithelial and endothelial cells in rhinitis patients and in bronchial biopsies obtained from asthmatics also after allergen challenge. Circulating forms of these adhesion molecules have been identified in the peripheral blood, bronchoalveolar lavage (BAL) fluid and nasal lavage in patients with asthma and rhinitis. Systemic and local up-regulation of sICAM-1 suggests a function role for this soluble form of ICAM in the allergic inflammation.