Background: Chronic inflammation with tissue eosinophilia plays a key role in the pathogenesis of asthma and nasal polyps in patients with aspirin hypersensitivity.
Objective: To evaluate the expression of vascular cell adhesion molecule 1 (VCAM-1) and intercellular adhesion molecule I (ICAM-1) and their ligands (the integrins lymphocyte function-associated antigen 1 and very late-activation antigen 4 [VLA-4]) in nasal polyps of patients with aspirin hypersensitivity compared with aspirin-tolerant individuals.
Methods: Immunohistochemical studies were performed using a peroxidase method and monoclonal antibodies on 6-microm-thick cryostat sections cut from frozen polyps collected during elective surgery from 21 aspirin-sensitive and 23 aspirin-tolerant patients.
Results: The mean +/- SD values of the semiquantitatively evaluated immunoexpression of ICAM-1, VCAM-1, and VLA-4 were significantly increased in patients with aspirin hypersensitivity compared with aspirin-tolerant patients (1.7 +/- 0.8 vs 0.9 +/- 0.8, P < .003; 1.8 +/- 0.8 vs 0.8 +/- 0.8, P < .001; and 2.2 +/- 0.7 vs 1.3 +/- 0.7, P < .001, respectively), whereas the mean +/- SD values of the expression of lymphocyte function-associated antigen 1 did not differ significantly (2.4 +/- 0.5 vs 2.2 +/- 0.9; P = .57). We found a correlation between the immunoexpression of VCAM-1 and its ligand VLA-4 in all studied tissue samples (r = 0.4; P < .02).
Conclusions: In nasal polyps of aspirin-hypersensitive patients, up-regulation of the adhesion molecules ICAM-1 and VCAM-1 and the integrin VLA-4 may play an important role in the development of chronic eosinophilic inflammation.