Differences in MMP-2, MMP-9, TIMP-1, and eosinophil inflammatory markers of nasal polyp homogenates between aspirin intolerant and tolerant asthma

Abstract

BACKGROUND AND OBJECTIVE: Nasal polyps are frequently found in patients with aspirin intolerant asthma (AIA). Matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) are thought to play a crucial role in airway inflammation and remodeling. Eosinophil and mast cell infiltration is a consistent finding in these polyps but few studies have studied the relationship between these cells and protease-antiprotease balance in the nasal polyp tissue of aspirin intolerant asthmatics. Our purpose was to compare the differences of eosinophil cationic protein (ECP), tryptase, MMP-2, MMP-9, and TIMP-1 between aspirin intolerant and tolerant asthmatics (ATA) and also to evaluate the relationship with inflammation in nasal polyp homogenates. MATERIALS AND METHODS: Nasal polyp tissue homogenates from 10 AIA subjects (group I) and 10 ATA subjects (group II) were compared. Inflammatory cell markers such as ECP and tryptase were measured by the CAP system (Pharmacia, Sweden). MMP-2, MMP-9, and TIMP-1 levels were measured by ELISA (Biotrack, UK). RESULTS: ECP levels were significantly higher in group I (p < 0.05) and tryptase levels tended to be higher in group I although it was not significant. MMP-2, followed by MMP-9 and TIMP-1, was the predominant form in both groups. TIMP-1 levels were significantly higher in group I than in group II (p < 0.05). MMP-9 levels tended to be higher in group I, although these differences were not significant (p > 0.05) and no significant differences were noted between MMP-2 levels between the two groups. MMP-9/TIMP-1 ratio was lower in group I than group II although this was not significant, and there were significant correlations between ECP, and MMP-9 (r=0.65, p < 0.05), MMP-2 (r=0.61, p < 0.05), and tryptase (r=0.58, p < 0.05), but not with TIMP-1. Significant correlations were also noted between tryptase, and MMP-9 (r=0.62, p < 0.05), and MMP-2 (r=0.47, p < 0.05), but not with TIMP-1. CONCLUSION: Nasal polyps from AIA patients had more severe eosinophilic inflammation compared to ATA subjects. MMP-9 and MMP-2 may contribute to eosinophil migration and inflammation.