OBJECTIVESTo study the concentration, distribution and expression of IL-5 in nasal polyp tissues and explore its significance in micro-environment differentiation of eosinophil accumulation.

METHODSThe concentration and expression of IL-5 in nasal polyp tissues of 40 patients were determined by ELISA and immunohistochemistry and inferior turbinate mucosa from patients with nasal polyps and healthy volunteers were used as control.

RESULTSIL-5 concentration in polyp tissues was significantly higher than that in turbinate mucosa (P < 0.05). There was no significant difference in the turbinate mucosae between patients with nasal polyps and healthy volunteers (P > 0.05). IL-5 concentrations in polyp tissues were markedly higher in patients with allergic rhinitis compared with those without (P < 0.05). IL-5 concentrations had no correlation with age and sex (P > 0.05). 80.1% of the eosinophils were positive for IL-5 and 90.9% of IL-5 positive cells were eosinophils. Only 3.7% of lymphocytes and neutrophils were positive for IL-5; IL-5 was not detectable in epithelial cells. IL-5 expression in eosinophils of polyp tissues was remarkably stronger than that of the turbinate mucosa (P < 0.05); there was no significant difference in the the turbinate mucosae between patients with nasal polyps and healthy volunteers (P > 0.05). IL-5 expression of eosinophils in polyp tissue was significantly stronger in patients with allergic rhinitis compared with those without (P < 0.05). There was no significant difference in IL-5 expression in lymphocytes and neutrophils between polyp tissues and turbinate nasal mucosa (both P > 0.05).

CONCLUSIONIL-5 is the key cytokine in eosinophilic pathologic mechanisms in nasal polyp tissues.

Adult ; Enzyme-Linked Immunosorbent Assay ; Eosinophils ; chemistry ; Female ; Humans ; Interleukin-5 ; analysis ; Lymphocytes ; chemistry ; Male ; Middle Aged ; Nasal Mucosa ; chemistry ; Nasal Polyps ; immunology ; Turbinates ; chemistry

Eosinophil and mast cell infiltrations are consistent findings in nasal polyp tissue. Previous studies have shown that matrix metalloproteinases (MMPs) may be involved in eosinophil infiltration in airway mucosa of asthmatic patients, and that transforming growth factor-beta1 (TGF-beta1) induces extracellular matrix deposition in nasal polyp tissue. The aim of this study was to evaluate the role of MMPs and tissue-inhibitor of metalloproteinase-1 (TIMP-1) in association with TGF-beta1, eosinophils and mast cell activation in nasal polyp tissue. Nasal polyp tissues from 20 patients who underwent polypectomies were collected and prepared into tissue homogenate. Eosinophil cationic protein (ECP) and tryptase levels were measured by CAP system (Pharmacia, Sweden). MMP-2, MMP-9, TIMP-1 and TGF-beta1 levels were measured by enzyme-liked immunosorbent assay. MMP-2 was the predominant form of MMPs, followed by MMP-9 and TIMP-1. There were significant correlations between ECP, and MMP-9, MMP-2, TGF-beta1 and tryptase, but not with TIMP-1. Significant correlations were noted between tryptase, and MMP-2, MMP-9, and TGF-beta1, but not with TIMP-1. Close correlations were noted between TGF-beta1, and MMP-9 and MMP-2, but not with TIMP-1. MMP-2, MMP-9, and TGF-beta1 may contribute to eosinophil and mast cell migrations into nasal polyp tissue.
Adult ; Asthma/complications ; Blood Proteins/analysis ; Chemotaxis, Leukocyte ; Eosinophilia/etiology ; Eosinophilia/metabolism* ; Eosinophilia/pathology ; Eosinophils/physiology ; Female ; Gelatinase A/analysis ; Gelatinase A/physiology* ; Gelatinase B/analysis ; Gelatinase B/physiology* ; Human ; Male ; Mast Cells/physiology ; Middle Aged ; Nasal Polyps/chemistry* ; Nasal Polyps/etiology ; Nasal Polyps/pathology ; Rhinitis/metabolism ; Rhinitis/pathology ; Ribonucleases* ; Serine Endopeptidases/analysis ; Tissue-Inhibitor of Metalloproteinase-1/analysis ; Tissue-Inhibitor of Metalloproteinase-1/physiology* ; Transforming Growth Factor beta/analysis ; Transforming Growth Factor beta/physiology*

Adult ; Aged ; Endothelial Growth Factors ; analysis ; physiology ; Female ; Humans ; Intercellular Signaling Peptides and Proteins ; analysis ; physiology ; Lymphokines ; analysis ; physiology ; Male ; Middle Aged ; Nasal Polyps ; chemistry ; etiology ; Vascular Endothelial Growth Factor A ; Vascular Endothelial Growth Factor Receptor-2 ; analysis ; Vascular Endothelial Growth Factors