A S Jang1, I S Choi, S Lee, J P Seo, S W Yang, C S Park. 1. Department of Internal Medicine, Seonam University College of Medicine, Seogu Marukdong 120-1, Kwangju, Korea 502-157. jas877@chollian.net
Abstract
BACKGROUND: Eosinophils play a pivotal role in asthmatic airway inflammation. Apoptosis is thought to be critically relevant in promoting the clearance of inflammatory cells and the resolution of inflammation. Bcl-2 inhibits apoptosis in cellular systems. A study was undertaken to determine whether bcl-2 expression in sputum reflects the clinical severity of patients with asthma. The relationship between bcl-2 expression in sputum eosinophils and eosinophil activation markers such as interleukin (IL)-5 and eosinophil cationic protein (ECP) levels in sputum supernatant was evaluated. METHODS: Sputum was obtained from 18 patients with asthma. Fresh expectorated sputum separated from saliva was treated with an equal volume of dithiothreitol 0.1%, cytospun for cell differentials and bcl-2 stain, and the supernatant was collected for biochemical assay. Bcl-2+ eosinophils were stained using immunocytochemistry, ECP was measured by fluoroimmunoassay, and IL-5 was detected by sandwich enzyme linked immunosorbant assay. RESULTS: Twelve patients with severe or life threatening asthma had more bcl-2+ eosinophils (mean difference 46.8% (95% CI 27.0 to 66.6), p<0.01) and a higher ECP level (p<0.01) in the sputum than those with mild to moderate asthma (n = 6). IL-5 was frequently detected in patients with severe or life threatening asthma (11/12 versus 1/6, p<0.01). There was a significant positive correlation between bcl-2+ eosinophils and ECP levels (r = 0.61, p<0.01) and between bcl-2+ eosinophils and IL-5 levels (r = 0.83, p<0.01). There was a significant negative correlation between bcl-2+ eosinophils and FEV(1)/FVC (r = -0.54, p<0.05). CONCLUSION: The increased expression of bcl-2 in eosinophils from sputum of subjects with severe asthma suggests that bcl-2 may prolong survival and decrease apoptosis of airway eosinophils in asthma.
BACKGROUND: Eosinophils play a pivotal role in asthmatic airway inflammation. Apoptosis is thought to be critically relevant in promoting the clearance of inflammatory cells and the resolution of inflammation. Bcl-2 inhibits apoptosis in cellular systems. A study was undertaken to determine whether bcl-2 expression in sputum reflects the clinical severity of patients with asthma. The relationship between bcl-2 expression in sputum eosinophils and eosinophil activation markers such as interleukin (IL)-5 and eosinophil cationic protein (ECP) levels in sputum supernatant was evaluated. METHODS: Sputum was obtained from 18 patients with asthma. Fresh expectorated sputum separated from saliva was treated with an equal volume of dithiothreitol 0.1%, cytospun for cell differentials and bcl-2 stain, and the supernatant was collected for biochemical assay. Bcl-2+ eosinophils were stained using immunocytochemistry, ECP was measured by fluoroimmunoassay, and IL-5 was detected by sandwich enzyme linked immunosorbant assay. RESULTS: Twelve patients with severe or life threatening asthma had more bcl-2+ eosinophils (mean difference 46.8% (95% CI 27.0 to 66.6), p<0.01) and a higher ECP level (p<0.01) in the sputum than those with mild to moderate asthma (n = 6). IL-5 was frequently detected in patients with severe or life threatening asthma (11/12 versus 1/6, p<0.01). There was a significant positive correlation between bcl-2+ eosinophils and ECP levels (r = 0.61, p<0.01) and between bcl-2+ eosinophils and IL-5 levels (r = 0.83, p<0.01). There was a significant negative correlation between bcl-2+ eosinophils and FEV(1)/FVC (r = -0.54, p<0.05). CONCLUSION: The increased expression of bcl-2 in eosinophils from sputum of subjects with severe asthma suggests that bcl-2 may prolong survival and decrease apoptosis of airway eosinophils in asthma.
Authors: H Chai; R S Farr; L A Froehlich; D A Mathison; J A McLean; R R Rosenthal; A L Sheffer; S L Spector; R G Townley Journal: J Allergy Clin Immunol Date: 1975-10 Impact factor: 10.793
Authors: A M Vignola; P Chanez; G Chiappara; L Siena; A Merendino; C Reina; R Gagliardo; M Profita; J Bousquet; G Bonsignore Journal: J Allergy Clin Immunol Date: 1999-04 Impact factor: 10.793
Authors: K Ogawa; R Hashida; M Miyagawa; S Kagaya; Y Sugita; K Matsumoto; T Katsunuma; A Akasawa; G Tsujimoto; H Saito Journal: Clin Exp Immunol Date: 2003-03 Impact factor: 4.330