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CD11B EXPRESSION IN THE AIRWAY IS ASSOCIATED WITH ASTHMA SEVERITY, AIRWAY INFLAMMATION, AND REDUCED PERCENTAGE OF CD-54POSITIVE BLOOD LYMPHOCYTES IN ASTHMATICS
Citation:
Yeatts, K. B., E. Svendsen, N. E. Alexis, W. Reed, S. Harder, J. Lay, P A. Bromberg, L Neas, AND R B. Devlin. CD11B EXPRESSION IN THE AIRWAY IS ASSOCIATED WITH ASTHMA SEVERITY, AIRWAY INFLAMMATION, AND REDUCED PERCENTAGE OF CD-54POSITIVE BLOOD LYMPHOCYTES IN ASTHMATICS. Presented at American Thoracic Society Annual Conference, San Diego, CA, March 20 - 25, 2005.
Description:
CD11b and its counter receptor CD54 (ICAM-1) are both essential for migration of blood monocytes and neutrophils into tissues in response to inflammatory stimuli. Methods: Forty induced sputum and peripheral blood samples were taken over a six week period from nine atopic adults with persistent asthma. Lung function (FEV1) was measured at each clinic visit. CD11b and CD54 expression were measured by flow cytometry on both airway and peripheral blood leukocytes and expressed as mean fluorescent intensity (MFI) and % positive cells, respectively. Results: Percent predicted FEV1 tended to be negatively correlated with CD11b expression on sputum monocytes (r= -.30, p=.046), and macrophages (r= -0.25, p=.094). Percent sputum neutrophils was positively correlated with CD11b expression on airway macrophages (R = 0.42, p=0.005) and neutrophils (R = 0.33, p=0.03). The percentage of CD54 positive blood lymphocytes was negatively correlated with CD11b expression on both airway monocytes, (R= -0.54, p=.0003) and neutrophils (R= - 0.48, p=.002). Conclusion: CD11b expression on airway macrophages and neutrophils is associated with markers of asthma severity (percent predicted FEV1) and airways neutrophilia. The intensity of chronic inflammation of the airways is associated with a reduced percentage of CD54-positive lymphocytes in the blood. The negative association between CD11b on airway cells and CD54 expression on blood lymphocytes, suggests that CD11b may play a role in signaling leukocyte influx to sites of allergic inflammation in the airways. These findings do not necessarily represent EPA policy. Funding: EPA Cooperative Agreement 829522.