TY - JOUR
T1 - The relationship of sputum eosinophilia and sputum cell generation of IL-5
AU - Liu, Lin Ying
AU - Swensen, Cheri A.
AU - Kelly, Elizabeth A.Becky
AU - Kita, Hirohito
AU - Busse, William W.
N1 - Funding Information:
Supported in part by Astra China (L.Y.L.) and an institutional Specialized Center of Research grant (HL56396) from the National Institutes of Health.
PY - 2000
Y1 - 2000
N2 - Background: Eosinophil recruitment to the airway after antigen challenge is regulated by many factors, including airway cell generation of cytokines. Objectives: The purpose of this study was to determine the relationship between sputum cell generation of IL-5 and the appearance of eosinophils in the sputum after antigen challenge. Method: Sputum samples from 11 allergic subjects were collected before and again 4 and 24 hours after antigen challenge. In 6 of these subjects, induced sputum samples were also obtained 48 hours and 7 days after challenge. Sputum leukocyte differential and cell counts and eosinophil-derived neurotoxin levels were determined. Sputum cells were then cultured with PHA (10 μg/mL) to stimulate IL-5 and IFN-γ, which were measured in culture supernatants. Result: An increase in sputum eosinophils and eosinophil-derived neurotoxin levels was detected at 4 hours after antigen challenge, with peak values at 24 hours. In contrast, significant increases in ex vivo generation of IL-5 by sputum cells was not seen until 24 hours after challenge. At 24 hours, PHA-induced IL-5 correlated with airspace eosinophil values (r(s) = 0.78, P <. 01). In addition, the ratio of IFN-γ/IL-5 decreased at 24 hours (P <. 05) and had an inverse correlation with sputum eosinophils (r(s) = -0.68, P <. 05). Conclusion: Although eosinophils are increased in the airway lumen as early as 4 hours, the ex vivo generation of IL-5 by sputum cells is first noted in samples obtained 24 hours after antigen challenge. This suggests that the early (4 hours) recruitment of eosinophils to the airway lumen may be regulated by factors other than IL-5 or that mucosal cells (rather than airspace cells) contribute to the IL-5 generation at this time point. Furthermore, IL-5 generation by airspace cells may be more responsible for either eosinophil recruitment or retention at later time points.
AB - Background: Eosinophil recruitment to the airway after antigen challenge is regulated by many factors, including airway cell generation of cytokines. Objectives: The purpose of this study was to determine the relationship between sputum cell generation of IL-5 and the appearance of eosinophils in the sputum after antigen challenge. Method: Sputum samples from 11 allergic subjects were collected before and again 4 and 24 hours after antigen challenge. In 6 of these subjects, induced sputum samples were also obtained 48 hours and 7 days after challenge. Sputum leukocyte differential and cell counts and eosinophil-derived neurotoxin levels were determined. Sputum cells were then cultured with PHA (10 μg/mL) to stimulate IL-5 and IFN-γ, which were measured in culture supernatants. Result: An increase in sputum eosinophils and eosinophil-derived neurotoxin levels was detected at 4 hours after antigen challenge, with peak values at 24 hours. In contrast, significant increases in ex vivo generation of IL-5 by sputum cells was not seen until 24 hours after challenge. At 24 hours, PHA-induced IL-5 correlated with airspace eosinophil values (r(s) = 0.78, P <. 01). In addition, the ratio of IFN-γ/IL-5 decreased at 24 hours (P <. 05) and had an inverse correlation with sputum eosinophils (r(s) = -0.68, P <. 05). Conclusion: Although eosinophils are increased in the airway lumen as early as 4 hours, the ex vivo generation of IL-5 by sputum cells is first noted in samples obtained 24 hours after antigen challenge. This suggests that the early (4 hours) recruitment of eosinophils to the airway lumen may be regulated by factors other than IL-5 or that mucosal cells (rather than airspace cells) contribute to the IL-5 generation at this time point. Furthermore, IL-5 generation by airspace cells may be more responsible for either eosinophil recruitment or retention at later time points.
KW - Allergy
KW - Eosinophil IL-5
KW - Sputum induction
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U2 - 10.1067/mai.2000.110792
DO - 10.1067/mai.2000.110792
M3 - Article
C2 - 11112887
AN - SCOPUS:0034538065
SN - 0091-6749
VL - 106
SP - 1063
EP - 1069
JO - Journal of Allergy and Clinical Immunology
JF - Journal of Allergy and Clinical Immunology
IS - 6
ER -