Evidence for systemic rather than pulmonary effects of interleukin-5 administration in asthma.

Abstract

BACKGROUND:

Interleukin 5 (IL-5) has an important role in mobilisation of eosinophils from the bone marrow and in their subsequent terminal differentiation. A study was undertaken to determine whether inhaled and intravenous IL-5 could induce pulmonary eosinophilia and bronchial hyperresponsiveness (BHR) independently of these effects.

METHODS:

Nine mild asthmatics received inhaled (15 microg) or intravenous (2 microg) IL-5 or placebo in random order in a double blind, crossover study. Blood samples were taken before and at 0.5, 1, 2, 3, 4, 5, 24, and 72 hours following IL-5 or placebo, and bronchial responsiveness (PC(20) methacholine) and eosinophil counts in induced sputum were determined.

RESULTS:

Serum IL-5 levels were markedly increased 30 minutes after intravenous IL-5 (p=0.002), and sputum IL-5 levels increased 4 and 24 hours after inhaled IL-5 (p<0.05). Serum eotaxin was raised 24 hours after intravenous IL-5 but not after inhaled IL-5 or placebo. Blood eosinophils were markedly reduced 0.5-2 hours after intravenous IL-5 (p<0.05), followed by an increase at 3, 4, 5, and 72 hours (p<0.05). Sputum eosinophils rose significantly in all three groups at 24 hours but there were no differences between the groups. Bronchial responsiveness was not affected by IL-5.

CONCLUSION:

The effects of IL-5 appear to be mainly in the circulation, inducing peripheral mobilisation of eosinophils to the circulation without any effect on eosinophil mobilisation in the lungs or on bronchial responsiveness.

• Authors: E L van Rensen, R G Stirling, J Scheerens, K Staples, P J Sterk, P J Barnes, K F Chung
• Journal: Thorax (Thorax) Vol. 56 Issue 12 Pg. 935-40 (Dec 2001) ISSN: 0040-6376 [Print] England
• PMID: 11713356 (Publication Type: Clinical Trial, Controlled Clinical Trial, Duplicate Publication, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• CCL11 protein, human
• Chemokine CCL11
• Chemokines, CC
• Interleukin-5

Topics

• Administration, Inhalation
• Adult
• Analysis of Variance
• Asthma (drug therapy, metabolism)
• Bronchial Provocation Tests
• Cell Count
• Chemokine CCL11
• Chemokines, CC (blood)
• Cross-Over Studies
• Double-Blind Method
• Enzyme-Linked Immunosorbent Assay
• Female
• Forced Expiratory Volume
• Humans
• Infusions, Intravenous
• Interleukin-5 (administration & dosage, analysis, pharmacology)
• Male
• Pulmonary Eosinophilia (chemically induced)
• Sputum (cytology)