Vm. Keatings et al., LATE RESPONSE TO ALLERGEN IS ASSOCIATED WITH INCREASED CONCENTRATIONSOF TUMOR-NECROSIS-FACTOR-ALPHA AND IL-5 IN INDUCED SPUTUM, Journal of allergy and clinical immunology, 99(5), 1997, pp. 693-698
Bronchial antigen challenge of sensitized atopic patients with asthma
results in an early fall in FEV1, followed in a proportion of patients
by a late (4 to 24 hours) fall, The Late response is accompanied by a
n increase in bronchial reactivity, which is widely believed to reflec
t local influx and degranulation of inflammatory cells, particularly e
osinophils, in association with elevated local secretion of cytokines,
We hypothesized that the development of a late-phase bronchoconstrict
or response and airway eosinophilia after allergen challenge of sensit
ized atopic patients with asthma is associated with elevated induced s
putum concentrations of the eosinophil-active cytokines IL-5 and granu
locyte-macrophage colony-stimulating factor and the proinflammatory cy
tokine tumor necrosis factor-alpha, We counted inflammatory leukocytes
and measured cytokine concentrations in induced sputum at baseline an
d 24 hours after inhalational allergen challenge of 15 atopic patients
with asthma who had previously demonstrated a late response, We obser
ved significant increases in the numbers of eosinophils and the concen
trations of their granule products, eosinophil cationic protein and eo
sinophil peroxidase, In contrast, the numbers of neutrophils and conce
ntrations of two of their products, myeloperoxidase and human neutroph
il lipocalin, did not significantly change, The numbers of sputum eosi
nophils correlated with the maximal late-phase fall in FEV1, Concentra
tions of IL-5 and tumor necrosis factor-alpha, but not granulocyte-mac
rophage colony-stimulating factor, were significantly elevated after a
llergen challenge, We conclude that the relatively noninvasive techniq
ue of induced sputum production can be used to monitor the effect of b
ronchial provocation on cytokine concentrations in asthma.