Am. J. Respir. Crit. Care Med., Vol 154, No. 6, Dec 1996, 1615-1622.
Seasonal comparison of cytokine profiles in atopic asthmatics and atopic non-asthmatics
C Tang, IM Rolland, C Ward, R Bish, F Thien and EH Walters
Department of Respiratory Medicine, Alfred Hospital, Melbourne, Victoria, Australia.
Previous studies have suggested that peripheral blood T cell cytokine
release may reflect the situation in the bronchial mucosa in atopic
asthmatics. We have therefore examined spontaneous, rye grass pollen-
stimulated, and PHA-stimulated secretion of IL-2, IL-4, IL-5, and IFN-
gamma in cultures of peripheral blood mononuclear cells (PBMC) from atopic
asthmatic, atopic non-asthmatic and normal controls in and out of the rye
grass pollen season. Compared to normal controls, both atopic groups showed
higher IL-2 and IL-5 production (p < 0.01 and p < 0.05) and higher
percentages of CD4 cells expressing CD25 and HLA-DR (p < 0.05) in
response to rye grass pollen, elevated IL-4 production in response to PHA
(p < 0.01), and a non-significant trend towards lower IFN-gamma
production. However, the capacity of PBMC from atopic asthmatics to produce
IL-5 was greater than that for atopic non- asthmatics (p < 0.05).
Furthermore, seasonal changes in symptom score, FEV1 % predicted, and PD20
methacholine correlated with seasonal elevated production of IL-5 by PBMC
in the asthmatic group (r = 0.862, - 0.679, and -0.620; p < 0.01, 0.02,
and 0.05, respectively). Our results suggest that elevated production of
IL-2 and IL-4 and higher percentages of activated CD4 T cells are
associated with atopy per se, but elevated production of IL-5 also relates
to the clinical expression of atopic asthma.
