T-cell cytokine profiles are altered in childhood asthma exacerbation.
OBJECTIVE
Stable asthma is characterized by the production of Th2 cytokines, although Th1 cytokines may play a key role in aspects such as airway hyper-responsiveness. This study explored cytokine profiles associated with asthma exacerbation.


METHODS
Intracellular T-cell cytokine production was measured in 16 children with acute severe asthma (emergency department), after convalescence (6 weeks, n = 13), with stable disease (after 6 months, n = 7) and in 14 age-matched hospital controls. Flow cytometry was used to identify CD4+ and CD8+ cells and to quantify intracellular T-cell production of the cytokines interferon (IFN)-gamma, IL-4 and IL-13. Cytokine production was compared using analysis of variance and random-effects generalized linear models and associations were examined using Pearson's correlation.


RESULTS
Cytokine production was evident in CD4+ and CD8+ cells, and compared with asthmatic children, non-asthmatics had a higher percentage of IFN-gamma+CD4+ cells (P = 0.01). The percentage of CD8+IFN-gamma+ cells was increased in the convalescent phase compared with acute (P = 0.009) and stable asthma (P = 0.004). IL-4+ cells were not significantly altered. IL-13 levels were higher in acute disease than in stable asthma (P = 0.009 in CD4+ cells) and IFN-gamma/IL-13 ratios indicated a Th2 profile during exacerbation (P = 0.005 in CD4+ cells).


CONCLUSIONS
IL-13, rather than IL-4, may play a pro-inflammatory role during acute severe asthma, whereas IFN-gamma responses were associated with recovery from acute severe asthma. These results suggest that altered T-cell cytokine profiles may contribute to the pathogenesis of and recovery from asthma exacerbations.
Calderon
Czarina
C
Department of Respiratory and Sleep Medicine, Monash University and Medical Centre, Melbourne, Victoria, Australia.
Rivera
Luis
L
Hutchinson
Paul
P
Dagher
Hayat
H
Villanueva
Elmer
E
Ghildyal
Reena
R
Bardin
Philip G
PG
Freezer
Nicholas J
NJ
D001249:Asthma / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D016516:CD4-CD8 Ratio; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D005434:Flow Cytometry; D005938:Glucocorticoids / Q000627:therapeutic use; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D007371:Interferon-gamma / Q000378:metabolism*; D018793:Interleukin-13 / Q000378:metabolism*; D015847:Interleukin-4 / Q000378:metabolism*; D008297:Male; D011239:Prednisolone / Q000627:therapeutic use; D013601:T-Lymphocytes / Q000378:metabolism* / Q000473:pathology; D018417:Th1 Cells / Q000378:metabolism / Q000473:pathology; D018418:Th2 Cells / Q000378:metabolism / Q000473:pathology
D005938:Glucocorticoids; D018793:Interleukin-13; D015847:Interleukin-4; D007073:Immunoglobulin E; D007371:Interferon-gamma; D011239:Prednisolone