Allergen-specific conventional immunotherapy decreases immunoglobulin E-mediated basophil histamine releasability.
BACKGROUND
Allergen-specific immunotherapy has proven to be clinically effective in the treatment of patients with atopic asthma; however, the mechanisms are still unclear. Several noted immunological changes include an increase of the allergen-specific IgG antibody, a reduction in the allergen-specific IgE antibody subsequent to transient increase, an allergen-specific T cell shift in cytokine production from Th2 to Th1, and a decrease in quantity and activity of basophils and mast cells.


OBJECTIVE
To analyse the changes of basophil histamine release in response to IgE-mediated and non-IgE-mediated stimuli before and after conventional house-dust mite immunotherapy in children who suffer from atopic asthma.


METHODS
Fourteen Dermatophagoides farinae (Df) sensitive asthmatic children with conventional immunotherapy were examined. Basophil histamine releasability was measured 0 months (just before immunotherapy), 4 months and 9 months after immunotherapy. Basophils were stimulated with Df and goat anti-human IgE antibody as IgE-mediated stimuli; and formyl-Met-Leu-Phe (fMLP) and calcium ionophore A23187 as non-IgE-mediated stimuli. Accordingly, the asthma symptom score was used to assess clinical outcome and the skin test reactivity to Df was measured.


RESULTS
In contrast to pre-immunotherapy activity, 4 and 9 months after immunotherapy there were significant decreases in histamine release by Df and by anti-IgE antibody. The histamine release by fMLP and by calcium ionophore showed no significant changes after immunotherapy. Histamine release by Df demonstrated significant correlation to that by anti-IgE antibody and by fMLP, yet there was no observable correlation between histamine release by Df and by calcium ionophore. The asthma symptom score decreased significantly 4 and 9 months after immunotherapy and showed significant correlation with histamine release by Df. The skin test reactivity (allergen/histamine ratio) remained constant 4 months after immunotherapy, but decreased significantly 9 months after immunotherapy.


CONCLUSIONS
Basophils have the potential to play an important role in the early clinical improvement of conventional immunotherapy in children with atopic asthma, which may be a result of the decreased IgE-mediated histamine releasability during immunotherapy.
Shim
J-Y
JY
Department of Pediatrics, Sungkyunkwan University School of Medicine, Seoul, Korea.
Kim
B-S
BS
Cho
S-H
SH
Min
K-U
KU
Hong
S-J
SJ
D000293:Adolescent; D000485:Allergens / Q000627:therapeutic use*; D001249:Asthma / Q000276:immunology* / Q000628:therapy; D001491:Basophils / Q000276:immunology / Q000378:metabolism*; D002648:Child; D040001:Dermatophagoides farinae; D040002:Dermatophagoides pteronyssinus; D005260:Female; D006636:Histamine Release; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology*; D007167:Immunotherapy / Q000379:methods*; D008297:Male; D018709:Statistics, Nonparametric; D013997:Time Factors
D000485:Allergens; D007073:Immunoglobulin E