Allergen-specific basophil suppression associated with clinical tolerance in patients with milk allergy.
BACKGROUND
Children with milk allergy who tolerate heat-denatured milk (HM) have less severe reactions and outgrow the condition earlier than those who react to HM, which might be related to differences in IgE-dependent effector cell function.


OBJECTIVE
We sought to apply a novel assay to test the hypothesis that HM-tolerant children have suppressed IgE-mediated basophil responses.


METHODS
Allergic, HM-tolerant, outgrown, or control subjects were defined based on oral food challenges. Whole blood cells were stimulated in vitro with a range of milk allergen doses in the presence or absence of autologous serum or with dilutions of autologous serum. Activated basophils were identified by means of flow cytometry as CD63(bright)CD123+CD203c+HLA-DR(-)CD41a(-).


RESULTS
HM-tolerant subjects' basophils were significantly less responsive to milk allergen stimulation at all doses than were basophils from HM-reactive (allergic) individuals. In the absence of autologous serum, HM-tolerant subjects' basophils were significantly more reactive at low allergen concentrations. To a lesser extent, autologous serum also inhibited IL-3- and anti-IgE-induced, but not N-formyl-methionyl-leucyl-phenylalanine-induced, responses. The allergen-specific responsiveness of HM-tolerant subjects' basophils increased with dilution of autologous serum with normal pooled serum.


CONCLUSIONS
Children with milk allergy with a favorable prognosis have evidence of extrinsically suppressed allergen-specific effector cell reactivity.
Division of Allergy and Immunology, Department of Pediatrics, Jaffe Food Allergy Institute, Mount Sinai School of Medicine, New York, NY 10029, USA.
Niya
N
Wanich
Anna
A
Nowak-Wegrzyn
Hugh A
HA
Sampson
Wayne G
WG
Shreffler
D000293:Adolescent; D000485:Allergens / Q000276:immunology*; D000888:Antibodies, Anti-Idiotypic / Q000494:pharmacology; D001491:Basophils / Q000502:physiology*; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007108:Immune Tolerance; D007223:Infant; D007377:Interleukin-3 / Q000494:pharmacology; D016269:Milk Hypersensitivity / Q000276:immunology*
D000485:Allergens; D000888:Antibodies, Anti-Idiotypic; D007377:Interleukin-3; C026408:anti-IgE antibodies