Antigen-induced expression of CD203c on basophils predicts IgE-mediated wheat allergy.
BACKGROUND
For in vitro diagnosis of wheat allergy, specific IgE to wheat is known to be a poor predictive marker. Oral food challenge, the gold standard for the diagnosis, is accompanied by a risk of severe induced reactions. Reliable in vitro tests are needed to be developed for safe indication for oral challenge.


OBJECTIVE
We examined the utility of a basophil activation marker, CD203c, for the diagnosis of IgE-mediated wheat allergy.


METHODS
Fifty-eight children with suspected wheat allergy with positive CAP-FEIA to wheat were enrolled. On 70 occasions, the clinical distinction between patients with wheat allergy (WA) and patients tolerant to wheat (TW) was made by means of an oral food challenge test or recent history of immediate allergic reactions or tolerance after ingestion of wheat. Twelve replicate evaluations were performed in 9 patients over more than a 6-month interval. Thirty two patients on 43 occasions were diagnosed with WA and 27 were confirmed to be TW. One patient had both diagnoses 18 months apart. Peripheral blood was incubated with fractionated wheat extracts, purified native omega-5 gliadin (nOG5) and recombinant omega-5 gliadin (rOG5). Expression of CD203c on basophils was then analyzed by flow cytometry using a commercial kit.


RESULTS
All wheat proteins induced concentration-dependent enhancement of CD203c expression in WA, but did not in TW. The analysis of receiver operating characteristics (ROC) showed that nOG5-induced CD203c(high)% values provided the best power for discriminating between WA and TW, with a sensitivity of 85.0% and specificity of 77.0% at the cut-off level of 14.4%. AUC for CD203c with nOG5 were significantly higher than that for conventional CAP-FEIA, 0.89 and 0.73, respectively (p < 0.01).


CONCLUSIONS
Measurement of nOG-induced enhancement of CD203c on basophils is useful for the diagnosis of immediate wheat allergy in children.
Tokuda
Reiko
R
Institute for Clinical Research, Mie National Hospital, Mie, Japan.
Nagao
Mizuho
M
Hiraguchi
Yukiko
Y
Hosoki
Koa
K
Matsuda
Tukasa
T
Kouno
Kunie
K
Morita
Eishin
E
Fujisawa
Takao
T
D000485:Allergens / Q000235:genetics / Q000276:immunology; D052179:Antigens, Plant / Q000235:genetics / Q000276:immunology*; D019540:Area Under Curve; D001491:Basophils / Q000276:immunology / Q000378:metabolism*; D002675:Child, Preschool; D005260:Female; D005903:Gliadin / Q000235:genetics / Q000276:immunology; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology*; D008297:Male; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism*; D010936:Plant Extracts / Q000276:immunology; D010940:Plant Proteins / Q000276:immunology; D011237:Predictive Value of Tests; D011755:Pyrophosphatases / Q000378:metabolism*; D012372:ROC Curve; D011994:Recombinant Proteins / Q000276:immunology; D012680:Sensitivity and Specificity; D021182:Wheat Hypersensitivity / Q000175:diagnosis* / Q000276:immunology
D000485:Allergens; D052179:Antigens, Plant; C427944:ENPP3 protein, human; D010936:Plant Extracts; D010940:Plant Proteins; D011994:Recombinant Proteins; C475180:omega-5 gliadin, wheat; D007073:Immunoglobulin E; D005903:Gliadin; D010727:Phosphoric Diester Hydrolases; D011755:Pyrophosphatases