Lipid transfer protein-linked hazelnut allergy in children from a non-Mediterranean birch-endemic area.
BACKGROUND
Hazelnut allergy in birch pollen-exposed areas is usually due to cross-reactivity (Cor a 1 and 2) and is usually mild in nature (oral allergy). In areas without birches, severe reactions are more prevalent and linked to sensitization to the lipid transfer protein (LTP) Cor a 8.


OBJECTIVE
We sought to investigate whether sensitization to LTP plays a role in more severe (objective) hazelnut-induced symptoms in children from a birch-endemic area.


METHODS
Sensitization to Cor a 8, Cor a 2, Cor a 1, and Bet v 1 was determined by means of RASTs and immunoblotting in hazelnut-sensitized children with (n = 8) and without (n = 18) objective reactions during double-blind, placebo-controlled food challenges. Additionally, samples from 191 hazelnut-sensitized nonchallenged children were analyzed.


RESULTS
Children with objective reactions during double-blind, placebo-controlled food challenge had higher IgE titers to hazelnut (P < .001) and recognized more allergens on immunoblotting (P = .001) than those without such reactions. All children with objective symptoms were sensitized to Cor a 8 (0.51-23.3 IU/mL) compared with only 1 child without objective reactions (0.90 IU/mL). In a multivariate analysis only IgE against Cor a 8 remained as an independent risk factor (undefined odds ratio; P < .0001). In the group of nonchallenged children (n = 191), the prevalence of LTP sensitization was greater than 30%. Unexpectedly, sensitization to Cor a 1 was observed in children not sensitized to Bet v 1.


CONCLUSIONS
Sensitization to hazelnut LTP is a risk factor for objective symptoms in children from a birch-endemic area.
Flinterman
Annebeth E
AE
Department of Dermatology/Allergology, University Medical Centre, Utrecht, The Netherlands. a.e.flinterman@umcutrecht.nl
Akkerdaas
Jaap H
JH
den Hartog Jager
Constance F
CF
Rigby
Neil M
NM
Fernandez-Rivas
Montserrat
M
Hoekstra
Maarten O
MO
Bruijnzeel-Koomen
Carla A
CA
Knulst
André C
AC
van Ree
Ronald
R
Pasmans
Suzanne G
SG
D000375:Aging / Q000276:immunology; D052179:Antigens, Plant / Q000276:immunology; D029662:Betula; D002352:Carrier Proteins / Q000276:immunology*; D002648:Child; D031211:Corylus / Q000737:chemistry; D004311:Double-Blind Method; D004777:Environment; D005260:Female; D006801:Humans; D007114:Immunization; D007073:Immunoglobulin E / Q000276:immunology; D008297:Male; D021184:Nut Hypersensitivity / Q000276:immunology / Q000503:physiopathology*; D010940:Plant Proteins / Q000276:immunology; D012307:Risk Factors; D012720:Severity of Illness Index
D052179:Antigens, Plant; D002352:Carrier Proteins; C527352:Cor a 8 allergen, Corylus avellana; C061277:Cor a I protein, hazel; D010940:Plant Proteins; C030363:lipid transfer protein; D007073:Immunoglobulin E