Measurement of lipid transfer protein in 88 apple cultivars.
BACKGROUND
Fruits are a major cause of food allergy in adults. Lipid transfer proteins (LTP) are implicated in severe allergic reactions to fruits, but little is known about LTP content in different cultivars.


OBJECTIVE
Determination of the levels of LTP in a wide range of apple cultivars.


METHODS
LTP was measured in apples from 53 cultivars grown in Italy and 35 grown in The Netherlands, using three different immunoassays: a competitive ELISA (cELISA), a sandwich ELISA (sELISA) and a RAST inhibition (RI). Selected cultivars were evaluated using the basophil histamine release test (BHR), skin prick test (SPT) and double-blind, placebo-controlled food challenge (DBPCFC).


RESULTS
LTP levels measured with the three immunoassays were significantly correlated, as judged by Pearson's correlation (0.61 < Rp < 0.65; p < 0.0001), but differed with respect to the actual quantities: 3.4-253.2 (sELISA), 2.7-120.2 (cELISA) and 0.4-47.3 microg/g tissue (RI). Between cultivars, LTP titers varied over about a two-log range. Pilot in vitro and in vivo biological testing (BHR, SPT and DBPCFC) with selected cultivars supported the observed differences in LTP levels.


CONCLUSIONS
Around 100-fold differences in LTP levels exist between apple cultivars. Whether the lowest observed levels of LTP warrant designation as hypo-allergenic requires more extensive confirmation by oral challenges. Determination of cultivar variation in LTP levels provides important information for growers and consumers. Comparison to earlier reported Mal d 1 levels in the same cultivars reveals that a designation as low allergenic does not always coincide for both allergens.
Sancho
Ana I
AI
Institute of Food Research, Norwich, UK.
van Ree
Ronald
R
van Leeuwen
Astrid
A
Meulenbroek
Bert J
BJ
van de Weg
Eric W
EW
Gilissen
Luud J W J
LJ
Puehringer
Helene
H
Laimer
Margit
M
Martinelli
Alessio
A
Zaccharini
Marzio
M
Vazquez-Cortés
Sonia
S
Fernandez-Rivas
Montserrat
M
Hoffmann-Sommergruber
Karin
K
Mills
E N Clare
EN
Zuidmeer
Laurian
L
D002352:Carrier Proteins / Q000009:adverse effects / Q000032:analysis* / Q000276:immunology; D004311:Double-Blind Method; D004797:Enzyme-Linked Immunosorbent Assay; D005512:Food Hypersensitivity / Q000097:blood / Q000276:immunology*; D006636:Histamine Release / Q000276:immunology; D006801:Humans; D027845:Malus / Q000737:chemistry* / Q000276:immunology; D011852:Radioallergosorbent Test; D011897:Random Allocation; D018709:Statistics, Nonparametric
D002352:Carrier Proteins; C030363:lipid transfer protein