Like many other allergies to fresh fruits and vegetables, apricot allergy can take two different forms. In the North of Europe, a milder form of apricot allergy is associated to birch-pollen allergy due to the similarity between a protein in birch that causes birch-pollen allergy, and an apricot protein. This is called the birch-fruit syndrome with symptoms confined largely to the mouth, causing a condition called “oral allergy syndrome” (OAS). The molecule, known as an allergen, involved in this kind of allergy does not survive cooking. Therefore, people who react to this allergen can tolerate cooked apricot. Individuals with apricot allergy might develop adverse reactions to other fruits including apple, pear, cherry, nuts such as hazelnut, or vegetables such as celeriac (celery tuber) and carrot.
In Mediterranean countries, people with apricot allergy do not have birch-pollen allergy. Instead they often have allergy to peach. These individuals develop adverse reactions to apricot because of the similarity between the allergens in peach and apricot. Symptoms are more severe including generalised urticaria, abdominal pain, vomiting and life-threatening symptoms, sometimes in addition to the OAS. The allergen that causes this kind of allergy is tough and the allergenicity survives in processed foods such as juices and jams. As a result, individuals with this kind of allergy cannot eat even cooked fruits. Individuals with apricot allergy also tend to develop adverse reactions to other fruits including peach, apple, cherry, plum, and nuts (such as hazelnut and walnut).
NEWT http://www.ebi.ac.uk/newt/display?from=ca&search=36596
Oropharyngeal sympotoms characteristic of the oral allergy syndrome (OAS) (Pastorello et al. 1994) [156], (Pastorello et al. 2001) [152] and systematic symptoms (Pastorello et al. 2000) [150]
In addition, Rodriguez et al. (2000) [491] described generalised anaphylaxis
Fresh fruit and commercial apricot extracts (Pastorello et al. 1994) [156]
Fresh fruit (Rodriguez et al. 2000) [491] (Pastorello et al. 2000) [150]
Pastorello et al. (1994) [156] and Pastorello et al. (2000) [150] used histamine dihydrochloride (10 mg/mL) as a positive control, and the glycerol-containing diluent of the prick solution as a negative control. A wheal graded at least 2+was regarded as positive.
Skin prick tests (SPTs) were carried out by the prick-prick technique. Histamine (10 mg/mL) and saline solution were used as positive and negative controls repectively. A positive SPT result was defined as a mean (average of orthogonal to largest diameter) wheal of 3 mm or greater (after subtracting the diameter of the wheal induced by the diluent control). (Rodriguez et al. 2000) [491]
21 patients (Pastorello et al. 1994) [156]
28 patients (Rodriguez et al. 2000) [491]
30 patients (Pastorello et al. 2000) [150]
All patients of Pastorello et al. (1994) [156] and Pastorello et al. (2000) [150] showed a positive SPT.
SPTs were positive in 14 patients (Rodriguez et al. 2000) [491]
Commercial extracts (Rodriguez et al. 2000) [491], (Pastorello et al. 2000) [150]
18 of 28 patients had specific IgE to apricot (Rodriguez et al. 2000) [491]
All patients had specific IgE to apricot (Pastorello et al. 2000) [150]
The extracts were separated in a discontinuous buffer system in an SDS-polyacrylamide gradient gel with a 6% stacking gel and a 7.5% to 20% separation gradient. Samples were boiled and reduced with beta-mercaptoethanol (Pastorello et al. 1994) [156], (Pastorello et al. 2000) [150]
The proteins were electroblotted to a nitrocellulose membrane, pore size 0.2 to 0.45 µm using a Trans-Blot Cell. The membrane was blocked with phosphate-buffered saline pH 7.4 with 0.5% (v/v) Tween 20 and incubated with the sera (diluted 1:4). The IgE-binding components were detected with iodine 125–labeled anti-human IgE antiserum diluted 1:4 (Pastorello et el. 1994) [156], (Pastorello et al. 2000) [150]
87.5% of sera (14 of 16) of Pastorello et al. 1994 [156], showed Ig E binding to a 13 kDa protein and 77% (14 of 18) to a 30 kDa protein . The other IgE -binding components were: 70 kDa (6 of 16, 37.5%), 20 kDa (5 of 16, 31%), 14 kDa (4 of 16, 25%), 40 kDa (4 of 16, 25%) and 30 kDa (2 of 16, 12.5%). Only the component at 13 kDa was detectable in patients with negative responses to birch pollen.
IgE immunoblotting in sera from the 30 patients showed IgE binding to proteins with molecular weights of 9 kDa (30 patients, 100%), 15 kDa (4 patients, 13.3%), 19 kDa (12 patients, 40%), 30 kDa (3 patients, 10%), 43 kDa (6 patients, 20%), 67 kDa (7 patients, 23.3%), and 80 kDa (4 patients, 13.3%) (Pastorello et al. 2000) [150]
Apricot fruit (Pastorello et al. 1994) [156], (Pastorello et al. 2000) [150]
A total of 17 g of dehydrated whole fruit was masked in a mix of orange (200 mL) and pineapple (200 mL) juices, sugar (16 g), wheat meal (13 g), and liquid coloring (Rodriguez et al. 2000) [491]
Open and DBPCFC (Rodriguez et al. 2000) [491]
28 patients with positive skin prick tests or CAP System FEIA to Rosaceae (Rodriguez et al. 2000) [491]
Oropharyngeal sympotoms (itching or tingling of the lips or oral mucosa) in 6 patients (Pastorello et al. 1994) [156]
3 patient had oropharyngeal sympotoms and two generalised anaphylaxis (Rodriguez et al. 2000) [491]
All patients reported OAS, and 2 reported systemic symptoms to apricot (Pastorello et al. 2000) [150]
O50001:Swissprot: http://ca.expasy.org/cgi-bin/niceprot.pl?O50001
U93165; AAB97141.1; EMBL / GenBank
Not known but likely to be thermostable and resistant to proteases as other members of the nsLTP family (Asero et al. 2000) [10]
IgE to Pru ar 3 cross-reacts with LTP's from other Prunoideae (eg. peach). IgE binding to nsLTP from some pollens has been implicated (Garcia-Selles et al., 2002 [594]; Pastorello et al., 2000) [150] but the relationship between allergy to pollen and fruit nsLTPs has not been clearly defined
Pru ar 3 has sequence identity to peach and almond LTPs of 91% and 94%, respectively (Conti et al. 2001) [38]
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