Abstract

Peach allergy is the most common form of IgE-mediated hypersensitivity to fresh fruits in the Mediterranean area. Its prevalence can be estimated to 10-40% ( Spain and Italy) in pollen allergic patients or even up to 75% (in Israel) in fruit and/or vegetable allergic individuals. Peach allergy is rarely observed as an isolated allergy, and most patients present with some other food or inhalant (mainly pollen) allergies. The foods most frequently associated are other members of the Rosaceae family, such as apple and pear (Pomoideae subfamily), and apricot, cherry and plum (Prunoideae subfamily). According to clinical observations, apple allergy is the most frequent food allergy associated to peach allergy.
As regards sensitization to fruits of the Rosaceae family, some differences are evident in populations from northern Europe and southern Europe. Rosaceae fruit allergy (typically apple) linked to birch pollinosis in nothern Europe is mainly due to cross- reactive IgE induced by Bet v 1 (the major birch pollen allergen). In contrast, Rosaceae fruit allergy (typically peach) in southern Europe not linked to birch pollen is a “true food allergy” in which sensitization and reactions are induced by stable fruit allergens such as lipid-transfer proteins (LTPs).

The spectrum of symptoms ranges from local symptoms (e.g. oral allergy syndrome, contact urticaria) to systemic symptoms including anaphylaxis (e.g. urticaria, angioedema, gastrointestinal and respiratory symptoms). Systemic symptoms are more frequently observed in patients who react to the ingestion of peach pulp or canned peach, and in those allergic to peach without pollinosis. Usually the allergenic potency of peach peel (skin) is higher than that of peach pulp (flesh) in peach allergic subjects. Two patient subgroups (80% with and 20% without pollinosis) have been reported in peach allergy. Peach allergic patients with associated pollinosis are more predisposed to experiencing asthma than pollinosic patients non-allergic to peach. Although adverse reactions to canned peach or in vitro IgE-binding to commercial peach juices and nectars have been reported, the diagnostic accuracy is highly dependent on the quality of extracts used in testing procedures. Skin tests (prick- to -prick tests) with fresh fruits are highly sensitive diagnostic tools as confirmed by oral challenges.

Pru p 3, the major allergen from peach, is a 9-kDa allergen belonging to the family of lipid-transfer proteins (LTP) which has been proven to be cross-reactive to homologous proteins both in Rosaceae fruits and in other plant derived foods. Other IgE-binding proteins have been reported: Profilin (Bet v 2 homologous), Bet v 1 homologous protein, and Cross-reactive Carbohydrate Determinants (CCD) of proteins >30 kDa.
The allergenicity of peach juices and nectars could only be reduced by lye peeling of fruits and ultrafiltration of juices, respectively. These findings suggest a marked resistance of the major peach allergen Pru p 3 to both phenoloxidase activity and heat treatment. Furthermore, Pru p 3 has recently been proven to be resistant against pepsin digestion.

The present data collection reviews detailed information on the prevalence and symptoms of peach allergy as well as diagnostic features, sensitization patterns, and the occurrence of cross-reactivities in tabular form.
 
 

Contents

1 Prevalence of Peach Allergy 2 Symptoms of Peach Allergy 3 Diagnostic Features of Peach Allergy 4 Therapy of Peach Allergy 5 Composition of Peach 6 Allergens of Peach 6.1 Sensitization to Peach Allergens 6.2 Properties of Lipid-transfer Protein (Pru p 3) 7 Isolation & Preparation 8 Cross-Reactivities 9 Stability of Peach Allergens 10 Allergen Sources 11 References

Disclaimer
The reference lists of the Allergen Data Collections are based mainly on searches of Medline and FSTA (Food Science & Technology Abstracts) databases up to the related dates of publication. The scientific rigor of the studies listed is variable and not subject of critique or evaluation by the authors or the editor of the Allergen Data Collections. The reader should be aware of considerable problems in comparing data from different studies (eg. patient cohorts, diagnostic performances, possible flaws in allergen preparations and methodologies for allergen characterization) and is encouraged to review the original publications.
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