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Peach

f421 Pru p 4

Allergen Component
Biological Function Actin-binding proteins
Code f421
Source Material Peach
Latin Name Prunus persica
Other Names Profilin
Categories Fruits, Food Of Plant Origin
Molecular Weight 14 kDa

Summary

The peach allergen, Pru p 4, is a profilin, which can act as an actin-binding protein. Peach profilin is one of the important pan-allergens. Pru p 4 in peach is reported to share similar amino-acid sequence with profilins from other members of the Rosaceae family, such as apple and cherry. It can also cross-react with profilin in pollens from unrelated families such as Artemisia vulgaris, Betula alba, Corylus avellanus, P amygdalus. Pollen food allergy syndrome (PFAS) is found to occur due to cross-reactivity between Pru p 4 and profilins present in trees, grass, and other weeds. Typically, Pru p 4 is found to be associated with mild symptoms of oral allergy syndrome (OAS). Pru p 4 was identified as a marker allergen for predicting non-systemic symptoms in peach allergy.

Epidemiology

Worldwide distribution

Pru p 4 in peach is a profilin which is an important pan-allergen found in various pollen and vegetable sources (1). A prospective cross-sectional study in Spain among 57 children identified Pru p 4 in peach as a minor allergen as the sensitization to Pru p 4 was quite low (10% of 39) (2). A cross-sectional study on 148 peach allergic patients from Italy showed that 40.8% (31/76) patients with Pru p 4 sensitivity showed mild OAS (3). Another study in Japan involving 27 peach allergic patients showed that Pru p 4 sensitization resulted in oral allergy symptoms (4). Furthermore, a retrospective study in Japan using 90 patients with peach allergy showed that sIgE to Pru p 4 was negatively associated with the occurrence of systemic symptoms due to peach (5). 

Environmental Characteristics

Source and tissue

The presence of Pru p 4 has been reported in both pulp and peel of peach fruit (2). 

Clinical Relevance

Disease Severity

A cross-sectional observational study in 148 peach-allergic individuals identified that Pru p 4 sensitivity is usually associated with mild symptoms of oral allergy syndrome (OAS) pertaining to the oral mucosa (3). In this study, around 41% (n=76) of patients had mild OAS symptoms while 18% (n=72) of patients suffered with severe OAS symptoms due to Pru p 4 sensitivity (3).

A study by Inomata et al. (2017) in Japan identified PFAS in most of the patients (80% of 100) either due to Pru p 1 and/or Pru p 4 sensitivity (6).

Cross-reactive molecules

PFAS can arise due to cross-reactivity between Pru p 4 in peach and profilins in tree, grass, and weed pollen (4). Although, alder pollen might be the primary contributor for oral symptoms in peach allergic patients with Pru p 1 and/or Pru p 4 sensitization (4).

In a prospective, cross-sectional study by Boyano-Martinez et al. (2013) a patient with positive Pru p 4 antibodies had reported similar symptoms of OAS with melon, watermelon, and pear (2). This could be due to the wide distribution of profilins in various pollens and fruits (7). 

Molecular Aspects

Biochemistry

Pru p 4, a profilin, is a eukaryotic protein  (8) that possess a molecular weight of 14 kDa (9). Profilins are generally actin-binding proteins which can help in several cell processes such as cell movement, signaling, etc. (10). Pru p 4 is also a typical pan-allergen (like Pru p 1 and Pru p 3) and hence can often cross-react (11). Pru p 4 is found to be labile at intense temperature and pH conditions and can get destroyed in the gastrointestinal tract (12).

Isoforms, epitopes, antibodies

Pru p 4 has two variants that are mentioned in the below table (9). A study reported that all tissues showed equal expression of Pru p 4 variants. These allergens can induce allergenicity in peeled peach fruit (12). 

Isoallergens of Pru p 4

Isoallergen and variants Features
Pru p 4.0101
  • Has a molecular weight of 14.00 kDa (7).
  • Of 29 patients, 15 showed sIgE binding to Pru p 4.01 (7).
  • Pru p 4.010 was expressed 105 more than Pru p 4.020 in fruit tissues of nectarine (8, 12). 
Pru p 4.0201
  • Weighs about 13.98 kDa (7).

Cross-reactivity

The Pru p 4 variants displayed about 80% similarity in their amino acid sequences. Pru p 4.0101 showed more than 90% sequence similarity to profilins from other Rosaceae fruits, such as cherry and apple (7). Pru p 4.0201 showed more than 70% similarity to amino acid sequence from botanically unrelated foods such as soybean and carrot and pollens such as birch and sunflower (7). A comparative study by Cuesta-Herranz et al. (1999) identified that cross-reactivity between peach profilins and botanically unrelated pollens (Artemisia vulgaris, Betula alba, Corylus avellanus, P amygdalus) exists (1). A recent study also showed that cross reactivity between a muskmelon profilin (Cuc m 2.0101) and Pru p 4.0101 exists due to similar amino acid sequence and identity (10). Additionally, a melon profiling study identified that profilin’s IgE cross reactivity depends more on the conformational structure than the amino acid sequence similarity rate (13).

Diagnostic Relevance

Disease Severity

A prospective study carried in 29 peach allergic patients pointed that individuals with a positive Pru p 4.01 but negative skin prick test (SPT) to Pru p 3 experienced more OAS symptoms and lesser systemic reactions than those with negative Pru p 4.01 and positive Pru p 3 (7). Evidence suggest that co-sensitization of Pru p 3, Pru p 1, and/or Pru p 4 among peach allergic patients may provide a shield against severe symptoms due to Pru p 3 (3, 14).

A retrospective study with 90 peach allergic children in Japan concluded that sIgE of Pru p 4 was an accurate predictor (100% specificity and 61% sensitivity) of non-systemic peach allergy (5).

Cross-reactivity

Rodriguez-Perez et al. (2003) identified in their study with 29 patients that all 15 sera with positive Bet v 2 reacted with Pru p 4 isoallergen (Pru p 4.01). Whereas no sera reacted with Pru p 4.01 in 14 patients without IgE antibodies to birch profilin. Thus, implying that sIgE to birch profilin (Bet v 2) can act as a diagnostic marker for detecting sensitivity to Rosaceae fruit profilins (7). 

Exposure

The main exposure route for this allergen is through ingestion (9).

Compiled By

Author: Turacoz Healthcare Solutions

Reviewer: Dr. Christian Fischer

 

Last reviewed: January 2021

References
  1. Cuesta-Herranz J, Lazaro M, Martinez A, Figueredo E, Palacios R, de-Las-Heras M, et al. Pollen allergy in peach-allergic patients: sensitization and cross-reactivity to taxonomically unrelated pollens. J Allergy Clin Immunol. 1999;104(3 Pt 1):688-94.
  2. Boyano-Martinez T, Pedrosa M, Belver T, Quirce S, Garcia-Ara C. Peach allergy in Spanish children: tolerance to the pulp and molecular sensitization profile. Pediatr Allergy Immunol. 2013;24(2):168-72.
  3. Pastorello EA, Farioli L, Pravettoni V, Scibilia J, Mascheri A, Borgonovo L, et al. Pru p 3-sensitised Italian peach-allergic patients are less likely to develop severe symptoms when also presenting IgE antibodies to Pru p 1 and Pru p 4. Int Arch Allergy Immunol. 2011;156(4):362-72.
  4. Ando Y, Miyamoto M, Kato M, Nakayama M, Fukuda H, Yoshihara S. Pru p 7 Predicts Severe Reactions after Ingestion of Peach in Japanese Children and Adolescents. Int Arch Allergy Immunol. 2020;181(3):183-90.
  5. Asaumi T, Sato S, Yanagida N, Takahashi K, Mori Y, Okazaki F, et al. IgE-specific Pru p 4 negatively predicts systemic allergy reaction to peach among Japanese children. Allergol Int. 2019;68(4):546-8.
  6. Inomata N, Miyakawa M, Aihara M. High prevalence of sensitization to gibberellin-regulated protein (peamaclein) in fruit allergies with negative immunoglobulin E reactivity to Bet v 1 homologs and profilin: Clinical pattern, causative fruits and cofactor effect of gibberellin-regulated protein allergy. J Dermatol. 2017;44(7):735-41.
  7. Rodriguez-Perez R, Fernandez-Rivas M, Gonzalez-Mancebo E, Sanchez-Monge R, Diaz-Perales A, Salcedo G. Peach profilin: cloning, heterologous expression and cross-reactivity with Bet v 2. Allergy. 2003;58(7):635-40.
  8. Botton A, Andreotti C, Costa G, Ramina A. Peach ( Prunus persica L. Batsch) Allergen-Encoding Genes Are Developmentally Regulated and Affected by Fruit Load and Light Radiation. J Agric Food Chem. 2009;57(2):724-34.
  9. WHO/IUIS. Pru p 4 - International Union of Immunological Societies Allergen Nomenclature 2019 [29-Dec-2020]. Available from: http://www.allergen.org/viewallergen.php?aid=559.
  10. Kapingidza AB, Pye SE, Hyduke N, Dolamore C, Pote S, Schlachter CR, et al. Comparative structural and thermal stability studies of Cuc m 2.0101, Art v 4.0101 and other allergenic profilins. Mol Immunol. 2019;114:19-29.
  11. Asero R, Barber D. C01. PROFILINS. In: Matricardi P. M., Kleine-Tebbe J., Hoffmann H. J. ea, editors. Molecular Allergology User's Guide. Switzerland: The European Academy of Allergy and Clinical Immunology (EAACI); 2016. p. 293-8.
  12. Yang Z, Ma Y, Chen L, Xie R, Zhang X, Zhang B, et al. Differential transcript abundance and genotypic variation of four putative allergen-encoding gene families in melting peach. Tree Genet Genom. 2011;7(5):903-16.
  13. Sankian M, Varasteh A, Pazouki N, Mahmoudi M. Sequence homology: a poor predictive value for profilins cross-reactivity. Clin Mol Allergy. 2005;3:13.
  14. Uasuf CG, Villalta D, Conte ME, Di Sano C, Barrale M, Cantisano V, et al. Different co-sensitizations could determine different risk assessment in peach allergy? Evaluation of an anaphylactic biomarker in Pru p 3 positive patients. Clin Mol Allergy. 2015;13:30.