+
For Patients & Caregivers
For Lab Professionals
Welcome! Click here for Patient or Laboratory Professional content
Are you a healthcare professional?

The information in this website is intended only for healthcare professionals. By entering this site, you are confirming that you are a healthcare professional.

Are you a laboratory professional?

The information in this website is intended only for laboratory professionals. By entering this site, you are confirming that you are a laboratory professional.

f214 Spinach

Whole Allergen
Code f214
LOINC 602775
Family Amaranthaceae
Genus Spinacia
Species Spinacia oleracea
Route of Exposure Ingestion
Source Material Spinach
Latin Name Spinachia oleracea
Common Name Spinach, Savoy spinach
Categories Food Of Plant Origin, Vegetables

Summary

Spinach is a nutritious, leafy vegetable consumed worldwide. The leaves can be consumed raw or cooked, and can also be dried to form a powder used as a natural food dye. Clinical reports of spinach allergy are rare. Case reports of single patients have shown that allergic reactions can occur through spinach ingestion of cooked or raw leaves, and inhalation. In the small number of cases reported, reaction to spinach ingestion appear to be similar to those of oral allergy syndrome. Cross-reactivity of spinach allergens have been linked to mushroom, tomato, mold and latex.

Allergen

Nature 

Foods

1.       General description of the species

Spinach is a nutritious, leafy vegetable, which was originally domesticated in the Middle-East but is now eaten worldwide (1, 2). It belongs to the family Amaranthaceae, which also includes other crops such as beet, quinoa and amaranth (1). Spinach is rich in mineral elements and vitamins, including high levels of vitamin A, C and E. Over 26.7 million tons of spinach were produced globally in 2016, with China accounting for the vast majority of this production (1).

Route of Exposure

Main 

The leaves can be consumed either raw or boiled and consist of three varieties: Savoy (wrinkled-leaf), smooth (flat leaf) and a hybrid, semi-savoy (semi-wrinkled leaf) (3, 4).

Other topics

Dried spinach powder can be used as a natural green coloring in foods such as pasta, and this powder can be inhaled (5).

Detection

Although spinach contains histamine (37.5 mg/dl), which can cause pseudoallergic reactions (6), reports of spinach allergy either by ingestion or inhalation are rare. This may be due to the rapid denaturation of the principal allergens during digestion (5). However, in a prospective study of 80 Indian children aged 2–14 years with wheezing or physician-diagnosed asthma, spinach was shown to be the most common sensitive food allergen out of the 13 food allergens examined by skin prick test, where 25 % of children showed skin reactions. (7).

In a UK prospective study assessing systemic reactions during skin prick testing between 2007-2013,   of approximately 31,000 who underwent skin prick testing  only 24 patients had systemic reactions, where 1 of these was an asthma patient having a mild systemic reaction to spinach (8).

Other reports of sensitization to spinach are limited to individual case reports: A 48 year-old woman with a positive skin prick test to spinach showed signs of oral allergy syndrome after spinach ingestion. (6). A 23-year-old, nonatopic woman presented with severe angioedema of the lips and tongue after ingestion of spinach leaves. The acute reaction was suspected to be IgE-mediated as the patient had positive skin prick tests and in vitro blood tests to spinach (and tomato). History revealed previous episodes of urticaria and angioedema after the ingestion of raw and cooked spinach and tomato, and rubisco was determined as the culprit allergen (9). One case of asthma induced by inhalation of dried spinach powder was reported in a 30-year-old male pasta factory technician, who had a positive skin prick test and positive in vitro blood test to spinach extract  (5).

Molecular Aspects

Allergenic molecules

Examination of spinach extract showed two main protein bands of 20 and 25 kDa, and several minor bands between 14–18 kDa. Immunoblotting of the spinach extract showed four bands from about 18–35 kDa (10).

Table adapted from Allergome.org (11).

Allergen

Source

Spi o

Amaranthaceae, Plants, Spinach, Spinacia oleracea

Spi o 2

Amaranthaceae, Plants, Spinach, Spinacia oleracea

Spi o RuBisCO

Amaranthaceae, Plants, Spinach, Spinacia oleracea

 

Based on their structure, spinach proteins are suspected to have low allergenic potential by AllerCatPro (12).

Cross-reactivity

Alternaria-spinach syndrome involves cross-reactivity from the mold Alternaria alternata and its major allergen Alt a 1, with allergens from spinach (and mushroom Agaricus bisporus). Cross-reactivity of a 30 kDa protein, suspected to be the Alt a 1 allergen was present in spinach extract (13). In addition to Alternaria alternata, a 30 kDa spinach protein showed cross reactivity to the molds Cladosporium herbarum and/or Aspergillus fumigatus in seven mold-allergic patients (14). There have also been single reports of cross reactivity to tomato (Solanum lycopersicum) (9) and mushroom (Agaricus bisporus) (10), as well as one report of exercise-induced anaphylaxis with a cross-reaction to latex (15).

Compiled By

Author: RubyDuke Communications

Reviewer: Dr. Michael Thorpe

 

Last reviewed: December  2021

References
  1. Ribera A, Bai Y, Wolters A-MA, van Treuren R, Kik C. A review on the genetic resources, domestication and breeding history of spinach (Spinacia oleracea L.). Euphytica. 2020;216(3):48.
  2. Ribera A, Treuren R, Kik C, Bai Y, Wolters A-M. On the origin and dispersal of cultivated spinach (Spinacia oleracea L.). Genetic Resources and Crop Evolution. 2021;68:1-10.
  3. Ernst T, Drost D, Black B. High Tunnel Winter Spinach Production. All Curret Publications 2012(299):1-9.
  4. Miano T. NUTRITIONAL VALUE OF SPINACIA OLERAECEA SPINACH-AN OVERVIEW. IJLSR. 2016;2:172-4.
  5. Schuller A, Morisset M, Maadi F, Kolopp Sarda MN, Fremont S, Parisot L, et al. Occupational asthma due to allergy to spinach powder in a pasta factory. Allergy. 2005;60(3):408-9.
  6. Sanchez I, Rodriguez F, Garcia-Abujeta JL, Fernandez L, Quiñones D, Martin-Gil D. Oral allergy syndrome induced by spinach. Allergy. 1997;52(12):1245-6.
  7. Meher BK, Pradhan DD, Mahar J, Sahu SK. Prevalence of Allergic Sensitization in Childhood Asthma. Cureus. 2021;13(5):e15311.
  8. Sellaturay P, Nasser S, Ewan P. The incidence and features of systemic reactions to skin prick tests. Ann Allergy Asthma Immunol. 2015;115(3):229-33.
  9. Foti C, Damiani E, Zambonin CG, Cassano N, Nettis E, Ferrannini A, et al. Urticaria and angioedema to rubisco allergen in spinach and tomato. Ann Allergy Asthma Immunol. 2012;108(1):60-1.
  10. Herrera I, Moneo I, Caballero ML, Paz S, Pimiento A, Rebollo S. Food allergy to spinach and mushroom. Allergy. 2002;57:261-2.
  11. Allergome. Allergome.com Allergome.com2003-2015 [cited 2021 26th October ]. Available from: http://allergome.com/script/search_step2.php.
  12. Krutz NL, Winget J, Ryan CA, Wimalasena R, Maurer-Stroh S, Dearman RJ, et al. Proteomic and Bioinformatic Analyses for the Identification of Proteins With Low Allergenic Potential for Hazard Assessment. Toxicol Sci. 2019;170(1):210-22.
  13. Popescu FD. Cross-reactivity between aeroallergens and food allergens. World J Methodol. 2015;5(2):31-50.
  14. Herrera-Mozo I, Ferrer B, Luís Rodriguez-Sanchez J, Juarez C. Description of a novel panallergen of cross-reactivity between moulds and foods. Immunol Invest. 2006;35(2):181-97.
  15. Maillard H, Lemerle E, Garot D, Leclech C, Machet L. [Crossed spinach-latex allergy revealed by exercise-induced anaphylaxis]. Allerg Immunol (Paris). 1999;31(5):156-7.