Agriculture Reference
In-Depth Information
and lifelong food allergy. Unlike some other allergenic foods such as
wheat, egg, milk, and soy, peanut allergy is more persistent and only
∼
20% of children outgrow this allergy (Finkelman 2010). A wide
spectrum of clinical reactions is seen in allergic diseases, the most
prominent symptoms being cutaneous (89%), respiratory (Boyano-
Martínez et al. 2002), and gastrointestinal (GI) symptoms (32%). Approx-
imately 31% of these individuals have combinations of two symptoms
and 21%have all three of the symptoms (Sicherer et al. 1998). Other less-
prevalent symptoms such as headache, sleeplessness, neurological
problems (such as irritability, nervousness, and mood swings), and
abrupt changes in body temperature have also been attributed to food
allergy. Very small doses of peanut can cause a range of these symptoms.
The only method for prevention of a food allergic reaction is total
avoidance of that food. It is increasingly dif
cult for an allergic individ-
ual to avoid an abundantly utilized and often disguised food source such
as peanuts, which can lead to anaphylaxis and occasionally death.
Twelve peanut allergens have been documented by the World Health
Organization and the International Union of Immunological Societies
(IUIS) Allergen Nomenclature committee (Chapman et al. 2007). These
food allergens are named according to the
first three letters of the genus
followed by the
first letter of the species and a number, which indicates
the order in which they were discovered.
Arachis hypogaea
allergens are
therefore named Ara h 1, Ara h 2, Ara h 3, Ara h 5
Ara
h 3 and Ara h 6 are considered the major peanut allergens and represent
highly homologous classes of seed storage proteins. These proteins are
considered major because they are recognized by the serum immuno-
globulin E (IgE) of more than 50% of peanut allergic individuals in the
United States (Burks et al. 1991, 1992). Ara h 5 (pro
-
Ara h 13. Ara h 1
-
lin) (Kleber-Janke
et al. 1999), Ara h 7 (2S albumin, conglutin) (Schmidt et al. 2010;
Codreanu et al. 2011), Ara h 8 (pathogenesis-related protein, Bet v 1-
related) (Mittag et al. 2004; Marsh et al. 2008; Riecken et al. 2008), Ara h 9
(lipid transfer protein or LTP) (Krause et al. 2009; Lauer et al. 2009), Ara
h 10 and Ara h 11 (oleosin) (Stevenson et al. 2009; Parthibane et al. 2012),
and Ara h 12 and 13 (defensins) are considered minor allergens because
they are recognized by
50% of the peanut allergic U.S. population. The
reason there are 12 allergens (although Ara h 13 has been found) is that
the Allergen Nomenclature committee concluded that Ara h 3 and Ara h
4 are the isoforms of the same protein. Therefore, Ara h 4 was eliminated
as an independent allergen (unpublished information). It was recently
demonstrated that the percentage of the populations in different countr-
ies that recognize various allergens vary among countries (Fernández-
Rivas et al. 2006; Chan et al. 2012; Ebo et al. 2012).
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