Allergy information for: Oat (Avena sativa)

  • Name: Oat
  • Scientific Name: Avena sativa
  • Occurrence: Oats are used to make porridge and a wide variety of cakes and biscuits. Oats are also found in muesli or granola. Beer can be made from oats. More information..
  • Allergy Information:

    Adverse reactions to wheat have been more frequently reported than to other cereal-based foods. The best defined of these are coeliac disease and IgE-dependent wheat allergy, both of which result from malfunctioning of the immune system. Allergies to other cereals such as maize, sorghum and millet, are not common and are not related to reactions triggered by wheat, rye, barley and oats. As a consequence individuals with wheat allergy, including coeliac disease, can usually eat maize-based foods such as polenta. However, allergic reactions to maize can result from the fruit allergies found in the South of Europe which often start with reactions to peach.

    Coeliac disease is triggered by the gluten fraction of wheat or by the gluten-like proteins found in other closely related cereals such as rye, barley. Some sensitive individuals may also react to oats. The gut reacts to the gluten and becomes smooth, loosing its ability to absorb nutrients; symptoms including diarrhoea as well as deficiencies in nutrients like vitamins. It can manifest itself in childhood, affecting children’s growth and development, or in adult hood. As there is no cure individuals with coeliac disease have to avoid eating gluten for life. However, coeliac disease does not cause the potentially fatal reaction of anaphylaxis if gluten is accidentally eaten.

    In contrast IgE-mediated cereal allergies can be caused by the antibody molecule IgE binding to many proteins, not just gluten. Sometimes the reactions (often severe) only develop if an individual takes exercise within a few hours of eating wheat or related cereals, in a condition called exercise-induced anaphylaxis. Individuals with wheat allergy often react to closely related cereals like barley and rye, less frequently to the more distant relative, oats. Diagnosis of cereal allergies can be complicated by the fact that some of the blood tests for cereal food allergy can accidentally detect allergy to grass pollens instead.

    As a consequence of these adverse reactions, cereals containing gluten, (i.e. wheat, rye, barley, oats, spelt or their hybridized strains) have been included in Annex IIIa of the food labelling directive along with derived products. Temporary exceptions to the labelling rule (derogations) have been granted for wheat based glucose syrups including dextrose, wheat based maltodextrins, glucose syrups based on barley and cereals used in distillates for spirits.
  • Other Information:
  • Taxonomic Information: NEWT http://www.ebi.ac.uk/newt/display?from=null&search=4498
  • Last modified: 18 October 2006

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    References (0)

      Clinical History

      • Number of Studies:1-5
      • Number of Patients:>50
      • Symptoms:

        Järvinen et al. (2003) [820] reported on 90 paediatric milk allergic patients who had residual symptoms after elimination of milk. 33 were challenged with oats (open) and 1 showed immediate symptoms (urticaria) while 24 showed delayed symptoms (16 eczematous rash, 6 diarrhoea, 1 eczematous rash and diarrhoea and 1 fever). Reactions that occurred within an hour from the last dose were defined as immediate.

        Varjonen et al. (1995) [225] reported on paediatric patients who had atopic dermatitis and a range of other symptoms on challenge with wheat, rye, barley and oats: asthma, urticaria, erythema, pruritus and allergic rhinitis.

        Varjonen et al. (1994) [223] reported on adult patients, 35 with severe chronic atopic dermatitis, 4 with urticaria and 1 with rhinitis on challenge with wheat, rye, barley and oats.

      Skin Prick Test

      • Number of Studies:1-5
      • Food/Type of allergen:Flour extracted with saline, 200 mg/0.3 ml. (Rasanen et al. 1994 [485]).
      • Protocol: (controls, definition of positive etc)

        A positive SPT response was defined as a wheal 3 mm larger than the negative (saline solution) control (Jones et al. 1995 [832]).

      • Number of Patients:

        33/90 children, aged 2.5 to 36 months, with residual symptoms after cow's milk elimination were tested with oats (Järvinen et al 2003 [820]).

        34 paediatric patients were studied who had atopic dermatitis and a range of other symptoms (Varjonen et al. 1995 [225]).

        145/360 patients from 3 months to 30 years, median 4.5 years gave a positive SPT to any cereal. 127 patients were tested with oats (Jones et al. 1995 [832]).

      • Summary of Results:

        6/33 children gave a positive SPT with oats, who were all positive on open challenge (Järvinen et al 2003 [820]).

        18/34 patients had a positive SPT reaction with oats (Varjonen et al. 1995 [225]).

        35/127 patients had a positive SPT with oats (Jones et al. 1995 [832])

      IgE assay (by RAST, CAP etc)

      • Number of Studies:0
      • Food/Type of allergen:Commercial extracts were used for RAST. Flour was extracted with potassium phosphate at pH 7.0 containing 400 mM NaCl or with 50 mM sodium acetate pH 3.8 for immunoblots.
      • IgE protocol:RAST
      • Number of Patients:

        34 paediatric patients were studied who had atopic dermatitis and a range of other symptoms: asthma, urticaria, erythema, pruritus and allergic rhinitis on challenge with oats (Varjonen et al. 1995 [225]).

        Sera from 15/145 patients of whom 9/15 were challenge positive to a cereal were studied (Jones et al. 1995 [832]).

        Sera from 40 adults, 35 with atopic dermatitis, 1 rhinitis and 4 urticaria (Varjonen et al., 1994 [223]).

        Sera from 3 children with atopic dermatitis (Rasenen et al, 1994 [485]).

      • Summary of Results:

        RAST showed 1.4, 8.0, 16.0, 28.0 and 71.0 kU/L of IgE to oats in the 5 challenge positive patients. The other 29 had 0.5-17.0 kU/L of IgE to oats (Varjonen et al. 1995 [225]).

        Oat specific RAST was determined for 40 patients; 3 had class 4, 7 class 3, 14 class 2 and 11 class 1 RAST results. 5 had class zero (i.e. no significant specific IgE binding). 33 patients gave IgE-positive immunoblots with oat proteins (Varjonen et al. 1994 [223]).

        1/3 children with atopic dermatitis gave a positive RAST to oats 13.5 kU/l and also reacted to challenge (Rasenen et al, 1994 [485]).

      Immunoblotting

      • Immunoblotting separation:

        Jones et al. (1995) [832] used 1D SDS-PAGE with a 3% stacking gel and 13.5% separating gel with samples reduced with dithiothreitol.

        Varjonen et al. (1994) [223] used 1D 5-17% SDS-PAGE under non-reducing conditions.

      • Immunoblotting detection method:

        Jones et al. (1995) [832] used nitrocellulose membranes and washed with Tween-containing solutions.

        Varjonen et al. (1994) [223] electrotransferred proteins onto 0.2µm nitrocellulose membranes which were cut into strips and incubated overnight with sera (1:4 dilution) in saline with 0.5% (v/v) Tween. Detection used 125I labelled anti-human IgE.

      • Immunoblotting results:

        Variable immunoblotting patterns were obtained; 67% of sera reacted with a 46 kDa band, 53% with a 66 kDa band, 35% with a 30 kDa band. Major allergen bands were 46 and 66 kDa. IgE from sera also reacted with proteins from wheat, rye and barley (Varjonen et al. 1995 [225]).

        Immunoblotting showed extensive IgE binding to proteins of wheat, rye, barley and oats, which was not always clinically relevant (Jones et al. 1995 [832]).

        The 66 kDa protein was most frequently recognised by IgE from 28/33 sera (84%). Proteins detected as intermediate allergens (10%-50%) ran at 23 kDa and 42 kDa. 7 minor allergens were also identified(Varjonen et al. 1994 [223]).

      Oral provocation

      • Number of Studies:1-5
      • Food used and oral provocation vehicle:After an initial drop tested on the lips, oral doses were 1, 5, and 10g of cereal as porridge cooked in water at 0.5h intervals on day 1 followed by normal eating of cereal on day 2 (Järvinen et al. 2003 [820]). Varjonen et al. 1995 [225] used the above doses but at a slower rate of two doses per day up to 2 doses of 10 g. They tested initially on wrist and upper lip.

        10% cereal cooked in water. Oral doses were 1, 2, 5, 10, 20, 50, 100mls at 1h intervals. Blind challenges were concealed in buckwheat (Rasenen et al. 1994 [485]).

      • Blind:

        Open (Järvinen et al 2003 [820]).

        Open Varjonen et al. (1995) [225].

        DBPCFC with negative checked by open challenge (Jones et al. 1995 [832]).

        Open or single blind (Rasenen et al. 1994 [485]).

      • Number of Patients:

        33 children (Järvinen et al 2003 [820]).

        34 children (Varjonen et al. 1995 [225]).

        29 children (Jones et al. 1995 [832]).

        3/39 atopic children (Rasenen et al, 1994 [485]).

      • Dose response:Not specified
      • Symptoms:

        25/33 children showed symptoms on open challenge with oats (Järvinen et al 2003 [820]). One immediate with urticaria and 24 delayed with 16 eczematous rash, 6 diarrhoea, 1 rash and diarrhoea and 1 fever. Reactions that occurred within an hour from the last dose were defined as immediate.

        5/34 patients gave a positive reaction on challenge with oats. One developed wheals at the skin contact site and 4 delayed reactions of erythema and pruritus (Varjonen et al. 1995 [225]). Reactions that occurred within 2 hours from the last dose were defined as immediate.

        5/29 patients gave a positive reaction on challenge with oats (Jones et al. 1995 [832]).

        1/3 children with atopic dermatitis gave an immediate reaction to oats (none gave delayed reactions) (Rasenen et al, 1994 [485]).

      IgE cross-reactivity and Polysensitisation

      Serum IgE binding to several cereals may be observed but may not always have clinical significance (Jones et al. 1995 [832]). Barley, wheat and rye are closely related cereals, all being members of the Triticeae, and have seed stirage prolamins as the major seed protein constituent. Oats are more distantly related and contain a lower proportion of storage prolamins which are structurally distinct from those of the Triticeae. Oats contain two types of storage proteins; 12S globulins and prolamin avenins. The latter are distantly related to seed storage proteins of the Triticeae (Shewry 1999 [511]). Palosuo et al (2001) [136] identified IgE cross-reactive proteins in wheat, barley and rye but not in oats.

      Other Clinical information

      Immediate and delayed reactions on challenge are discussed in the wheat entry.

      Food protein-induced enterocolitis syndrome may also involve oats (Nowak-Wegrzyn et al. 2003 [895]).

      Reviews (0)

        References (8)

        • Jones SM, Magnolfi CF, Cooke SK, Sampson HA.
          Immunologic cross-reactivity among cereal grains and grasses in children with food hypersensitivity.
          J Allergy Clin Immunol. 96(3):341-351.. 1995
          PUBMEDID: 7560636
        • Järvinen, K.-M., Turpeinen, M. & Suomalainen, H.
          Concurrent cereal allergy in children with cow's milk allergy manifested with atopic dermatitis.
          Clinical & Experimental Allergy 33 (8), 1060-1066.. 2003
          PUBMEDID: 12911779
        • Rasanen L, Lehto M, Turjanmaa K, Savolainen J, Reunala T.
          Allergy to ingested cereals in atopic children.
          Allergy 49:871-876.. 1994
          PUBMEDID: 7535982
        • Varjonen E, Vainio E, Kalimo K, Juntunen-Backman K, Savolainen J.
          Skin-prick test and RAST responses to cereals in children with atopic dermatitis. Characterization of IgE-binding components in wheat and oats by an immunoblotting method.
          Clin Exp Allergy 25:1100-1107.. 1995
          PUBMEDID: 8581843
        • Varjonen E, Savolainen J, Mattila L, Kalimo K.
          IgE-binding components of wheat, rye, barley and oats recognized by immunoblotting with sera from adult atopic dermatitis patients.
          Clin Exp Allergy 22:481-489.. 1994
          PUBMEDID: 8087661
        • Nowak-Wegrzyn A, Sampson HA, Wood RA, Sicherer SH.
          Food protein-induced enterocolitis syndrome caused by solid food proteins.
          Pediatrics 111(4 Pt 1):829-835.. 2003
          PUBMEDID: 12671120
        • Palosuo K, Alenius H, Varjonen E, Kalkkinen N, Reunala T.
          Rye gamma-70 and gamma-35 secalins and barley gamma-3 hordein cross-react with omega-5 gliadin, a major allergen in wheat dependent, exercise-induced anaphylaxis.
          Clin Exp Allergy 31:466-473.. 2001
          PUBMEDID: 11260160
        • Shewry PR .
          Avenins: The Prolamins of Oats.
          In: Seed Proteins (Shewry PR & Casey R eds), Kluwer, pp79-92. 1999
          PUBMEDID:

        Biochemical Information for 66 kDa Allergen

        • Allergen Name:66 kDa Allergen
        • Alternatve Allergen Names:
        • Allergen Designation:Major
        • Protein Family:Not known
        • Sequence Known?:No
        • Allergen accession No.s:

          N/A

        • 3D Structure Accession No.:Not determined
        • Calculated Masses:Not known
        • Experimental Masses:66 kDa
        • Oligomeric Masses:Not known
        • Allergen epitopes:Not known
        • Allergen stability:
          Process, chemical, enzymatic:          The stability cereal allergens from wheat, rye, barley and oat was studied by Varjonen et al. (1996) [911] who found that no processing condition entirely abolished IgE binding.
        • Nature of main cross-reacting proteins:In the study of Varjonen et al. (1994) [223] oat allergic sera cross-reacted with proteins from wheat, rye and barley.
        • Allergen properties & biological function:The major storage proteins of oats are not prolamins, the avenins, but globulins. The avenins are a highly polymorphic group with Mr 20-30,000 and a minor group Mr 30-40,000. The oat globulins consist of 12S species, with Mr 330,000 comprising six subunits of about Mr 55,000 comprising Mr 33,000 and Mr 23,000 chains linked by S-S bonds. It is likely that these are involved as allergens in oats.
        • Allergen purification:The purification (and properties) of oat avenins is reviewed by Shewry, 1999 [511] and that of the 12S globulins by Shotwell, 1999 [199].
        • Other biochemical information:Allergens have been identified by immunoblotting and gave variable IgE-binding patterns (Varjonen et al. 1994 [223], 1995 [225]). Thus in children (Varjonen et al. 1994 [223]) 67% of sera reacted with a 46 kDa band, 53% with a 66 kDa band, 35% with a 30 kDa band. Major allergen bands were 46 and 66 kDa. In adults (Varjonen et al. 1995 [225]) the most frequently recognised polypeptide was a 66 kDa protein, with 23 and 42 kDa proteins being recognised at a lower frequency.

        References (5)

        • Shewry PR .
          Avenins: The Prolamins of Oats.
          In: Seed Proteins (Shewry PR & Casey R eds), Kluwer, pp79-92. 1999
          PUBMEDID:
        • Varjonen E, Savolainen J, Mattila L, Kalimo K.
          IgE-binding components of wheat, rye, barley and oats recognized by immunoblotting with sera from adult atopic dermatitis patients.
          Clin Exp Allergy 22:481-489.. 1994
          PUBMEDID: 8087661
        • Varjonen E, Vainio E, Kalimo K, Juntunen-Backman K, Savolainen J.
          Skin-prick test and RAST responses to cereals in children with atopic dermatitis. Characterization of IgE-binding components in wheat and oats by an immunoblotting method.
          Clin Exp Allergy 25:1100-1107.. 1995
          PUBMEDID: 8581843
        • Varjonen E, Bjorksten F, Savolainen J.
          Stability of cereal allergens.
          Clin Exp Allergy. 26(4):436-443.. 1996
          PUBMEDID: 8732241
        • Shotwell MA.
          Oat Globulins in Seed Proteins (Shewry PR & Casey R eds)
          Kluwer pp389-400.. 1999
          PUBMEDID: