Allergy information for: Avocado (Persea americana )

  • Name: Avocado
  • Scientific Name: Persea americana
  • Occurrence: Avocado is consumed as a fresh fruit and in sauces such as guacamole.
  • Allergy Information:

    Avocado allergy can take two different forms: one associated with allergy to tree pollen, such as birch, and another type associated with latex allergy. People with birch-pollen allergy can develop symptoms either immediately or up to 1 hour after eating fresh avocado or an avocado-containing food. Symptoms comprise local reactions in the mouth and throat with itching and inflammation (called oral allergy syndrome, OAS).

    Others develop an avocado allergy because of the similarity between the allergens in avocado and natural rubber latex (e.g. gloves, condoms, balloons) a condition known as the latex-fruit syndrome. Symptoms developed by these individuals comprise generalised urticaria, abdominal pain, vomiting and sometimes life-threatening symptoms. These individuals may also develop adverse reactions to chestnut, banana, mango and kiwi.
  • Other Information:
  • Taxonomic Information: NEWT http://www.ebi.ac.uk/newt/display?from=ca&search=3435
  • Last modified: 18 October 2006

Reviews (0)

    References (0)

      Clinical History

      • Number of Studies:6-10
      • Number of Patients:>50
      • Symptoms:

        7 patients developed systemic anaphylaxis and 2 angioedema (Ahlroth et al. 1995) [255]

        Systemic anaphylaxis in 7 patients with angioedema/urticaria in 6, vomiting in 2, bronchial asthma in 1, and rhinoconjuntivitis in 1 (Blanco et al. 1994) [287].

        Urticaria and lip pruritus or glossitis in 25 patients. Rhinitis in 3 patients , facial angioedema in 2 patients and anaphylaxis in 2 patients (Blanco et al. 1994) [288].

        The prevalence of clinical reactions to avocado among 17 latex-allergic patients was: 72% with asymptomatic sensitivity; 16% with anaphylaxis ; 2% with pruritus and 4% with generalized urticaria (Blanco et al. 1999) [289].

        The clinical data for 16 avocado-allergic patientes was: 6 patients had systemic anaphylactic episodes; 2 with urticaria; 4 with angioedema; 3 with bronchial asthma and 4 with oral allergy syndrome (Chen et al. 1998) [36].

      Skin Prick Test

      • Number of Studies:11-20
      • Food/Type of allergen:

        Fresh avocado (Blanco et al 1994) [288] and (Blanco et al 1994) [287], (Lavaud et al 1995) [102], (Ahlroth et al. 1995) [255], (Telezdiaz et al. 1995) [962]

        Dilution 1/10 of a commercially available avocado extract (Beezhold et al 1996) [281].

        Avocado extracts prepared as follows. Avocado pulp was ground in a mortar with cold acetone and then defatted with the same solvent (3× 1:5 (wt/vo)] for 1 hour at 4° C). The dried residues were extracted with 0.1 mol/L sodium phosphate buffer (pH 7.0) in 0.15 mol/L NaCl (PBS) (1× 1:5 (wt/vol) for 1 hour at 4° C), and after centrifugation, the supernatants were dialyzed against H2O and freeze-dried (crude extracts). To obtain protein preparations enriched in chitinases, the PBS extracts (supernatants) were salted-out with 80% saturated (NH4)2SO4. The pellets were collected by centrifugation, dissolved in PBS buffer, and then the pH was brought to 3.5 by addition of 0.1 mol/L HCl. After centrifugation, the supernatants were dialyzed against distilled H2O and freeze-dried. Purified class I (Prs a 1) and class II avocado chitinases. (Blanco et al 1999) [289]

        Avocado extracts. The consumable parts of avocado fruits (400 g) were homogenized in 1 L acetone solution containing 10% TCA at -70 °C, gently stirred for one hour and centrifuged for 10 min (-20 °C, 36 000 g ). The pellet was resuspended in acetone at -70 °C and centrifuged again. Residual acetone was removed by lyophilization (Posch et al. 1999) [163]

        Avocado extract and fresh fruit (Isola et al. 2003) [598]

      • Protocol: (controls, definition of positive etc)

        The positive results of the tests were designated as follows: + ; positive surface reference (histamine control: 10 mg/ml), ++ ; positive reference, +++ > positive reference, and ++++ > twice reference (Lavaud et al 1995) [102]

        Prick-prick SPT results were graded using the size of histamine (10 mg/ml) reaction as a reference as follows: 4+ (2x histamine wheal), 3+ (1x histamine wheal), 2+ (0.5x histamine wheal), 1+ (<0.5x histamine wheal), and 0 (negative). (Ahlroth et al. 1995) [255]

        Histamine and the diluent were used as positive and negative controls respectively (Beezhold et al 1996) [281].

        Patients with a negative SPT to extracts were tested by prick-to-prick with the fresh fruit (Isola et al. 2003) [598]

      • Number of Patients:

        25 patients with latex allergy. 9 of them showed avocado hypersensitivity with positive SPT. (Blanco et al 1994) [288]

        17 patients with immediate-hypersensitivity to avocado. All patients were SPT positive with avocado (cultivar Strong) and 14 with the Hass avocado variety. (Blanco et al 1994) [287]

        17 patients with latex allergy, 10 of them with a clinical history of avocado allergy (Lavaud et al 1995) [102]

        18 patients with latex allergy (Ahlroth et al. 1995) [255]

        47 latex allergic patients. (Beezhold et al 1995) [281]

        100 consecutive atopic patients with allergic rhinitis (Telezdiaz et al. 1995) [962]

        18 latex-allergic patients with a clinical history of allergy to chestnut, avocado, or both (Blanco et al 1999) [289]

        20 latex-allergic subjects (Posch et al. 1999) [163]

        82 patients with latex allergy.(Isola et al. 2003) [598]

      • Summary of Results:

        9/25 patients showed avocado hypersensitivity with a positive skin prick test. (Blanco et al. 1994) [288]

        All patients had a positive SPT with avocado (cv. Strong) but only 14 had a positive SPT with cv. Hass. (Blanco et al. 1994)

        10/17 patients with clinical history of avocado allergy had a positive SPT to avocado. (Lavaud et al 1995) [102]

        7/11 patients had a positive SPT to avocado (Ahlroth 1995).

        53% of the latex -allergic patients and only 7% of the control non allergic were SPT positive to avocado (Beezhold et al. 1995)

        The avocado allergen Prs a 1 elicited positive SPT responses in 12 out of 18 (67%) latex- fruit allergic patients. By contrast, avocado class II chitinase did not show any SPT responses . (Blanco et al. 1999)

        8 of the patients were SPT positive with avocado extract and 3 with a negative SPT to extract were positive by prick-prick to avocado (Isola et al. 2003)

        12 subjects had a positive response (Posh et al. 1999)

        Of the 100 atopic patients not selected for avocado sensitivity, 21 had positive SPTs to avocado. (Telezdiaz et al. 1995)

      IgE assay (by RAST, CAP etc)

      • Number of Studies:0
      • Food/Type of allergen:

        The pulp of avocado was extracted with NTE 1N solution: NaCl 1mol/L, Tris 0,1mol/lL ethylenediaminetetraacetic acid 0.01mol/L (Lavaud et al 1995) [102]

        Avocado extracts (Posch et al. 1999)

      • IgE protocol:

        RAST (Lavaud et al 1995) [102]

        CAP System RAST FEIA. Levels of specific IgE higher than 0.35 kU/L (class 1 and up) were considered positive (Blanco et al. 1999)

      • Number of Patients:

        17 patients with latex allergy (Lavaud et al 1995) [102]

        18 latex-allergic patients allergic with a clinical history to chestnut, avocado, or both (Blanco et al. 1999)

        20 latex-allergic subjects (Posch et al. 1999)

      • Summary of Results:

        10/17 had RAST responses to avocado Patients were grouped as follows: Group 1 comprised serum samples from patients with a clinical history of latex allergy, no clinical evidence for a fruit allergy, positive prick test and RAST responses to latex, negative SPT responses to fruits; Group 2 comprised serum samples from 10 patients with a latex allergy and a fruit allergy (suggestive symptoms, positive prick test and RAST responses) (Lavaud et al 1995) [102]

        3/18 were IgE negative (Blanco et al. 1999)

        13 subjects had a positive response by CAP (Posch et al. 1999)

      Immunoblotting

      • Immunoblotting separation:

        Proteins were separated on 15% acrylamide SDS-PAGE under reducing conditions (Lavaud et al 1995) [102]

        The allergen extracts were separated by sodium dodecylsulfate–polyacrylamide gel electrophoresis (SDS-PAGE) with a 5% stacking gel and a 13% polyacrylamide gel (Moller et al. 1998).

      • Immunoblotting detection method:

        The proteins were transferred onto a nitrocellulose sheet. The nitrocellulose sheet was blocked with 3% (w/v) skimmed milk and incubated with patient sera (1:100). IgE antibody detection was performed with alkaline phosphatase-conjugated goat anti-human IgE (1:100) and blots were developed with AP Conjugate Substrate (Lavaud et al 1995) [102].

        The proteins were transferred onto a nitrocellulose membrane (0.2 µm) using a semi-dry blotting apparatus. Membranes were cut and blocked with 5% (w/v) skimmed milk and 0.1% (v/v) Tween 20 in PBS. The strips were incubated with patient sera. After incubation with rabbit anti-human IgE (1:4000), biotinylated goat anti-rabbit IgG (1:6000) and streptavidin-horseradish peroxidase-conjugated (1:20000), the blots were stained with 3,3",5,5"-tetramethylbenzidine-dioctylsodiumsulphosuccinate (Moller et al. 1998).

      • Immunoblotting results:

        All patients' sera from group 2 (fruit and latex allergy) reacted to avocado proteins. The most important allergen in the extract was at about 30 kDa. A minor band was found at 21 kDa in one serum. Two sera from group 1 (monoallergy to latex) reacted with the 30 kDa protein (Lavaud et al 1995) [102].

        IgE binding components of 43, 52, 58 and 65 kDa were detected by 3, 5, 7 and 5 serea respectively. One serum showed IgE binding to a protein of 27 kDa (Moller et al. 1998).

      Oral provocation

      • Number of Studies:1-5
      • Food used and oral provocation vehicle:Stewed avocado fruit (Posch et al. 1999)
      • Blind:DBPCFC
      • Number of Patients:2 latex-allergic subjects with positive SPT and CAP responses to avocado and latex.
      • Dose response:None
      • Symptoms:

        Oral as well as gastro-intestinal symptoms after ingesting avocado fruit

      IgE cross-reactivity and Polysensitisation

      Cross-reactivity among latex, avocado, and banana (Blanco et al. 1994) [288], (Blanco et al. 1999), (Lavaud et al 1995) [102], (Delbourg et al. 1996) (Chen et al. 1998), (Brehler et al. 1997), has been demonstrated by RAST-inhibition or immunoblot inhibition (Moller et al. 1998).

      Cross-sensitization between avocado and latex proteins is explained by cross-reactivity with latex proteins mainly a 20-kDa allergen, most likely prohevein (Sowka et al. 1998)

      Other Clinical information

      Reviews (0)

        References (14)

        • Isola S, Ricciardi L, Saitta S, Fedele R, Mazzeo L, Fogliani O, Gangemi S, Purello-D'Ambrosio F.
          Latex allergy and fruit cross-reaction in subjects who are nonatopic.
          Allergy Asthma Proc. 24(3):193-197.. 2003
          PUBMEDID: 12866323
        • Brehler R, Theissen U, Mohr C, Luger T
          "Latex-fruit syndrome": frequency of cross-reacting IgE antibodies.
          Allergy 52: 404-410.. 1997
          PUBMEDID: 9188921
        • Beezhold D.H., Sussman G. L., Liss G.M. and Chang N.S.
          Latex allergy can induce clinical reactions to specific foods.
          Clin. Exp. Allergy 26: 416-422.. 1996
          PUBMEDID: 8732238
        • Lavaud F, Prevost A, Cossart C, Guerin L, Bernard J, Kochman S
          Allergy to latex, avocado pear, and banana: Evidence for a 30Kd antigen in immunoblotting.
          J. Allergy Clin Immunol 95: 557-564.. 1995
          PUBMEDID: 7852672
        • Ahlroth M, Alenius H, Turjanmaa K, Makinen-Kiljunen S, Reunala T, Palosuo T.
          Cross-reacting allergens in natural rubber latex and avocado.
          J. Allergy Clin. Immunol. 96:167-173.. 1995
          PUBMEDID: 7636053
        • Blanco C., Diaz-Perales A., Collada C., Sánchez-Monge R., Aragoncillo C., Castillo R., Ortega O., Alvarez M., Carrillo T. and Salcedo G.
          Class I chitinases as potential panallergens involved in the latex-fruit syndrome.
          J Allergy Clin Immunol. 103(3 Pt 1):507-513. 1999
          PUBMEDID: 10069887
        • Blanco C., Carrillo T., Castillo R., Quiralte J. and Cuevas M.
          Latex allergy: Clinical features and cross-reactivity with fruits.
          Ann. Allergy 73(4): 309-314.. 1994
          PUBMEDID: 7943998
        • Blanco C., Carrillo T., Castillo R., Quiralte J. and Cuevas M.
          Avocado hypersensitivity.
          Allergy 49: 454-459.. 1994
          PUBMEDID: 8074265
        • Posch A., Wheeler C.H., Chen Z., Flagge A., Dunn M.J., Papenfuss F., Raulf -Heimsoth M. and Bauer X.
          Class I endochitinase containing a hevein domain is the causative allergen in latex-associated avocado allergy.
          Clin. Exp. Immunol. 29: 667-672. 1999
          PUBMEDID: 10231327
        • Chen Z., Posch A., Cremer R., Raulf-Heimsoth M. and Baur X.
          Identification of hevein (Hev b 6.02) in Hevea latex as a major cross-reacting allergen with avocado fruit in patients with latex allergy.
          J.Allergy Clin. Immunol. 102: 476-481.. 1998
          PUBMEDID: 9768591
        • Moller M, Kayma M, Vieluf D, Paschke A, Steinhart H
          Determination and characterization of cross-reacting allergens in latex, avocado, banana, and kiwi fruit.
          Allergy 53: 289-296.. 1998
          PUBMEDID: 9542609
        • Sowka S, Hsieh L, Krebitz M, Akasawa A, Martin,BM, Starrert D, Peterbauer CK, Schneiner O, Breiteneder H
          Identification and cloning of Prs a 1 a 32-kDa endochitinase and major allergen of avocado, and Its expression in the yeast Pichia pastoris.
          J.Biol.Chem. 273: 28091-28097. 1998
          PUBMEDID: 9774427
        • Telezdiaz G, Ellis MH, Moralesrusso F, Heiner DC
          Prevalence of avocado allergy among atopic patients
          Allergy Proceedings 16 (5): 241-243. 1995
          PUBMEDID: 8566736
        • Delbourg MF, Guilloux L, Moneret-Vautrin DA, Ville G
          Hypersensitivity to banana in latex-allergic patients. Identification of two major banana allergens of 33 and 37 kD
          Ann. Allergy Asthma Immunol. 76: 321-326.. 1996
          PUBMEDID: 8612113

        Biochemical Information for Pers a 1

        • Allergen Name:Pers a 1
        • Alternatve Allergen Names:Chitinase class I
        • Allergen Designation:Major
        • Protein Family:

          Chitin recognition protein, Pfam, PF00187

          Chitinase class I, Pfam, PF00182

        • Sequence Known?:Yes
        • Allergen accession No.s:

          P93680: Swissprot: http://ca.expasy.org/cgi-bin/niceprot.pl?P93680

          Z78202 EMBL

        • 3D Structure Accession No.:Not determined
        • Calculated Masses:32011.82 Da
        • Experimental Masses:32 kDa
        • Oligomeric Masses:
        • Allergen epitopes:Not known
        • Allergen stability:
          Process, chemical, enzymatic:

          Prs a 1 is a thermolabile allergen (Sanchez-Monge et al. 2000) [1076]

          This protein is degraded when subjected to simulated gastric fluid. The resulting peptides were reactive both in vivo and in vitro (Diaz-Perales et al. 2003) [904]

        • Nature of main cross-reacting proteins:

          Prs a 1 is a panallergen involved in the latex-fruit syndrome. There are IgE cross-reactions with other class I endochitinases of fruits such as banana, kiwi, mango and seeds like chestnut and the homologous chitin-binding domain of the latex allergen, hervein. (Sanchez-Monge et al. 2000) [1076]

          Sequence comparison showed that Prs a 1 and hevein had 70% similarity in their chitin-binding domains (Sowka et al. 1998) [519]

        • Allergen properties & biological function:Prs a 1 is an endochitinase with a possible defence function against plant pathogens and belongs to pathogenesis-related protein family PR3.
        • Allergen purification:

          Avocado pulp is ground in cold acetone and then defatted with 3x 1:5 (w/v) of the same solvent for 1h at 4C. After allowing solvent to evaporate the dried residue is extracted with 5 volumes of 0.1M sodium phosphate buffer, pH 7.0 containing 0.15M NaCl (PBS) for 1h at 4C. After centrifugation the chitinase is precipitated from the supernatant with 80% ammonium sulphate. Following centrifugation the pellet was dissolved in PBS and acidified to pH 3.5 with 0.1M HCl. After another centrifugation step the supernatant was retained, dialysed against water and freeze-dried. The chitinases were then purified by affinity chromatography in on a column of regenerated chitin in 20mM Tris-HCl pH 8.0 and eluted using a step-wise gradients of 20mM sodium acetate pH 5.5, followed by 20mM acetic acid pH 3.2. Chitinase containing fractions were collected and then subjected to a final purification step on a cation exchange column (MonoS) equilibrated in 10mM sodium acetate (pH 5.3) and eluted with a salt gradient to 0.5M NaCl. (Diaz-Perales et al 1998) [315].

          Prs a 1 has also been expressed in the yeast Pichia pastoris and purified by cation exchange chromatography (Sowka et al. 1998) [519].
        • Other biochemical information:

          Prs a 1 has a calculated pI of 8.43 (Sowka et al. 1998) [519].

        References (5)

        • Diaz-Perales A, Blanco C, Sanchez-Monge R, Varela J, Carrillo T, Salcedo G
          Analysis of avocado allergen (Prs a 1) IgE-binding peptides generated by simulated gastric fluid digestion
          J Allergy Clin Immunol. 112(5):1002-7. 2003
          PUBMEDID: 14610495
        • Posch A., Wheeler C.H., Chen Z., Flagge A., Dunn M.J., Papenfuss F., Raulf -Heimsoth M. and Bauer X.
          Class I endochitinase containing a hevein domain is the causative allergen in latex-associated avocado allergy.
          Clin. Exp. Immunol. 29: 667-672. 1999
          PUBMEDID: 10231327
        • Sowka S, Hsieh L, Krebitz M, Akasawa A, Martin,BM, Starrert D, Peterbauer CK, Schneiner O, Breiteneder H
          Identification and cloning of Prs a 1 a 32-kDa endochitinase and major allergen of avocado, and Its expression in the yeast Pichia pastoris.
          J.Biol.Chem. 273: 28091-28097. 1998
          PUBMEDID: 9774427
        • Diaz-Perales A, Collada C, Blanco C, Sanchez-Monge R, Carrillo T, Aragoncillo C, Salcedo G
          Class I chitinases with hevein-like domain, but not class II enzymes, are relevant chestnut and avocado allergens.
          J. Allergy Clin. Immunol 102: 127-133. 1998
          PUBMEDID: 9679856
        • Sanchez-Monge R, Blanco C, Perales AD, Collada C, Carrillo T, Aragoncillo C, Salcedo G
          Class I chitinases, the panallergens responsible for the latex-fruit syndrome, are induced by ethylene treatment and inactivated by heating
          J Allergy Clin Immunol. 106(1):190-5.. 2000
          PUBMEDID: 10887324