Allergy information for: Coconut (Cocos nucifera)

Clinical History

• Number of Studies:1-5
• Number of Patients:6-10
• Symptoms:

  Couturier et al. (1994) [308] reported vomiting, diarrhoea, failure to thrive in an infant.

  Teuber and Peterson (1999) [205] reported angioedema, nausea, vomiting and asthma in 2 patients.

  Rosado et al. (2002) [685] reported anaphylaxis in a patient after eating cocnut icecream.

  Tella et al. (2003) [686] reported sudden abdominal pain, vomiting, oral allergy syndrome, and edema of the eyelids in a 3 year old child.

  Nguyen et al. (2004) [939] reported a patient with anaphylaxis with coconut and oral symptoms against hazelnut.

Skin Prick Test

• Number of Studies:1-5
• Food/Type of allergen:

  Rosado et al. (2002) [685] used prick tests with coconut ice-cream and fresh coconut.

  Tella et al. (2003) [686] used a prick test with fresh coconut and with other foods.

  Nguyen et al. (2004) [939] used fresh coconut and commercial extracts of coconut, almond, Brazil nut, cashew, pecan, walnut, and hazelnut.

• Protocol: (controls, definition of positive etc)

  Prick-Prick. Controls not reported.

• Number of Patients:

  3

• Summary of Results:

  Rosado et al. (2002) [685] found positive SPTs (wheal diameters of 9 and 13 mm, respectively) with both coconut ice-cream and fresh coconut.

  Tella et al. (2003) [686] found positive SPTs to coconut and negative SPTs to other foods except for a weak positive to almond (almond was negative on challenge).

  Nguyen et al. (2004) [939] found positive SPT to coconut and to several tree nut extracts.

IgE assay (by RAST, CAP etc)

• Number of Studies:0
• Food/Type of allergen:Slurry prepared from ground coconut, defatted and extracted in 0.06M Tris-HCl buffer containing 2% (w/v) SDS for 4 hours at 4°C. Slurry centrifuged at 3000g for 10min at 4°C. Supernatant passed through a 5.0-µm Millex-SV syringe filter (Millipore, Bedford, Mass) and then through an Extracti-Gel D AffinityPak Column (Pierce Chemical Co, Rockford, Ill) to remove residual SDS and concentrated (Teuber and Peterson 1999 [205]).
• IgE protocol:

  Teuber and Peterson (1999) [205] and Rosado et al. (2002) [685] used Pharmacia ImmunoCAP (Pharmacia, Inc, Diagnostics, Columbus, Ohio). Tella et al. (2003) [686] used RAST.

• Number of Patients:

  Teuber and Peterson (1999) [205] used sera from 2 patients.

  Rosaldo et al. (2002) [685] used sera from one patient.

  Tella et al. (2003) [686] used sera from one patient.

  Nguyen et al. (2004) [939] used sera from one patient.

• Summary of Results:

  Teuber and Peterson (1999) [205] report both patients had strongly positive results to English walnut (food; class 5 and 4, respectively), coconut (class 4 in both), almonds (class 5 and 3, respectively) and one had reactions to peanut (class 5).

  Rosaldo et al. (2002) [685] found that specific immunoglobulin E (IgE) to coconut (CAP System, Pharmacia) was 18.30 kU/l.

  Tella et al. (2003) [686] found serum-specific IgE to coconut was positive (RAST class 3).

  Nguyen et al. (2004) [939] reported that serum specific IgE was present for coconut, hazelnut, Brazil nut, and cashew.

Immunoblotting

• Immunoblotting separation:

  Teuber and Peterson (1999) [205] used a12% SDS-polyacrylamide Laemmli gel. Samples were boiled for 5 minutes in sample buffer (60 mmol/L Tris-HCl, pH 6.8, 2% SDS, 10% glycerol, 100 mmol/L dithiothreitol, and 0.01% bromophenol blue), and electrophoresis was carried out overnight at 8 mA constant current with a SE600 Vertical Slab Gel Unit (Pharmacia Biotech, Piscataway, NJ). A was used. A nonreduced sample (without dithiothreitol) was also subjected to SDS-PAGE.

• Immunoblotting detection method:Teuber and Peterson (1999) [205] transfered proteins to 0.22-µm nitrocellulose membranes (MSI, Westborough, Mass) overnight at 30 V with a TE 42 Transphor Electro-Transfer Unit (Pharmacia Biotech). The reduced protein coconut blot was cut into 4 mm–wide strips containing 25 µg of protein per strip. Strips were blocked for 1 hour at room temperature in PBS/3% (w/v) nonfat dry milk/0.2% (v/v)Triton X-100 (TX-100). Sera, which had been incubated overnight at room temperature in PBS/3% nonfat milk/0.2% TX-100 and 400 µg/mL nut or coconut extract, were added to the strips and incubated overnight at room temperature. Strips from the nonreduced coconut blot were incubated with sera from the 2 patients, atopic control sera, and a buffer control. The strips were then washed for 20 minutes 3 times in PBS/0.01% TX-100 and incubated overnight at room temperature with ¹²⁵I-antihuman IgE (Sanofi Diagnostics/Pasteur, Chaska, Minn) diluted 1:5 in the nonfat milk buffer. The strips were washed for 20 minutes 3 times and exposed to x-ray film at –70°C for 72 hours.
• Immunoblotting results:

  Teuber and Peterson (1999) [205] report that IgE binding proteins of 55, 36.5, and 35 kDa were observed on the nonreduced coconut protein immunoblot and these bands were immunologically cross-reactive with seed storage proteins from walnut, almond, and peanut by blot inhibition. The 55 kDa protein was only reactive to sera from one of the two patients.

  Rosaldo et al. (2002) [685] report intense reactivity to a protein of 78 kDa in the IgE immunoblot, as well as weaker bands for 15-20, 22 and 30 kDa. They suggest that the lack of reactivity at 35-36 kDa may be because their patient was monosensitised to coconut.

  Tella et al. (2003) [686] report that IgE-immunoblotting after SDS-PAGE under nonreducing conditions showed an IgE binding protein of about 18 kDa, and two weaker bands of about 25 and 75 kDa.

  Nguyen et al. (2004) [939] reported IgE binding to 35- and 50-kDa protein bands in the coconut and hazelnut extracts. Inhibition assays using coconut demonstrated complete inhibition of hazelnut specific IgE, but inhibition assays using hazelnut showed only partial inhibition of coconut specific IgE.

Oral provocation

• Number of Studies:1-5
• Food used and oral provocation vehicle:"maternalised" infant formula (Couturier et al. 1994 [308]).
• Blind:Open
• Number of Patients:1
• Dose response:Not stated
• Symptoms:Couturier et al. (1994) [308] reported vomiting and diarrhoea.

IgE cross-reactivity and Polysensitisation

Other Clinical information

Reviews (0)

References (7)

• Tella R, Gaig P, Lombardero M, Paniagua MJ, Garcia-Ortega P, Richart C.
  A case of coconut allergy
  Allergy 58(8):825-826.. 2003
  PUBMEDID: 12859570
• Rosado A, Fernandez-Rivas M, Gonzalez-Mancebo E, Leon F, Campos C, Tejedor MA.
  Anaphylaxis to coconut.
  Allergy 57(2):182-3. 2002
  PUBMEDID: 11929430
• Kim KT and Hussain H
  Prevalence of food allergy in 137 latex-allergic patients.
  Allergy Asthma Proc 20: 95-97.. 1999
  PUBMEDID: 10209685
• Suraiya C
  Food allergies
  In: Indian Journal of Clinical Practice, Allergy and asthma: a clinical primer Shaikh W, Editor, pp94-98. 1999
  PUBMEDID:
• Teuber SS and Peterson WR
  Systemic allergic reaction to coconut (Cocos nucifera) in 2 subjects with hypersensitivity to tree nut and demonstration of cross-reactivity to legumin-like seed storage proteins: new coconut and walnut food allergens.
  J Allergy Clin Immunol 103: 1180-1185.. 1999
  PUBMEDID: 10359903
• Couturier P, Basset-Stheme, D, Navette N, Sainte-Laudy J
  [A case of coconut oil allergy in an infant: responsibility of "maternalized" infant formulas] French
  J Allerg Immunol (Paris) 26: 386-387. 1994,
  PUBMEDID: 7702732
• Nguyen SA, More DR, Whisman BA, Hagan LL.
  Cross-reactivity between coconut and hazelnut proteins in a patient with coconut anaphylaxis.
  Ann Allergy Asthma Immunol. 92(2):281-4.. 2004
  PUBMEDID: 14989401

Biochemical Information for Cocosin

• Allergen Name:Cocosin
• Alternatve Allergen Names:11S seed storage globulin
• Allergen Designation:
• Protein Family:Pfam PF00190; Cupin; 11S seed storage globulin
• Sequence Known?:No
• Allergen accession No.s:N/A
• 3D Structure Accession No.:Not determined
• Calculated Masses:N/A
• Experimental Masses:

  35 and 36kD - Acidic subunit only (Teuber et al. 1999) [205]
  32 kDa and 22 kDa by SDS-PAGE and 250-300 kDa by gel filtration (Plumb et al. 1990 [688]).

• Oligomeric Masses:

  Hexamer

• Allergen epitopes:Not known but IgE only recognised the acidic polypeptide in a reduced form, and not when disulphide bonded to the smaller basic polypeptide.
• Allergen stability:
  Process, chemical, enzymatic:Not known but likely to be thermostable like other 11S seed storage globulins.
• Nature of main cross-reacting proteins:Walnut (Juglans regia), peanut and almond extracts inhibited IgE binding to coconut proteins. Teuber and Peterson (1999) [205] suggest primary sensitisation is to walnut, with coconut a clinically relevant cross-reaction.
• Allergen properties & biological function:Cocosin is one of the legumin family of 11S seed storage globulins.
• Allergen purification:Meat from coconut was ground and defatted with petroleum ether and extracted overnight in 0.2M sodium phosphate, 0.2M potassium phosphate and 10% (w/v) NaCl (pH 6.8) at 4° C and for 30 min. at 40° C. Slurry filtered (several times with filter paper down to 0.22 µm pores) and butanol (33% v/v) added to the solution with stirring. Centrifuged at 16000 X g and the butanol decanted off. Dialysed against distilled water (several changes) and centriguged at 16000 X g for 30 min. Precipitate resuspended in 4% (w/v) ammonium sulfate and centrifuged at 38000 X g for 1 hour. The 33-50% ammonium sulfate cut was collected (centrifuging at 38000 X g for 1 hour) and the precipitate dialysed before gel filteration on Superose 6 HR 10/30 in 50 mM Tris/HCl pH 8.2 with 0.5M NaCl. The main peak was collected (Plumb et al. 1990 [688]).
• Other biochemical information:

  Two studies on the 11S globulin of coconut, cocosin, describe purification, characterization and crystallization (Balasundaresan et al. 2002 [687]; Carr et al. 1990 [688]). Sjögren and Spychalski in their initial purification (1930) gave a molecular mass of 208 kDa which is lower than more recent estimates.

  Teuber et al. (1999) [205] suggested that the 35 and 36kD polypeptides probably correspond to the acidic polypeptides of the 11S globulin but that the 55kD IgE binding protein is not the 11S globulin.

References (3)

• Carr HJ, Plumb GW, Parker ML, Lambert N
  Characterization and crystallization of an 11S seed storage globulin from coconut (Cocos nucifera)
  FOOD CHEMISTRY 38 (1): 11-20. 1990
  PUBMEDID:
• Balasundaresan D, Sugadev R, Ponnuswamy MN.
  Purification and crystallization of coconut globulin cocosin from Cocos nucifera.
  Biochim Biophys Acta 1601(1):121-122.. 2002
  PUBMEDID: 12429510
• Teuber SS and Peterson WR
  Systemic allergic reaction to coconut (Cocos nucifera) in 2 subjects with hypersensitivity to tree nut and demonstration of cross-reactivity to legumin-like seed storage proteins: new coconut and walnut food allergens.
  J Allergy Clin Immunol 103: 1180-1185.. 1999
  PUBMEDID: 10359903