Allergy information for: Courgette, zucchini (Cucurbita pepo )

Clinical History

• Number of Studies:1-5
• Number of Patients:6-10
• Symptoms:The following symptoms have been reported after ingestion of cougette: Oral allergy syndrome, urticaria, angioedema, nausea, diarrhoea, pruritus (Reindl et al. 2000) [169], (Vieths et al., 2002) [885].

Skin Prick Test

• Number of Studies:1-5
• Food/Type of allergen:Raw zucchini (Reindl et al. 2000) [169]
• Protocol: (controls, definition of positive etc)

  Prick-to-prick-testing with raw zucchini and skin prick test with different commercial extracts, including , latex, and birch, ragweed, and grass pollen (Reindl et al. 2000) [169].

• Number of Patients:4 (Reindl et al. 2000) [169]
• Summary of Results:Prick-to-prick-testing with raw zucchini was positive in all 4 patients (Reindl et al. 2000) [169]

IgE assay (by RAST, CAP etc)

• Number of Studies:0
• Food/Type of allergen:Low temperature extracts (Reindl et al. 2000) [169], (Vieths et al., 2002) [885].
• IgE protocol:

  EAST (EAST classes correspond to RAST classes) (Vieths et al., 2002) [885], (Reindl et al. 2000) [169]

• Number of Patients:

  4 (Reindl et al. 2000) [169] (Vieths et al., 2002) [885].

• Summary of Results:

  All patients were positive in the zucchini EAST, with one class 3, two class 2, and one class 1 result (Reindl et al. 2000) [169] (Vieths et al. 2002) [885].

Immunoblotting

• Immunoblotting separation:Proteins were separated by SDS-PAGE under reducing conditions following Laemmli's method [948] (Reindl et al. 2000) [169] (Vieths et al. 2002) [885].
• Immunoblotting detection method:The proteins were transferred to nitrocellulose membranes by semidry blotting and blocked twice in 0.05 mol/L TRIS/hydrogen chloride buffer (pH 7.4), which contains 0.15 mol/L sodium chloride and 0.3% polysorbate 20 (TBST buffer). Nitrocellulose strips were probed with human sera (1:6.7). Immunostaining of bound IgE antibodies was performed with alkaline phosphatase conjugated mouse anti-human IgE (1:1000, 4 hours) and an alkaline phosphatase–staining kit (Vieths et al. 2002) [885] (Reindl et al. 2000) [169]
• Immunoblotting results:

  IgE from one patient strongly reacted with 3 proteins at about 16 to 17 kDa. Besides this, weaker bands ranging from 14.4 to 67 kDa were detected. Multiple bands above 29 kDa were recognized from IgE of two other sera. Another patient showed a totally different binding pattern. Only two bands at approximately 15 kDa were specifically detected (Reindl et al. 2000) [169] (Vieths et al. 2002) [885]

Oral provocation

• Number of Studies:1-5
• Food used and oral provocation vehicle:

  DBPCFCs were conducted with raw zucchini with cooked broccoli used as a placebo and to disguise the taste of zucchini. The placebo drink contained 50 g of cooked broccoli in a total of 143.5 g of drink (broccoli broth, cream, yogurt, water, and salt). The zucchini drink contained 20 g of raw zucchini (approximately 0.7 g per teaspoon) and 30 g of cooked broccoli in a total of 143.5 g of drink (same ingredients as above). (Reindl et al. 2000) [169]

  Raw zucchini was hidden in a broccoli drink containing cooked broccoli, broccoli fond, cream, yoghurt, water, and salt. After excluding reactivity to the placebo by open challenges, a spit-and-swallow protocol was applied. Patients who did not react to increasing amounts in the spit-protocol were allowed to swallow the drinks. Subjects consistently complaining about symptoms to the active drink three times but never to the placebo drink were considered to be responders. One millilitre of the active drink contained 0.144 g of raw celeriac or zucchini (Vieths et al. 2002) [885]

• Blind:yes
• Number of Patients:

  4 (Reindl et al. 2000) [169] (Vieths et al., 2002) [885].

• Dose response:

  A spit-and-swallow protocol was used. In the spit protocol the patients were advised to keep the drink in the mouth for 1 min and spit it out thereafter. Reactions were monitored for 15 min or longer until they subsided. Between switching the double blind labeled drinks the patient was instructed to rinse the oral cavity with water. First the patients were challenged with one teaspoon of placebo and continued with the first drink if no reaction occurred. The dose was doubled up to 8 teaspoons at intervals of 15 min. Then the drinks were switched and the second drink was given in the same setting. If no reaction occurred the spit protocol was continued up to 8 teaspons. Patients without reactions in the spit protocol underwent the swallow protocol, only allowing one drink a day and starting with one tablespoon and doubling the dose every 15 min up to a total of 143.5 g of the drink (Reindl et al. 2000) [169]

  A spit-and-swallow protocol was applied. Patients who did not react to increasing amounts in the spit-protocol were allowed to swallow the drinks. Subjects consistently complaining about symptoms to the active drink three times but never to the placebo drink were considered to be responders. One millilitre of the active drink contained 0.144 g of raw celeriac or zucchini (Vieths et al. 2002) [885]

• Symptoms:

  Oral allergy syndrome (OAS) with 0.7 g zucchini in the spit protocol, nausea, persistent diarrhea, pruritus, swelling of the throat (Reindl et al. 2000) [169] (Vieths et al. 2002) [885]

IgE cross-reactivity and Polysensitisation

Other Clinical information

Reviews (0)

References (3)

• Reindl J, Anliker MD, Karamloo F, Vieths S, Wuthrich B.
  Allergy caused by ingestion of zucchini (Cucurbita pepo): characterization of allergens and cross-reactivity to pollen and other foods.
  J Allergy Clin Immunol.106:379-85.. 2000
  PUBMEDID: 10932084
• Vieths S, Luttkopf D, Reindl J, Anliker MD, Wuthrich B, Ballmer-Weber BK
  Allergens in celery and zucchini
  Allergy. 57 Suppl 72:100-5.. 2002
  PUBMEDID: 12144566
• Laemmli UK
  Cleavage of structural proteins during the assembly of the head of bacteriophage T4
  Nature 227:680-685. 1970
  PUBMEDID: 5432063