Allergy information for: Date (Phoenix dactylifera )

Clinical History

• Number of Studies:1-5
• Number of Patients:11-20
• Symptoms:Ingestion of dates is known to cause itching of the mouth and throat in some individuals and even anaphylactic shock (Gonzalo et al 1997; Kwaasi et al. 1999)

Skin Prick Test

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

  Extract of fruits from eight cultivars (Kwaasi et al. 1999). After washing the fruits, the seeds were aseptically removed and then extracted in phosphate-buffered saline (PBS, 1:5 w/v). Afterward, 2% polyvinylpolypyrrolidone (PPVP), 2 mM ethylene-diaminetetraacetic acid (EDTA), and 10 mM diethyldithiocarbamate (DIECA) were added to prevent proteolysis, and thiomersal (0.02%) was added as preservative. The slurry was centrifuged (20 000 g for 30 min at 10°C), and the supernatant was extensively dialyzed (4°C, 72 h) and freeze-dried. Some lyophilized samples were reconstituted in distilled water (1/10, w/v) and glycerinated (1:20 w/v) for skin testing.

  Fresh date and extracts (Gonzalo et al. 1997). Crushes dates without seeds were extracted at 20% (w/v) by shaking for 1h at room temperature in ammonium bicarbonate 50 mM, pH 8, followed by 30 min, 10°C, centrifugation at 20 000 g. The supernatant was filtered, delaysed against water, lyophilised and stored at 4 until use.

• Protocol: (controls, definition of positive etc)Prick-prick technique. Saline solution was used as a negative control and 10 mg/ml phosphate histamine as a positive control. Reactions were positive if the largest wheal diameter was > 3 mm (Gonzalo et al. 1997).
• Number of Patients:

  19 patients (Kwaasi et al. 1999).

  A 65-year-old man (Gonzalo et al. 1997)

• Summary of Results:

  All the 19 patients were SPT positive to at least two fruit extracts (Kwaasi et al. 1999).

  SPT was positive with fresh date and date extract (Gonzalo et al. 1997)

IgE assay (by RAST, CAP etc)

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

  Extract fruits from eight cultivars (Kwaasi et al. 1999). After washing the fruits, the seeds were aseptically removed and then extracted in phosphate-buffered saline (PBS, 1:5 w/v). Afterward, 2% polyvinylpolypyrrolidone (PPVP), 2 mM ethylene-diaminetetraacetic acid (EDTA), and 10 mM diethyldithiocarbamate (DIECA) were added to prevent proteolysis, and thiomersal (0.02%) was added as preservative. The slurry was centrifuged (20 000 g for 30 min at 10°C), and the supernatant was extensively dialyzed (4°C, 72 h) and freeze-dried.

  Date extracts (Gonzalo et al. 1997). Crushes dates without seeds were extracted at 20% (w/v) by shaking for 1h at room temperature in ammonium bicarbonate 50 mM, pH 8, followed by 30 min, 10°C, centrifugation at 20 000 g. The supernatant was filtered, delaysed against water, lyophilised and stored at 4 until use.

• IgE protocol:

  RAST, ELISA and Immunoblotting (Kwaasi et al. 1999 and 2002).

  RAST, histamine release and immunoblotting (Gonzalo et al. 1997)

• Number of Patients:

  19 patients (Kwaasi et al. 1999 and 2002).

  A 65-year-old man (Gonzalo et al. 1997)

• Summary of Results:

  Negative results of RAST were due to the quality of the date extract. However specific IgE to date allergens was observed with a histamine release assay (Gonzalo et al. 1997)

  RAST was 1+ in 3 patients, 2++ in 3 patients, 3+++ in three patients and 4++++ in other 4 patients. IgE ELISA results revealed that sera from seven of the patients in whom positive SPT responses were elicited to the different extracts gave relatively low ELISA scores (Kwaasi et al 1999).

  66% of individuals with date hypersensity had serum IgE to putative date fruit profilin (Kwaasi et al. 2002)

Immunoblotting

• Immunoblotting separation:

  SDS-PAGE was carried out using 13.5% separating and 5% stacking gels (Kwaasi et al. 1999)

  SDS-PAGE was carried out using either 13% or 5-15% gradient gels (Kwaasi et al. 2002)

• Immunoblotting detection method:

  Polypeptides were electrotransferred from SDS-PAGE gels onto nitrocellulose membranes (0.4 µm), and the membranes were blocked with either 3% (w/v) BSA or 5% (w/v) nonfat dried milk in PBS or TBS. These were then allowed to react overnight with individual or pooled human sera appropriately diluted. For IgE blots, membranes were probed with rabbit anti-human IgE followed, after washing, by goat anti-rabbit alkaline phosphatase-labeled secondary antibody (Kwaasi et al. 1999)

  The protein components of extracts were electrotransferred onto nitrocellulose membranes (0.45 µm pore size). After transfer, the membranes were treated with 3% (w/v) BSA to block non-specific binding sites. Membranes were allowed to react with appropriate dilutions of the various sera and antisera followed after washes by the addition of secondary antibodies (Kwaasi et al. 2002)

• Immunoblotting results:

  All sera from the 13 fruit and 16 pollensensitive individuals reacted strongly to two main bands of 6.5-14 and 27-33 kDa. About 50% of sera from both groups bound to a band of 54-58 kDa with minor reactivities to bands of 44 and 70 kDa(Kwaasi et al. 1999)

  Patients reacted to two main bands of 14 and 30 kDa (Kwaasi et al. 2002).

Oral provocation

• Number of Studies:
• Food used and oral provocation vehicle:None
• Blind:
• Number of Patients:
• Dose response:
• Symptoms:

IgE cross-reactivity and Polysensitisation

Other Clinical information

Reviews (0)

References (3)

• Kwaasi A, Parhar RS, AlSedairy ST, Collison KS, AlMohanna FA, Harfi HA, Panzani RC
  Allergy to date fruits: characterization of antigens and allergens of fruits of the date palm (Phoenix dactylifera L.)
  Allergy. 54(12):1270-7.. 1999
  PUBMEDID: 10688430
• Gonzalo MA, Moneo I, Ventas P, Polo F, Garcia JM
  Immediate hypersensitivity reaction to date
  Allergy. 52(5):598-9.. 1997
  PUBMEDID: 9201379
• Kwaasi AA, Harfi HA, Parhar RS, Saleh S, Collison KS, Panzani RC, Al-Sedairy ST, Al-Mohanna FA
  Cross-reactivities between date palm (Phoenix dactylifera L.) polypeptides and foods implicated in the oral allergy syndrome
  Allergy. 57(6):508-18. 2002
  PUBMEDID: 12028116