Oropharyngeal symptoms characteristic of the oral allergy syndrome (OAS) (Pastorello et al. 1994) [156], (Pastorello et al. 2001) [152]

In addition, Rodriguez et al. (2000) [491] described gastrointestinal symptoms and generalised anaphylaxis

Fresh fruit and commercial plum extracts (Pastorello et al. 1994) [156]

Commercial plum extract (Asero et al. 2000) [10]

Fresh fruit (Rodriguez et al. 2000) [491]

Pastorello et al. 1994 [156] used histamine dihydrochloride (10 mg/mL) as a positive control, and the glycerol-containing diluent of the prick solution as a negative control. A wheal graded at least 2+was regarded as positive.

SPT were carried out on the volar side of the forearm with a sterile, 1 mm-tip lancet pricking through the drop of the extract. Readings were taken after 15 min. Histamine (10 mg/mL) and saline solution were used as positive and negative controls repectively. Wheals with a diameter below 50% of the positve control were considered negative. (Asero et al. 2000) [10].

SPT were carried out by the prick-prick technique. Histamine (10 mg/mL) and saline solution were used as positive and negative controls repectively. A positive skin prick test result was defined as a mean (average of orthogonal to largest diameter) wheal of 3 mm or greater (after subtracting the diameter of the wheal induced by the diluent control). (Rodriguez et al. 2000) [491]

21 patients (Pastorello et al. 1994) [156]

498 patients (Asero et al. 2000) [10]

28 patients (Rodriguez et al. 2000) [491]

All patients of Pastorello et al. 1994 [156] showed a positive SPT.

49 patients (10%) had a positive SPT (Asero et al. 2000) [10]

Skin prick tests were positive in 19 patients (Rodriguez et al. 2000) [491]

28 patients (Rodriguez et al. 2000) [491]

23 patients (Pastorello et al. 2001) [152]

16 out of 28 patients had specific IgE to plum (Rodriguez et al. 2000) [491]

All patients had specific IgE to plum (Pastorello et al. 2001) [152]

The extracts were separated in a discontinuous buffer system in an SDS-polyacrylamide gradient gel with a 6% stacking gel and a 7.5% to 20% separation gradient. Samples were boiled and reduced with beta-mercaptoethanol (Pastorello et al. 1994) [156]

The proteins were electroblotted to a nitrocellulose membrane, pore size 0.2 to 0.45 µm using a Trans-Blot Cell. The membrane was blocked with phosphate-buffered saline pH 7.4 with 0.5% (v/v) Tween 20 and incubated with the sera (diluted 1:4, v/v). The IgE-binding components were detected with iodine 125–labeled anti-human IgE antiserum diluted 1:4 (Pastorello et el. 1994) [156].

87% of sera (14 of 16) of Pastorello et al. 1994 [156], showed Ig E binding to a 13 kDa protein and 77% (14 of 18) to a 30 kDa protein . The other IgE -binding components were: 70 kDa (5 of 16, 31%), 20 kDa (6 of 16, 37%), 14 kDa (6 of 16, 37%), 40 kDa (6 of 16, 37%), 30 kDa (3 of 16, 18.7%) and 48 kDa (3 of 16, 18.7%). These bands were detectable in all but one patient with negative responses to birch pollen.

Plum (Pastorello et al. 1994) [156], (Pastorello et al. 2001) [152]

A total of 17 g of dehydrated whole fruit was masked in a mix of orange (200 mL) and pineapple (200 mL) juices, sugar (16 g), wheat meal (13 g), and liquid coloring (Rodriguez et al. 2000) [491]

Open (Pastorello et al. 1994) [156], (Pastorello et al. 2001) [152]

Open and DBPCFC (Rodriguez et al. 2000) [491]

21 patients (Pastorello et al. 1994) [156]

23 patients (Pastorello et al. 2001) [152]

Patients chewed the fruit for 1 minute and then spat it out. If no symptoms appeared within 15 minutes, the challenge was repeated with increasing amounts from 250mg up to 64 g. Patients were asked not to spit out the last two doses but to swallow the fruit instead. (Pastorello et al. 1994) [156]. The same protocol was used by Pastorello et al. (2001) [152] but using doses from 4g up to 64 g.

Oropharyngeal sympotoms (itching or tingling of the lips or oral mucosa) in 8 patients (Pastorello et al. 1994) [156]

All the patients showed oral allergy syndrome (OAS) (Pastorello et al. 2001) [152]