Evaluation of two commercial peach extracts for skin prick testing in the diagnosis of hypersensitivity to lipid transfer protein. A multicenter study.

Summary: The clinical usefulness of two commercial peach extracts for SPT (by Lofarma SpA and ALK-Abellò, respectively) was compared in a multicenter study carried out in Italy. Peach allergic patients were tested with the two extracts in parallel and underwent the detection of IgE specific for all three peach allergens currently available (Pru p1, Pru p3, and Pru p4, respectively). The two extracts were almost identical in terms of sensitivity and specificity, being able to detect virtually all patients sensitized to stable peach allergens (lipid transfer protein (LTP) and, presumably, peamaclein) but scoring negative in patients exclusively sensitive to labile allergens (either PR-10 and/or profilin). Thus, the two extracts represent an excellent tool to carry out a preliminary component-resolved diagnosis of peach allergy at the first patient visit.

Sensitization to Gibberellin-Regulated Protein (Peamaclein) Among Italian Cypress Pollen-Sensitized Patients.

BACKGROUND AND OBJECTIVES: Peach gibberellin-regulated protein (peamaclein) has recently emerged as a relevant food allergen in cypress pollen-hypersensitive patients. Objective: We investigated monosensitization to peamaclein among Italian cypress pollen-allergic patients. MATERIAL AND METHODS: A total of 835 cypress pollen-hypersensitive patients from 28 Italian allergy centers underwent a thorough work-up to determine food-allergic reactions and performed skin prick testing with a commercial peach extract containing peamaclein. IgE to rPru p 3 was measured in peach reactors, and those with negative results were enrolled as potentially monosensitized to peamaclein. IgE reactivity to rPru p 7 was evaluated using immunoblot and an experimental ImmunoCAP with rPru p 7. RESULTS: Skin prick tests were positive to peach in 163 patients (19.5%); however, 127 (77.9%) were excluded because they reacted to Pru p 3. Twenty-four patients (14.7%) corresponding to 2.8% of the entire study population) were considered potentially monosensitized to peamaclein. No geographic preference was observed. Seventeen of the 24 patients (70.8%) had a history of food allergy, mainly to peach (n=15). Additional offending foods included other Rosaceae, citrus fruits, fig, melon, tree nuts, and kiwi. On peach immunoblot, only 3 of 18 putative peamaclein-allergic patients reacted to a band at about 7 kDa; an additional 4 patients reacted at about 50-60 kDa. Ten of 18 patients (56%) had a positive result for Pru p 7 on ImmunoCAP. CONCLUSION: Allergy and sensitization to peamaclein seem rare in Italy. Most patients react to peach, although other Rosaceae fruits and several citrus fruits may also be offending foods. Peach and cypress pollen probably also share cross-reacting allergens other than peamaclein.

Baseline serum tryptase levels and adverse reactions to injection specific immunotherapy with airborne allergens: is there a relationship?

BACKGROUND: Elevated baseline serum tryptase levels are associated with severe systemic reactions following hymenoptera stings or venom immunotherapy. Little is known about baseline tryptase levels in patients with respiratory allergy and whether a relationship exists with systemic reactions induced by injection specific immunotherapy (SIT) with airborne allergens. The objective of this study was to measure tryptase levels in subjects with respiratory allergy and analyze the results in the light of tolerance/intolerance to injection SIT. METHODS: Baseline serum tryptase levels were measured in 106 adults allergic to different airborne allergens and in 40 normal controls. Thirty-one patients underwent injection SIT, and 15 of these 31 experienced at least one SIT-induced systemic reaction. RESULTS: Patients and normal controls showed similar median tryptase levels (2.98 vs. 3.13 ng/ml, respectively), although these were elevated in 6 patients (6%) versus 0 of 40 controls (0%). Tryptase levels did not differ between those patients with or without a history of systemic reactions (median 3.7 vs. 5.91 ng/ml, not significant). Three of 4 patients showing elevated tryptase levels belonged to the SIT-tolerant group. Elevated tryptase levels were not associated with specific allergens nor with distance from the specific pollen season. A bone marrow aspirate performed in the only patient with a history of systemic reactions following injection SIT and tryptase >11.4 ng/ml showed a normal morphology and phenotype. CONCLUSIONS: Unlike patients with hymenoptera venom allergy, in patients with respiratory allergy, elevated serum tryptase levels do not represent a risk factor for adverse reactions to SIT.

The major allergen of peach (Prunus persica) is a lipid transfer protein.

BACKGROUND: Allergy to fresh fruits and vegetables is mostly observed in subjects with pollinosis, especially from birch, because of cross-reacting allergens in vegetable foods and pollens. However, allergic reactions to fruits, specifically Rosaceae fruits, have been reported in subjects without pollinosis. OBJECTIVE: This study evaluated the pattern of IgE reactivity, identifying the allergen responsible in 2 groups of patients with oral allergy syndrome to peach with or without birch pollinosis. METHODS: The allergenic components of peach were detected by SDS-PAGE and immunoblotting. The major peach allergen was purified by HPLC with a cation-exchange column followed by gel filtration chromatography. Its IgE-binding capacity and its homology with the protein of the crude extract were demonstrated by immunoblotting inhibition techniques. To better characterize this allergen, periodic acid-Schiff stain and isoelectrofocusing were used. The amino acid sequencing was done with a gas-phase sequencer. RESULTS: SDS-PAGE and immunoblotting of the 15 patients allergic to peach, 8 without and 7 with birch pollinosis, showed that they all recognized a protein with a molecular weight of 9 kd. This was the only allergen recognized by patients not sensitized to pollen, whereas the birch pollen-sensitive patients had IgE binding to other allergenic proteins at higher molecular weights. The purified 9-kd protein retained its IgE-binding capacity, was negative to periodic acid-Schiff stain, and had an isoelectric point value of greater than 9. A search in the Swiss Prot Bank showed this was a lipid transfer protein, belonging to a group of molecules involved in the defensive system of plants. CONCLUSIONS: The major allergen of peach is a 9-kd protein belonging to the group of lipid transfer proteins. This is the only allergen recognized by patients allergic to peach but not sensitized to birch pollen.

Identification of the allergenic components of kiwi fruit and evaluation of their cross-reactivity with timothy and birch pollens.

BACKGROUND: Only a few food allergens have as yet been identified, mainly because of the difficulty of obtaining a sufficient number of patients who are clinically sensitized to a given food. This is more feasible in the case of the oral allergy syndrome (OAS), a common form of food allergy, which is especially prevalent in patients with pollinosis. OBJECTIVE: We designed a study to identify the allergens of kiwi fruit (Actinidia chinensis) by analyzing the sera of patients with OAS for kiwi and to examine the cross-reactivity of these allergens with timothy and birch pollen allergens. METHODS: Twenty-seven patients with OAS for kiwi, a positive skin prick test response and serum IgE antibody to kiwi, and a positive open kiwi challenge test result and three patients who had OAS with severe systemic symptoms, which excluded a challenge test, were included in this study. The different polypeptide components of an extract of fresh kiwi were separated by sodium dodecylsulfate-polyacrylamide gel electrophoresis and analyzed by IgE immunoblotting with sera from these patients. Cross-reactivity with the two pollen extracts was assessed by inhibition of the immunoblots with pooled and individual patients' sera. RESULTS: Twelve IgE-binding components with molecular weights ranging from 12 to 64 kd were identified in the kiwi extract, but only a 30 kd component acted as major allergen, being recognized by sera of 100% of these patients. Inhibition of kiwi immunoblots with timothy and birch pollen extracts demonstrated strong cross-reactivity with some of the kiwi allergens, suggesting complete identity between certain food and pollen allergens; whereas others, particularly the 30 kd allergen, were only partially inhibited, suggesting much weaker cross-reactivity. CONCLUSIONS: Kiwi fruit contains a large number of allergens widely cross-reacting with allergens in grass and birch pollen extracts. Nevertheless, the major allergen at 30 kd appears to be specific for kiwi.

Allergenic cross-reactivity among peach, apricot, plum, and cherry in patients with oral allergy syndrome: an in vivo and in vitro study.

BACKGROUND: Oral allergy syndrome in response to fruits and vegetables frequently occurs as clusters of hypersensitivity to members of the same botanical family, for which the immunologic basis lies in a number of common allergens, most of them still unidentified. OBJECTIVE: This study was designed to assess the in vivo and in vitro cross-reactivity between fruits of the Prunoideae subfamily (i.e., peach, cherry, apricot, and plum) and to identify their major allergens and the cross-reactivity of the peach extract with grass and birch pollen. METHODS: The in vivo study was conducted by skin prick tests and open food challenges with fresh fruits in 23 patients with oral allergy syndrome for peach and positive skin prick test and RAST results for the other Prunoideae. In vitro sodium dodecylsulfate-polyacrylamide gel electrophoresis was followed by immunoblotting and immunoblotting-inhibition. RESULTS: A 13 kd component was identified as the only major allergen common to all the Prunoideae, the other major allergens were found at 14 kd in peach and at 30 kd in cherry. Immunoblotting inhibition showed wide cross-reactivity within the Prunoideae, whereas grass and birch pollen partially inhibited the peach blotting. CONCLUSIONS: Clinical cross-reactivity to Prunoideae is essentially due to a common 13 kd IgE-binding component, which seems to be the most important major allergen of this subfamily, not shared with grass and birch pollen.

A double-blind, placebo-controlled study of immunotherapy with an alginate-conjugated extract of Parietaria judaica in patients with Parietaria hay fever.

A double-blind, placebo-controlled study was conducted to evaluate the efficacy and safety of immunotherapy (IT) with a partially purified alginate-conjugated extract of Parietaria judaica (Conjuvac Parietaria, Dome/Hollister-Stier) in patients suffering from rhinoconjunctivitis caused by Parietaria pollen. Eighteen patients (10 women, 8 men, mean age 35 years) received active treatment and 17 (10 women, 7 men, mean age 42.5 years) received placebo. Actively treated patients had significantly lower nasal symptom/medication scores (running nose P = 0.0087 and sneezing P = 0.048) during the Parietaria pollen season. Significant decreases in specific skin (P < 0.01), nasal (P < 0.05), and conjunctival (P < 0.01) reactivity to the Parietaria extract and significant increases of specific IgG (P < 0.001), IgG1 (P < 0.001), and IgG4 (P < 0.001) in actively treated patients, but not in placebo, were found. IT was well tolerated, the active extract inducing five mild systemic reactions (four rhinitis and one urticaria) and placebo two (rhinitis). A significant correlation was found between low skin reactivity and high specific IgG (P = 0.0002) and IgG4 (P = 0.036). These findings indicate that IT with a partially purified P. judaica extract is an effective and safe treatment for Parietaria pollen allergy. The correlation between low immediate skin reactivity and high specific IgG and IgG4 suggests that, at least in the studied cutaneous model, these antibodies may exert a blocking effect.

Clinical and immunological effects of immunotherapy with alum-absorbed grass allergoid in grass-pollen-induced hay fever.

A double-blind, placebo-controlled study of immunotherapy was conducted in 19 patients with grass-pollen hay fever to evaluate the efficacy and safety of a formalinized depot grass allergoid. The patients were assessed before and during IT by clinical (symptom-medication scores during the grass- pollen season, specific nasal and skin reactivity) and immunological (specific IgE, IgG, IgG1 and IgG4 antibodies) parameters. High doses of grass allergoid, corresponding to a cumulative pre-seasonal dosage of 46,050 PNU, were administered, with only one systemic reaction. The actively treated patients had significantly lower symptom-medication scores than placebo (p less than 0.01) during the month of May and showed a significant decrease in specific skin (p less than 0.01) and nasal (p less than 0.05) reactivity, and a significant early increase in specific IgE (p less than 0.01), IgG (p less than 0.0005), IgG1 (p less than 0.001) and IgG4 (p less than 0.05), with a subsequent decrease of IgE and IgG1. No differences were detected in any of these parameters in the placebo group. A correlation was found between high IgG4/IgG1 ratio and the specific skin reactivity decrease (r = 0.691, p less than 0.05), whereas a high IgG4/IgG1 ratio was associated with higher symptom-medication scores (r = 0.654, p less than 0.05). Possible explanations of these apparent discrepancies are proposed.

The role of suggestion in asthma. I. Effects of inactive solution on bronchial reactivity under bronchoconstrictor or bronchodilator suggestion.

Twenty-eight subjects affected by perennial asthma were selected in order to investigate the possibility of inducing or relieving an asthmatic attack by means of suggestion. Twenty-five were positive to methacholine challenge test and, among them, eleven reacted to an ultrasonic nebulized distilled water test. The effect of suggestion on airway response was assessed by eight inhalations of normal saline at 32 degrees C alternately presented as a bronchoconstrictor or as a bronchodilator drug. Eight inhalations of the same diluent without any psychic stimulus were used as control test. Seven patients reacted with bronchoconstriction to both positive and negative suggestion and to control test. Further, this group of patients showed a lower methacholine PD20 when compared with the other subjects. In this study, the effects of suggestion on bronchial reactivity were not observed and bronchoconstriction belonged to an individual hyperreactivity of the airways.

The role of suggestion in asthma. II. Effects of a bronchoconstrictor drug on bronchial reactivity under bronchoconstrictor or bronchodilator suggestion.

Previous studies have shown that suggestion may modify bronchial reactivity to both inactive diluents and pharmacologically bronchoconstrictor or dilator substances. In our study, 14 patients were subjected to two methacholine challenge tests presented, respectively, as a bronchoconstrictor or as a bronchodilator drug. Forced expiratory volumes in one second were recorded and a PD20 was determined. No significant differences were reported in PD20 values of each patient after the two kinds of suggestion.

Antihistaminic treatment of allergic rhinitis: a double-blind study with terfenadine versus dexchlorpheniramine.

A double-blind study was carried out in 65 patients with seasonal rhinitis to compare the effectiveness and tolerance of terfenadine and dexchlorpheniramine. Patients were allocated at random to receive treatment for 1 week with either 60 mg terfenadine twice daily or 2 mg dexchlorpheniramine maleate 3-times daily. Before and after treatment, patients underwent RAST and skin prick tests for reactivity to pollen and those who were positive also had rhinomanometric measurements made of nasal resistance. Diary cards were used by patients to record the severity of nasal obstruction, rhinorrhoea, sneezing, watery, irritated and red eyes, itching of the nose, throat and eyes, and cough. Details were also kept of the frequency and severity of any side-effects. Pollen counts were taken daily during the treatment period. The results showed that both terfenadine and dexchlorpheniramine produced good or excellent relief of the main symptoms in 78% and 73% of the patients, respectively. There was no significant correlation between the pollen count and reduced symptom severity. Both drugs produced a reduction in total nasal resistance but this was not significantly different from initial values, neither was there a significant difference between treatment. Terfenadine was well tolerated and side-effects incidence was significantly lower (p less than 0.01) than in patients treated with dexchlorpheniramine, particularly so with reference to drowsiness.