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Biomedical subjects

G Mistrello

Publications and source records attributed to G Mistrello.

At least 19 recordsLinked to original sources
PubMed2001

A case of allergy to beer showing cross-reactivity between lipid transfer proteins.

BACKGROUND: Lipid transfer proteins (LTPs) are highly conserved proteins present in a broad spectrum of fruits and vegetables that might represent a novel plant panallergen. OBJECTIVE: To demonstrate that LTP is an important allergen in beer and that beer LTP cross-reacts with LTP from botanically unrelated plant-derived foods. METHODS: Serum from a patient with clinical allergy to both beer and Rosaceae was studied for IgE reactivity to LTP to several vegetable foods by RAST, ELISA, immunoblot, and inhibition studies. RESULTS: Patient's serum showed a strong IgE reactivity to LTP purified from peach peel, carrot, and broccoli, and to a 10 kD protein in both apple and peach immunoblots, whereas no reactivity to birch cross-reactive allergens such as Bet v 1, profilin, or carbohydrates was found. In inhibition studies, preabsorption of serum with apple, walnut, hazelnut, peanut, corn, and rice caused a fall of 97%, 20%, 66%, 91%, 94%, and 93%, respectively, of its reactivity to peach LTP. Beer RAST fell from 1.8 IU/mL to <0.1 IU/mL when a patient's serum was preabsorbed with recombinant carrot LTP. CONCLUSIONS: LTP is a relevant allergen in beer. Beer LTP may cross-react with LTP from several other plant-derived foods.

Adult↗
PubMed2001

Allergy to nonspecific lipid transfer proteins in Rosaceae: a comparative study of different in vivo diagnostic methods.

BACKGROUND: Lipid transfer proteins (LTPs) are the major allergens in patients sensitive to Rosaceae (apple, peach, apricot, cherry, plum, and pear) who are not allergic to birch pollen. OBJECTIVE: The purpose of this study was to find a sensitive, specific, and relatively easy method for detection of LTP-sensitive patients. METHODS: We studied 36 persons who experienced oral allergy syndrome after the ingestion of fruits in the family Rosaceae. This study cohort was divided into two groups: 18 without allergy to birch pollen (patients) and 18 with birch pollen allergy (control subjects). All were tested by skin prick tests (SPTs) with fresh Golden Delicious apple, fresh peach, and extracts of peel and pulp from both fruits. Their specific IgE reactivities against peach peel extract were further investigated by immunoblot analysis. RESULTS: All 18 subjects in the control group showed strongly positive skin reactions with both fresh apple and fresh peach, whereas no skin reactivity was found with extracts from peach peel, peach pulp, or apple pulp. Extract of apple peel produced positive skin reactions in 17 of 18 control subjects; however, the wheals were generally smaller than those induced by fresh fruits. Immunoblot analysis showed no reactivity for peach peel extract. In contrast, the SPTs with fresh fruits showed that some of the 18 patients had strongly positive reactions, but others had weak reactions or negative responses. Further, in a high proportion of the patients, consecutive SPT with fresh apple yielded inconsistent results. In all patients, SPTs with extracts from apple pulp and peach pulp were negative, whereas SPTs with peel extracts were strongly positive in all patients. In most patients, the wheal area induced by SPT with peel extracts was larger than that induced by SPTs with fresh fruits. Immunoblot analysis showed that serum specimens from all 18 patients reacted with a 10-kD protein in peach peel. This is the molecular mass of LTPs. CONCLUSIONS: In birch pollen-allergic patients, the SPTs with fresh foods still remains the most reliable method of diagnosing vegetable food hypersensitivity. In contrast, in patients not allergic to birch pollen, the most reliable strategy for detection of patients sensitive to LTPs is skin prick testing with properly prepared fruit peel extracts. The loss of Bet v 1- and Bet v 2-like structures, which probably occurs during extraction, may facilitate immediate identification of the relevant allergen.

Antigens, Plant↗
PubMed2001

Pharmacokinetics of an allergen and a monomeric allergoid for oromucosal immunotherapy in allergic volunteers.

BACKGROUND AND OBJECTIVE: Little is known about the pharmacokinetics of allergens for local immunotherapy. Thus, we studied the pharmacokinetics in allergic volunteers of a commercial allergenic vaccine in orosoluble tablets (LAIS(R), Lofarma S.p.A). METHODS: The carbamylated monomeric allergoid derived from Parietaria judaica major allergen (Par j 1), characterized by maintenance of the original molecular size, and the native allergen, were radiolabelled with 123I, then incorporated into the commercial soluble tablets and administered to allergic subjects. Early sequential and late static scintigraphic acquisitions were performed, and plasma radioactivity was measured at different time intervals. RESULTS: No difference in local pharmacokinetics was observed between the allergen and the allergoid: part of the tracer was retained in the mouth for at least 2 h after swallowing. No direct absorption through the oral mucosa could be detected, as plasma radioactivity increased only after swallowing and peaked at 2 h. However, the plasma peak attained with the allergoid in tablets was significantly higher with respect to the native allergen. Finally, some undegraded allergoid, but not the allergen, could be constantly detected in the bloodstream at plasma peak. CONCLUSIONS: The results showed a similar behaviour of the allergoid and the allergen in tablets as far as their local kinetics are concerned, whereas plasma peak was higher with the allergoid than with the allergen. Therefore we conclude that the chemical modification of the allergen may affect its pharmacokinetics, by making it less susceptible to enzymatic degradation.

Administration, Sublingual↗
PubMed2000

Detection of allergens in plantain (Plantago lanceolata) pollen.

BACKGROUND: Allergens in Plantago lanceolata have not been characterized yet. The objective was to characterize some plantain-pollen allergens and to investigate the cross-reactivity between plantain and grass pollens. METHODS: Sera from four patients monosensitive to plantain pollen and from eight grass-pollen-allergic patients showing strong skin reactivity to plantain pollen in the skin prick test (SPT) underwent immunoblot analysis with both Plantago and grass mix extract. Moreover, immunoblot inhibition experiments were done with grass mix extract as inhibitor. RESULTS: All four sera from plantain-allergic patients reacted to two distinct bands at 17 and 19 kDa, and 2/4 sera showed further reactivity to a 40-kDa protein, which in one case represented the most prominent IgE-binding allergen. Plantain-monosensitive subjects did not show any reactivity to grass-pollen extract, and preabsorption of their sera with grass-pollen extract did not cause any loss of reactivity to plantain pollen. Sera from all eight grass-pollen-allergic controls reacted to a 30-kDa protein in plantain pollen, and some sera showed cross-reactivity to higher and lower molecular-weight structures as well. In all cases, plantain reactivity was totally abolished by preabsorption of sera with grass-pollen extract. A preliminary investigation by immunoblot showed that polyclonal IgG anti-Phl p 5 (but not polyclonal Phl p 1) from rabbit reacted to a 30-kDa protein in plantain pollen. CONCLUSIONS: Three specific allergens (of 17, 19, and 40 kDa, respectively) have been detected in plantain pollen. Further studies on a larger number of patients will determine whether these proteins may be considered major allergens. Cross-reactivity between grass and plantain pollen is mainly caused by a 30-kDa protein in plantain pollen. Group 5 grass-pollen allergen is probably responsible for most grass/plantain cross-reactivity.

Adult↗
PubMed2000

Lipid transfer protein: a pan-allergen in plant-derived foods that is highly resistant to pepsin digestion.

BACKGROUND: Lipid transfer proteins (LTPs) are small molecules of approximately 10 kD that demonstrate high stability. They have recently been identified as allergens in the Rosaceae subfamilies of the Prunoideae (peach, apricot, plum) and of the Pomoideae (apple). They belong to a family of structurally highly conserved proteins that are also present in non-Rosaceae vegetable foods. OBJECTIVE: The aim of this study was to investigate the cross-reactivity to non-Rosaceae LTPs, and to study the role of protein stability in allergenicity. METHODS: Thirty-eight patients with a positive SPT to Rosaceae fruit extracts enriched for LTP were characterized by interview and SPT. To investigate IgE cross-reactivity between Rosaceae and non-Rosaceae LTPs, RAST and RAST inhibition as well as ELISA and ELISA inhibition were performed, using whole food extracts and purified LTPs. Both purified natural LTPs (peach, carrot and broccoli) and Pichia pastoris recombinant LTPs (carrot and wheat) were included. Pepsin digestion was used to address the role of stability in the allergenicity of LTPs. RESULTS: IgE antibodies to Rosaceae LTPs reacted to a broad range of vegetable foods, including Gramineae (cereals), Leguminosae (peanut), Juglandaceae (walnut), Anacardiaceae (pistachio), Brassicaceae (broccoli), Umbelliferae (carrot, celery), Solanaceae (tomato), Cucurbitaceae (melon), and Actinidiaceae (kiwi). Binding and inhibition studies with purified natural and recombinant LTPs confirmed their role in this cross-reactivity. Many of these cross-reactivities were accompanied by clinical food allergy, frequently including systemic reactions. Antibody binding to LTP was shown to be resistant to pepsin treatment of whole extract or purified LTP. CONCLUSION: LTP is a pan-allergen with a degree of cross-reactivity comparable to profilin. Due to its extreme resistance to pepsin digestion, LTP is a potentially severe food allergen.

Adolescent↗
PubMed1998

Dot immunobinding assay for detection of mite antigens in house-dust samples.

A new test was developed specifically to detect mite antigens in house-dust. It uses a nitrocellulose dipstick spotted with specific antimite antibodies that act as a capture matrix; the same antibodies act as a detecting reagent when conjugated with colloidal dye particles. Aclotest is a 1-step assay, where a spotted dipstick is placed in a tube containing the detecting reagent and the house-dust sample. No instrumentation or previous extraction procedure of the sample is required, and the test response is visible as a colored spot, after 1 h incubation. The sensitivity and specificity of the new test were compared with those of Acarex and Der p1/Der f1 ELISA tests.

Animals↗