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Biomedical subjects

G Mistrello

Publications and source records attributed to G Mistrello.

At least 37 records · Page 2Linked to original sources
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↗
PubMed1997

Absorption and distribution kinetics of the major Parietaria judaica allergen (Par j 1) administered by noninjectable routes in healthy human beings.

BACKGROUND AND OBJECTIVE: The clinical effectiveness of noninjectable routes for specific immunotherapy has been demonstrated in many studies, but no data are available on the kinetics of allergens administered by these routes. Therefore we studied the kinetics of the radiolabeled purified major Parietaria judaica allergen (Par j 1) after sublingual, oral, and intranasal administration to healthy human beings. METHODS: After tracer administration (10 to 12.5 microg of Par j 1 labeled with iodine 123) to nonallergic volunteers, scintigraphic images were recorded at various times. Blood samples were also obtained at serial intervals to evaluate the absorption and distribution of radioactivity in plasma and to identify circulating radioactive species by molecular exclusion gel chromatography. RESULTS: When the sublingual route was used, no circulating radioactivity was detected until the tracer was kept under the tongue. The labeled allergen was rapidly degraded and absorbed in the gastrointestinal tract after swallowing. Plasma radioactivity peaked at about 1.5 to 3 hours and was mostly represented by free radioiodine and small radiolabeled peptides. Some activity not caused by free 123I remained associated with the oral mucosa up to 18 to 20 hours after administration. When the oral route was used, the results were similar to those observed after swallowing the sublingually administered allergen but without any persistence of the tracer in the mouth. When the intranasal route was used, the pattern of plasma radioactivity mimicked that of the sublingual and oral routes, with absorption of activity from the radiolabeled allergen occurring in the gastrointestinal tract after transport to the pharynx by mucociliary clearance. A relevant fraction of the tracer was retained on the nasal mucosa up to 48 hours after administration. CONCLUSION: The data in this study provide the first experimental basis for exploring the in vivo kinetics of allergen administered through noninjectable routes for specific immunotherapy in human beings.

Abdomen↗