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Biomedical subjects

D Roncarolo

Publications and source records attributed to D Roncarolo.

At least 19 recordsLinked to original sources
PubMed2006

Peach fuzz contains large amounts of lipid transfer protein: is this the cause of the high prevalence of sensitization to LTP in Mediterranean countries?

BACKGROUND: Allergy to lipid transfer protein (LTP) is quite common in the Mediterranean countries but virtually absent in Northern Europe. The reasons for this latitude-dependent distribution are unclear. One hypothesis is that peach, the primary sensitizer to LTP, may lose in part its allergenicity as a consequence of treatments (handling, brushing, washing, and packaging) preceding marketing in Northern European. Peach surface fuzz might represent a potential vehicle of LTP. OBJECTIVE: To detect LTP in peach fuzz, and compare IgE reactivity to peach fuzz and peel of sera from LTP-allergic patients. METHODS: IgE reactivity to peach peel and peach fuzz extract was measured by ELISA using sera from 2 LTP-allergic PATIENTS. Purified peach LTP was used in inhibition studies. RESULTS: Both sera strongly reacted both to peach peel and fuzz but reactivity to fuzz was stronger than to peel. Pre-absorption of one serum with peach LTP caused an 87% reduction of IgE reactivity to peach fuzz extract. CONCLUSION: Peach fuzz contains large amounts of LTP and might be a potential vehicle of this allergen causing sensitization in genetically predisposed subjects. Fuzz loss during pre-marketing handling of peaches might be at the basis of the geographic differences that characterize allergy to LTP.

Antigens, Plant↗
PubMed2005

Why do lipid transfer protein-hypersensitive patients tolerate bean (and other legumes)?

BACKGROUND: Patients allergic to nonspecific lipid transfer protein (LTP) frequently score positive on SPT with legumes but virtually never report adverse reactions eating these foods. OBJECTIVE: This study investigated the IgE reactivity to legumes of LTP-allergic patients and aimed to establish whether legumes can be considered safe in LTP-allergic patients. METHODS: Skin reactivity as well as clinical allergy to bean and pea were evaluated in a large cohort of LTP-hypersensitive patients. Sera from 12 patients showing clinical allergy to a number of botanically unrelated plant-derived foods and high levels of IgE to peach LTP were employed in in vitro studies (ELISA, ELISA inhibition, SDS-PAGE/immunoblot) aiming to investigate IgE reactivity to bean. RESULTS: Preabsorption of patients' sera with boiled bean extract did not cause any loss of IgE reactivity to peach LTP (whereas boiled apple totally abolished it). Immunoblot analysis did not show any IgE reactivity to bean proteins at about 10 kDa, and the SDS profile of bean showed little or no staining at 10 kDa. CONCLUSION: Sera from LTP-allergic patients do not seem to show any IgE reactivity to 10-kDa proteins in bean. Whether this is caused by epitopic differences between Rosaceae and bean LTPs or by the fact that LTP is not expressed in bean remains to be established. This study explains why virtually all LTP-allergic patients tolerate legumes and suggests that these foods should be considered safe for patients sensitized to this protein.

Antigens, Plant↗
PubMed2004

Bee moth (Galleria mellonella) allergic reactions are caused by several thermolabile antigens.

BACKGROUND: Exposure and contact with bee moth (Galleria mellonella) larvae (Gm) can cause an allergic reaction both in anglers and breeders. We described the case of an amateur fisherman who experienced an allergic reaction using Gm but not using heat-treated Gm (h-Gm) (mummies). The aim of this study was to demonstrate by immunoblotting and radioallergosorbent test (RAST)-inhibition experiments the loss of allergenic epitopes in h-Gm extracts. METHODS: Galleria mellonella larvae and h-Gm were homogenized and extracted at 10% (w/v) in 0.5 M phosphate-buffered saline, pH 7.4 containing 0.5% NaN(3) for 16 h at 4 degrees C. Gm and h-Gm extracts were electrophoresed in a 10% polyacrylamide precast Nupage Bis-Tris gel at 180 mA for 1 h and the resolved proteins stained with 0.1% Coomassie brilliant blue and the molecular weight calculated. For the immunoblotting detection of allergenic components the resolved extracts were transferred onto a nitrocellulose membrane and incubated with the patient's serum. Bound specific-IgE was detected by peroxidase-conjugated anti-human IgE. RAST inhibition experiments were performed according to the Ceska method. RESULTS: The protein profile of Gm and h-Gm extracts resulted markedly different in number, intensity and the position of bands, indicating that heat-treatment modifies the chemical-physical characteristics of the protein contents. The Gm extract showed a strong-coloured band at 73 kDa and more than 20 components ranging from 12 to 133 kDa; h-Gm showed two main band at 77 and 38 kDa and about 15 faint bands between 20 and 133 kDa apparently without any correspondence to the bands present in the Gm extract. Immunoblotting with the patient's serum demonstrated several bands of reactivity with the Gm extract ranging from 20 to 100 kDa and no recognizable bands, but only a diffuse smear with h-Gm. When used in a RAST inhibition experiment the h-Gm extract demonstrated an inability to compete with the Gm one for the binding to patient's IgE serum. CONCLUSIONS: The h-Gm seems to lose the allergenic epitopes and has two advantages for anglers: to avoid new possible sensitizations as well as allergic symptoms in sensitized people, without interfering with their skills and satisfaction in their fishing performance.

Adult↗
PubMed2004

Airborne allergy to sunflower seed.

BACKGROUND: There is increasing evidence that bird fanciers may develop airborne allergies to unusual allergens. OBJECTIVE: To detect the allergen source in a bird fancier with a history of asthma associated with bird cage cleaning activities and with contact with a Brazil parrot. METHODS: SPT with a large series of both airborne and food allergens were carried out. IgE reactivity to allergens causing wheal and flare reactions was confirmed by in-vitro investigations including ELISA/ELISA inhibition and immunoblot analysis. RESULTS: Strong skin reactivity to sunflower seed was observed. Immunoblot analysis showed IgE reactivity to low m.w. proteins, most probably 2S albumin, and ELISA inhibition studies showed the absence of cross-reactivity to mustard. CONCLUSION: Sunflower seed dust may sensitize patients via the respiratory tract. Differently from previously reported cases of sunflower seed allergy, no cross-reactivity to 2S albumin from botanically unrelated seeds was found.

Allergens↗
PubMed2002

Immunological cross-reactivity between lipid transfer proteins from botanically unrelated plant-derived foods: a clinical study.

BACKGROUND: Lipid transfer proteins (LTP) are highly conserved and widely distributed throughout the plant kingdom. Recent studies demonstrated immunological cross-reactivity between LTP from many botanically unrelated fruits and vegetables and concluded that LTP are pan-allergens. This study aimed to evaluate the clinical relevance of such cross-reactivity in a group of subjects monosensitized to LTP. METHODS: Twenty LTP-hypersensitive patients were selected from a population of about 600 subjects with history of Rosaceae allergy by means of: 1) negative skin prick test (SPT) with a commercial birch pollen extract; 2) positive SPT with a commercial plum extract, rich in LTP but virtually lacking both Bet v 1-like proteins and profilin; 3) in-vitro IgE reactivity to the 9-10 kDa fraction of peach peel or immunoblot with peach peel showing a single band at 10 kDa; and 4) total inhibition of reactivity to whole peach extract (containing Bet v 1-related allergen, profilin, and LTP) by purified peach LTP on enzyme-linked immunoassay (ELISA). Allergy to foods other than Rosaceae was ascertained by careful interview and analysis of medical recordings. SPT with a large series of plant-derived foods were carried out as well. The cross reactivity between LTPs from botanically unrelated plant-derived foods was assessed by ELISA inhibition tests using walnut and peanut extracts as substrate, and peach LTP as inhibitor. RESULTS: All patients reported allergic reactions after the ingestion of at least one from a large number of vegetable foods other than Rosaceae, and in several cases clinical reactions were very severe (anaphylaxis, asthma, urticaria/angioedema). Nuts and peanuts were the most frequently reported causes of allergic reactions (80% and 40% of patients, respectively). All patients showed positive SPT to several non-Rosaceae food extracts. SPT with nuts, peanut, legumes, celery, rice, and corn were positive in the majority of patients. In ELISA inhibition studies, absorption of sera with peach LTP caused complete inhibition of IgE reactivity to walnut and peanut in all cases. CONCLUSION: LTP is a clinically relevant pan-allergen. Most Rosaceae-allergic, LTP-hypersensitive patients experience adverse reactions after ingestion of botanically unrelated plant-derived foods as well. In view of the high prevalence and severity of the allergic reactions induced, hazelnut, walnut, and peanut should be regarded as potentially hazardous for these patients.

Allergens↗
PubMed2002

Allergenic relevance of Cupressus arizonica pollen extract and biological characterization of the allergoid.

BACKGROUND: Cupressaceae (cypress) pollens can cause pollinosis in winter. However, the lack of specific commercial extracts combined with the early pollination period of cypress trees make a precise diagnosis difficult. The need for a reliable and effective cypress extract for diagnostic and therapeutic purposes is increasingly felt. METHODS: Mixed or single Cupressus arizonica, lusitanica and sempervirens pollen extracts precipitated with ammonium sulfate (PPT) were compared by direct RAST, RAST inhibition and SDS-PAGE techniques. The major allergen of C. arizonica (Cup a 1), purified by anion exchange chromatography, was checked by immunoblotting experiments before chemical modification, in parallel with a C. arizonica extract, with potassium cyanate (KCNO) to obtain a monomeric allergoid. The allergoid extract was characterized for its biological, chemico-physical and immunological features by RAST inhibition, SDS-PAGE and ELISA assays. RESULTS: Direct RAST, RAST inhibition, and SDS-PAGE data indicated that the PPT C. arizonica pollen extract showed the most allergenic potential, and it can be considered representative of the Cupressus spp. Immunoblotting data confirmed Cup a 1 as a major allergen. RAST inhibition and ELISA showed that modified PPT C. arizonica extract had less IgE reactivity than the native, non-modified extract, while preserving the immunogenic capacity typical for an allergoid. Finally, the SDS-PAGE profile of Cup a 1 allergoid was similar to native Cup a 1 allergen, suggesting the modified C. arizonica extract shows the characteristics of a monomeric allergoid. CONCLUSIONS: The PPT C. arizonica pollen extract shows good in vitro diagnostic potential and its chemically modified form offers the features of a monomeric allergoid. It might therefore lend itself to the development of a product to be administered by the sublingual or oromucosal route for immunotherapy of individuals with cypress pollinosis.

Allergens↗
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↗
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↗