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A Díaz-Perales

Publications and source records attributed to A Díaz-Perales.

11 recordsLinked to original sources
PubMed2005

Latex-vegetable syndrome due to custard apple and aubergine: new variations of the hevein symphony.

An increasing number of vegetables with crossreactions to latex are being described in patients with latex-vegetable syndrome. We present two of these vegetables, custard apple linked in two previous cases with latex sensitisation, and aubergine, that had not been described up to now in patients with latex sensitisation. The diagnosis of both cases was based on the clinical history, positive skin prick test (SPT) and specific IgE to the offending vegetables, as well as to positive SPT and specific IgE levels to latex and the major fruits involved in the latex-fruit syndrome (avocado, banana, and chestnut). Further, crude extracts from latex, custard apple and aubergine, as well as the purified allergens Hev b 6.02 and Prs a 1 were used in in vitro and in vivo assays: IgE immunodetection, histamine release (HRT) and basophil activation (BAT) tests and skin prick tests. In case 1, both purified Hev b 6.02 and Prs a 1 induced positive responses in skin prick tests, high levels of basophil activation and histamine release. Specific IgE immunodetection uncovered a reactive band of 45 kd in the crude custard apple extract, which was also recognized by anti-chitinase monospecific antibodies. The serum from patient 1 also detected Prs a 1 in immunodetection. Hev b 6.02 produced positive skin responses and showed high biological activity in HRT and BAT in the case of patient 2. However, Prs a 1 was reactive neither in SPT nor in IgE immunodetection. In fact, no band was detected using the serum of patient 2 in avocado or aubergine extracts. By contrast, Prs a 1 reached high values of basophil activation and over 10% of histamine release in case 2.

Adult↗
PubMed2004

Respiratory allergy to peach leaves and lipid-transfer proteins.

BACKGROUND: Several lipid-transfer proteins (LTPs) have been identified as important food allergens, especially in fruits of the Rosaceae family. The major peach (Prunus persica) allergen has been identified, sequenced and designated Pru p 3. OBJECTIVE: To present Pru p 3 as an aeroallergen able to induce occupational asthma. METHODS: A thorough investigation was performed in a fruit grower with occupational asthma. Skin prick-prick tests with peach leaves and prick tests with perennial respiratory allergens and pollens, fruits and peach leaf extracts were done. Serum-specific IgE was tested for peach leaf, peach fruit, peach skin and respiratory allergens that were positive in skin prick tests. Specific bronchial provocation tests (BPTs) with extracts of peach leaf were also done. Before and 24 h after the BPT, BPTs with methacholine and sputum induction were done. The IgE reactivity pattern to peach leaf and fruit extracts and to Pru p 3 was identified by using SDS-PAGE and immunoblotting. Blotting inhibition of peach leaf extract by Pru p 3 was also performed. The putative allergen was quantified in leaf and fruit skin extracts with ELISA based on an anti-Pru p 3 antibody. RESULTS: Skin tests were positive for peach leaf and fruit. The BPT was positive, with immediate and delayed response. This test induced a decrease in PD20 (dose of agonist that induces a 20% fall in FEV1) methacholine and an increase in eosinophils and eosinophil cationic protein in sputum. Peach leaf extract contained concentrations of Pru p 3 similar to those found in peach skin. Specific IgE immunodetection showed that patient's sera reacted with Pru p 3, and with a single major band from the peach leaf extract fully inhibited by Pru p 3. CONCLUSION: Pru p 3 from peach leaves can act as a respiratory allergen and cause occupational rhinoconjunctivitis and asthma.

Adult↗
PubMed2004

Prevalence of sensitization to Artemisia allergens Art v 1, Art v 3 and Art v 60 kDa. Cross-reactivity among Art v 3 and other relevant lipid-transfer protein allergens.

BACKGROUND: Artemisia vulgaris is a widespread weed in the Mediterranean area and several allergens have been detected in its pollen. One of them, Art v 3, belongs to the lipid-transfer protein (LTP) family and its prevalence in Artemisia-sensitized patients or its relationship with other LTP allergens is not clear. OBJECTIVE: To assess the pattern of sensitization to an array of mugwort allergens in a Mediterranean population, and to study the cross-reactivity of Art v 3 with Pru p 3 and Par j 1, relevant LTP allergens in the area. METHODS: Skin prick test was performed with whole extracts (A. vulgaris, Parietaria judaica and peach) and pure natural allergens Art v 1, Art v 3, Art v 60 kDa and Par j 1 in 24 mugwort-allergic patients from a Mediterranean area. In vitro assays included measurement of specific IgE and ELISA inhibition among LTP allergens. RESULTS: The three Artemisia allergens elicited a positive skin response in 70-80% of the patients. Seven patients were clearly sensitized to Par j 1 and 11 to Pru p 3. There was no correlation between Par j 1 and Pru p 3 sensitization, but a highly significant correlation was found between peach extract and Art v 3 as regards the skin response. No IgE cross-reactivity was observed between Art v 3/Par j 1 or Pru p 3/Par j 1. In contrast, Art v 3 significantly inhibited the binding to Pru p 3 of IgE from three patients' sera out of six studied, but Pru p 3 was not able to inhibit the IgE binding to Art v 3. CONCLUSION: Art v 3 is a major mugwort allergen and in some patients with IgE to both Art v 3 and Pru p 3, Art v 3 behaves as the primary sensitizing agent.

Allergens↗
PubMed2003

Peach profilin: cloning, heterologous expression and cross-reactivity with Bet v 2.

BACKGROUND: Peach is among the main foods causing allergic reactions in the Mediterranean adult population. Only a single peach allergen, named Pru p 3, has been characterized. However, a potential role of profilin has also been suggested in grass pollen-associated allergy to peach. METHODS: Complementary DNA clones for two different peach profilin isoforms were obtained by reverse transcriptase polymerase chain reaction using non-degenerated primers. Expression of recombinant peach profilin was performed in Escherichia coli, and confirmed using rabbit polyclonal antibodies to sunflower pollen profilin. Twenty-nine individual sera from patients with peach allergy proved by double-blind, placebo-controlled food challenges (DBPCFC), either with (n = 15) or without (n = 14) specific IgE to Bet v 2, were used in immunodetection assays to test recombinant peach profilin reactivity. RESULTS: Each peach profilin cDNA included an open reading frame coding for a 131 amino acid protein. The peach profilin isoforms, designated Pru p 4.01 and Pru p 4.02, showed 80% of amino acid sequence identity, and were very similar (>70% identity) to allergenic profilins from plant foods and pollens. Recombinant Pru p 4.01 was expressed in E. coli as a nonfusion protein, displaying the expected molecular size and reacting with anti-profilin antibodies. rPru p 4.01 was recognized by all sera (15 of 15) with specific IgE to Bet v 2, whereas no sera (zero of 14) without IgE to this birch allergen reacted with rPru p 4.01. CONCLUSIONS: Peach profilin Pru p 4 is very closed to other allergenic profilins from plant foods and pollens. A complete correlation between reactivity to rPru p 4 and rBet v 2 has been found in sera from peach allergic patients.

Adolescent↗
PubMed2000

Lipid-transfer proteins as potential plant panallergens: cross-reactivity among proteins of Artemisia pollen, Castanea nut and Rosaceae fruits, with different IgE-binding capacities.

BACKGROUND: Lipid-transfer proteins (LTPs), but not Bet v 1 homologues, have been identified as major allergens of apple and peach in the Rosaceae fruit-allergic population in the Mediterranean area. Many of these patients show cosensitization to mugwort pollen. LTPs have an ubiquitous distribution in tissues of many plant species, and have been proposed as a novel type of plant panallergens. OBJECTIVE: We sought to isolate LTPs from Artemisia pollen and from a plant food not belonging to the Rosaceae family, such as chestnut nut, and to compare their amino acid sequences and IgE-binding capacities with those of apple and peach LTPs. METHODS: Allergens (LTPs) were isolated by different chromatographic methods (gel-filtration, ion exchange and/or reverse-phase HPLC), and characterized by N-terminal amino acid sequencing and MALDI analysis. Specific IgE-quantification and immunodetection, as well as immunoblot and ELISA inhibition assays, were carried out using sera from patients allergic to both apple and peach. RESULTS: Purified LTPs from Artemisia pollen and from chestnut seed showed molecular masses about 9 700d, and 43-50% sequence identity with the equivalent allergens of apple and peach in the first 30 N-terminal residues, which comprise about one third of the total amino acid sequence. A similar degree of sequence identity (50%) was found between the Artemisia and chestnut proteins. Both isolated LTPs bound specific IgE of sera from Rosaceae fruits allergic patients. However, substantially lower values of specific IgE-binding and maximum ELISA inhibition percentages were obtained for Artemisia and chestnut LTPs when compared to those from apple and peach. CONCLUSION: LTPs from Artemisia pollen and chestnut crossreact with allergens (LTPs) of Rosaceae fruits, but significant differences in specific IgE-binding capacities were observed among members of the plant LTP family. Thus, further studies are needed to evaluate the clinical significance of the observed cross-reactivities of plant LTPs.

Allergens↗
PubMed2000

Isolation and characterization of relevant allergens from boiled lentils.

BACKGROUND: Lentils seem to be the most common legume implicated in pediatric allergic patients in the Mediterranean area. However, no lentil allergen has been isolated and characterized. OBJECTIVE: We sought to purify and characterize relevant IgE-binding proteins from boiled lentil extracts. METHODS: IgE-binding proteins from crude and boiled lentil extracts were detected with a pool of sera from patients with lentil allergy. Allergens were isolated by gel-filtration chromatography followed by cation- and anion-exchange chromatography or by reverse-phase HPLC. Their characterization included N-terminal amino acid sequencing, complex asparagine-linked glycan detection, specific IgE immunodetection with 22 individual sera from allergic patients, and immunoblot and CAP inhibition assays. RESULTS: Heat treatment of lentils produced substantial changes in the SDS-PAGE patterns of whole extracts, mainly a strong increase of 12- to 16-kd bands and a decrease of 25- to 45-kd components. Major IgE-binding proteins from the boiled lentil extract were located in the 12- to 16-kd and 45- to 70-kd ranges. Two allergens of 16 kd, proteins L1 and L2, and another one of 12 kd, protein L3, were purified. N-terminal sequencing indicated that all 3 were related and allowed their identification as gamma-vicilin subunits. Protein L1 was recognized by 68% of the individual sera tested and inhibited 64% of the IgE binding by commercial lentil CAPs. A second type of allergen of 66 kd, named protein H, was also isolated and identified as a seed-specific biotinylated protein. Protein H reacted with 41% of the individual sera and produced 45% inhibition in CAP inhibition assays. CONCLUSIONS: Two different types of allergens have been identified in boiled lentils. Those of 12 to 16 kd, called Len c 1, correspond to gamma-vicilin subunits, and those of 66 kd, designated Len c 2, correspond to seed-specific biotinylated protein. Homology with proteins from other legume species can explain potential cross-reactions among these foods.

Allergens↗
PubMed1999

Isolation and characterization of major banana allergens: identification as fruit class I chitinases.

BACKGROUND: Banana allergy has been associated with the latex-fruit syndrome. Several IgE-binding components, the relevant ones being proteins of 30-37-kDa, have been detected in banana fruit, but none of them have been isolated and characterized yet. Objective To purify and characterize the 30-37 kDa banana allergens. METHODS: Fifteen patients allergic to banana were selected on the grounds of a latex-allergic population. Prick by prick tests to this fruit were performed. Total and specific IgE to banana were determined. Banana allergens were isolated by affinity chromatography, followed by cation-exchange chromatography. Their characterization includes N-terminal sequencing, enzymatic activity assays, immunodetection with sera from allergic patients and with antichitinase antibodies, and CAP and immunoblot inhibition tests. Skin prick tests with banana extracts and with the purified allergens were also carried out. RESULTS: Two major IgE-binding proteins of 34 and 32 kDa, also recognized by polyclonal antibodies against chestnut chitinases, were immunodetected in crude banana extracts. Purification and characterization of both proteins have allowed their identification as class I chitinases with an hevein-like domain. Each isolated allergen reached inhibition values higher than 90% in CAP inhibition assays, and fully inhibited the IgE-binding by the crude banana extract when tested by an immunoblot inhibition method. The two purified allergens provoked positive skin prick test responses in more than 50% of the banana-allergic patients. CONCLUSIONS: Class I chitinases with an hevein-like domain are major allergens in banana fruit. Their presence in other fruits and nuts, such as avocado and chestnut, could explain the cross-sensitization among these foods.

Adolescent↗
PubMedDate not supplied

Enhancement of tomato allergenicity after treatment with plant hormones.

BACKGROUND: Practical applications to enhance the productivity of agriculture by using plants with improved resistance to pathogens are expected to increase in the near future. Although tomato has been widely investigated for breeding purposes, there have been no studies on tomato allergenicity after plant hormones treatments. METHODS: Prick by prick tests were carried out with different tomato samples (fruits grown under biological conditions without addition of chemical products, and treated with ethylene and salicylic acid) in eight patients with ages between 12 and 27 years who suffered from anaphylaxis episodes after eating raw tomatoes. An immunoblot experiment with the different tomato extracts was performed using sera from these eight patients and controls. RESULTS: The wheals obtained in prick tests were significantly higher with the extracts of tomato treated with ethylene and SAA (chi(2) = 31.3, p < 0.0001) and the patients who presented higher wheal diameters in skin tests were those who had more severe episodes of anaphylaxis. Neither the protein stain nor the IgE immunodetection patterns clearly varied between the untreated and the hormone-treated samples. CONCLUSIONS: In the case of anaphylaxis induced by tomato, the treatment with plant hormones induced a higher cutaneous response than with non-treated tomato, but the "in vitro" response was similar.

Adolescent↗