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Biomedical subjects

R Sánchez-Monge

Publications and source records attributed to R Sánchez-Monge.

At least 19 recordsLinked to original sources
PubMed2006

Allergic hypersensitivity to the lentil pest Bruchus lentis.

BACKGROUND: Lentils are the most common legume involved in allergic reactions in the Mediterranean area and India. Lentil crops could be attacked by a wide range of insect species. Occupational asthma caused by the lentil pest Bruchus lentis has been described in the present study. OBJECTIVE: We studied the possibility of immunoglobulin (Ig)E-mediated hypersensitivity to lentil pests in 16 patients who suffered from allergic symptoms (asthma and anaphylaxis) related to inhalation of lentil particles or ingestion of lentils, in which sensitization to legume proteins was not clear. METHODS: Extracts prepared either from noninfested and infested lentils, and from the lentil parasite B. lentis were used for skin prick testing (SPT), bronchial and oral challenges and in vitro determinations. RESULTS: Skin prick test were positive to infested lentils and B. lentis in all patients and negative to noninfested lentil extracts. Five asthmatic patients reacted in the bronchial challenge test with Bruchus extract. Oral challenges performed with boiled infested lentils were positive in six of seven patients. Immunoglobulin E immunoblotting with Bruchus and infested lentils extracts revealed protein bands that were reactive to serum IgE from six and four, respectively, out of 16 patients. These patients had no IgE to lentil-specific proteins as determined by immunoblotting and Len c 1-specific IgE test. CONCLUSIONS: Lentil pest proteins can be a cause of IgE-mediated rhinoconjunctivitis and asthma in patients eating or inhaling infested lentil particles.

Adolescent↗
PubMed2005

Allergenic reactivity of the melon profilin Cuc m 2 and its identification as major allergen.

BACKGROUND: Melon allergy is commonly associated with oral allergy syndrome (OAS) and with hypersensitivity to pollens and other plant foods. No melon allergen responsible for these clinical characteristics has yet been isolated, although profilin has been proposed as a potential target. OBJECTIVE: To isolate natural and recombinant melon profilin, to evaluate its in vivo and in vitro reactivity, and to analyse its behaviour in simulated gastric fluid (SGF) and heat treatments. METHODS: A pool or individual sera from 23 patients, and an additional group of 10 patients, all of them with melon allergy, were analysed by in vitro and in vivo tests, respectively. Natural melon profilin (nCuc m 2) and its recombinant counterpart (rCuc m 2) were isolated by poly-l-proline affinity chromatography, and characterized by N-terminal amino acid sequencing, matrix-assisted laser desorption/ionization analysis, DNA sequencing of cDNAs encoding rCuc m 2, and immunodetection with anti-profilin antibodies. In vitro analysis included IgE immunodetection, specific IgE determination, ELISA-inhibition assays, and histamine release (HR) tests. In vivo activity of nCuc m 2 was established by skin prick testing (SPT). The effect of SGF and heat treatment on rCuc m 2 was followed by immunodetection, ELISA inhibition, and HR assays. RESULTS: Both purified forms of melon profilin were recognized by rabbit anti-profilin antibodies and IgE of sera from allergic patients, and showed molecular sizes typical of the profilin family. nCuc m 2 had a blocked N-terminus, whereas rCuc m 2 rendered the expected N-terminal amino acid sequence, its full protein sequence being highly similar (98--71% identity) to those of profilins from plant foods and pollens. The natural allergen displayed a slightly higher IgE-binding capacity than its recombinant counterpart. Specific IgE to nCuc m 2 and rCuc m 2 was found in 100% and 78% of the 23 individual sera analysed, respectively. nCuc m 2 evoked positive SPT responses in all (10/10) patients tested, and rCuc m 2 induced HR in two out of three sera assayed. SGF treatment readily inactivated rCuc m 2, as shown by its loss of recognition by anti-profilin antibodies, lack of IgE binding, and inability to induce HR. In contrast, heat treatment did not affect the IgE-binding capacity of rCuc m 2. CONCLUSIONS: Profilin is highly prevalent in melon-allergic patients, and promptly inactivated by SGF, as expected for an allergen mainly linked to OAS.

Adult↗
PubMed2005

Isolation, cloning and allergenic reactivity of natural profilin Cit s 2, a major orange allergen.

BACKGROUND: Orange is among the most widely consumed fruits, and among the plant food sources causing allergic reactions according to popular perception. However, its relevant allergenic components are virtually unknown. Profilin is a well-defined minor plant panallergen, showing prevalences around 30% in fruits and vegetables. METHODS: Twenty-three orange-allergic patients were studied. Natural orange profilin, named Cit s 2, was purified by affinity chromatography and characterized by N-terminal amino acid sequencing, matrix-assisted laser desorption/ionization mass spectrometry analysis and isolation of its coding cDNA. Reactivity to Cit s 2 was analyzed in vivo by skin prick tests (SPT) and in vitro by IgE immunodetection, specific IgE determination in individual sera and enzyme-linked immunosorbent assay-inhibition assays. RESULTS: The N-terminal amino acid sequence and molecular mass of natural Cit s 2, both fully in agreement with the complete amino acid sequence deduced from its coding cDNA, demonstrated its profilin nature. An unexpectedly high reactivity to Cit s 2 was found in vivo (78% of positive SPT responses) and in vitro (87% of sera from orange allergic patients had specific IgE to Cit s 2). The purified allergen inhibited around 50% of the IgE binding to an orange pulp extract. CONCLUSION: Orange profilin Cit s 2, unlike other plant food profilins, is a major and highly prevalent allergen.

Adolescent↗
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↗
PubMed2002

What is the role of the hevein-like domain of fruit class I chitinases in their allergenic capacity?

BACKGROUND: Class I chitinases are the major panallergens in fruits associated with the latex-fruit syndrome. These enzymes contain an N-terminal hevein-like domain homologous to latex hevein, and a larger catalytic domain. The role of these domains in their allergenic capacity is still controversial. OBJECTIVE: We sought to evaluate the role of both domains of class I chitinases in their IgE-binding properties, using Cas s 5, the major allergen from chestnut, as a model. METHODS: Recombinant Cas s 5 and its deleted form, lacking the hevein-like domain, designated rCat, were expressed in Pichia pastoris using the pPIC 9 vector. Both recombinant products were purified from the supernatants of transformed yeast cultures by gel-filtration and cation-exchange chromatography. The isolated proteins were characterized by N-terminal sequencing, enzymatic activity and N-glycosylation tests, anti-chitinase and specific IgE immunodetection. Immunoblot, RAST and CAP inhibition assays were also performed. RESULTS: Both purified rCas s 5 and rCat showed the expected N-terminal amino acid sequences and an enzymatic activity similar to that of their natural counterparts isolated from chestnut seeds, and were strongly recognized by anti-chitinase antibodies. In contrast, only rCas s 5, but not rCat, bound specific IgE from sera of patients suffering from the latex-fruit syndrome, and fully inhibited IgE-binding to natural Cas s 5 in immunoblot inhibition assays. Latex hevein also exerted a strong immunoblot inhibition of IgE-binding to chestnut Cas s 5. RAST and CAP inhibition using whole chestnut extract on the solid phase, rendered inhibition levels around 70-90% for rCas s 5 and 60% for rCat, in contrast to the immunoblotting results. CONCLUSIONS: Recombinant Cas s 5 behaves like natural Cas s 5 in IgE-binding assays in vitro. The hevein-like domain of allergenic class I chitinases seems to include all their main IgE-binding epitopes when tested by immunodetection and immunoblot inhibition experiments. RAST and CAP inhibition assays, on the contrary, suggest that relevant epitopes are also harboured in the catalytic domain of these allergens.

Adult↗
PubMed2002

Allergy after ingestion or inhalation of cereals involves similar allergens in different ages.

BACKGROUND: Cereals are among the major foods that account for food hypersensitivity reactions. Salt-soluble proteins appear to be the most important allergens contributing to the asthmatic response. In contrast, very limited information is available regarding cereal allergens responsible for allergic reactions after ingestion of cereal proteins. OBJECTIVE: The aim of this study was to evaluate the allergenic reactivity of ingested and inhaled cereal allergens in different ages, in order to investigate if the response to different allergens would depend on the sensitization route. METHODS: We included 66 patients in three groups. Group 1: 40 children aged 3 to 6 months who suffered from diarrhoea, vomiting, eczema or weight loss after the introduction of cereal formula in their diet and in which a possibility of coeliac disease was discarded. Group 2: 18 adults with food allergy due to cereals tested by prick tests, specific IgE and food challenge. Group 3: eight patients previously diagnosed as having baker's asthma. Sera pool samples were collected from each group of patients and IgE immunoblotting was performed. RESULTS: We found an important sensitization to cereal in the 40 children. The most important allergens were wheat followed by barley and rye. Among the adults with cereal allergy, sensitization to other allergens was common, especially to Lolium perenne (rye grass) pollen. Immunoblotting showed similar allergenic detection in the three groups. CONCLUSION: Clinically significant reactivity to cereal may be observed in early life. Inhalation and ingestion routes causing cereal allergy seem to involve similar allergens. The diet control was more effective in children. The possibility of cereal allergy after the introduction of cereal formula during the lactation period should not be underestimated.

Administration, Inhalation↗
PubMed2001

Anaphylaxis associated with antiphospholipid syndrome.

BACKGROUND: To our knowledge, no previously published reports have described food-induced anaphylaxis associated with the antiphospholipid syndrome. OBJECTIVE: We undertook a study of four patients with thrombosis associated with the antiphospholipid syndrome after each patient experienced anaphylaxis attributable to ingestion of vegetal foods. METHODS: IgE antibody levels to various foods were determined in serum specimens from the study patients, and skin prick tests with the same allergens were conducted to determine their in vivo responses. Hematologic, cardiopulmonary, vascular, and rheumatologic studies were also performed. IgG anticardiolipin antibody levels were determined by ELISA. RESULTS: All four patients fulfilled the criteria for antiphospholipid syndrome and had high levels of specific IgE antibodies for certain food allergens. By immunoblot analysis, the presence of serum IgE specific for a 45-kD protein band in an almond extract was detected in these four patients who experienced food-related anaphylaxis. No specific IgE was detected in sera from normal subjects. No IgE antibodies specific for the food panallergen lipid transfer proteins were detected. CONCLUSIONS: This is the first report of severe food-precipitated anaphylaxis associated with the antiphospholipid syndrome and the first description of a patient with allergy to blackberry. The possible involvement of food panallergens distinct from lipid transfer proteins is also discussed.

Adult↗
PubMed2000

Biotic and abiotic stress can induce cystatin expression in chestnut.

A cysteine proteinase inhibitor (cystatin) from chestnut (Castanea sativa) seeds, designated CsC, has been previously characterized. Its antifungal, acaricide and inhibitory activities have allowed to involve CsC in defence mechanisms. The CsC transcription levels decreased during seed maturation and increased throughout germination, an opposite behavior to that shown by most phytocystatins. No inhibition of endogenous proteinase activity by purified CsC was found during the seed maturation or germination processes. CsC message accumulation was induced in chestnut leaves after fungal infection, as well as by wounding and jasmonic acid treatment. Induction in roots was also observed by the last two treatments. Furthermore, CsC transcript levels strongly raised, both in roots and leaves, when chestnut plantlets were subjected to cold- and saline-shocks, and also in roots by heat stress. All together, these data suggest that chestnut cystatin is not only involved in defence responses to pests and pathogen invasion, but also in those related to abiotic stress.

Acetates↗
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

Class I chitinases, the panallergens responsible for the latex-fruit syndrome, are induced by ethylene treatment and inactivated by heating.

BACKGROUND: Class I chitinases have been identified as the major panallergens in fruits associated with the latex-fruit syndrome, such as avocado, banana, and chestnut. However, other plant foods containing these enzymes have not been related to this syndrome. OBJECTIVE: We sought out class I chitinases in the green bean, a legume that is known to express chitinases but is not associated with latex allergy, and examined whether the content or allergenic activity of chitinases can be modified by physical or chemical treatments. METHODS: IgE-binding proteins in untreated bean samples, as well as in ethylene- and heat-treated samples, were detected by using a pool of sera from patients with latex-fruit allergy. Putative allergens were purified by cation-exchange chromatography and characterized by N-terminal sequencing, enzymatic activity assays, immunodetection with sera and antichitinase antibodies, and immunoblot inhibition tests. Skin prick tests with untreated and heated purified allergens were also carried out. RESULTS: An IgE-binding protein of 32 kd that was also recognized by antichitinase antibodies was detected in green bean extracts. This reactive component was strongly induced by ethylene treatment. The protein, designated PvChI, was identified as a class I chitinase closely related to the major avocado allergen Prs a 1. Immunoblot inhibition assays demonstrated cross-reactivity between both allergens. Purified PvChI induced positive skin prick test responses in 7 of 8 patients with latex-fruit allergy. Heat treatment of both Prs a 1 and PvChI produced a full loss of their allergenic capacities both in vitro and in vivo. No IgE-binding component was detected in the white mature bean in which the main isolated 32-kd protein corresponded to a nonreactive phytohemagglutinin. CONCLUSIONS: Ethylene treatment induces the expression of plant class I chitinases. The allergenic activity of plant class I chitinases seems to be lost by heating. This fact could explain why plant foods containing these putative allergens that are consumed after cooking are not usually associated with the latex-fruit syndrome.

Amino Acid Sequence↗
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

Class I chitinases as potential panallergens involved in the latex-fruit syndrome.

BACKGROUND: Latex-fruit cross-sensitization has been fully demonstrated. However, the antigens responsible for this "latex-fruit syndrome" have not been identified. We have recently shown that class I chitinases are relevant chestnut and avocado allergens. OBJECTIVE: We sought to evaluate the in vivo and in vitro reactions of purified chestnut and avocado chitinases in relation to the latex-fruit syndrome. METHODS: From a latex-allergic population, eighteen patients allergic to chestnut, avocado, or both were selected. Skin prick tests (SPTs) were performed with crude chestnut and avocado extracts, chitinase-enriched preparations, and purified class I and II chitinases from both fruits. CAP-inhibition assays with the crude extracts and purified proteins were carried out. Immunodetection with sera from patients with latex-fruit allergy and immunoblot inhibition tests with a latex extract were also performed. Eighteen subjects paired with our patients and 15 patients allergic to latex but not food were used as control groups. RESULTS: The chestnut class I chitinase elicited positive SPT responses in 13 of 18 patients with latex-fruit allergy (72%), and the avocado class I chitinase elicited positive responses in 12 of 18 (67%) similarly allergic patients. By contrast, class II enzymes without a hevein-like domain did not show SPT responses in the same patient group. Each isolated class I chitinase reached inhibition values higher than 85% in CAP inhibition assays against the corresponding food extract in solid phase. Immunodetection of the crude extracts and the purified class I chitinases revealed a single 32-kd band for both chestnut and avocado. Preincubation with a natural latex extract fully inhibited the IgE binding to the crude extracts, as well as to the purified chestnut and avocado class I chitinases. CONCLUSION: Chestnut and avocado class I chitinases with an N-terminal hevein-like domain are major allergens that cross-react with latex. Therefore they are probably the panallergens responsible for the latex-fruit syndrome.

Adolescent↗
PubMed1999

Lipid-transfer proteins are relevant allergens in fruit allergy.

BACKGROUND: Allergy to apple and Prunus fruits is frequently associated with birch pollinosis, with the principal cross-reacting allergens involved being members of the Bet v 1 family. However, a major 13-kd component, nonimmunologically related to Bet v 1, has been implicated as allergen in patients allergic to Prunoideae fruit but not to birch pollen. OBJECTIVE: We sought to isolate and characterize the 13-kd allergen present in apple and peach. METHODS: Sera from patients allergic to both fruits were selected on the basis of clinical symptoms, skin prick tests responses, and specific IgE levels. Allergens were purified by reverse-phase HPLC and characterized by N-terminal amino acid sequencing, MALDI analysis, specific IgE immunodetection, and immunoblot inhibition assays. RESULTS: A 13-kd protein band was recognized in crude apple and peach extracts by 9 of 10 and 10 of 10 sera from patients allergic to fruit, respectively. The isolation and characterization of the corresponding allergens allowed their identification as lipid-transfer proteins, with a molecular mass of 9058 d for the apple protein and 9138 d for the peach protein. Both purified allergens were recognized by sera from patients allergic to fruit and fully inhibited the IgE binding by the 13-kd component present in the 2 crude fruit extracts. CONCLUSION: Lipid-transfer proteins are relevant apple and peach allergens and, considering their ubiquitous distribution in tissues of many plant species, could be a novel type of panallergen of fruits and vegetables.

Adult↗