hevein and Food-Hypersensitivity

Approximately 30-50% of individuals who are allergic to natural rubber latex (NRL) show an associated hypersensitivity to some plant-derived foods, especially freshly consumed fruits. This association of latex allergy and allergy to plant-derived foods is called latex-fruit syndrome. An increasing number of plant sources, such as avocado, banana, chestnut, kiwi, peach, tomato, potato and bell pepper, have been associated with this syndrome. The prevailing hypothesis is that allergen cross-reactivity is due to IgE antibodies that recognize structurally similar epitopes on different proteins that are phylogenetically closely related or represent evolutionarily conserved structures. Several types of proteins have been identified to be involved in the latex-fruit syndrome. Two of these are plant defence proteins. Class I chitinases containing an N-terminal hevein-like domain cross-react with hevein (Hev b 6.02), a major IgE-binding allergen for patients allergic to NRL. A beta-1,3-glucanase was identified as an important latex allergen which shows cross-reactivity with proteins of bell pepper. Another important NRL allergen, Hev b 7, is a patatin-like protein that shows cross-reactivity with its analogous protein in potato. Furthermore, patients with allergy to plant-derived foods and associated pollinosis show a high frequency of IgE reactivity to the pan-allergen profilin, which may cause positive serum IgE determinations to NRL. Although there is much information about the plant-derived foods and some data about the allergens involved in the latex-fruit syndrome, it is not always clear whether latex sensitization precedes or follows the onset of food allergy.

Topics: Antimicrobial Cationic Peptides; beta-Glucosidase; Carboxylic Ester Hydrolases; Chitinases; Contractile Proteins; Food Hypersensitivity; Fruit; Glucan 1,3-beta-Glucosidase; Humans; Immunoglobulin E; Latex Hypersensitivity; Microfilament Proteins; Plant Lectins; Plant Proteins; Profilins

Natural rubber latex is used in the manufacture of many products in the United States. As natural rubber latex allergy becomes of increasing concern, dietitians need to have an understanding of this allergy and how it relates to workplace safety, employee health, and patient feeding and counseling. Natural rubber latex contains more than 35 proteins that may be related to Type I, Ig-E-mediated allergy in numerous segments of the population, including health care workers and patients. Many foods, especially chestnut, banana, and avocado, have the potential to cross-react with natural rubber latex. Chitinase enzymes, related to plant defense, are believed to be involved in this cross-reaction. A strong connection between food allergy and natural rubber latex allergy is recognized and described in this review.

Topics: Allergens; Antimicrobial Cationic Peptides; Chitinases; Cross Reactions; Food Hypersensitivity; Humans; Latex; Latex Hypersensitivity; Lectins; Plant Lectins; Plant Proteins; Prevalence; Rubber

Allergies to certain fruits such as banana, avocado, chestnut and kiwi are described in 30-70% of latex-allergic patients. This association is attributed to the cross-reactivity between the major latex allergen hevein and hevein-like domains (HLDs) from fruit class I chitinases. We aimed to assess the extent of cross-reactivity between hevein and HLDs using sera from latex-allergic patients with and without plant food allergy. Hevein and HLDs of latex, banana, and avocado chitinases were expressed in Escherichia coli as fusion proteins with the maltose-binding protein and purified by affinity chromatography. IgE binding to these proteins was studied in sera from 59 latex-allergic patients and 20 banana-allergic patients without latex allergy by ELISA and ELISA inhibition. Additionally, 16,408 allergic patients' sera were tested for IgE binding to hevein, latex chitinase, and wheat germ agglutinin using an allergen microarray. Hevein-specific IgE was detected in 34/59 (58%) latex-allergic patients' sera. HLDs of latex, banana, and avocado chitinases were recognized by 21 (36%), 20 (34%), and 9 (15%) sera, respectively. In contrast, only one of 20 banana-allergic patients without latex allergy was sensitized to chitinase HLDs. In most tested latex-allergic patients' sera, IgE binding to hevein was only partially reduced by preincubation with HLDs. Among hevein-sensitized, latex-allergic patients, the percentage of plant food allergy (15/34 = 44%) was equal to latex-allergic patients without hevein sensitization (11/25 = 44%). In the general allergic population, 230 of 16,408 sera (1.4%) reacted to hevein and/or a hevein-like allergen. Of these, 128 sera showed an isolated sensitization to hevein, whereas only 17 bound to latex chitinase or wheat germ agglutinin without hevein sensitization. In conclusion, the IgE response to HLDs is elicited by hevein as sensitizing allergen in most cases. Despite considerable cross-reactivity between these allergens, no correlation between latex-associated plant food allergy and sensitization to hevein or HLDs was found.

Topics: Adolescent; Adult; Aged; Allergens; Amino Acid Sequence; Antimicrobial Cationic Peptides; Child; Child, Preschool; Chitinases; Female; Food Hypersensitivity; Humans; Immunization; Immunoassay; Immunoglobulin E; Latex; Latex Hypersensitivity; Male; Middle Aged; Molecular Sequence Data; Musa; Plant Lectins; Protein Structure, Tertiary; Recombinant Proteins; Structural Homology, Protein; Young Adult

Individuals with natural rubber latex allergy often have immediate reactions to plant-derived foods and fresh fruits, such as avocado and banana. IgE of these patients has been shown to bind endochitinases containing an N-terminal hevein-like domain (HLD). However, evidence on 31-kd endochitinase-induced reactions in vivo is lacking.. We sought to assess the clinical significance of 31-kd endochitinases and isolated HLDs in latex-fruit syndrome.. The 31-kd endochitinases and corresponding HLDs were purified or produced from avocado, banana, latex, and wheat germ. Skin prick test reactivities against purified proteins were examined in 15 patients with natural rubber latex allergy. The binding efficiency of IgE to purified proteins was studied by using an inhibition ELISA. Experimentally resolved or modeled structures of the proteins were compared to clarify the molecular basis of clinical reactions.. Eleven (73%) patients had skin prick test reactions to isolated HLDs of avocado and banana, but only 1 (7%) patient reacted to their corresponding 31-kd endochitinases. HLDs from avocado and banana inhibited binding of IgE to prohevein (Hev b 6.01) in 59% and 38% of patients, respectively, whereas corresponding percentages for 31-kd endochitinases were 17% and 20%, respectively. Isolated HLDs of wheat germ agglutinin and 18-kd wheat germ agglutinin did not significantly inhibit IgE binding to hevein.. The isolated HLD molecules alone, but not when linked to endochitinases, seem to be responsible for IgE-mediated clinical reactions in latex-fruit syndrome. Careful selection of relevant allergens in their proper molecular form is therefore crucial in forming a reliable diagnosis of latex-fruit syndrome.

Topics: Adult; Allergens; Amino Acid Sequence; Antimicrobial Cationic Peptides; Chitinases; DNA Primers; Enzyme-Linked Immunosorbent Assay; Female; Food Hypersensitivity; Humans; Immunoglobulin E; Latex; Latex Hypersensitivity; Male; Middle Aged; Molecular Sequence Data; Musa; Persea; Plant Lectins; Protein Structure, Tertiary; Sequence Homology, Amino Acid; Skin Tests; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

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.

Topics: Adult; Allergens; Antigens, Plant; Antimicrobial Cationic Peptides; Basophils; Chitinases; Cross Reactions; Female; Food Hypersensitivity; Histamine Release; Humans; Hypersensitivity, Immediate; Immunoglobulin E; In Vitro Techniques; Latex; Latex Hypersensitivity; Malus; Plant Lectins; Plant Proteins; Skin Tests; Solanum melongena

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.. We sought to evaluate the in vivo and in vitro reactions of purified chestnut and avocado chitinases in relation to the latex-fruit syndrome.. 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.. 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.. 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.

Topics: Adolescent; Adult; Allergens; Antibody Specificity; Antigens, Plant; Antimicrobial Cationic Peptides; Chitinases; Cross Reactions; Female; Food Hypersensitivity; Humans; Immunoglobulin E; Latex; Latex Hypersensitivity; Lauraceae; Lectins; Male; Middle Aged; Nuts; Plant Lectins; Plant Proteins; Prospective Studies; Protein Structure, Tertiary; Skin Tests; Structure-Activity Relationship

In the medical literature immunoglobulin (Ig)E-mediated sensitization to avocado is rarely reported. On the other hand, more than 50% of subjects having IgE-mediated natural rubber latex allergy are sensitized to avocado fruit as demonstrated by skin-prick testing and/or specific IgE measurements and about 10-20% report hypersensitivity reactions after ingesting avocado.. The underlying pathomechanism of latex-associated avocado allergy is still unknown. The conserved hevein domain of the major latex allergen prohevein (Hev b 6.01) is a ubiquitous chitin-binding protein structure that can be found in several plant proteins and may be responsible for the observed cross-reactivity between latex and avocado fruit.. Chitin-binding avocado proteins (CBAPs) were isolated by affinity-chromatography and their IgE-binding characteristics were studied by immunoblotting using the sera from 15 avocado-sensitized latex patients. Inhibition experiments using isolated hevein and CBAPs as inhibitor solutions were performed to study the immunological cross-reactivity between both protein species and to assess the role of the CBAPs as mediators in latex-associated avocado allergy.. In 80% of avocado-sensitized subjects (n = 15), IgE antibodies directed against a 31-kDa allergen were detected by immunoblotting. This IgE-binding protein was identified by protein sequencing to be a class I endochitinase containing a hevein domain at the N-terminus. Purified native and digested (using simulated gastric fluid) endochitinase were able to completely block all avocado-specific IgE antibodies in six out of seven avocado patients.. Sensitization to endochitinase class I containing a hevein domain is the main underlying pathomechanism in latex-mediated avocado allergy.

Topics: Allergens; Antigens, Plant; Antimicrobial Cationic Peptides; Chitin; Chitinases; Cross Reactions; Food Hypersensitivity; Health Personnel; Humans; Immunoblotting; Immunoglobulin E; Latex; Latex Hypersensitivity; Lauraceae; Lectins; Plant Lectins; Plant Proteins; Protein Precursors; Skin Tests

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.. 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.. 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.. 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.

Topics: Adolescent; Adult; Allergens; Amino Acid Sequence; Antimicrobial Cationic Peptides; Chitinases; Cross Reactions; Electrophoresis, Polyacrylamide Gel; Female; Food Hypersensitivity; Humans; Immunoblotting; Immunoglobulin E; Lectins; Male; Middle Aged; Molecular Sequence Data; Plant Lectins; Plant Proteins; Prospective Studies; Skin Tests; Zingiberales

Several foods associated with the latex-fruit syndrome present relevant allergens of around 30 kd. Neither these components nor any other responsible for the reported cross-reactions have been identified and purified.. We sought to isolate and characterize the 30 kd allergens from avocado fruit and chestnut seed, two of the main allergenic foods linked with latex allergy.. Sera from patients allergic to chestnut and avocado were selected according to clinical symptoms, specific IgE levels, and positive skin prick test responses. Class I and II chitinases were purified by affinity and cation-exchange chromatography and characterized by specific IgE and anti-chitinase immunodetection, immunoblot inhibition assays, enzymatic activity tests, and N-terminal sequencing.. Relevant 32 kd allergens were detected by specific IgE immunodetection in both avocado and chestnut crude extracts. The same bands, together with others of 25 kd, were revealed by a monospecific antiserum against class II chitinases. Purification and characterization of the 32 kd allergens from both plant sources allowed their identification as class I chitinases with an N-terminal hevein-domain. The purified allergens fully inhibited IgE binding by the corresponding crude extract when tested in immunoblot inhibition assays. Highly related 25 kd class II chitinases that lack the hevein-like domain were also isolated from the same protein preparations. No IgE-binding capacity was shown by these class II enzymes.. Class I chitinases are relevant allergens of avocado and chestnut and could be the panallergens responsible for the latex-fruit syndrome. The hevein-like domain seems to be involved in their allergenic reactivity.

Topics: Adult; Allergens; Amino Acid Sequence; Antimicrobial Cationic Peptides; Binding Sites; Chitinases; Female; Food Hypersensitivity; Fruit; Humans; Immunoglobulin E; Lauraceae; Lectins; Male; Molecular Sequence Data; Plant Lectins; Plant Proteins

Recent studies demonstrated that allergy to natural rubber latex is frequently associated with hypersensitivity to avocado fruit. The responsible cross-sensitizing allergen has not been identified.. The purpose of this study was to investigate the cross-reactivity of a latex major allergen, hevein, with avocado proteins.. Serum samples from 118 health care workers (HCWs) allergic to latex (HCW group) and 78 patients with spina bifida (SB) allergic to latex (SB group) were included in this study. Anti-hevein and anti-avocado IgE antibodies were measured by enzyme-linked allergosorbent assay. Cross-reactivity of hevein to avocado proteins was assessed by inhibition of the IgE binding in individual patients' sera containing IgE antibodies to both hevein and avocado.. The prevalence of seropositive IgE antibodies to avocado was found to be strongly associated with the presence of hevein-specific IgE antibodies in subjects of both groups (P < .001). Sixty-seven of 91 (73%) subjects from the HCW group and all 19 subjects in the SB group with positive IgE antibodies to hevein also had elevated IgE values to avocado. Competitive RAST inhibition with 42 sera showed that IgE binding to avocado could be completely inhibited in 27 (64%) sera by preincubation with hevein. By contrast, the degrees of inhibition of IgE to hevein by avocado extract ranged from 0% to 36% (n = 16). These results indicate that sensitization to avocado in most patients allergic to latex is caused exclusively by IgE-binding epitopes present in hevein. Results of immunoblots and immunoblot inhibition with 11 serum samples confirmed that a 30-kd protein in avocado was the major IgE-binding component; the IgE-binding reactivity to this protein could be inhibited by hevein in all sera tested.. Hevein is the major cross-reacting allergen with avocado in subjects with latex allergy.

Topics: Adolescent; Adult; Allergens; Amino Acid Sequence; Antimicrobial Cationic Peptides; Child; Child, Preschool; Cross Reactions; Euphorbiaceae; Female; Food Hypersensitivity; Fruit; Health Personnel; Humans; Immunization; Immunoblotting; Immunoglobulin E; Latex; Latex Hypersensitivity; Lauraceae; Lectins; Male; Middle Aged; Molecular Sequence Data; Plant Lectins; Plant Proteins; Sequence Homology, Amino Acid; Spinal Dysraphism