Latex-allergic patients sensitized to the major allergen hevein and hevein-like domains of class I chitinases show no increased frequency of latex-associated plant food allergy

Abstract

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.

The Latex Story

“…About 30-50% of latex-allergic patients show allergic symptoms to plant-derived foods, especially fresh fruits [34] . The association was called latexfruit syndrome [ 35 , 36 ] and a huge and constantly increasing number of fruits are described, and the most commonly involved are avocado, banana, chestnut and kiwi.…”

Recent research on natural rubber latex (NRL) allergy

“…The coinciding allergies are known as latexfruit syndrome and the mechanisms behind the cross-reactivity are based Table 18.5 Rubber chemicals shown to cause allergic reactions (allergic contact dermatitis, Type IV hypersensitivity reaction) ∑ Thiazoles (e.g., 2-mercaptobenzo-thiazole, 2 MBT) ∑ Thiurams (e.g., tetramethylthiuram monosulfide, TMTM) ∑ Dithiocarbamates (e.g., zinc dibutyl-dithiocarbamate, ZDBC) ∑ Guanidines ∑ Thioureas (e.g., dibutylthiourea, DBTU) ∑ Amine aldehydes on structural homologies between different NRL proteins and various plant proteins (reviewed in Radauer et al, 2011). Recently, clinically relevant new cross-sensitisation between NRL and goldenrod was reported by Bains et al (2010).…”

Molecular diagnosis of fruit and vegetable allergy

“…This crossreactivity has been attributed to the major latex allergen, hevein and the hevein-like domains (HLDs) from class I chitinases in fruits. In a recent in-vitro study by Radauer et al [51] the role of hevein and HLDs sensitization was investigated in a selected latex allergic patient group and in a retrospective study comprising 16 408 participants with any IgE-mediated allergy symptom. In accordance with previous reports hevein was identified as the sensitizing agent for patients with hevein and HLDs sensitization.…”