Sesame oleosins are minor allergens

Abstract

Background In daily practice, one-third of sesame allergic patients, confirmed by clinical history or food challenge, do not show any detectable specific IgE using current diagnostics. Currently used sesame extracts are water-based and therefore lacking hydrophobic proteins like oleosins. Oleosins, the stabilizer of lipid droplets in plants, are described as allergens in sesame, peanut and hazelnut. In this study, we examine the role of oleosins in sesame allergy and their potential cross-reactivity between sesame and (pea)nuts. Methods Specific IgE and IgG sensitisation to native and heterologously expressed sesame components and oleosins from other nuts, free of seed storage proteins, was assessed by line blot and sera from 17 sesame allergic patients without detectable specific IgE sensitisation to sesame, and compared to 18 sesame allergic and 13 tolerant patients with specific IgE sensitisation to sesame. Results Sesame allergic patients without sensitisation showed no specific IgE to the tested sesame oleosins or components. Low levels of specific IgE to sesame oleosins were detected in 17% of sesame allergic and 15% of tolerant patients with sIgE sensitisation. Oleosins were recognised by serum IgG from multiple patients confirming immune reactivity and excluding technical issues leading to lack of specific IgE-binding to oleosins. Conclusion Sesame oleosins are minor allergens and appear to have no additonal value in diagnosing sesame allergy in adults based on sIgE and sIgG detection. There is a high need for additional diagnostic tools in those patients to minimize the number of required food challenges. Electronic supplementary material The online version of this article (10.1186/s13601-019-0271-x) contains supplementary material, which is available to authorized users.

Sesame eliciting and safe doses in a large sesame allergic population

“…Also, the use of a low‐fat sesame flower could have impacted the ED estimation due to lower quantity of oleosins. However, as the storage protein ses i 1 is considered the main sesame allergen, 43 in oppose to oleosins which were demonstrated as minor allergens, 44 this effect is likely negligible. Finally, safe doses were analyzed in patients older than 3.7 y/o only, as this was the age limit for starting OIT.…”

Sesame allergy in children: New insights into diagnosis and management

“…12,17 Ses i 1 has also been identified as a major sesame allergen (>50% prevalence) and as a clinically relevant marker of severe allergic reactions. 17 Sesame oleosins have been characterized as minor allergens, 32 although they have also been identified as the dominant allergen in some patients who reported anaphylaxis to sesame. 5 As noted in Table 1, some sesame components are related to those found in peanut (a legume) and tree nuts (hazelnut, walnut, black walnut, cashew, macadamia, and pistachio) with reported cosensitizations.…”

“…Ses i 1 has also been identified as a major sesame allergen (>50% prevalence) and as a clinically relevant marker of severe allergic reactions 17 . Sesame oleosins have been characterized as minor allergens, 32 although they have also been identified as the dominant allergen in some patients who reported anaphylaxis to sesame 5 …”

Highlights and recent developments in allergic diseases in EAACI journals (2019)

“…A recommendation of wheat consumption, if considered safe to the patient based on case-history and challenge results could be advised [ 75 ]. Sesame oleosins are minor allergens [ 76 ]. Lipid Transfer Protein allergy was characterized in the United Kingdom and compared with a matched Italian cohort [ 77 ].…”