WHO/IUIS Allergen Nomenclature: Providing a common language

A systematic nomenclature for allergens originated in the early 1980s, when few protein allergens had been described. A group of scientists led by Dr. David G. Marsh developed a nomenclature based on the Linnaean taxonomy, and further established the World Health Organization/International Union of Immunological Societies (WHO/IUIS) Allergen Nomenclature Sub-Committee in 1986. Its stated aim was to standardize the names given to the antigens (allergens) that caused IgE-mediated allergies in humans. The Sub-Committee first published a revised list of allergen names in 1986, which continued to grow with rare publications until 1994. Between 1994 and 2007 the database was a text table online, then converted to a more readily updated website. The allergen list became the Allergen Nomenclature database (www.allergen.org), which currently includes approximately 880 proteins from a wide variety of sources. The Sub-Committee includes experts on clinical and molecular allergology. They review submissions of allergen candidates, using evidence-based criteria developed by the Sub-Committee. The review process assesses the biochemical analysis and the proof of allergenicity submitted, and aims to assign allergen names prior to publication. The Sub-Committee maintains and revises the database, and addresses continuous challenges as new “omics” technologies provide increasing data about potential new allergens. Most journals publishing information on new allergens require an official allergen name, which involves submission of confidential data to the WHO/IUIS Allergen Nomenclature Sub-Committee, sufficient to demonstrate binding of IgE from allergic subjects to the purified protein

Peptidomics characterization of allergenic and non-allergenic tropomyosin orthologs

Background The cleavage and the digestion patterns of allergenic proteins play a key role in allergenicity. The transformation of food proteins starts with their denaturation by the acidic environment of the stomach. However, protein denaturation is not enough to completely remove allergenic properties of a protein, but it is necessary a complete enzymatic digestion. Whether the enzymatic digestion is not efficient, the persistence of bigger peptides can occur and put the basis for the development of the sensitization process.The hypothesis of the current work takes into consideration the probability that shrimp tropomyosin (TM) is not fully digested or presents a digestion pattern that generates some peptides that can be immunogenic.Therefore, the work plan designed, aims to study the cleavage pattern of: purified chicken TM, recombinant chicken TM, purified TM of Penaeus monodon (Pen m 1), recombinant TM of Penaeus monodon (rPen m 1) and recombinant TM of Crangon crangon (rCrac c 1). Methods One mg of each ortholog has been processed through simulated mouth, gastric and intestinal digestion. The sample was frozen to block the digestion and, after this step, concentrated and cleaned through protein precipitation. The protein pellet was processed for peptidomic analysis through 1D Tricine gel electrophoresis, 2D Tricine gel electrophoresis and mass spectrometry. Results Simulated gastric digestion pattern of shrimp TM highlighted the presence of a resistant band at an average MW of 25 kDa that could be involved in the immunogenic process. Conclusions This innovative approach (peptidomics study through 1D-2D Tricine/MS) could represent a milestone for the study of digestion patterns of allergenic proteins or for the study of allergenic potential of novel foods

Standardization of double blind placebo controlled food challenge with soy within a multicentre trial

Background: Multicentre trials investigating food allergies by double blind placebo controlled food challenges (DBPCFC) need standardized procedures, challenge meals and evaluation criteria. We aimed at developing a standardized approach for identifying patients with birch related soy allergy by means of DBPCFC to soy, including determination of threshold levels, in a multicentre setting. Methods: Microbiologically stable soy challenge meals were composed of protein isolate with consistent Gly m 4 levels. Patients sensitized to main birch allergen Bet v 1 and concomitant sensitization to its soy homologue Gly m 4 underwent DBPCFC. Outcome was defined according to presence and/or absence of ten objective signs and intensity of eight subjective symptoms as measured by visual analogue scale (VAS). Results: 138 adult subjects (63.8% female, mean age 38 years) underwent DBPCFC. Challenge meals and defined evaluation criteria showed good applicability in all centres involved. 45.7% presented with objective signs and 65.2% with subjective symptoms at soy challenge. Placebo challenge meals elicited non-cardiovascular objective signs in 11.6%. In 82 (59.4%) subjects DBPCFC was judged as positive. 70.7% of DPBCFC+ showed objective signs and 85.4% subjective symptoms at soy challenge. Subjective symptoms to soy challenge meal in DBPCFC+ subjects started at significantly lower dose levels than objective signs (p < 0.001). Median cumulative eliciting doses for first objective signs in DBPCFC+ subjects were 4.7 g [0.7–24.7] and 0.7 g [0.2–4.7] total soy protein for first subjective symptoms (p = 0.01). Conclusions: We present the hitherto largest group of adults with Bet v 1 and Gly m 4 sensitization being investigated by DBPCFC. In this type of food allergy evaluation of DBPCFC outcome should not only include monitoring of objective signs but also scoring of subjective symptoms. Our data may contribute to standardize DBPCFC in pollen-related food allergy in multicentre settings. Trial registration EudraCT: 2009-011737-27

Soybean (Glycine max) allergy in Europe: Gly m 5 (beta-conglycinin) and Gly m 6 (glycinin) are potential diagnostic markers for severe allergic reactions to soy

BACKGROUND: Soybean is considered an important allergenic food, but published data on soybean allergens are controversial. OBJECTIVE: We sought to identify relevant soybean allergens and correlate the IgE-binding pattern to clinical characteristics in European patients with confirmed soy allergy. METHODS: IgE-reactive proteins were identified from a soybean cDNA expression library, purified from natural soybean source, or expressed in Escherichia coli. The IgE reactivity in 30 sera from subjects with a positive double-blind, placebo-controlled soybean challenge (n = 25) or a convincing history of anaphylaxis to soy (n = 5) was analyzed by ELISA or CAP-FEIA. RESULTS: All subunits of Gly m 5 (beta-conglycinin) and Gly m 6 (glycinin) were IgE-reactive: 53% (16/30) of the study subjects had specific IgE to at least 1 major storage protein, 43% (13/30) to Gly m 5 , and 36% (11/30) to Gly m 6. Gly m 5 was IgE-reactive in 5 of 5 and Gly m 6 in 3 of 5 children. IgE-binding to Gly m 5 or Gly m 6 was found in 86% (6/7) subjects with anaphylaxis to soy and in 55% (6/11) of subjects with moderate but only 33% (4/12) of subjects with mild soy-related symptoms. The odds ratio (P < .05) for severe versus mild allergic reactions in subjects with specific IgE to Gly m 5 or Gly m6 was 12/1. CONCLUSION: Sensitization to the soybean allergens Gly m 5 or Gly m 6 is potentially indicative for severe allergic reactions to soy

Lichenometric studies on moraines in the Polar Urals

Lichenometry was used to study fluctuations of six glaciers in the Polar Urals over the last millennium (viz: IGAN, Obrucheva, Anuchina, Shumskogo, Avsiuka and Berga glaciers). In order to estimate the growth rate of Rhizocarpon subgenus Rhizocarpon lichens we used recently deglaciated surfaces as calibration sites. These sites, on glacier forelands, were dated using topographic maps, aerial photographs (from 1953, 1958, 1960, 1968, 1973, 1989), terrestrial photogrammetry, field photographs (from the 1960s to 2005), and satellite images (from 2000 and 2008). We also used pits and quarries abandoned between the 1940s–1980s and a road built in the early 1980s as calibration sites. Optimum diametral growth rates of Rhizocarpon subgenus Rhizocarpon are estimated by the new curve to be c. 0.25 mm/year for the last 100 years, assuming linear growth as deduced from the shape of other curves from northern Scandinavia. Due to the lack of old control points we used a reconstructed mass balance curve (from 1816 to 2008) to indirectly constrain the age of pre-twentieth-century moraines. The following moraine groups were identified near the modern fronts of glaciers: ablation moraines de-glaciated during the last 40 to 60 years; lateral moraines formed in the early twentieth century (largest lichen diameter (DLL) = 20 mm), ice-cored moraines, probably from the 1880s (DLL= 24–26 mm); moraines probably deposited in the middle of the nineteenth century and c. 200 years ago (DLL= 30–33 mm and 44–47 mm, respectively); as well as several more ancient moraines (DLL= 70 mm, 90 mm and 110–153 mm) deposited during glacier advances of almost identical extent. According to our tentative lichenometric-age estimates most moraines were formed during the last 450 years – consistent with upper tree-limit altitude variations previously identified for this region. Glacier fluctuations in the Polar Urals are in agreement with tree-ring based reconstructions of summer temperature spanning the last millennium, and are also in tune with glacier behaviour elsewhere in the Northern Hemisphere

NACA Research Memorandums

"An investigation was conducted on a 35 degree swept-wing model to determine the aerodynamic characteristics and suction requirements of a model having a leading-edge area-suction flap deflected 40 degrees" (p. 1). The procedures, corrections needed, force characteristics, suction requirements, and pressure distributions are described