Purification and Characterization of Naturally Occurring Post-Translationally Cleaved Ara h 6, an Allergen That Contributes Substantially to the Allergenic Potency of Peanut

The 2S albumin Ara h 6 is one of the most important peanut allergens. A post-translationally cleaved Ara h 6 (pAra h 6) was purified from Virginia type peanuts, and the cleavage site was mapped using high-resolution mass spectrometry. Compared to intact Ara h 6, pAra h 6 lacks a 5-amino acid stretch, resembling amino acids 43−47 (UniProt accession number Q647G9) in the nonstructured loop. Consequently, pAra h 6 consists of two chains: an N-terminal chain of approximately 5 kDa and a C-terminal chain of approximately 9 kDa, held together by disulfide bonds. Intermediate post-translationally cleaved products, in which this stretch is cleaved yet still attached to one of the subunits, are also present. The secondary structure and immunoglobulin E (IgE) binding of pAra h 6 resembles that of intact Ara h 6, indicating that the loss of the nonstructured loop is not critical for maintaining the protein structure. Commercially available monoclonal and polyclonal immunoglobulin G (IgG) antibodies directed to Ara h 6 react with both intact Ara h 6 and pAra h 6, suggesting that the involved epitopes are not located in the area that is post-translationally cleaved. No differences between intact Ara h 6 and pAra h 6 in terms of IgE binding were found, suggesting that the area that is post-translationally cleaved is not involved in IgE epitopes either. For all main cultivars Runner, Virginia, Valencia, and Spanish, intact Ara h 6 and pAra h 6 occur in peanut at similar levels, indicating that pAra h 6 is a consistent and important contributor to the allergenic potency of peanut

Allergenicity attributes of different peanut market types

Four different market classes of peanut (Runner, Virginia Spanish, and Valencia) are commonly consumed in Western countries, but for some consumers peanuts are a main cause of food-induced anaphylaxis. Limited information is available on the comparative allergenicity of these distinct market classes. The aim of this study was to compare allergenicity attributes of different peanut cultivars. The protein content and protein profiles were highly comparable for all tested cultivars. All cultivar samples contained the major allergens Ara h 1, Ara h 2, Ara h 3 and Ara h 6, as assessed by SDS-PAGE and RP-HPLC, although some minor differences in major allergen content were found between samples. All samples were reactive in commercial ELISAs for detection and quantification of peanut protein. IgEbinding potency differed between samples with a maximum factor of 2, indicating a highly comparable allergenicity. Based on our observations, we conclude that peanuts from the main market types consumed in Western countries are highly comparable in their allergenicity attributes, indicating that safety considerations with regard to peanut allergy are not dependent on the peanut cultivar in question

Regional differences among female patients with heart failure from the Cardiac Insufficiency BIsoprolol Study in ELDerly (CIBIS-ELD)

Background: The aim of our study was to examine regional differences in the demographics, etiology, risk factors, comorbidities and treatment of female patients with heart failure (HF) in the Cardiac Insufficiency BI soprolol Study in ELDerly (CIBIS-ELD) clinical trial.Methods and results: One hundred and fifty-nine female patients from Germany and 169 from Southeastern (SE) Europe (Serbia, Slovenia and Montenegro) were included in this subanalysis of the CIBIS-ELD trial. Women comprised 54% of the study population in Germany and 29% in SE Europe. German patients were significantly older. The leading cause of HF was arterial hypertension in German patients, 71.7% of whom had a preserved ejection fraction. The leading etiology in SE Europe was the coronary artery disease; 67.6% of these patients had a reduced left ventricular ejection fraction (34.64 ± 7.75%). No significant differences were found in the prevalence of traditional cardiovascular risk factors between the two regions (hypertension, diabetes, hypercholesterolemia, smoking and family history of myocardial infarction). Depression, chronic obstructive pulmonary disease and malignancies were the comorbidities that were noted more frequently in the German patients, while the patients from SE Europe had a lower glomerular filtration rate. Compared with the German HF patients, the females in SE Europe received significantly more angiotensin converting enzyme inhibitors, loop diuretics and less frequently angiotensin receptor blockers and mineralocorticoid receptor antagonists.Conclusions: Significant regional differences were noted in the etiology, comorbidities and treatment of female patients with HF despite similar risk factors. Such differences should be considered in the design and implementation of future clinical trials, especially as women remain underrepresented in large trial populations.

IgE reactivity to alpha-Gal in relation to Lyme borreliosis

Background An association between tick bites, the development of immunoglobulin E (IgE) antibodies to galactose-alpha-1, 3-galactose (alpha-Gal) and red meat allergy has recently been reported. Here we wanted to elucidate the relation between tick exposure, IgE antibodies to alpha-Gal and Lyme borreliosis (LB). Methods In the highly LB endemic area of Kalmar County, Sweden, serum samples and health inquiries from 518 blood donors were included. All sera were investigated for multiple IgG antiBorrelia antibodies using a multiplex assay (recomBead, Mikrogen). In addition, three serially collected sera over a six month period from 148 patients with clinically defined erythema migrans (EM) were included. IgE antibodies against alpha-Gal were determined using ImmunoCAP (Thermo Fisher Scientific). Results In blood donors reporting previous LB (n = 124) IgE to alpha-Gal was found in 16%, while in donors denying previous LB but with multiple anti-Borrelia antibodies (n = 94; interpreted as asymptomatic LB) 10% were IgE alpha-Gal-positive. Finally, in donors without Borrelia antibodies denying previous LB (n = 300) 14% showed IgE to alpha-Gal. No significant difference in proportions among the groups were found. In EM patients, IgE to alpha-Gal was found in 32/148 (22%) at diagnosis, 31/148 (21%) after two-three months and 23/148 (16%) after six months. A significant reduction of proportion and level of IgE to alpha-Gal was found between the second and third sample (pamp;lt; 0.01). A positive IgE anti alpha-Gal was more common among men compared with women both in blood donors and in EM patients (p amp;lt;= 0.01). Conclusions IgE to alpha-Gal reactivity was common in a tick endemic area but showed no significant relation to previous LB. IgE anti-alpha-Gal reactivity in EM patients peaked within three months of diagnosis of EM, after which it waned indicating that recent tick exposure is of importance in alpha-Gal sensitization. Furthermore, IgE anti alpha-Gal was more common in men compared with women.Funding Agencies|Thermo Fisher Scientific, Uppsala, Sweden; Swedish Asthma and Allergy Foundation; Stockholm County Council (ALF Medicin); Swedish Research Council; Swedish Heart-Lung Foundation; Swedish Cancer and Allergy Foundation; King Gustaf V 80th Birthday Foundation; Hesselman Foundation; Konsul Th C Bergh Foundation; Magnus Bergvall Foundation; Medical Research Council in the South-east of Sweden</p

The α-Gal epitope - the cause of a global allergic disease

The galactose-α-1,3-galactose (α-Gal) epitope is the cause of a global allergic disease, the α-Gal syndrome (AGS). It is a severe form of allergy to food and products of mammalian origin where IgE against the mammalian carbohydrate, α-Gal, is the cause of the allergic reactions. Allergic reactions triggered by parenterally administered α-Gal sources appear immediately, but those triggered via the oral route appear with a latency of several hours. The α-Gal epitope is highly immunogenic to humans, apes and old-world monkeys, all of which produce anti-α-Gal antibodies of the IgM, IgA and IgG subclasses. Strong evidence suggests that in susceptible individuals, class switch to IgE occurs after several tick bites. In this review, we discuss the strong immunogenic role of the α-Gal epitope and its structural resemblance to the blood type B antigen. We emphasize the broad abundance of α-Gal in different foods and pharmaceuticals and the allergenicity of various α-Gal containing molecules. We give an overview of the association of tick bites with the development of AGS and describe innate and adaptive immune response to tick saliva that possibly leads to sensitization to α-Gal. We further discuss a currently favored hypothesis explaining the mechanisms of the delayed effector phase of the allergic reaction to α-Gal. We highlight AGS from a clinical point of view. We review the different clinical manifestations of the disease and the prevalence of sensitization to α-Gal and AGS. The usefulness of various diagnostic tests is discussed. Finally, we provide different aspects of the management of AGS. With climate change and global warming, the tick density is increasing, and their geographic range is expanding. Thus, more people will be affected by AGS which requires more knowledge of the disease

IgE anti-α-Gal positive rate in blood donors according to <i>Borrelia</i> status.

<p>IgE anti-α-Gal positive rate in blood donors according to <i>Borrelia</i> status.</p

Correlation between total IgE and IgE responses to α-Gal in erythema migrans patients (n = 27).

<p>Correlation between total IgE and IgE responses to α-Gal in erythema migrans patients (n = 27).</p