Self‐reported adverse reactions and IgE sensitization to common foods in adults with asthma

BACKGROUND: There is very few data available on the prevalence of food hypersensitivity among adults with asthma. The aim of this study was to explore the prevalence of self-reported adverse reactions and IgE sensitization to the different foods and to determine the spectrum and the prevalence of food-related gastrointestinal symptoms in adults with and with no asthma. METHODS: A cross sectional study based on interviews and questionnaire responses from 1527 subjects, aged 18–75 years of age, from Västra Götaland in Sweden, as part of the larger West Sweden Asthma Study. IgE analyses were performed in sera from all subjects. RESULTS: Fifty three percent of adults with asthma reported adverse reactions to foods compared to 30 % of non-asthmatics. Most asthmatics reported symptoms from eating hazelnut, followed by other nuts, birch-related foods, milk, peanut and shellfish. Furthermore, adults with asthma experienced significantly more often gastrointestinal symptoms from hazelnut, apple and milk and were found to significantly more often be sensitized to the most common foods compared to the non-asthmatic subjects. The asthmatics showed a significant correlation between IgE to both hazelnut and birch and self-reported symptoms after ingestion of hazelnut and to a lesser extent to almonds. CONCLUSIONS: The prevalence of self-reported adverse reactions and sensitization to the most common foods was much higher among the asthmatic subjects. Hazelnut was the food that asthmatics most frequently experienced adverse reactions from, and the strong correlation between IgE to hazelnut and birch indicate that the observed adverse reactions are partly due to sensitization to allergens from the PR-10 family. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13601-015-0067-6) contains supplementary material, which is available to authorized users

Proteolytic Activity as a Regulator of the Transmission of Orally Fed Proteins from the Gut to the Blood Serum in the Suckling Rat

14-day-old rats were orally fed with porcine colostrum or serum having a low or high activity of protease inhibitors (i.e., sow colostrum trypsin-chymotrypsin inhibitor or soybean trypsin inhibitor). The uptake of undigested porcine albumin and IgG to the blood serum of these rats was studied 4 h after feeding. The effect of the exclusion of proteases to the intestinal lumen by means of pancreatic duct ligation prior to feeding was also studied. The results from these feeding experiments in the presence of protease inhibitors or in the absence of pancreatic proteases agreed well. It was concluded that for the suckling rat the intraluminal proteolytic activity in the gastrointestinal tract is a regulator for nonselective protein uptake, as represented by albumin, while the selective absorption of IgG was unaffected.</jats:p

Maternal dietary antigens and the immune response in the offspring of the guinea-pig.

Guinea-pig dams and their litters were raised on either a cow's milk protein-containing diet (MCD) or a milk-free diet (MFD). At 8 weeks of age all litters were challenged i.p. with 50 micrograms milk whey-protein concentrate (V67) and 100 mg A1(OH)3 in saline. The immune response was estimated 2 weeks later as the serum IgG antibody titres against V67, beta-lactoglobulin (beta-LG) and alpha-lactalbumin (alpha-LA) using enzyme-linked immunosorbent assay (ELISA) and the tracheal Schulze-Dale response to these antigens. Feeding milk protein antigen to dams from birth and during pregnancy induces antigen-specific hyporesponsiveness (tolerance) in their offspring, despite no direct contact between the offspring and the milk proteins. Tolerance seems to be induced by the antigen itself since withdrawal of the MCD 10 days before delivery reduced tolerance in the offspring. No tolerance was produced in the offspring of dams fed the antigen from 3 months of age (adult). beta-LG appears to be a major antigen in milk whey while alpha-LA is a minor one since there was almost no antibody or tracheal response to alpha-LA in any of the animals tested. The results indicate that maternal antigen experience and antigens present during pregnancy are important for the subsequent immune response to these antigens in offspring

Intestinal Macromolecular Transmission in the Young Rat: Influence of Protease Inhibitors during Development

Intestinal macromolecular transmission in young rats of 10, 14, 18, 22 and 30 days of age was measured as the blood serum levels of markers 6 h after oral feeding of a solution containing bovine IgG (BIgG), bovine serum albumin (BSA) and fluorescein-isothiocyanate-labeled dextran 70,000 (FITC-D), either alone (controls) or with soybean trypsin inhibitor (SBTI) or swine colostrum trypsin inhibitor (SCTI). In the 10- and 14-day-old rats, transmission of all three macromolecular markers was high, with a preference for IgG. Transmission was greatly reduced by the age of 18 days and totally arrested for the protein markers at 22 days, with a low transmission of FITC-D remaining at 30 days of age. Addition of either of the two protease inhibitors significantly elevated the transmission of the protein markers in the rats aged 10, 14 and 18 days, while the transmission of the protease-independent marker FITC-D was unaffected. From 14 days of age, the rats have a functioning intestinal proteolysis, since only small amounts of marker proteins were left in the gut lumen 6 h after feeding, and since the addition of protease inhibitors resulted in increased amounts of undegraded proteins intraluminally. The results indicate that the increase of intraluminal proteolytic activity during development and the presence of protease inhibitors in the food are of importance for the intestinal transmission of undegraded proteins in the young rat. The Fc receptor for IgG in the enterocyte is not sufficient to maintain an optimal transmission of IgG, since the intraluminal proteolytic activity also appears to be of importance.</jats:p

Development of phospholipase A2 and lysophosphatidylcholine metabolising enzyme activities in the neonatal rat intestine

We have studied the development of phospholipase A2 (PLA2) and lysophosphatidylcholine (lysoPC)-metabolising enzyme activities in the neonatal rat intestine and its relation to the intestinal permeability of macromolecules. The permeability was determined by feeding young rats a mixture of bovine serum albumin, bovine immunoglobulin G and fluorescein-isothiocyanate-conjugated dextran 70,000, and analysing the serum concentrations after six hours. The animals were then killed and the intestinal mucosa was homogenised and assessed for PLA2 and lysoPC-metabolising enzyme activities. The intestine was 'open' to the macromolecules in 14 day old animals, but 'closed' in 22 and 32 day old animals and in 14 day old rats treated with cortisone acetate on day 10, 11, and 12 postpartum. The activity of PLA2 (at pH 6 and 2 mM Ca2+) was higher in 32, 22, and cortisone treated 14 day old animals, than in untreated, 14 day old animals. Incubation of 14C-acyl-lysoPC mucosa from 14 day old rats did not change the radioactivity pattern as shown by thin layer chromatography, whereas after incubation with mucosa from 22 or 32 day old animals all the radiolabel was found in free 14C-fatty acid and in 14C-phosphatidylcholine. These findings indicate that mucosal PLA2 activity increases during intestinal maturation and that the mucosa acquires the ability to acylate and deacylate lysoPC when it is 'closed' to macromolecules