Ulf Bengtsson

Standardization of food challenges in patients with immediate reactions to foods – position paper from the European Academy of Allergology and Clinical Immunology

At present, the double blind placebo controlled foodchallenge(DBPCFC)representstheonlywaytoestablishorruleoutanadversereactiontoafoodinolderchildrenand adults, whereas an open challenge controlled bytrained personnel is sufficient in infants and youngchildren (1). The challenge procedure is not, however,C.Bindslev-Jensen

Food-Related Gastrointestinal Symptoms in the Irritable Bowel Syndrome

Background/Aims: Postprandial symptoms are common in patients with irritable bowel syndrome (IBS). However, existing studies have come to different conclusions about the role of food in the pathophysiology of IBS. We explored the prevalence of subjective food-related gastrointestinal (GI) symptoms and its relationship to clinical characteristics and psychological factors in IBS. Methods: 330 patients with IBS and 80 healthy volunteers completed a food questionnaire developed for this study. The subjects graded their subjective symptoms after 35 different foods and a food score was obtained by adding the item scores. The relationship between subjective food-related GI symptoms and referral status, IBS subgroup (predominant bowel pattern), sex, anxiety, depression and body mass index (BMI) was estimated. Results: In 209 (63%) of the patients the GI symptoms were related to meals. Gas problems and abdominal pain were the most frequently reported symptoms. Foods rich in carbohydrates, as well as fatty food, coffee, alcohol and hot spices were most frequently reported to cause symptoms. The food score was higher in patients than in controls (p < 0.0001). In the IBS group higher scores were observed in patients with anxiety (p = 0.005), and females (p < 0.001), but the results were unrelated to IBS subgroup, referral status or BMI. The BMI did not differ between groups. Conclusion: A majority of IBS patients consider their symptoms to be related to meals. Especially foods rich in carbohydrates and fat cause problems. Nevertheless, the majority of IBS patients are normal or overweight. Female sex and anxiety predict a high degree of food-related symptoms in IBS.

Self-Reported Food-Related Gastrointestinal Symptoms in IBS Are Common and Associated With More Severe Symptoms and Reduced Quality of Life

OBJECTIVES:Despite the fact that food and diet are central issues, that concern patients with irritable bowel syndrome (IBS), the current understanding about the association between the intake of certain foods/food groups and the gastrointestinal (GI) symptom pattern, psychological symptoms, and quality of life is poor. The aim of this study was to determine which food groups and specific food items IBS patients report causing GI symptoms, and to investigate the association with GI and psychological symptoms and quality of life.METHODS:We included 197 IBS patients (mean age 35 (18–72) years; 142 female subjects) who completed a food questionnaire in which they specified symptoms from 56 different food items or food groups relevant to food intolerance/allergy. The patients also completed questionnaires to assess depression and general anxiety (Hospital Anxiety and Depression), GI-specific anxiety (Visceral Sensitivity Index), IBS symptoms (IBS-Severity Scoring System), somatic symptoms (Patient Health Questionnaire-15), and quality of life (Irritable Bowel Syndrome Quality of Life Questionnaire).RESULTS:In all, 84% of the studied population reported symptoms related to at least one of the food items surveyed. Symptoms related to intake of food items with incompletely absorbed carbohydrates were noted in 138 (70%) patients; the most common were dairy products (49%), beans/lentils (36%), apple (28%), flour (24%), and plum (23%). Of these, 58% experienced GI symptoms from foods rich in biogenic amines, such as wine/beer (31%), salami (22%), and cheese (20%). Histamine-releasing foods, such as milk (43%), wine/beer (31%), and pork (21%), were also considered causes of symptoms in IBS patients. GI symptoms were also frequently reported after intake of fried and fatty foods (52%). With increasing IBS symptom severity, patients reported more food items responsible for their GI symptoms (P=0.004), and this was also found in patients with more severe somatic symptoms (P<0.0001). Women tended to report more food items causing symptoms than men (P=0.06). A high number of food items causing GI symptoms was also associated with reduced quality of life and this was significant for the following domains: sleep (r=−0.25; P=0.001), energy (r=−0.21; P=0.005), food (r=−0.29; P<0.001), social functioning (r=−0.23; P=0.001), and physical status (r=−0.16; P<0.05). However, the number of food items reported to provoke GI symptoms was unrelated to body mass index, age, IBS subtype, anxiety, depression, or GI-specific anxiety.CONCLUSIONS:The majority of IBS patients believe that certain food items are important triggers of their GI symptoms. This is especially true for foods containing carbohydrates and fat, and also may be relevant for histamine-releasing food items and foods rich in biogenic amines. Self-reported food intolerance is associated with high symptom burden and reduced quality of life.

Provocations with perfume in the eyes induce airway symptoms in patients with sensory hyperreactivity

Background: In earlier studies, we have shown that patients with a history of sensory hyperreactivity develop asthma‐like symptoms when exposed to strong scents, even if they cannot smell any scent.

Eosinophil cationic protein and histamine after intestinal challenge in patients with cow's milk intolerance

BACKGROUND Mast cells and eosinophils are key cells in the development of active symptoms in allergic diseases and other inflammatory conditions, and they mediate their action through the release of very potent granule constituents. METHODS Five patients with milk-related gastrointestinal symptoms diagnosed by double-blind placebo-controlled milk challenges, but with negative responses to skin prick tests and RASTs with milk, and eight healthy control subjects were investigated. Repeated perfusion studies were performed with a two-balloon, six-channel tube by using milk, casein, and whey as antigens. Luminal eosinophil cationic protein, histamine, and albumin were measured by radioimmunoassay. RESULTS Luminal cows milk induced a pronounced increase in intestinal secretion of histamine and eosinophil cationic protein in patients, but not control subjects, during the first 20 minutes after challenge (histamine from 123 +/- 12 to 543 +/- 175 ng/cm, hr; eosinophil cationic protein from 80 +/- 23 to 686 +/- 262 ng/cm, hr). Albumin, as a marker of plasma leakage, was also significantly increased. CONCLUSION These data indicate that mast cells and eosinophils are effector cells not only in patients with allergic disease but also in patients intolerant to foods and lacking circulating antibodies. The underlying mechanisms may be a reaction mediated by locally appearing antibodies or an immunologic activation resembling that found in intestinal disorders such as celiac disease.

Evaluation of IgE Antibodies to Recombinant Peanut Allergens in Patients with Reported Reactions to Peanut

Background: Peanut may cause severe reactions in allergic individuals. The objective was to evaluate IgE antibodies to various recombinant (r) peanut and birch pollen allergens in relation to IgE levels to whole peanut extract and severe allergic reactions to peanut. Methods: Seventy-four Swedish peanut-allergic patients (age: 14–61 years) reported previous peanut exposure and associated symptoms using a questionnaire. Their IgE reactivity to peanut, birch pollen and individual allergen components was analyzed using ImmunoCAP®. Results: Of the 48 subjects sensitized to Ara h 1, 2 or 3, 60% had peanut-specific IgE levels >15 kUA/l, while 100% of the subjects without detectable IgE to these allergens had low peanut-specific IgE levels (<10 kUA/l). The levels of IgE to rAra h 8, rBet v 1 and birch pollen were highly correlated (rS = 0.94, p < 0.0001). Fifty-eight patients reported adverse reactions after accidental or deliberate peanut exposure (oral, inhalation or skin) of whom 41 had IgE to rAra h 1, 2 or 3. Symptoms of respiratory distress were associated with sensitization to Ara h 1, 2 or 3 (56 vs. 18%, p < 0.01). Two cases of anaphylaxis were reported among the individuals sensitized to Ara h 1–3. IgE to rAra h 8, rAra h 9, profilin or cross-reactive carbohydrate determinants were not associated with severe symptoms. Conclusions: The results indicate that IgE reactivity to Ara h 1, 2 and 3 is associated with severe reactions after exposure to peanut in Swedish patients.

Bet v 1 homologues in strawberry identified as IgE-binding proteins and presumptive allergens

Background:  No strawberry allergen has so far been identified and characterized.

Double‐blind placebo‐controlled challenges for peanut allergy the efficiency of blinding procedures and the allergenic activity of peanut availability in the recipes

Background:  A firm diagnosis of double‐blind placebo‐controlled food challenge (DBPCFC) would facilitate the diagnosis in patients with uncertain history of reaction. Guidelines are lacking for an upper provoking dose and how to hide high concentrations of peanuts.

Interpretation of subjective symptoms in double-blind placebo-controlled food challenges : interobserver reliability

Background:  Subjective symptoms after food challenges are difficult to interpret and no standard is available. We discuss a strategy for how to interpret a diary. Furthermore, the interobserver reliability is evaluated.

Intestinal reactivity in allergic and nonallergic patients: An approach to determine the complexity of the mucosal reaction

BACKGROUND To determine whether inflammatory markers and mediators were released in response to different intestinal antigens, studies were performed in atopic patients allergic to birch, patients allergic to psyllium powder (ispaghula), and patients intolerant to milk. METHODS Allergy to birch and psyllium powder was documented by the presence of circulating IgE antibodies and positive skin tests. Patients intolerant to milk had negative outcomes of radioallergosorbent tests and skin tests but positive results of double-blind, placebo-controlled tests. Challenge of the intestine with different antigens was achieved by perfusion of a jejunal segment occluded between balloons. Basal and antigen-activated release of mast cell/basophil and eosinophil products and of substances emanating from the plasma and interstitial fluid was compared in perfusate fluid from patients (n = 8) and matched healthy controls (n = 8). RESULTS Perfusate levels of albumin and hyaluronan (previous name hyaluronic acid) were increased threefold to fivefold by antigen in all patients, but not in controls. Eosinophilic cationic protein increased in patients but also in ispaghula controls. Histamine was released in response to milk, but not in patients allergic to birch or ispaghula. Prostaglandin E2 increased in milk- and birch-sensitive patients. In response to ispaghula, however, it was released in both patients and controls. CONCLUSIONS We conclude that subclinical intestinal challenge with antigen induces an increase in the appearance rate of albumin and hyaluronan in the intestinal lumen both in atopic patients (with target organs such as the lungs or nose and eyes) and in patients with intestinal intolerance to milk. These changes in permeation are similar to those reported from other organs such as the lung. They may reflect a common response in early phase I reactions that are either IgE-mediated or occur in response to food antigens without any obvious involvement of an IgE-mediated mechanism. Subclinical provocation with intestinal antigens should prove useful for further elucidation of mechanisms underlying intestinal mucosal reactions to exogenous stimuli.