[Reflections on the sulfite test in sulfite intolerance]. / Quelques réflexions sur le sulfi-test dans l'intolérance aux sulfites.

Detection of sulphite sensitivity can be simplified by use of sulphite test. However, because of the precautions and limitations it is difficult to suggest its use for all patients.

Cell-mediated immune responses to artificial food additives in chronic urticaria.

In some cases of chronic urticaria it is suspected that food additives such as tartrazine and sodium benzoate or salicylates may play a role in the pathogenesis of the condition. Since, at times, chronic urticaria may appear histologically similar to a mild cell-mediated immune response, the release of the T cell-derived lymphokine leucocyte inhibitory factor (LIF), in response to incubation with these additives and with acetylsalicylic acid (ASA), was measured in vitro using cells from normal controls, from patients with chronic urticaria with or without clinically associated additive sensitivity and from patients with asthma with or without associated ASA sensitivity. It was found that significant production of LIF occurred in response to tartrazine and sodium benzoate in those individuals with chronic additive induced urticaria. In addition, tartrazine caused LIF release from mononuclear cells of ASA-sensitive asthmatics. These results may indicate a possible role for additive-induced cell-mediated immune responses in the pathogenesis of some cases of chronic urticaria and suggest a potential diagnostic test for this condition.

Immunology of foods.

Investigation of food sensitivity is difficult and often confusing. However, there are multiple articles in the literature which illustrate that food is absorbed from the gastro-intestinal tract in an antigenic fashion and that the entire immune system is stimulated by these antigenic food particles. All four Gell and Coombs varieties of immunologic reactions have been demonstrated as causes of symptoms in patients. Test techniques are available for each of these immunologic reactions, as is treatment for their noxious effects.

Extravasation assay for the assessment of intestinal reactions to orally presented compounds.

Adverse reactions characteristic of food intolerance are claimed to occur in susceptible individuals following exposure to various chemical additives used to colour, flavour or preserve food. The objective of the present study was to develop a method suitable for investigating the nature and mechanism of these reactions in an animal model. Our results demonstrate that intestinal responses, elicited either specifically following oral challenge by antigen or non-specifically by the direct action of a chemical, can be quantified by evaluating the intestinal extravasation (IEV) of intravenously administered 125I-labelled rat albumin.

Changes in the coagulation system during pseudoallergic anaphylactoid reactions to drugs and food additives.

In 10 patients with known anaphylactoid reactions to drugs and food additives, oral provocation tests were performed with increasing doses of the implicated agents. Clinical reactions, vital signs, bleeding time, prothrombin time, partial thromboplastin time and platelet aggregation were measured before and 15 min after each oral dose. Six patients reacted clinically. In all 10 patients, platelet aggregation decreased with increasing challenging doses. All other parameters remained stable or changed without any correlation to the drug, the type or the severity of the reaction. Measurement of the bleeding time is, therefore, of no diagnostic value in anaphylactoid reactions, and major alterations in the coagulation system do not explain their pathogenesis.

Value of oral provocation tests to aspirin and food additives in the routine investigation of asthma and chronic urticaria.

Nonsteroidal anti-inflammatory drugs and certain food or drug additives are known to induce acute bronchospasms, angioneurotic edema, and urticaria in susceptible patients. Thirty-four patients (17 with asthma and 17 with urticaria), whose case history suggested such intolerance, were challenged orally with increasing doses of seven compounds: acetylsalicylic acid, glafenine, sodium benzoate, sulfur dioxide, potassium sorbate, sodium glutamate, and tartrazine. Among 162 oral provocation tests, 38 were positive (20% decrease in peak flow rate or appearance of acute urticaria/angioneurotic edema). Twenty-four of the 34 patients (nine with asthma and 15 with urticaria) were intolerant to at least one compound. However, no serious reaction was observed. In 20 of these 24 patients (six with asthma and 14 with urticaria), a diet free of additives and nonsteroidal anti-inflammatory drugs resulted, within 5 days, in a marked improvement of symptoms, which persisted 8 to 14 mo after starting the diet. Age, prevalence of IgE-mediated allergy, and nasal polyposis were similar in patients with or without reactions of intolerance. Under the conditions used, oral provocation tests proved to be feasible, safe, and useful in many patients not helped by existing methods.

Irritable bowel syndrome and hypersensitivity to food.

Food hypersensitivity as a cause of irritable bowel syndrome was investigated by means of exclusion diet and blind provocation. Twelve atopic and twelve non-atopic individuals entered into the study. Skin prick testing with 20 foods and food additives and RAST specific for food only, were done in all cases. Serum IgE level was also measured. In 14 patients one or several food or additives were shown to induce the typical symptoms of IBS. In at least nine cases of atopy, an IgE-mediated mechanism could be incriminated. Among other potential pathogenetic mechanisms, the presence in the intestinal tract of yeast (Candida albicans, Geotrichum candidum) seems to be of major importance. Yeast apparently favor the development of allergic as well as pseudo-allergic reactions, at least in some patients. Finally, at least in atopic patients complaining of IBS, it is of importance to search for a food component. Dramatic clinical improvements can result from the introduction of an adequate exclusion diet.

Immunogenicity of foods and food additives--in vivo testing of gums arabic, karaya and tragacanth.

An inexpensive animal model is described, for investigation of the immunogenicity of substances such as food additives. Inbred mice were immunised with antigen emulsified in complete Freund's adjuvant, and specific cell-mediated immunity subsequently measured by a footpad swelling test. This method has been applied in an investigation of the immunogenicity of the exudate gums, gum arabic, gum karaya and gum tragacanth. These substances are capable of eliciting an immune response which is comparable to the specific immune responses elicited by a protein antigen, e.g. hens' egg ovalbumin. Purification of commercially available gum preparations led to a significant (P less than 0.005) reduction of the immune response under in vivo test conditions.

[Acetylsalicylic acid and food additive intolerance in urticaria, bronchial asthma and rhinopathy]. / Acetylsalicylsäure- und Lebensmitteladditiva-Intoleranz bei Urtikaria, Asthma bronchiale und chronischer Rhinopathie.

Adverse reactions (urticaria, angio-edema, bronchoconstriction, purpura) to Aspirin (ASS) and food-and-drug additives such as the yellow dye tartrazine and the preservative benzoate are observed all over the world. Since the exact pathogenetic mechanisms of this condition is unknown, it is described as intolerance or pseudo-allergy and has been related to an imbalance of prostaglandin synthesis. Among 620 patients with urticaria, bronchial asthma or chronic rhinitis, oral provocation tests with ASS, tartrazine or benzoic acid revealed in 165 (26.6%) intolerance to ASS or additives. Frequency of intolerance to tartrazine varied between 6.1% in urticaria (n=308), 7.3% in asthma (n=96) and 14.5% in urticaria and asthma patients, while intolerance to benzoate varied from 2.5% in rhinitis (n=40) to 11.5% in asthma. More than two thirds of the intolerant patients were improved by an elimination diet and by the avoidance of "aspirin-like" drugs. More than one third of chronic urticaria patients became symptomfree. In Switzerland exact declaration of all food additives is urgently needed. Moreover, azo-dyes must no longer be used for colouring of drugs.

[Foodstuff additive-induced intolerance reactions]. / Durch Lebensmittel-Additivstoffe ausgelöste Intoleranzreaktionen.

Additional materials in food and consumers' goods can produce different allergic reactions. The more important additional materials and reactions produced by them are discussed. They introduce to us the phenomenon of the intolerance and the different cross reactions during treatment of the pathomechanism. The causal clearing up of the intolerance reactions is made by provocation tests, with the help of which pathological reactions may be prevented.