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Notes: Thirty-nine patients sensitized to Alternaria were evaluated using titrated skin-prick test (SPT), histamine release studies (HR), inhibition of RAST and immunoblotting studies. To determine the relevance of the major allergen, Alt a I, specific rabbit antibodies against Alt a I and Alt a B were used. The antibodies were preincubated at different concentrations: (i) with the Alternaria allergen dose required for maximum response in the HR assay (10 BU/ml) and (ii) with the Alternaria antigen coupled to RAST paper discs (1000 BU/disc). Dose dependent inhibition of histamine release (n= 30, x̄= 80%± 4%, IC30 = 0.69 μg/ml) and of RAST (n= 7, IC30 = 4.4 μg/ml) was found in all patients sensitized to Alternaria as indicated by allergen induced HR. The greater the response to Alternaria in HR, the higher the antibody concentrations necessary for inhibition (P〈0.05). Immunoblot experiments (n=25) using SDS-PAGE showed in all cases IgE- and IgG binding at approximately 28 kD, which is the size reported for the major allergen. All a I. In two cases, slight IgE binding at 45 and 66 kD was also found, while in two other patients, only IgE binding at 66 kD was seen. Our findings emphasize the major importance of Alt a I in patients sensitized to Alternaria.

Notes: Background Previous studies have shown a 10-fold discrepancy of self-reported food-induced symptoms and physician-diagnosed food hypersensitivity. Little information is available on the prevalence of food hypersensitivity in unselected paediatric populations. No data were available for German children.Objective To study the perception of food-induced symptoms in the paediatric population, to investigate the allergens accused, to objectify patients' reports, and to identify subgroups at risk of having food-induced allergy (FA) or non-allergic food hypersensitivity (NAFH) reactions.Methods This paper presents the data of the paediatric group (0–17 years) of a representative, randomly sampled, cross-sectional population-based survey studying 13 300 inhabitants of the German capital city Berlin regarding food-related symptoms. Instruments included mailed questionnaires, structured telephone interviews, physical examination, skin-prick tests, specific serum IgE and standardized, controlled and blinded oral food challenges.Results Two thousand three hundred and fifty-four individuals were contacted by mailed questionnaire, 739 (31.4%) responses could be fully evaluated. Four hundred and fifty-five (61.5%) participants reported symptoms related to food ingestion, 284 (38.4%) affirmed reproducible symptoms in the standardized telephone interview. One hundred and eighty-four (24.8%) individuals were fully examined. Reproducible symptoms to food were found in 31 (4.2%) children and adolescents: 26 (3.5%) showed symptoms of FA and five (0.7%) of NAFH. The oral allergy syndrome was most often observed. Foods most commonly identified by oral challenges were apple, hazelnut, soy, kiwi, carrot and wheat.Conclusion: The perception of food-related symptoms is common among children and adolescents from the general population. Self-reports could be confirmed in around one out of 10 individuals, still resulting in 4.2% of proven clinical symptoms. However, most reactions were mild and mainly because of pollen-associated FA, while NAFH reactions were less common. Severe IgE-mediated FA was observed in individuals with pre-existing atopic disease, who should be fully investigated for clinically relevant FA.

Notes: Background Adverse reactions after ingestion of alcoholic beverages are common. Metabolic differences in individuals and also the histamine content in alcoholic beverages have been implicated. By contrast pure ethanol has rarely been reported as a cause of hypersensitivity reactions and its mechanism has not been clarified yet.Objective To determine whether ethanol itself accounts for alcohol hypersensitivity in patients with anaphylactic reactions after alcohol intake. In search of possible pathomechanisms all patients were analysed by skin prick testing and sulfidoleukotriene production of peripheral leucocytes using ethanol and its metabolites.Methods Double-blind, placebo-controlled food challenges with a cumulated amount of 30 mL ethanol were performed in 12 adult patients with a positive history of adverse reactions after consumption of different alcoholic beverages. Skin prick tests and measurement of sulfidoleukotriene production were performed using different concentrations of ethanol and acetaldehyde from 50 to 1000 mm.Results Oral challenges with pure ethanol were positive in six out of eleven patients. All challenge-positive patients, but also four out of five challenge-negative patients, showed an increased sulfidoleukotriene production in-vitro compared with healthy controls. Skin prick tests using alcoholic beverages, ethanol, acetaldehyde and acetic acid were negative in all patients (12/12).Conclusion Our study shows that ethanol itself is a common causative factor in hypersensitivity reactions to alcoholic beverages. These reactions occur dose-dependent and a non-IgE-mediated pathomechanism is likely, because skin prick tests were negative in all cases. Increased sulfidoleukotriene production was determined in some patients, but is no reliable predictor. Therefore oral provocation tests remain indispensable in making the diagnosis of ethanol hypersensitivity.

Notes: Recently, we identified a subgroup of patients with atopic dermatitis (AD) with a clinical relevant food intolerance proven by double blind placebo controlled challenge. In search of possible pathomechanisms involved in this food intolerance, which leads to aggravation of the disease, the aim of the present study was to determine sulfidoleukotriene production in these patients using isolated leucocytes from the peripheral blood after stimulation with different food additives.Leukotriene production of peripheral leucocytes was detected by incubation of isolated cells with the food additives at different concentrations ranging from 0.2 to 200 µg/mL after pre-stimulation with IL-3. Ten non-atopic donors (A), nine AD patients of the diet responder group with negative oral provocation test against food additives (B) and nine patients of the responder group with positive reactions after the oral provocation test (C) were investigated.In the non-atopic group (A), no increased sulfidoleukotriene (sLT) release was observed for all food additives tested. In group B, increased sLT production was determined using tartrazine in one patient (1/9) and using nitrite in two patients (2/9), whereas sLT production remained below the cut-off range in all patients of group B (9/9) using benzoate, metabisulfite and salicylate. By contrast, in group C increased sLT production was observed with food colour mix in 1/9, with tartrazine in 3/9, with benzoate in 4/9, with nitrite in 5/9, with salicylate in 2/9 and with metabisulfite in 1/9. However, no increased sLT concentration was determined in the presence of the tested food additives in two patients of group C.Increased sLT production by peripheral leucocytes in the presence of single food additives was observed in the majority of patients with a proven food intolerance towards food additives proven by double-blind-placebo-controlled challenges. These food additives were particulary tartrazine, benzoate and nitrite. These findings indicate that single food additives as aggravating factors in AD patients may trigger the disease through increased sLT production as a pathophysiological mechanism.

Notes: Background CD23 plays an important role in IgE regulation. The modulation of CD23 expression during specific immunotherapy (SIT) has been described previously. In the present study, we investigated in detail the effects of complete birch pollen allergen extract (BPA) on CD23 expression of peripheral blood mononuclear cells (PBMCs) in vitro.Methods PBMCs from 14 birch pollen-allergic (bp-allergic) patients and eight non-bp-allergic controls were stimulated with IL-4 and increasing doses of BPA. CD23 expression on monocytes and B cells was measured by flow cytometry; sCD23 release and the levels of IFN-γ and IL-10 secretion were determined by ELISA. To analyse the mechanisms on CD23 expression in more detail, neutralizing anti-IFN-γ and anti-IL-10 antibodies were added to IL-4 and BPA-stimulated cultures.Results IL-4 induced CD23 expression on B cells and on monocytes and sCD23 release in the bp-allergic and non-bp-allergic groups. The addition of BPA to IL-4-stimulated PBMC decreased CD23 expression significantly and dose-dependently on B cells in both groups. CD23 expression on monocytes was also decreased in both groups after the addition of BPA, but higher doses were required in the non-bp-allergic population. IL-4-induced sCD23 release was also significantly decreased after the addition of BPA. IFN-γ and IL-10 were induced by BPA in both the bp-allergic and non-bp-allergic groups. The addition of neutralizing anti-IFN-γ antibodies increased CD23 expression on B cells, which were stimulated with IL-4 and BPA, but had no effect on monocytes, whereas the addition of anti-IL-10 antibodies increased CD23 expression on monocytes but not on B cells.Conclusion These data indicate that early immunological effects like down-regulation of CD23 on B cells and monocytes, which are observed during SIT are dose dependent, mediated by IFN-γ and IL-10 and seem not to depend per se on the sensitization state of an individual.

Notes: Abstract: Until recently, mast cells have been viewed primarily as harmful because of their key role as effector cells of allergic and potentially lethal anaphylactic reactions. Their contribution to human health appeared instead to be limited to the elimination of parasites. There is, however, growing evidence for additional beneficial functions of mast cells, particularly regarding the initiation of acquired immune reactions. Thus, mast cells can phagocytize diverse particles, take up antigens, and express a number of receptors, particularly MHC class I and II antigens, ICAM-1 and -3, CD43, CD80, CD86 and CD40L which allow them to interact with T and B lymphocytes. They can also secrete numerous cytokines that induce and enhance recruitment and functions of lymphocytes. Finally, there is good evidence that mast cells present e.g. pollen and bacterial antigens, respond to bacterial superantigens, but fail to react to endogenously produced antigens or superantigens. Mast cells can also activate B cells directly to produce IgE, but this activity and the ability to produce IL-4 or IL-13 is restricted primarily to basophil leukocytes and mucosal mast cells. Finally, recent evidence attributes a pivotal role to the cells in natural immunity to bacteria. There is also emerging evidence that mast cells can downmodulate the immune response. While these data require further clarification, the basic ability of mast cells to initiate innate and acquired immune reactions can no longer be questioned.

Notes: Contact sensitivity to toothpaste is rare and usually due to preservatives or flavourings, of the latter, mint components being the most important sensitizers (1).