Allergy: European Journal of Allergy and Clinical Immunology

Background:  In atopic dermatitis (AD) a Th1/Th2 imbalance has been reported, and interleukin (IL)‐13 seems to play a pivotal role in the inflammatory network. We tried to assess the correlation between the immunological marker CD4⁺IL‐13⁺ and the clinical phase of extrinsic AD in children.

Methods:  Twenty children with AD were studied. Assessed parameters were: clinical severity (SCORAD index), total serum immunoglobulin E (IgE), blood eosinophil count, and percentage of CD4⁺IFNγ⁺, CD4⁺IL‐4⁺, CD4⁺IL‐13⁺ T cells. Determinations were carried out in the acute phase and after clinical remission were achieved. Ten nonatopic‐matched children served as controls.

Results:  At baseline, AD was mild in 25%, moderate in 50% and severe in 25% of children. In the acute phase a significant relationship between the eosinophil count and the SCORAD index was found (P = 0.0001). Blood CD4⁺IL‐4⁺ were significantly higher in the AD group (median 17.0, range: 13.7–21.4) than in controls (12.6, 6.4–17.2, P < 0.0001). CD4⁺IL‐13⁺ cells in the AD group well correlated (P = 0.0007) with SCORAD index. At remission, a significant correlation between SCORAD index and eosinophil count was found (P < 0.03) and the percentage of CD4⁺IL‐13⁺ cells globally decreased (P < 0.0001), while no difference was found among SCORAD classes.

Conclusion:  This study confirms the Th2 profile predominance in the peripheral blood of children with AD, and evidences close relationship between the number of CD4⁺IL‐13⁺ T cells and the disease's severity.

Sera from two groups of patients receiving grass pollen immunotherapy were tested on IgG reactivity with group V allergen from six different grass species. One group of patients was treated with a mixture of 10 grass species, and the other with a mixture of five. Only Lolium perenne, Dactylis glomerata, and Phleum pratense were present in both mixtures. Although Anthoxanthum odoratum and Secale cereale were absent from the mixture of five, IgG responses to Ant o V and Sec c V were comparable in both patient groups. This reactivity was inhibited for 92–99% with L. perenne extract, illustrating the cross‐reactive nature of the IgG antibodies. The presence of A. odoratum and S. cereale in the mixture resulted in only minor amounts of species‐specific anti‐group V IgG. These results indicate that application of just one grass species in immunotherapy might be sufficient to induce an IgG response that covers other relevant Gramineae species as well.

The impact of pollen on the respiratory mucosa was modeled by studying the process by which solutes are eluted from pollen grains. Rye grass (Loliuin perenne), short ragweed (Ambrosia artemisiifolia), and white oak (Quercus alba) pollens were packed between glass wool plugs in small columns. Water was pumped through the columns and the eluate solute yield was determined by measurement of the dry solute weight. Solute separation was rapid, and concentrations and osmolalities of the eluate decreased exponentially. Theoretical initial solute concentrations were 179 g/1 for rye grass, 55 g/1 for short ragweed and 349 g/1 for oak pollen eluates. Theoretical initial osmolarities of the same eluates were 321 mOsm/kg for rye grass, 196 mOsm/kg for ragweed and 424 mOsm/kg for oak pollen. Sequential separation of allergens (Lol p I, Amb a I, Ainb a V), enzymes and proteins was demonstrated by specific assays. These observations suggest that the complex stimulus produced immediately after pollen grain hydration at the respiratory mucosal fluid interface is much more intense than previously envisioned. Sequential separation of pollen components has important implications for the production of improved allergenic extracts.

Background: Dust reservoir sampling is the most commonly used method for assessment of indirect allergen exposure. Because assessment of personal exposure using person‐carried pumps is time‐consuming and expensive we evaluated the Petri dish sampling method for measurement of airborne cat allergen in classrooms.

Methods: Petri dish sampling was evaluated in three study parts. Part I: by comparison between Petri dish sampling and personal air sampling in 44 classrooms with many (≥ 20%) and few (≤ 10%) cat owners and by additional Petri dish sampling in 40 pet‐free homes. Part II: by sampling with duplicate Petri dishes in 28 classrooms. Part III: by sampling in three classrooms at four sampling heights during different sampling times. All samples were analyzed for cat allergen (Fel d 1) content with a monoclonal antibody two‐site ELISA (enzyme linked immunosorbent assay), using signal amplification when necessary.

Results: There was a significant correlation between Petri dish sampling and personal air sampling (r = 0.66; P < 0.0001). Levels were five‐fold higher in classes with many cat owners than in classes with few cat owners, regardless of method. A corresponding difference was found in the homes. Duplicate sample values were in fair agreement (Bland‐Altman test) and were correlated (r = 0.77; P < 0.0001). Cumulative levels collected weekly in one Petri dish were lower than using five daily Petri dishes, regardless of sampling height.

Conclusions: Petri dish sampling can be useful as an alternative method to personal air sampling of airborne allergens.

Synthetic pyrethroids are increasingly used as insecticides and marketed as having relatively low human toxicity. The aim of this study was to examine the in vitro effects of the synthetic pyrethroid S‐bioallethrin on human blood lymphocytes and basophils in atopic individuals and nonatopic control subjects. S‐bioallethrin caused inhibition of lymphocyte proliferation after a 72‐h culture period in a concentration‐dependent manner. The inhibition of the lymphocyte proliferation by S‐bioallethrin at the concentration 6.5 nM correlated well with the total serum IgE values (r=‐0.89, f < 0.001). Samples from atopic subjects were more sensitive to this inhibition than those from nonatopic volunteers. The regulatory interleukin‐4/interferon‐gamma (JL‐4/ IFN‐y) balance showed a significant difference between atopic and nonatopic subjects after a short‐term culture period (24 h) in the presence of the same concentration range of S‐bioallethrin (P<0.001). Additionally, IFN‐y secretion was consistently lower in cells from the atopic donors. Furthermore, S‐bioallethrin induced histamine release from human basophils in a concentration‐dependent manner. Although the effect was small compared to histamine liberators such as N‐formyl‐Met‐Leu‐Phe and anti‐IgE, the response to S‐bioallethrin was significantly different in atopic donors from nonatopic (p = 0.0431). These findings are the first demonstration of the immunotoxicologic properties of the synthetic pyrethroid S‐bioallethrin by this combined in vitro approach with human lymphocytes and basophils. Further studies will investigate the responses of lymphocytes from patients who are sensitive to these agents.

Only seldom have food additives been shown to cause true allergic (immunological) reactions. Adverse effects due to various pharmacological or other mechanisms are much more common. The individual tolerance may be decreased for one reason or another, and may fluctuate from time to time. Many patients suffering from food additive reactions have atopic constitutions and such clinical symptoms as flexural dermatitis, rhinitis and asthma. The most important skin symptoms caused by food additives are urticaria, angioneurotic edema, and contact urticaria. Azo dyes, benzoic acid and several other common food additives may aggravate or, more rarely, even cause urticaria. Spices are one of the most common causes of immunological contact urticaria. Non‐immunological contact urticaria is produced by numerous spices, benzoic acid, sorbic acid, cinnamic acid, and many essential oils. Asthma and rhinitis are the main hypersensitivity symptoms in the respiratory tract, and azo dyes, benzoic acid, and sulfitic food additives are the most common causative agents. Systemic and respiratory reactions to food colorants and benzoates have been claimed to occur more frequently in acetylsalicylic acid‐ (ASA‐)sensitive patients than in non‐reactors. Hypersensitivity reactions in organs other than the skin and respiratory tract are rare or poorly documented. Psychological factors play an essential role in both food and food additive reactions.