Factor In Atopic Dermatitis Research Articles

Characterization of Proteases, Proteins, and Eicosanoid-Like Substances in Soluble Extracts from Allergenic Pollen Grains

Background: Pollen is an important trigger of seasonal rhinitis, conjunctivitis, and/or allergic asthma, and an exacerbating factor in atopic dermatitis. Pollen grains contain allergen proteins, enzymes, and bioactive lipid mediators, the latter two possibly involved in the pathogenesis of allergic diseases through IgE-independent mechanisms. Methods: We analyzed the patterns of release of endopeptidases from allergenic pollen of Japanese cedar, Japanese cypress, and Rocky mountain juniper, which belong to the Cupressaceae/Taxodiaceae family, and birch, ragweed, and two grasses, Kentucky blue and cultivated rye, using synthetic substrates, class-specific inhibitors, and zymography. The proteins released were analyzed by gel electrophoresis. Eicosanoid-like substances were measured by enzyme-linked immunosorbent assays for prostaglandin E₂ and leukotriene B₄. Results: Major fractions of proteins, eicosanoid-like substances, and at least one molecular species of serine endopeptidase were released into phosphate-buffered saline from the pollen grains at 37°C within 25 min or 60 min without sonication. In the Cupressaceae/Taxodiaceae family, sonication was necessary for the release of other proteins and another serine endopeptidase. In birch, ragweed, and the grasses, most of the serine and cysteine endopeptidases were released without sonication. Proteases released within 25 min digested gelatin and/or casein differently among plant species. Conclusions: Grains of allergenic pollen release proteases, which can digest not only short synthetic substrates but also protein substrates, along with eicosanoid-like substances and proteins. The release of these components could contribute to the formation of a microenvironment optimum for initiation of the sensitization or the exacerbation of pollen allergy in tissues exposed to pollen grains.

Epidemiology of Atopic Dermatitis in Primary Schoolchildren in Turkey

The present study aimed to investigate the prevalence of atopic dermatitis in primary schoolchildren in Denizli, Turkey, and to determine the possible risk factors for atopic dermatitis in home environment. A self-administered questionnaire was handled to the parents of 2,100 children aged 7 to 15 years, from three randomized primary schools and 1,644 (78.9%) completed and returned the questionnaire. The questionnaire included the United Kingdom Working Party diagnostic criteria and asked about conditions that could affect the course of atopic dermatitis. The prevalence of atopic dermatitis and coexisting factors that may affect the course of the disease were evaluated in 1,644 children (825 girls and 819 boys). The prevalence of atopic dermatitis was detected as 4.9%. Passive smoking, heating systems either in the house or in the child's bedroom, and the number of people living in the house had no significant effect (p > 0.005). The difference in prevalence of atopic dermatitis between developed and developing countries is striking. The determination of the factors that have an influence in this issue will probably enable us to change the course and frequency of atopic dermatitis.

Protease Activity of Allergenic Pollen of Cedar, Cypress, Juniper, Birch and Ragweed

Pollen is an important trigger of allergic rhinitis, conjunctivitis, and/or asthma, and an exacerbating factor in atopic dermatitis. Although it is proposed that protease activity from allergen sources, such as mites, enhances allergenicity, little information is available on that from relevant allergenic pollens such as Japanese cedar and Japanese cypress pollens, which are the major cause of pollinosis in Japan. We analyzed the protease activities derived from allergenic pollen of Japanese cedar, Japanese cypress, and Rocky mountain juniper, which belong to the Cupressaceae/Taxodiaceae family, and white birch and short ragweed, using synthetic substrates and class-specific inhibitors. We found that the pollen of the three members of the Cupressaceae/Taxodiaceae family contained serine protease activity, that the pollen of white birch and short ragweed contained not only serine protease activity but also cysteine protease activity, that all five types of pollen tested contained at least one other type of serine protease, whose sensitivity to a serine protease-specific inhibitor was relatively low, and that the content and releasability of the pollen-derived proteases differed according to the plant families. Clinically relevant allergenic pollens tested in the present study can release serine and/or cysteine endopeptidases. Information on the spectrum of the endopeptidase activities from these allergenic pollen grains will be useful for investigating their contribution to the pathogenesis of allergies.

Staphylococcus species as potential virulence factors in atopic dermatitis

Staphylococcus species as potential virulence factors in atopic dermatitis

Loss-of-Function Mutations in the Filaggrin Gene and Alopecia Areata: Strong Risk Factor for a Severe Course of Disease in Patients Comorbid for Atopic Disease

Alopecia areata (AA) is a common dermatological disease, which affects nearly 2% of the general population. Association of AA with atopic disease has been repeatedly reported. Loss-of-function mutations in the filaggrin gene (FLG) may be considered as promising candidates in AA, as they have been observed to be a strong risk factor in atopic dermatitis. The FLG mutations R501X and 2282del4 were genotyped in a large sample of AA patients (n=449) and controls (n=473). Although no significant association was observed in the patient sample overall, FLG mutations were significantly associated with the presence of atopic dermatitis among AA patients. Furthermore, the presence of FLG mutations had a strong impact on the clinical course of AA in comorbid patients. For example, 19 of the 22 mutation carriers among AA patients with atopic dermatitis showed a severe form of the disease (P=0.003; odds ratio (OR)=5.47 (95% confidence interval (CI): 1.59-18.76)). In conclusion, our data suggest that when AA occurs in conjunction with FLG-associated atopic disorder, the clinical presentation of AA may be more severe.

Is staphylococcal alpha-toxin a critical pathogenetic factor of atopic dermatitis in highly atopic individuals?

Is staphylococcal alpha-toxin a critical pathogenetic factor of atopic dermatitis in highly atopic individuals?

Pursuits of host initiating factors for atopic dermatitis in babies

Evaluation of: Sugiyama M, Arakawa H, Ozawa K et al. Early-life risk factors for occurrence of atopic dermatitis during the first year. Pediatrics 119(3), 716–723 (2007).The pathogenesis of atopic dermatitis (AD) involves the interaction between environmental aeroallergens and immune-mediated skin hypersensitivity, in which preceding skin barrier dysfunction has been speculated to facilitate the permeation of large molecular aeroallergens into the skin. The paper under evaluation presents a prospective birth cohort study that planned to search for perinatal predictors of infantile AD. Fetal cord blood analyses for cytokines have demonstrated a negative relationship between the concentration of macrophage inflammatory protein-1β and later AD development, which seems to be compatible with the reported decrease of macrophage inflammatory protein-1β production by both CD4+ and CD8+ T cells under the dominance of Th2 responses over Th1 responses. However, no reduced stratum corneum (SC) hydration has been foun...

Common loss-of-function variants of the epidermal barrier protein filaggrin are a major predisposing factor for atopic dermatitis

Common loss-of-function variants of the epidermal barrier protein filaggrin are a major predisposing factor for atopic dermatitis

Childhood Obesity as a Possible Aggravating Factor of Atopic Dermatitis

Childhood Obesity as a Possible Aggravating Factor of Atopic Dermatitis

Detection and Quantification of Specific IgE Antibodies against Eight Malassezia Species in Sera of Patients with Atopic Dermatitis by Using an Enzyme‐Linked Immunosorbent Assay

The lipophilic yeast Malassezia, a member of the cutaneous microflora, is an exacerbating factor in atopic dermatitis (AD). Of the 11 currently recognized species, M. globosa and M. restricta are found to frequently colonize the skin of AD patients. In this study, we attempted to quantify specific IgE antibodies against eight Malassezia species, namely, M. dermatitis, M. furfur, M. globosa, M. obtusa, M. pachydermatis, M. slooffiae, M. sympodialis, and M. restricta, in sera from AD patients by using an enzyme-linked immunosorbent assay (ELISA). The specific IgE value against M. restricta was greater than those against other Malassezia species. Competitive ELISA inhibition tests revealed that M. restricta contained species specific as well as shared antigens. Therefore, M. restricta could be considered as a candidate diagnostic antigen for detecting anti-Malassezia IgE in sera from AD patients.

Early Environmental Factors for Atopic Dermatitis in Children: Pilot Study of Taiwan Birth Cohort Study (TBCS)

Early Environmental Factors for Atopic Dermatitis in Children: Pilot Study of Taiwan Birth Cohort Study (TBCS)

Cytokine secretion profile of human keratinocytes exposed toMalasseziayeasts

The lipophilic yeast Malassezia is an exacerbating factor in atopic dermatitis (AD). Among organisms of the Malassezia species, Malassezia globosa and Malassezia restricta are particularly dominant on the skin of AD patients. However, the precise role of Malassezia yeasts in the pathophysiology of AD remains uncertain. Keratinocytes play a critical role in cutaneous inflammatory and immune responses by secreting cytokines. In this study, we attempted to determine the cytokine secretion profiles of human keratinocytes that were exposed to Malassezia yeasts. The human keratinocyte cell line PHK16-0b was cocultivated with M. globosa or M. restricta for 24 h, and the resulting cytokine secretion profile was analysed using a cytokine antibody array. The keratinocytes responded to the two Malassezia species with different Th2-type cytokine profiles, i.e. M. globosa induced IL-5, IL-10 and IL-13 secretion from the keratinocytes, whereas M. restricta induced IL-4 secretion. Similar results were obtained with primary normal human epidermal keratinocytes. cDNA microarray analysis confirmed that IL-5, IL-10, and IL-13 mRNAs were induced only by M. globosa, while IL-4 mRNA expression was induced only by M. restricta. These findings suggest that M. globosa and M. restricta play a synergistic role in triggering or exacerbating AD by stimulating the Th2 immune response.

Atopic dermatitis and house dust mites.

The occurrence of house dust mites (Dermatophagoides spp) was investigated in the homes of 26 patients with atopic dermatitis (AD), 20 patients with psoriasis and 41 randomly selected homes in Arhus, Denmark. The AD patients with moderate to severe eczema had an increased concentration of mites (median 85 mites/0.1 g mattress dust) compared with the controls (median 8 mites/0.1 g mattress dust). The higher exposure to house dust mites corresponded to a relative risk of 4.6 and a clear dose-response relationship between exposure and disease could be demonstrated. Our results illustrate a clear association between moderate to severe atopic dermatitis and increased exposure to house dust mites in the patients' homes, and support the hypothesis that mite antigens could be an aetiological factor in atopic dermatitis.

Malassezia-Hefen und ihre Bedeutung in der Dermatologie

Yeasts of the genus Malassezia belong to the normal microflora of the human skin. In addition they are known to cause a variety of skin diseases; the most frequent of which is pityriasis versicolor. Malassezia yeasts are also thought to be associated with seborrheic dermatitis, dandruff and Malassezia folliculitis. Recently the significance of Malassezia yeasts as a trigger factor for atopic dermatitis of the head and neck region has been pointed out. The role of the Malassezia yeasts in these different diseases has been controversial in the past and remains an issue because of difficulties in isolation, culture and differentiation of the organism. Thanks to molecular techniques, 10 species can actually be differentiated. The article presents the different Malassezia-associated diseases, their clinical picture, diagnosis and appropriate therapy. In addition the speciation of Malassezia is reviewed.

Diagnosis and treatment of atopic dermatitis in children and adults: European Academy of Allergology and Clinical Immunology/American Academy of Allergy, Asthma and Immunology/PRACTALL Consensus Report

There are remarkable differences in the diagnostic and therapeutic management of atopic dermatitis practiced by dermatologists and pediatricians in different countries. Therefore, the European Academy of Allergy and Clinical Immunology and the American Academy of Allergy, Asthma and Immunology nominated expert teams who were given the task of finding a consensus to serve as a guideline for clinical practice in Europe as well as in North America. The consensus report is part of the PRACTALL initiative, which is endorsed by both academies.

Japanese cedar pollen as an exacerbation factor in atopic dermatitis: results of atopy patch testing and histological examination

Atopy patch testing with Japanese cedar pollen extract has been used to investigate patients with atopic dermatitis whose condition is exacerbated by contact with Japanese cedar pollen. Comparative atopy patch testing, scratch tests, and assays for total IgE and specific IgE were performed in 74 patients with atopic dermatitis, 5 patients with Japanese cedar pollinosis and 15 control subjects. A skin biopsy was performed on any sites that were positive to Japanese cedar pollen patch test. The results after 48 h of atopy patch testing were compared with the patient's history, skin scratch test and specific IgE. Twenty-two of the 74 patients (30%) had a history of exacerbation every spring after contact with Japanese cedar. Of these patients 68% showed a positive reaction to Japanese cedar pollen extract, as did 21% of patients with atopic dermatitis without a history of exacerbation by Japanese cedar pollen, 20% of patients with Japanese cedar pollinosis without eruption and 7% of control subjects. A histological examination revealed eczematous changes and infiltration of lymphocytes and eosinophils in atopy patch testing positive sites. In conclusion, atopy patch testing with Japanese cedar pollen extract is a useful method for investigating trigger factors for eczematous skin lesions in a subgroup of patients with atopic dermatitis.

Faecal Eosinophilic Protein X (f-EPX), Atopic Dermatitis, Sensitisation and Gastrointestinal Permeability in Infants Aged 3-6 Months

RATIONALE: Gastrointestinal (GI) inflammation has been implicated as a contributing factor in atopic dermatitis (AD) and has been reported in children with food allergies and AD. The role of faecal EPX in investigating and monitoring gastrointestinal inflammation associated with AD was studied. METHODS: Infants aged 3-6 months enrolled: AD-severity scored (SCORAD-Index), serum specific IgE, gastrointestinal permeability (Lactulose/Mannitol test) measured. Stool samples were collected from 239 infants (n=203 AD, n=36 healthy); extracts for f-EPX analysis were prepared as previously described (Peterson et al. 2002). Faecal-EPX was measured by UniCAP® (Pharmacia Diagnostics AB, Sweden). Data were log-transformed, results presented as geometric mean (GM) with 95% confidence intervals (95%CI). RESULTS: F-EPX levels significantly higher in infants with AD compared to healthy controls (GM 2506 ng/g [2146-2926] vs. 1635 ng/g [1193-2241]; p=0.032). F-EPX did not correlate with AD-severity (SCORAD-score). Sensitisation to food allergens was significantly associated with higher f-EPX levels (Sensitised 3200ng/g [1960-6463] vs. not sensitised 2050 ng/g [914-4725], p=0.021) and specific IgE levels to egg allergen correlated with f-EPX levels (R=0.26; p=0.005). Infants (AD or healthy) with normal gastrointestinal permeability had significantly lower f-EPX levels compared to those with increased permeability (normal permeability: 1252 ng/g [775-2034] vs. increased permeability 2409 ng/g [1305-5570]; p=0.012). CONCLUSIONS: Faecal EPX is high in infants with AD, sensitised infants and in infants with increased gastrointestinal permeability. This suggests increased eosinophilic inflammation in the gastrointestinal tract. F-EPX may be useful in monitoring the progression of gastrointestinal inflammation in these infants and further our understanding of underlying pathophysiological processes

The medical effects of mold exposure

Exposure to molds can cause human disease through several well-defined mechanisms. In addition, many new mold-related illnesses have been hypothesized in recent years that remain largely or completely unproved. Concerns about mold exposure and its effects are so common that all health care providers, particularly allergists and immunologists, are frequently faced with issues regarding these real and asserted mold-related illnesses. The purpose of this position paper is to provide a state-of-the-art review of the role that molds are known to play in human disease, including asthma, allergic rhinitis, allergic bronchopulmonary aspergillosis, sinusitis, and hypersensitivity pneumonitis. In addition, other purported mold-related illnesses and the data that currently exist to support them are carefully reviewed, as are the currently available approaches for the evaluation of both patients and the environment.

Risk Factors for Atopic Dermatitis in New Zealand Children at 3.5 Years of Age

Risk Factors for Atopic Dermatitis in New Zealand Children at 3.5 Years of Age

2. Superantigens, steroid insensitivity and innate immunity in atopic eczema

There is now considerable evidence that colonization or infection with Staphylococcus aureus is an exacerbating factor in atopic dermatitis (AD) (1). Numerous studies have shown that the superantigens produced by staphylococci and streptococci are implicated in the pathogenesis of various inflammatory skin diseases. The skin lesions of patients with AD predominantly contain infiltrating T cells and monocyte/macrophages which can be activated by superantigenic toxins from these microbes. This review focuses on two specific aspects of the involvement of S. aureus in AD. These are mechanisms by which superantigens can induce skin inflammation and impair the response of the inflammatory process to corticosteroids, and the inability of the innate immune system in atopic skin to counteract staphylococcal skin colonization and infection.