Sensitization to Skin-associated Microorganisms in Adult Patients with Atopic Dermatitis is of Importance for Disease Severity.

Atopic dermatitis (AD) is a chronic inflammatory skin disease. Environmental and genetic factors, as well as microbial products from yeasts and bacteria, play a role in triggering the disease. A cohort of 619 adult patients with AD was screened for severity of AD, sensitization to Malassezia sympodialis, Candida albicans, Staphylococcus aureus enterotoxins and Dermatophagoides pteronyssinus. Serum levels of interleukin (IL)-18 were measured. Immunoglobulin E (IgE) sensitization to the combination of both yeast and mite antigens was found to be associated with more severe disease and higher levels of total IgE. AD patients with IgE sensitization to several microbial antigens had more severe disease than those with no IgE sensitization to microbial antigens. Sera from patients with IgE-associated AD showed higher levels of IL-18. Skin-associated microorganisms are exogenous factors triggering IgE-response and severity of AD. These findings are clinically important, and sensitization to these organisms should be assessed and considered in treatment strategies

Does vitamin d intake during infancy promote the development of atopic allergy?

The active metabolite of vitamin D, 1,25-(OH)2D3, has immunomodulatory properties in addition to its more established action on bone and calcium metabolism. Recently vitamin D has been proposed as one of several environmental factors responsible for the increase in atopic diseases during the last decades. The objective of this study was to determine whether the estimated dose of dietary vitamin D3 during the first year of life is associated with atopic diseases up to the age of 6 years. In a prospective birth cohort study 123 six-year-old children were investigated for the cumulative incidence of atopic dermatitis, allergic rhinitis or asthma by means of a postal questionnaire. Their vitamin D3 intake during infancy was recorded in a previous study and the relationship between lower or higher vitamin D3 intake and atopic illness later in childhood was assessed. Atopic manifestations were more prevalent in the group with higher intake of vitamin D3. Although small, this study supports previous investigations suggesting a role of vitamin D intake during infancy in the development of atopic allergy later in childhood. If these findings are confirmed in prospective controlled clinical trials, prevention through modified vitamin D3 supplementation in infancy could be discussed to reduce the burden of atopic illnesses

Serum IgE reactivity to Malassezia furfur extract and recombinant M-furfur allergens in patients with atopic dermatitis

IgE reactivity to the opportunistic yeast Malassezia furfur can be found in patients with atopic dermatitis (AD). We have previously cloned and expressed 6 recombinant allergens (rMal f 1. rMal f 5-9) from M. furfur. In the present study, we used ImmunoCAP to investigate whether these rMal f allergens can be useful in the diagnosis of M. furfur-associated AD compared with the M. furfur extract. A total of 156 adult patients with a clinical diagnosis of AD participated in the study. Sixty-four percent had increased total serum IgE levels, 79% had specific IgE antibodies to common inhalant allergens and 47% had IgE antibodies to M. furfur extract. IgE antibodies to any of the rMal f allergens were detected among 86 (55%) of the patients, 14 (16%) of whom did not react to the M. furfur extract. Any individual rMal f allergen detected between 32% and 89% of the patients ImmunoCAP-positive to the M. fin fur extract, with the highest sensitivity for rMal f 9. Therefore, a couple of individual rMal f allergens can improve the diagnosis of M. furfur-associated I-E allergies in patients with AD

Skin barrier impairment correlates with cutaneous Staphylococcus aureus colonization and sensitization to skin-associated microbial antigens in adult patients with atopic dermatitis.

Atopic dermatitis (AD) is a chronic inflammatory skin disease. The pathogenesis of AD involves skin barrier defects and dysregulation of innate and adaptive immunity. Some environmental factors such as stress, infections, and allergens are associated with aggravation of AD. The aim of the study was to investigate the relationship between skin barrier function, skin colonization of Staphylococcus aureus, and sensitization to antigens of skin-associated microorganisms in adult patients with AD

Decreased frequency of intracellular IFN-gamma producing T cells in whole blood preparations from patients with atopic dermatitis.

There have been contradictory reports on the shift in the T-cell cytokine expression pattern of peripheral blood mononuclear cells from patients with atopic dermatitis (AD); more specifically the interleukin (IL)-4 and interferon (IFN)-gamma profiles. The aim of this study was to shed further light on this contradiction by measuring the intracellular cytokines IL-4 and IFN-gamma by flow cytometry on unseparated whole blood to obtain results that, as accurately as possible, reflect the situation in circulating cells in vivo. The patient group including 64 patients with AD was compared with 18 nonatopic healthy adults. The results showed that the percentage of CD4+ T cells expressing IFN-gamma was significantly decreased (P <= 0.001), as well as the percentage expressing IL-4 (P < 0.05) in AD patients compared with healthy controls. Furthermore, in supernatants from whole blood samples stimulated with phorbol 12-myristate 13-acetate and ionomycin, production of IFN-gamma was significantly decreased, while IL-4 production remained unchanged in AD patients compared with healthy controls. We also investigated if there was a relationship between serum IgE level and Phadiatop®, a screening test for atopy, vs. the levels of IL-4 and IFN-gamma , but found no correlation with either. However, there was a significant correlation between disease severity and the level of total IgE (r = 0.67, P < 0.05). In conclusion, our results support the evidence for a decreased ability of peripheral CD4+ T cells to produce IFN-gamma among AD patients

The prevalence of Malassezia Yeasts in patients with atopic dermatitis, seborrhoeic dermatitis and healthy controls

Cultures for Malassezia yeasts were taken from both normal-looking skin and lesional skin in 124 patients with atopic dermatitis, 16 patients with seborrhoeic dermatitis and from normal skin of 31 healthy controls. Positive Malassezia growth was found in fewer patients with atopic dermatitis (56%) than in patients with seborrhoeic dermatitis (88%) or in healthy controls (84%, p < 0.01). In the patients with atopic dermatitis, fewer positive cultures were found in lesionall (28%) than in non-lesional skin (44%, p < 0.05), while positive cultures were found in 75% of both lesional and non-lesional skin of patients with seborrhoeic dermatitis (not significant). M. sympodialis dominated in patients with atopic dermatitis (46%) and in healthy controls (69%). In patients with seborrhoeic dermatitis both M. sympodialis and M. obtusa were cultured in 43%. A Malassezia species extract mixture would increase the possibility of detecting IgE sensitization to Malassezia in patients with atopic dermatitis