Radioautography of Noradrenaline-14C in Atopic Dermatitis

Since storage-time of administered noradrenaline in the skin of patients with atopic dermatitis may be prolonged, it would be of interest to demonstrate the site of uptake of noradrenaline-¹⁴C in atopic dermatitis as compared with other eczematous and normal skins. Two adult patients with longstanding atopic dermatitis, a patient with contact dermatitis to nickel and one with normal skin, were studied. Identical sites in the four patients were injected intradermally with 0.02 μg. DL-noradrenaline-7-¹⁴C acetate. An 8-mm. punch biopsy of the injected site was performed 24 hours later. Radioautographs were developed between three and 199 days, according to the technique of Kopriwa and Leblond.² At 199 days, the number of grains in atopic dermatitic skin was greater than in contact dermatitis or normal skin. There was a concentration of grains over arrectores pilorum muscles and the upper one-third of the epidermis of atopic skin. Grains were also visible in proximity to arteriolar walls. There were few grains visible in the control sections. The results confirm earlier studies suggesting that atopic dermatitic skin retains noradrenaline longer than other dermatoses. Noradrenaline concentrates in the arrectores pilorum muscles and the upper epidermis. These findings may explain the cutis anserina (goose-flesh) appearance in atopic dermatitis.     

Genome-Wide Analysis in German Shepherd Dogs Reveals Association of a Locus on CFA 27 with Atopic Dermatitis

Humans and dogs are both affected by the allergic skin disease atopic dermatitis (AD), caused by an interaction between genetic and environmental factors. The German shepherd dog (GSD) is a high-risk breed for canine AD (CAD). In this study, we used a Swedish cohort of GSDs as a model for human AD. Serum IgA levels are known to be lower in GSDs compared to other breeds. We detected significantly lower IgA levels in the CAD cases compared to controls (p = 1.1×10⁻⁵) in our study population. We also detected a separation within the GSD cohort, where dogs could be grouped into two different subpopulations. Disease prevalence differed significantly between the subpopulations contributing to population stratification (λ = 1.3), which was successfully corrected for using a mixed model approach. A genome-wide association analysis of CAD was performed (n _cases = 91, n _controls = 88). IgA levels were included in the model, due to the high correlation between CAD and low IgA levels. In addition, we detected a correlation between IgA levels and the age at the time of sampling (corr = 0.42, p = 3.0×10⁻⁹), thus age was included in the model. A genome-wide significant association was detected on chromosome 27 (p_raw = 3.1×10⁻⁷, p_genome = 0.03). The total associated region was defined as a ∼1.5-Mb-long haplotype including eight genes. Through targeted re-sequencing and additional genotyping of a subset of identified SNPs, we defined 11 smaller haplotype blocks within the associated region. Two blocks showed the strongest association to CAD. The ∼209-kb region, defined by the two blocks, harbors only the PKP2 gene, encoding Plakophilin 2 expressed in the desmosomes and important for skin structure. Our results may yield further insight into the genetics behind both canine and human AD.     

Atopic Dermatitis (Eczema): An Appraisal

Atopic (spontaneous) allergies and nonatopic (induced) allergies are often confused. The meaning of these terms is definite, but the occurrence of either (in a given individual) may depend upon his autonomic nervous system control. The evidence that allergens produce the cutaneous changes in atopic dermatitis is flimsy, and neurodermatitis would be a more appropriate term since the entity falls into that pattern of skin changes. Treatment carried out, from infancy sometimes to old age, consists of careful management of the patient in the physical and emotional spheres, avoidance of external irritation and the use of a multiplicity of anti-pruritic, anti-inflammatory and sedative agents.     

Topical Application of Flurandrenolone in the Treatment of Atopic Dermatitis

The effect of flurandrenolone, 0.05%, in a cream base was compared with that of hydrocortisone, 1%, in the same base in 35 cases of atopic dermatitis, using contralateral application technique. The efficacy of flurandrenolone was found to be superior to that of hydrocortisone in 23 instances and equal in 12 cases. A fourfold dilution of this cream, flurandrenolone 0.0125%, was compared with 1% hydrocortisone cream in 18 patients and similar results were obtained. The superiority of flurandrenolone was particularly evident during the first week of application. The therapeutic efficacy of small amounts of flurandrenolone results in economic advantage to the patient and enables him to use applications of this preparation more freely.     

Identification of Malassezia Species in Patients with Seborrheic Dermatitis in China

Background

The causes of seborrheic dermatitis (SD) are complex and incompletely understood. Among the factors, Malassezia yeasts have been reported to play a major etiological role in SD. Many previous studies adopted conventional culture methods that were disadvantaged to detect Malassezia microflora in SD patients, resulting in a low detection rate for each species and high variance in types of microflora observed.

Objective

This study analyzed Malassezia microflora in SD patients by applying a transparent dressing to the lesional skin and using direct detection of fungal DNA using nested PCR.

Methods

We collected samples from the lesional skin of 146 SD patients in China and extracted fungal DNA directly from the lesional samples without culture. Specific primers for each Malassezia species were designed to amplify existing yeasts in each sample. Some samples were randomly selected to culture and identified by morphological and physiologic criteria.

Results

M. globosa and M. restricta were found in 87.0 and 81.5 % of seborrheic dermatitis patients, respectively, which together accounted for more than 50 % of Malassezia spp. recovered in these Chinese patients. The majority of SD patients (82.9 %) showed co-colonization of two or more Malassezia species.

Conclusion

M. globosa and M. restricta predominated in Malassezia colonization in Chinese SD patients. Compared with conventional culture, non-culture-based methods may more accurately reflect Malassezia microflora constitution.     

Observations on the Antipruritic Effect of Guanethidine in Atopic Dermatitis

Guanethidine, 0.75 to 1.25 mg. per kg. per day, was found to alleviate the pruritus of acute atopic dermatitis in 19 out of 20 patients. It was not effective in patients with other dermatoses. An apparent partial tolerance to this treatment developed in six out of 10 patients re-treated. It had little or no therapeutic effect in 10 patients with a variety of other pruritic dermatoses, suggesting that this drug has a specific antipruritic action in patients with atopic dermatitis. In a double-blind study, 11 of 12 patients with atopic dermatitis treated with guanethidine experienced relief of pruritus. Four out of 12 patients using a placebo had complete or partial relief. Guanethidine, 1% to 10%, used topically was therapeutically no more effective than placebo. In view of the reported side effects and the anesthetic hazard encountered with guanethidine, further long-term studies are indicated before this drug is adopted for clinical use in the treatment of atopic dermatitis. The findings support the hypothesis that atopic dermatitis may be a manifestation of a hereditary defect in cutaneous noradrenaline binding.     

Indoor Air Pollution Aggravates Symptoms of Atopic Dermatitis in Children

Most of researches on the impact of indoor air pollutants on atopic dermatitis (AD) have been based upon animal models, in vitro experiments and case-control studies. However, human data to elucidate the role of indoor air pollution on worsening symptoms of pre-existing AD from a longitudinal study are scarce. The objective of this prospective study was to evaluate the effect of indoor air pollution on AD symptoms in children. We surveyed 30 children with AD in a day-care centre, which moved to a new building during the study. These children stayed there for 8 hours a day Monday through Friday, and their daily symptom scores were recorded. Indoor and outdoor air pollutant levels were continuously measured 24 hours a day for 12 months (Period 1 to 4). Data were analyzed using a generalized linear mixed model. Compared to the period before moving (Period 1), concentrations of indoor air pollutants mostly increased after moving (Period 2) and decreased by natural ventilation and bake-out (Periods 3 and 4). The rate of positive AD symptom increased from 32.8% (Period 1) up to 43.8% (Period 2) and 50.5% (Period 3), then decreased to 35.4% in Period 4 (P < 0.0001). When the delayed effects of indoor air pollutants on AD symptoms 2 days later were evaluated, AD symptoms significantly increased by 12.7% (95% CI: -0.01 to 27.1) as toluene levels increased by 1 ppb (P = 0.05). In conclusion, indoor air pollutants increase the risk of AD aggravation in children and toluene in the indoor environment might act as an aggravating factor.     

Common FLG Mutation K4671X Not Associated with Atopic Dermatitis in Han Chinese in a Family Association Study

Background

Filaggrin gene (FLG) mutations have been identified as the cause of ichthyosis vulgaris (IV) and major predisposing factors for atopic dermatitis (AD). The relationship among AD, IV and FLG mutations has not been clarified yet. Mutations 3321delA and K4671X, two of the most common mutations in Chinese patients, were both statistically associated with AD in case-control studies.

Materials and Methods

A group of 100 family trios (a total of 300 members with one affected AD proband and both parents) were recruited and screened for three filaggrin null mutations (3222del4, 3321delA and K4671X). The subjects’ manifestations of AD and IV were assessed by two experienced dermatologists and recorded in detail. The relationship of common mutations to AD were assessed using both case-control and family-based tests of association. Filaggrin expression was measured in skin of 3 subjects with K4671X heterozygote and the normal control using quantitative real-time RT-PCR and immunohistochemistry.

Results

Of 100 probands for AD, 22 were carriers for common FLG mutations and only 2 of them were from 40 none-IV family trios (5.00%), consistent with that of the healthy control group (3.99%, P>0.05). Significant statistical associations were revealed between AD and 3321delA (P<0.001, odds ratio 12.28, 95% confidence interval 3.35–44.98) as well as K4671X (P = 0.002, odds ratio 4.53, 95% confidence interval 1.77–11.60). The family-based approach revealed that 3321delA was over-transmitted to AD offspring from parents (T:U = 12∶1, P = 0.003) but failed to demonstrate transmission disequilibrium between K4671X and AD (T:U = 10∶8, P = 0.815). Moreover, compared to the normal control, filaggrin expression at both mRNA and protein levels in epidermis of subjects with K4671X^heter was not reduced.

Conclusions

AD patients from none-IV family trios have low probability of carrying FLG mutations. The present family samples confirmed the susceptibility of mutation 3321delA to AD in Han Chinese. K4671X was not a pathogenic mutation.     

Altered lipid properties of the stratum corneum in Canine Atopic Dermatitis

Skin barrier disruption plays a role in the pathogenesis of atopic dermatitis (AD) in humans. However, little is known about skin barrier (dys-) function in Canine Atopic Dermatitis. The properties of lipids located in the outermost layer of the skin, the stratum corneum (SC) are considered to be important for the barrier. In the present study the lipid composition and lipid organization of the SC of AD dogs and control dogs were examined. The lipid composition of lesional AD skin as compared to control skin, showed a reduced free fatty acid level and a decreased ratio of ceramide[NS] C44/C34, in which C44 and C34 are the total numbers of carbon atoms of the sphingosine (S) and non-hydroxy (N) acyl chains. As a consequence of the observed changes in lipid composition in AD lesional skin the lamellar organization of lipids altered and a shift from orthorhombic to hexagonal lipid packing was monitored. Simultaneously an increased conformational disordering occurred. These changes are expected to compromise the integrity of the skin barrier. The C44/C34 chain length ratio of ceramide[NS] also showed a decreasing nonlinear relationship with the AD severity score (CADESI). Taken together, canine atopic skin showed alterations in SC lipid properties, similar to the changes observed in atopic dermatitis in humans, that correlated with a disruption of the skin barrier. Hence lipids play an important role in the pathogenesis of Canine Atopic Dermatitis.     

Profiling of Serum and Urinary MicroRNAs in Children with Atopic Dermatitis

Background

Atopic dermatitis (AD) is the most prevalent chronic inflammatory skin disease in children characterized by dermatitis and pruritus. MicroRNAs (miRNAs) have been shown as great potential biomarkers for disease fingerprints to predict prognostics. We aimed to identify miRNA signature from serum and urine for the prognosis of AD patient by genome-wide miRNA profiling analysis.

Methods

Serum and urine from 30 children with AD and 28 healthy children were collected and their genome-wide miRNA expression profiles were measured by TaqMan-based array and confirmed by quantitative real-time PCR. Inflammatory factors in serum were detected by Antibody Array System.

Results

miR-203 and miR-483-5p were significantly up-regulated in serum of children with AD compared with healthy children. The level of miR-483-5p in serum was significantly associated with other atopic conditions, such as rhinitis and/or asthma. However, miR-203 was markedly decreased in urine of children with AD compared with healthy children. Down-regulated miR-203 in urine was significant associated with abnormal level of serum IgE in AD patients. 7 inflammatory factors in serum were altered in children with AD compared with healthy children. Up-regulated miR-203 in serum was significantly associated with increased sTNFRI and sTNFRII.

Conclusions

Up-regulated miR-483-5p in serum may be indicative of other atopic conditions in children with AD. Down-regulated miR-203 in urine may serve as a biomarker for the severity of inflammation in children with AD.     

Allergen-Specific Immunotherapy with Monomeric Allergoid in a Mouse Model of Atopic Dermatitis

Atopic dermatitis (AD) is a widespread and difficult to treat allergic skin disease and is a tough challenge for healthcare. In this study, we investigated whether allergen-specific immunotherapy (ASIT) with a monomeric allergoid obtained by succinylation of ovalbumin (sOVA) is effective in a mouse model of atopic dermatitis. An experimental model of AD was reproduced by epicutaneous sensitization with ovalbumin (OVA). ASIT was performed with subcutaneous (SC) administration of increasing doses of OVA or sOVA. The levels of anti-OVA antibodies, as well as cytokines, were detected by ELISA. Skin samples from patch areas were taken for histologic examination. ASIT with either OVA or sOVA resulted in a reduction of both the anti-OVA IgE level and the IgG1/IgG2a ratio. Moreover, ASIT with sOVA increased the IFN-γ level in supernatants after splenocyte stimulation with OVA. Histologic analysis of skin samples from the sites of allergen application showed that ASIT improved the histologic picture by decreasing allergic inflammation in comparison with untreated mice. These data suggest that ASIT with a succinylated allergen represents promising approach for the treatment of AD.     

In vitro Release of Eosinophil Proteins in Allergic and Atopic Dermatitis Patients

To investigate whether eosinophils are stimulated in vivo or have acquired an increased susceptibility to stimuli from the coagulation cascade, the release of eosinophil proteins was compared for three groups of donors with different levels of serum IgE. (1) with atopic dermatitis (s-IgE > 5000 IU/ml, n = 11); (2) with inhalant allergy (200 < s-IgE < 2 000 IU/ml, n = 10); and (3) non-allergic (s- IgE < 100 IU/ml, n = 10). The levels of eosinophil cationic protein and eosinophil protein X (ECP, EPX) were determined in serum (clotting time = 2.0 h) and plasma. Serum and plasma ECP in normal donors demonstrated large intra-personal variations (C.V. 50-80%), but serum-ECP (mean 8.1 ng/ml) was clearly distinguishable from plasma ECP (mean 1.0 ng/ml) by a factor of 8 (range: 5.6-11.6). The ECP released during clotting was markedly increased in the atopic dermatitis group (serum:plasma ratio 13.5, p < 0.003) compared with the other groups (6.7 and 5.6). EPX, having a higher plasma level, demonstrated a less pronounced release (serum: plasma ratios 2.0, 1.7 and 1.4), with no statistical difference between donor groups. Considering all donors together the levels of ECP and EPX in plasma and in serum were correlated to the number of eosinophils (coefficients of correlation 0.54-0.58, p < 0.002).