Disease definition and measures of disease frequency

Transcriptomes from German shepherd dogs reveal differences in immune activity between atopic dermatitis affected and control skin

Canine atopic dermatitis (CAD) is an inflammatory and pruritic allergic skin disease with both genetic and environmental risk factors described. We performed mRNA sequencing of non-lesional axillary skin biopsies from nine German shepherd dogs. Obtained RNA sequences were mapped to the dog genome (CanFam3.1) and a high-quality skin transcriptome was generated with 23,510 expressed gene transcripts. Differentially expressed genes (DEGs) were defined by comparing three controls to five treated CAD cases. Using a leave-one-out analysis, we identified seven DEGs: five known to encode proteins with functions related to an activated immune system (CD209, CLEC4G, LOC102156842 (lipopolysaccharide-binding protein-like), LOC480601 (regakine-1-like), LOC479668 (haptoglobin-like)), one (OBP) encoding an odorant-binding protein potentially connected to rhinitis, and the last (LOC607095) encoding a novel long non-coding RNA. Furthermore, high mRNA expression of inflammatory genes was found in axillary skin from an untreated mild CAD case compared with healthy skin. In conclusion, we define genes with different expression patterns in CAD case skin helping us understand post-treatment atopic skin. Further studies in larger sample sets are warranted to confirm and to transfer these results into clinical practice.

Multiple regulatory variants located in cell type-specific enhancers within the PKP2 locus form major risk and protective haplotypes for canine atopic dermatitis in German shepherd dogs

Background

Canine atopic dermatitis (CAD) is a chronic inflammatory skin disease triggered by allergic reactions involving IgE antibodies directed towards environmental allergens. We previously identified a ~1.5 Mb locus on canine chromosome 27 associated with CAD in German shepherd dogs (GSDs). Fine-mapping indicated association closest to the PKP2 gene encoding plakophilin 2.

Results

Additional genotyping and association analyses in GSDs combined with control dogs from five breeds with low-risk for CAD revealed the top SNP 27:19,086,778 (p = 1.4 × 10⁻⁷) and a rare ~48 kb risk haplotype overlapping the PKP2 gene and shared only with other high-risk CAD breeds. We selected altogether nine SNPs (four top-associated in GSDs and five within the ~48 kb risk haplotype) that spanned ~280 kb forming one risk haplotype carried by 35 % of the GSD cases and 10 % of the GSD controls (OR = 5.1, p = 5.9 × 10⁻⁵), and another haplotype present in 85 % of the GSD cases and 98 % of the GSD controls and conferring a protective effect against CAD in GSDs (OR = 0.14, p = 0.0032). Eight of these SNPs were analyzed for transcriptional regulation using reporter assays where all tested regions exerted regulatory effects on transcription in epithelial and/or immune cell lines, and seven SNPs showed allelic differences. The DNA fragment with the top-associated SNP 27:19,086,778 displayed the highest activity in keratinocytes with 11-fold induction of transcription by the risk allele versus 8-fold by the control allele (p_difference = 0.003), and also mapped close (~3 kb) to an ENCODE skin-specific enhancer region.

Conclusions

Our experiments indicate that multiple CAD-associated genetic variants located in cell type-specific enhancers are involved in gene regulation in different cells and tissues. No single causative variant alone, but rather multiple variants combined in a risk haplotype likely contribute to an altered expression of the PKP2 gene, and possibly nearby genes, in immune and epithelial cells, and predispose GSDs to CAD.

Electronic supplementary material

The online version of this article (doi:10.1186/s12863-016-0404-3) contains supplementary material, which is available to authorized users.

Resolution of severe atopic dermatitis after tacrolimus withdrawal

Tacrolimus is an immunosuppressive agent used in solid organ and islet transplantation. Its topical form has shown benefit in the treatment of inflammatory skin conditions. Although tacrolimus has a wide spectrum of side effects, dermatological complications related to systemic tacrolimus therapy are limited in the literature. Atopic dermatitis (AD) is a chronic pruritic cutaneous condition that usually begins in infancy and is characterized by an increased Th2 response. We report the case of a patient with type 1 diabetes mellitus (T1DM) and history of AD latent for 10 years who developed severe dermatitis and alopecia 5 months after undergoing allogeneic islet transplantation and initiating a steroid-free immunosuppressive regimen with sirolimus and tacrolimus maintenance. After exclusion of other possible causes for the progression and exacerbation of the clinical presentation of AD, discontinuation of tacrolimus and introduction of mycophenolate mofetil resulted in full remission of the symptoms. The beneficial effects of tacrolimus withdrawal suggest a cause-effect relationship between this adverse event and the utilization of the drug. Islet graft function remained stable after modification of the therapeutic regimen (stable glycemic control and unchanged C-peptide).

Asma em escolares de 13 e 14 anos do Município de Nova Iguaçu, Rio de Janeiro, Brasil: estimativas de prevalência, gravidade e diferenças de gênero

O objetivo deste estudo foi descrever a prevalência, a gravidade e os sintomas associados à asma e sua relação com o gênero em escolares de 13 e 14 anos do Município de Nova Iguaçu, Rio de Janeiro, Brasil. Trata-se de estudo transversal, no qual se utilizou o questionário escrito auto-aplicável para asma do International Study of Asthma and Allergies in Childhood (ISAAC). Participaram 3.033 escolares de 37 escolas públicas e privadas selecionadas aleatoriamente. A prevalência de sibilância alguma vez na vida foi de 26% e nos últimos 12 meses (asma atual) de 11,7%, sendo essas taxas maiores entre as meninas (razão de prevalência - RP = 1,46; IC95%: 1,31-1,62 e RP =1,72; IC95%: 1,35-2,21, respectivamente). Sintomas associados à gravidade da doença, como distúrbio do sono e limitação da fala por sibilos, também se associaram positivamente com o gênero feminino (RP = 2,57; IC95%:1,77-3,73 e RP = 2,07; IC95%:1,25-3,43). A prevalência da asma mostrou-se menor quando comparada com as de outras cidades brasileiras, porém ainda é alta entre adolescentes de Nova Iguaçu, sendo mais freqüente e mais grave no gênero feminino. Outros estudos são necessários para explicar tais diferenças.

Long-term safety of tacrolimus ointment in children treated for atopic dermatitis

Atopic dermatitis (AD) is a chronic, relapsing, highly pruritic inflammatory skin disease that is particularly prevalent in the paediatric population. Emollients and topical corticosteroids have represented the standard of treatment for patients with AD, despite their numerous adverse effects and patients' tendency towards steroid resistance. Topical tacrolimus marks the introduction of an entirely new class of medications, the non-corticosteroid topical immunomodulators. Numerous short- and long-term and ongoing paediatric and adult studies have demonstrated the excellent efficacy and superb safety profile of this anti-inflammatory agent. The authors review many of these landmark studies and discuss the mechanism of action and safety profile of tacrolimus, in the context of the pathophysiology of AD.