In this consensus document we summarize the current knowledge on major asthma, rhinitis, and atopic dermatitis endotypes under the auspices of the PRACTALL collaboration platform. PRACTALL is an ...initiative of the European Academy of Allergy and Clinical Immunology and the American Academy of Allergy, Asthma & Immunology aiming to harmonize the European and American approaches to best allergy practice and science. Precision medicine is of broad relevance for the management of asthma, rhinitis, and atopic dermatitis in the context of a better selection of treatment responders, risk prediction, and design of disease-modifying strategies. Progress has been made in profiling the type 2 immune response-driven asthma. The endotype driven approach for non-type 2 immune response asthma, rhinitis, and atopic dermatitis is lagging behind. Validation and qualification of biomarkers are needed to facilitate their translation into pathway-specific diagnostic tests. Wide consensus between academia, governmental regulators, and industry for further development and application of precision medicine in management of allergic diseases is of utmost importance. Improved knowledge of disease pathogenesis together with defining validated and qualified biomarkers are key approaches to precision medicine.
Atopic dermatitis (AD) is a complex skin disease frequently associated with other diseases of the atopic diathesis. Recent evidence supports the concept that AD can also recognize other ...comorbidities, such as chronic inflammatory bowel or cardiovascular diseases. These comorbidities might result from chronic cutaneous inflammation or from a common, yet-to-be-defined immunologic background leading to immune deviations. The activation of immune cells and their migration to the skin play an essential role in the pathogenesis of AD. In patients with AD, an underlying immune deviation might result in higher susceptibility of the skin to environmental factors. There is a high unmet medical need to define immunologic endotypes of AD because it has significant implications on upcoming stratification of the phenotype of AD and the resulting targeted therapies in the development of precision medicine. This review article emphasizes studies on environmental factors affecting AD development and novel biological agents used in the treatment of AD. Best evidence of the clinical efficacy of novel immunologic approaches using biological agents in patients with AD is available for the anti–IL-4 receptor α-chain antibody dupilumab, but a number of studies are currently ongoing with other specific antagonists to immune system players. These targeted molecules can be expressed on or drive the cellular players infiltrating the skin (eg, T lymphocytes, dendritic cells, or eosinophils). Such approaches can have immunomodulatory and thereby beneficial clinical effects on the overall skin condition, as well as on the underlying immune deviation that might play a role in comorbidities. An effect of these immunologic treatments on pruritus and the disturbed microbiome in patients with AD has other potential consequences for treatment.
Atopic dermatitis (AD) is a paradigmatic chronic inflammatory skin disease characterized by a complex pathophysiology and a wide spectrum of the clinical phenotype. Despite this high degree of ...heterogeneity, AD is still considered a single disease and usually treated according to the “one-size-fits-all” approach. Thus more tailored prevention and therapeutic strategies are still lacking. As for other disciplines, such as oncology or rheumatology, we have to approach AD in a more differentiated way (ie, to dissect and stratify the complex clinical phenotype into more homogeneous subgroups based on the endophenotype panel of biomarkers) with the aim to refine the management of this condition. Because we are now entering the era of personalized medicine, a systems biology approach merging the numerous clinical phenotypes with robust (ie, relevant and validated) biomarkers will be needed to best exploit their potential significance for the future molecular taxonomy of AD. This approach will not only allow an optimized prevention and treatment with the available drugs but also hopefully help assign newly developed medicinal products to those patients who will have the best benefit/risk ratio.
Allergic Contact Dermatitis Kostner, Lisa; Anzengruber, Florian; Guillod, Caroline ...
Immunology and allergy clinics of North America,
02/2017, Letnik:
37, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Allergic contact dermatitis (ACD) is a common skin disease caused by a T cell-mediated immune reaction to usually innocuous allergens. ACD can have grave medical and socioeconomic consequences. ACD ...and irritant contact dermatitis often occur together. A detailed history and clinical examination are crucial and guide patch testing, which is the gold standard to diagnose ACD. T-cell clones persisting in the skin may explain the tendency of ACD to relapse even after years of allergen avoidance. Traditional treatments for ACD are topical steroids, calcineurin inhibitors, phototherapy, retinoids (including the recent alitretinoin), and immunosuppressants. Targeted therapies are lacking.
Background Hay fever or seasonal allergic rhinitis (AR) is a chronic disorder associated with IgE sensitization to grass. The underlying genetic variants have not been studied comprehensively. There ...is overwhelming evidence that those who have older siblings have less AR, although the mechanism for this remains unclear. Objective We sought to identify common genetic variant associations with prevalent AR and grass sensitization using existing genome-wide association study (GWAS) data and to determine whether genetic variants modify the protective effect of older siblings. Method Approximately 2.2 million genotyped or imputed single nucleotide polymorphisms were investigated in 4 large European adult cohorts for AR (3,933 self-reported cases vs 8,965 control subjects) and grass sensitization (2,315 cases vs 10,032 control subjects). Results Three loci reached genome-wide significance for either phenotype. The HLA variant rs7775228, which cis -regulates HLA-DRB4 , was strongly associated with grass sensitization and weakly with AR ( Pgrass = 1.6 × 10−9 ; PAR = 8.0 × 10−3 ). Variants in a locus near chromosome 11 open reading frame 30 (C11orf30) and leucine-rich repeat containing 32 (LRRC32) , which was previously associated with atopic dermatitis and eczema, were also strongly associated with both phenotypes (rs2155219; Pgrass = 9.4 × 10−9 ; PAR = 3.8 × 10−8 ). The third genome-wide significant variant was rs17513503 (Pgrass = 1.2 × 10−8 ; PAR = 7.4 × 10−7 ) which was located near transmembrane protein 232 (TMEM232) and solute carrier family 25, member 46 ( SLC25A46 ). Twelve further loci with suggestive associations were also identified. Using a candidate gene approach, where we considered variants within 164 genes previously thought to be important, we found variants in 3 further genes that may be of interest: thymic stromal lymphopoietin ( TSLP ), Toll-like receptor 6 ( TLR6 ) and nucleotide-binding oligomerization domain containing 1 ( NOD1/CARD4 ). We found no evidence for variants that modified the effect of birth order on either phenotype. Conclusions This relatively large meta-analysis of GWASs identified few loci associated with AR and grass sensitization. No birth order interaction was identified in the current analyses.
Background Keratinocyte (KC) apoptosis is an important mechanism of eczema and spongiosis in patients with atopic dermatitis (AD) and is mediated by IFN-γ, which is secreted by TH 1 cells. IL-32 is a ...proinflammatory cytokine that is involved in the inflammatory processes of rheumatoid arthritis, chronic obstructive pulmonary disease, and Crohn disease. Recently, it was shown that upregulation of IL-32 induces apoptosis. Objective The aim of the study was to investigate the expression and function of IL-32 in patients with AD. Methods The expression of IL-32 in KCs was analyzed by means of RT-PCR, ELISA, and flow cytometry. Transfections of small interfering RNA were performed in primary KCs, and apoptosis was analyzed by means of terminal deoxynucleotidyl transferase–mediated dUTP nick end-labeling, annexin-V, and 7-amino actinomycin D stainings. Immunofluorescence stainings were used to detect IL-32 in skin biopsy specimens, and serum levels of IL-32 were analyzed by means of ELISA. Results We report that IL-32 is expressed in human primary KCs on stimulation with IFN-γ, TNF-α, and TH 1 cells in contrast to TH 2, regulatory T (Treg), or TH 17 cells, which showed no effect. Transfection of primary KCs and artificial skin equivalents with small interfering RNA to IL-32, which resulted in a clear decrease in IL-32 expression, significantly reduced KC apoptosis. Immunofluorescence staining demonstrated that IL-32 was expressed in AD lesional skin, whereas it was present in neither skin biopsy specimens from healthy donors nor in lesional skin from patients with psoriasis. Serum levels of IL-32 from patients with AD correlated with disease severity, but increased serum levels of IL-32 were also detected in asthmatic patients. Conclusion The present study demonstrates KCs as a source of IL-32, which modulates KC apoptosis and contributes to the pathophysiology of AD.
Background Activation of skin keratinocytes followed by their apoptotic death leads to eczema and spongiosis formations in patients with atopic dermatitis (AD). TNF-like weak inducer of apoptosis ...(TWEAK) binds to its receptor, fibroblast growth factor-inducible 14 (Fn14), and controls many cellular activities, including proliferation, migration, differentiation, apoptosis, angiogenesis, and inflammation. Objective The aim of the study was to investigate the role of TWEAK and Fn14 in the formation of eczema in patients with AD. Methods Primary keratinocytes were isolated from nonlesional skin from patients with AD and psoriasis and from normal skin of healthy donors. Apoptosis analysis was performed by using annexin V/7-aminoactinomycin D and terminal deoxynucleotidyl transferase–mediated dUTP nick end-labeling staining. The expression and regulation of TWEAK, TNF-α, Fn14, TNF receptor (TNFR) 1, and TNFR2 were measured by means of RT-PCR, flow cytometric analysis, and ELISA. TWEAK and Fn14 expression of lesional AD and psoriatic skin and normal control skin was analyzed by using immunohistochemistry and immunofluorescence. Results TWEAK and TNF-α cooperate in the induction of apoptosis in primary keratinocytes obtained from patients with AD, patients with psoriasis, and healthy subjects and in artificial skin equivalents. TNFR1 and Fn14 were the main receptors involved. TWEAK upregulates TNF-α expression in primary keratinocytes, whereas TNF-α did not affect the expression of TWEAK and its receptors. High TWEAK expression was observed in AD lesions but not in psoriatic lesions or normal skin. Fn14 was highly expressed in the lesional skin of patients with AD and patients with psoriasis and in healthy control skin. Conclusion The high expression of TWEAK in lesional AD skin contributes to the difference in keratinocyte apoptosis and lesional formation between AD and psoriasis.
The Role of Fungi in Atopic Dermatitis Glatz, Martin; Bosshard, Philipp; Schmid-Grendelmeier, Peter
Immunology and allergy clinics of North America,
02/2017, Letnik:
37, Številka:
1
Journal Article
Recenzirano
Odprti dostop
There is little doubt that Malassezia spp plays a role in atopic dermatitis because it may interact with the local skin immune responses and barrier function, and sensitization against this ...skin-colonizing yeast can correlate with disease activity. Also, antifungal therapy shows beneficial effects in some patients. However, the pathogenetic mechanism and mutual interaction between Malassezia spp and atopic dermatitis still remain partly unclear and need further investigation.
Background Atopic eczema (AE) is the most common chronic inflammatory skin disease. Recent data demonstrate the presence of autoreactive serum IgE antibodies correlating with the severity of the ...disease. Objective Although several IgE-binding self-antigens have been reported, the whole repertoire of IgE-binding self-antigens is unknown. We aimed to estimate the repertoire size of autoreactive proteins related to AE and clone, produce, and characterize humoral and T-cell responses against novel self-antigens. Methods Phage surface–displayed human cDNA libraries were enriched for clones binding to serum IgE from patients with AE and screened by using high-throughput technology. Selected clones were used to produce the encoded proteins, to test their IgE-binding ability in Western blots and ELISAs, and their ability to induce mediator release from basophils of sensitized individuals. Results One hundred forty sequences encoding potential IgE-binding self-antigens associated with AE were identified. Sixteen sequences encoded already described self-antigens. Three new sequences showed homology with environmental allergens, 86 encoded known human proteins, 7 predicted proteins, and 28 showed sequence identity with genomic contigs. Immunoblotting and ELISA experiments demonstrated the presence of IgE antibodies in sera from patients with AE to 5 selected recombinant self-antigens and their ability to induce mediator release from basophils of patients with AE who have self-antigen–specific IgE antibodies. Conclusion These data demonstrate a broad spectrum of at least 140 IgE-binding self-antigens associated with AE. By binding IgE antibodies or activating specific T cells, they might promote, perpetuate, or both existing skin inflammation.
A 21-year-old man presented with multiple erythematous nonfollicular papules partially confluent to plaques on his breast and lower abdomen that had been present for 1 month. Grouped pustules were ...present under the right breast. The patient had been taking finasteride over the past 3 months for androgenetic alopecia. His medical history was negative for psoriasis. Our initial differential diagnosis included dyskeratosis follicularis Darier, allergic contact dermatitis, infectious folliculitis, varicella zoster virus infection, fixed drug eruption, and IgA pemphigus. The white blood cell count and differential were within the normal limits. Results of viral cultures and PCR, as well as bacterial and fungal cultures of skin lesions proved negative. A lesional biopsy specimen showed a slight psoriasiform acanthosis in association with spongiosis and infiltration of both the epidermis and dermis by neutrophils and eosinophils, resulting in formation of subcorneal, intraepidermal, and subepidermal pustules. The results of direct immunofluorescence were negative, excluding an IgA pemphigus. The result of a lymphocyte transformation test was positive for finasteride. On the basis of the time relationship between the administration of finasteride and the development of the skin disease in combination with symptoms resolution on cessation of the drug, the histologic findings, and the positive lymphocyte transformation test result, we consider this to be an unusual type of acute generalized exanthematous pustulosis defined as acute localized exanthematous pustulosis caused by finasteride. Within 4 weeks after withdrawal of finasteride, the rash resolved without any specific therapy. Transient discrete residual hyperpigmentation and scaling were present. The patient refused an oral provocation challenge.
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