Alefacept (lymphocyte function-associated molecule 3/IgG fusion protein) treatment for atopic eczema

T cell co-stimulatory and co-inhibitory pathways in atopic dermatitis

The use of immune checkpoint inhibitors (ICIs) targeting the T cell inhibitory pathways has revolutionized cancer treatment. However, ICIs might induce progressive atopic dermatitis (AD) by affecting T cell reactivation. The critical role of T cells in AD pathogenesis is widely known. T cell co-signaling pathways regulate T cell activation, where co-signaling molecules are essential for determining the magnitude of the T cell response to antigens. Given the increasing use of ICIs in cancer treatment, a timely overview of the role of T cell co-signaling molecules in AD is required. In this review, we emphasize the importance of these molecules involved in AD pathogenesis. We also discuss the potential of targeting T cell co-signaling pathways to treat AD and present the unresolved issues and existing limitations. A better understanding of the T cell co-signaling pathways would aid investigation of the mechanism, prognosis evaluation, and treatment of AD.

Sophoricoside from Styphnolobium japonicum improves experimental atopic dermatitis in mice

BACKGROUND

Abnormal immune responses, specifically excessive differentiation of Th2 cells, are associated with the development of atopic dermatitis (AD). Sophoricoside, the genistein-4'-β-D-glucoside isolated from Styphnolobium japonicum, has previously demonstrated anti-inflammatory and immunosuppressive effects along with IL-3 and IL-5 inhibitory activities. Therefore, we speculated that sophoricoside could regulate AD by regulating abnormal immune responses.

PURPOSE

To investigate the role of sophoricoside on AD-like allergic skin inflammation induced by ovalbumin (OVA) or 2,4,6-trinitrochlorobenzene (TNCB) in mouse models.

METHODS

Sophoricoside was isolated from the 70% ethanol extract of S. japonicum dried mature seeds. After being submitted to a purification process, its purity was assessed by high-performance liquid chromatography (HPLC). The effects of sophoricoside were determined in vivo by OVA- and TNCB-induced AD-like allergic skin inflammation in mice. Skin tissues were subjected with hematoxylin-eosin (H&E), Giemsa and toluidine blue staining. In vitro CD4⁺ T cell differentiation was performed and the levels of serum immunoglobulins, cytokines, and genes related to CD4⁺ T cell differentiation were determined by enzyme-linked immunosorbent assay (ELISA) and quantitative real-time PCR. Cytokine bioassay, mixed lymphocytes reaction and cell viability assay were performed.

RESULTS

Topical application of sophoricoside decreased the symptoms of AD-like allergic skin inflammation, including elevated hypertrophic scars with spongiotic epidermis, epidermal hyperplasia, hyperkeratosis, infiltration of immune, and mast cells, dermal thickness, amounts of immunoglobulins, and pro-inflammatory cytokines, and the mast cell population in the skin. Sophoricoside also decreased T cell antigen receptor (TCR)-mediated immune responses. In particular, sophoricoside suppressed the differentiation of naïve CD4⁺ T cells into Th cell subsets, including Th1, Th2, and Th17, by inhibiting the expression of their subset-specific master transcription factors, leading to suppression of the expression and production of these cell subset-specific cytokines.

CONCLUSION

Sophoricoside can improve AD-like allergic skin diseases mainly by inhibiting pathogenic CD4⁺ T cell differentiation and immune responses.

Biologics for Allergic Dermatologic Diseases

PURPOSE OF REVIEW

Atopic dermatitis (AD), chronic spontaneous urticaria (CSU), and allergic contact dermatitis (ACD) represent three important allergic dermatoses with many unmet therapeutic needs. The development of biologic agents has opened the door to both new treatment options and improved understanding of the underlying pathophysiology, both shared and unique for these entities. With several FDA-approved medications available and many more in development, the biologic revolution has begun for allergic dermatoses.

RECENT FINDINGS

This is a narrative review on the current state of pathomechanisms and appropriately targeted biologic agents for these three common allergic skin conditions. The importance of Th2 inflammation and the effect of inflammatory cytokines on the skin barrier may help explain the impressive efficacy of biologic agents, while maintaining relative safety. While some of the biologic agents show efficacy across multiple allergic dermatoses, more often it seems these more targeted pathways show accordingly precise efficacy. However, in each disease, multiple agents hold promise, and may be differentiated by safety and adverse effect profile rather than simply by efficacy. New understanding of the pathogenesis of the allergic dermatoses has ushered in a new era of biologic therapies. Competing mechanisms and molecules will continue to be developed and vetted in trials with hopes of continuously refined precision therapies with optimized safety and efficacy profiles.

Racial differences in atopic dermatitis

OBJECTIVE

To summarize studies investigating ethnical and racial differences in atopic dermatitis (AD) epidemiology, clinical features, and skin and blood phenotypes.

DATA SOURCES

PubMed literature review (years 2000-2018).

STUDY SELECTIONS

Articles discussing primarily human disease.

RESULTS

Higher overall rates of AD were found in Africa and Oceania as opposed to India and Northern and Eastern Europe. In the United States, AD prevalence was found to be higher in African American (19.3%) compared with European American (16.1%) children. Although several studies have consistently found FLG loss-of-function mutations in up to 50% of European and 27% of Asian patients with AD, FLG mutations were 6 times less common in African American than in European American patients, even in patients with severe AD. Thus, FLG mutations seem to play less a pathogenic role in patients of African origin than in individuals of European or Asian ancestry. The immune phenotype of all ethnic groups was characterized by strong TH2 activation, but important differences in immune polarization exist among the different ethnicities. Asian patients with AD had stronger TH17/TH22 activation than African American and European American patients with AD, whereas African American patients had the highest serum IgE levels among all groups, while largely lacking TH1 and TH17 activation.

CONCLUSION

AD is a heterogeneous disease that has differences among various ethnic and racial groups, which might be important for the development of future, targeted treatments and for personalized medicine approaches.

Immunologic, microbial, and epithelial interactions in atopic dermatitis

OBJECTIVE

To provide an overview of studies contributing to the understanding of immunologic, microbial, and epithelial interactions in atopic dermatitis.

DATA SOURCES

PubMed literature review (2000-2017) and meeting abstracts from recent international dermatology conferences.

STUDY SELECTIONS

Articles discussing primarily human disease.

RESULTS

Clinical studies showed that atopic dermatitis is a type 2 immune-centered disease with a systemic inflammatory component but with heterogeneous treatment responses. This suggests that other factors are likely involved in shaping the skin disease phenotype, including microbial dysbiosis and epidermal barrier dysfunction.

CONCLUSION

Recent clinical investigation has significantly expanded our knowledge on disease pathogenesis in atopic dermatitis, and current and future clinical trials will most likely further help to elucidate this complex, heterogeneous skin disease.

Biological Therapeutic Treatment of Atopic Dermatitis

Atopic dermatitis is a chronic recurrent inflammatory disease caused, inter alia, by violations of the barrier function of the skin and pathological immune response in the form of an imbalance of Th1 and Th2 lymphocytes with increased production of IL-4, IL-5, IL-13, IL-31. Treatment of severe forms of atopic dermatitis is not an easy task due to the variability of the individual response to treatment, the short duration of the therapeutic effect and the frequent development of undesirable phenomena associated with the use of existing methods of systemic immunosuppressive therapy. The study of the pathogenesis of atopic dermatitis made it possible to identify the spectrum of molecular targets, providing the basis for researching alternative variants to the previously used systemic therapy methods – genetic engineering biological preparations. Contemporary data on the pathogenesis of atopic dermatitis as well as potential molecular targets for innovative biological preparations, the efficacy of which has been evaluated through clinical trials, are presented in the review. 

Novel Therapeutic Approaches to Atopic Dermatitis

Atopic dermatitis (AD) is one of the most common inflammatory skin diseases. The number of people affected by AD is relatively high and seems to be rising. Although mild and moderate forms of the disease can be well controlled by the use of emollients, topical corticosteroids, and topical calcineurin inhibitors, treatment of severe is still a huge challenge. The new hope is biologic drugs, magic bullets in allergy, targeted at different points of the complex pathomechanism of inflammation in AD. In this review, novel biologic therapies are discussed, including recombinant monoclonal antibodies directed against various interleukin pathways (such as IL-4, IL-13, TSLP, IL-31, and IL-12/23), on immunoglobulin E, molecules acting as T cells, B cells, etc. Of biological drugs, the most promising seems to be anti-IL-4/IL-13 therapy (dupilumab-the biological agent) and phosphodiesterase-4 inhibitor (crisaborole-a small molecule). A deep understanding of the AD pathomechanism provides a new perspective for tailor-made treatment of severe atopic dermatitis.

The immunology of atopic dermatitis and its reversibility with broad-spectrum and targeted therapies

Atopic dermatitis (AD), the most common chronic inflammatory skin disease, is driven by both terminal keratinocyte differentiation defects and strong type 2 immune responses. In contrast to chronic plaque-type psoriasis, AD is now understood to be a much more heterogeneous disease, with additional activation of T_H22, T_H17/IL-23, and T_H1 cytokine pathways depending on the subtype of the disease. In this review we discuss our current understanding of the AD immune map in both patients with early-onset and those with chronic disease. Clinical studies with broad and targeted therapeutics have helped to elucidate the contribution of various immune axes to the disease phenotype. Importantly, immune activation extends well beyond lesional AD because nonlesional skin and the blood component harbor AD-specific inflammatory changes. For this reason, future therapeutics will need to focus on a systemic treatment approach, especially in patients with moderate-to-severe disease.

The Changing Landscape of Alopecia Areata: The Therapeutic Paradigm

Alopecia areata (AA), a prevalent inflammatory cause of hair loss, lacks FDA-approved therapeutics for extensive cases, which are associated with very poor rates of spontaneous hair regrowth and major psychological distress. Current treatments for severe cases include broad immune-suppressants, which are associated with significant adverse effects, precluding long-term use, with rapid hair loss following treatment termination. As a result of the extent of the disease in severe cases, topical contact sensitizers and intralesional treatments are of limited use. The pathogenesis of AA is not yet fully understood, but recent investigations of the immune activation in AA skin reveal Th1/IFN-γ, as well as Th2, PDE4, IL-23, and IL-9 upregulations. Tissue analyses of both animal models and human lesions following broad-acting and cytokine-specific therapeutics (such as JAK inhibitors and ustekinumab, respectively) provide another opportunity for important insights into the pathogenesis of AA. As reviewed in this paper, numerous novel therapeutics are undergoing clinical trials for AA, emphasizing the potential transformation of the clinical practice of AA, which is currently lacking. Dermatologists are already familiar with the revolution in disease management of psoriasis, stemming from better understanding of immune dysregulations, and atopic dermatitis will soon follow a similar path. In light of these recent developments, the therapeutic arena of AA treatments is finally getting more exciting. AA will join the lengthening list of dermatologic diseases with mechanism-targeted drugs, thus changing the face of AA.

Can We Repurpose FDA-Approved Alefacept to Diminish the HIV Reservoir?

Current anti-retroviral treatment (ART) for HIV is effective in maintaining HIV at undetectable levels. However, cessation of ART results in immediate and brisk rebound of viremia to high levels. This rebound is driven by an HIV reservoir mainly enriched in memory CD4+ T cells. In order to provide any form of functional HIV Cure, elimination of this viral reservoir has become the focus of current HIV cure strategies. Alefacept was initially developed for the treatment of chronic plaque psoriasis. Alefacept is a chimeric fusion protein consisting of the CD2-binding portion of human leukocyte function antigen-3 (LFA3) linked to the Fc region of human IgG1 (LFA3-Fc). Alefacept was designed to inhibit memory T cell activation that contributes to the chronic autoimmune disease psoriasis by blocking the CD2 coreceptor. However, it was found to deplete memory T cells that express high levels of CD2 via NK cell-mediated antibody dependent cell cytotoxicity (ADCC) in vivo. Phase II and phase III clinical trials of alefacept with psoriasis patients demonstrated promising results and an excellent safety profile. Subsequently, alefacept has been successfully repurposed for other memory T cell-mediated autoimmune diseases including skin diseases other than psoriasis, organ transplantation and type I diabetes (T1D). Herein, we review our specific strategy to repurpose the FDA approved biologic alefacept to decrease and hopefully someday eliminate the HIV reservoir, for which CD2hi memory CD4+ T cells are a significant contributor.

Past, present, and future for biologic intervention in atopic dermatitis

Atopic dermatitis (AD) is a debilitating disease that significantly alters the quality of life for one in four children and one in 10 adults. Current management of AD utilizes combinations of treatments to symptomatically alleviate disease by suppressing the inflammatory response and restoring barrier function in the skin, reducing disease exacerbation and flare, and preventing secondary skin infections. Resolution is temporary and long-term usage of these treatments can be associated with significant side-effects. Antibody therapies previously approved for inflammatory diseases have been opportunistically evaluated in patients with atopic dermatitis; however, they often failed to demonstrate a significant clinical benefit. Monoclonal antibodies currently in development offer hope to those individuals suffering from the disease by specifically targeting immune and molecular pathways important for the pathogenesis of atopic dermatitis. Here, we review the underlying biological pathways and the state of the art in therapeutics in AD.

EAACI IG Biologicals task force paper on the use of biologic agents in allergic disorders

Biologic agents (also termed biologicals or biologics) are therapeutics that are synthesized by living organisms and directed against a specific determinant, for example, a cytokine or receptor. In inflammatory and autoimmune diseases, biologicals have revolutionized the treatment of several immune-mediated disorders. Biologicals have also been tested in allergic disorders. These include agents targeting IgE; T helper 2 (Th2)-type and Th2-promoting cytokines, including interleukin-4 (IL-4), IL-5, IL-9, IL-13, IL-31, and thymic stromal lymphopoietin (TSLP); pro-inflammatory cytokines, such as IL-1β, IL-12, IL-17A, IL-17F, IL-23, and tumor necrosis factor (TNF); chemokine receptor CCR4; and lymphocyte surface and adhesion molecules, including CD2, CD11a, CD20, CD25, CD52, and OX40 ligand. In this task force paper of the Interest Group on Biologicals of the European Academy of Allergy and Clinical Immunology, we review biologicals that are currently available or tested for the use in various allergic and urticarial pathologies, by providing an overview on their state of development, area of use, adverse events, and future research directions.

Biological Treatments in Atopic Dermatitis

Atopic dermatitis (AD) is one of the most common chronic inflammatory skin diseases that affect both children and adults with a prevalence of 30% and 10%, respectively. Even though most of patients respond satisfactory to topical anti-inflammatory drugs, about 10% require one or more systemic treatments to achieve good control of their illness. The progressive and increasingly detailed knowledge in the immunopathogenesis of AD has allowed research on new therapeutic targets with very promising results in the field of biological therapy. In this article, we will review the different biological treatments with a focus on novel drugs. Their mechanism of action, current status and results from clinical trials and observational studies will be specified.

Novel targeted therapies for eosinophil-associated diseases and allergy

Eosinophil-associated diseases often present with life-threatening manifestations and/or chronic organ damage. Currently available therapeutic options are limited to a few drugs that often have to be prescribed on a lifelong basis to keep eosinophil counts under control. In the past 10 years, treatment options and outcomes in patients with clonal eosinophilic and other eosinophilic disorders have improved substantially. Several new targeted therapies have emerged, addressing different aspects of eosinophil expansion and inflammation. In this review, we discuss available and currently tested agents as well as new strategies and drug targets relevant to both primary and secondary eosinophilic diseases, including allergic disorders.

Immunology of atopic eczema: overcoming the Th1/Th2 paradigm

Atopic eczema (AE) is a challenge for modern medicine, because it is prevalent, severely affects quality of life of patients and their families, and causes high socioeconomic costs. The pathogenesis of AE is complex. While initial studies suggested a Th2 deviation as primary reason for the disease, numerous studies addressed a genetically predetermined impaired epidermal barrier as leading cause in a subgroup of patients. Recently, immune changes beyond the initial Th2 concept were defined in AE, with a role for specialized dendritic cells as well as newly identified T helper cell subsets such as Th17 and Th22 cells. Furthermore, trigger factors are expanded beyond classical Th2 allergens such as pollen or house dust mites to microbial products as well as self-antigens. This review pieces together our current understanding of immune as well as barrier abnormalities into the pathogenesis mosaic of AE.

New era of biologic therapeutics in atopic dermatitis

INTRODUCTION

Atopic dermatitis (AD) is a common inflammatory skin disease regulated by genetic and environmental factors. Both skin barrier defects and aberrant immune responses are believed to drive cutaneous inflammation in AD. Existing therapies rely largely on allergen avoidance, emollients and topical and systemic immune-suppressants, some with significant toxicity and transient efficacy; no specific targeted therapies are in clinical use today. As our specific understanding of the immune and molecular pathways that cause different subsets of AD increases, a variety of experimental agents, particularly biologic agents that target pathogenic molecules bring the promise of safe and effective therapeutics for long-term use.

AREAS COVERED

This paper discusses the molecular pathways characterizing AD, the contributions of barrier and immune abnormalities to its pathogenesis, and development of new treatments that target key molecules in these pathways. In this review, we will discuss a variety of biologic therapies that are in development or in clinical trials for AD, perhaps revolutionizing treatment of this disease.

EXPERT OPINION

Biologic agents in moderate to severe AD offer promise for controlling a disease that currently lacks good and safe therapeutics posing a large unmet need. Unfortunately, existing treatments for AD aim to decrease cutaneous inflammation, but are not specific for the pathways driving this disease. An increasing understanding of the immune mechanisms underlying AD brings the promise of narrow targeted therapies as has occurred for psoriasis, another inflammatory skin disease, for which specific biologic agents have been demonstrated to both control the disease and prevent occurrence of new skin lesions. Although no biologic is yet approved for AD, these are exciting times for active therapeutic development in AD that might lead to revolutionary therapeutics for this disease.

Difficult to control atopic dermatitis

Difficult to control atopic dermatitis (AD) presents a therapeutic challenge and often requires combinations of topical and systemic treatment. Anti-inflammatory treatment of severe AD most commonly includes topical glucocorticosteroids and topical calcineurin antagonists used for exacerbation management and more recently for proactive therapy in selected cases. Topical corticosteroids remain the mainstay of therapy, the topical calcineurin inhibitors tacrolimus and pimecrolimus are preferred in certain locations. Systemic anti-inflammatory treatment is an option for severe refractory cases. Microbial colonization and superinfection contribute to disease exacerbation and thus justify additional antimicrobial / antiseptic treatment. Systemic antihistamines (H1) may relieve pruritus but do not have sufficient effect on eczema. Adjuvant therapy includes UV irradiation preferably of UVA1 wavelength. “Eczema school” educational programs have been proven to be helpful.

Novel targeted therapies for eosinophilic disorders

Hypereosinophilic syndromes (HESs) are a diverse group of conditions characterized by clinical manifestations attributable to eosinophilia and eosinophilic infiltration of tissues. HESs are chronic disorders with significant morbidity and mortality. Although the availability of targeted chemotherapeutic agents, including imatinib, has improved quality of life and survival in some patients with HESs, additional agents with increased efficacy and decreased toxicity are sorely needed. The purpose of this review is to provide an overview of eosinophil biology with an emphasis on potential targets of pharmacotherapy and to provide a summary of potential eosinophil-targeting agents, including those in development, in clinical trials, or approved for other disorders.

Guidelines for treatment of atopic eczema (atopic dermatitis) Part II

The existing evidence for treatment of atopic eczema (atopic dermatitis, AE) is evaluated using the national standard Appraisal of Guidelines Research and Evaluation. The consensus process consisted of a nominal group process and a DELPHI procedure. Management of AE must consider the individual symptomatic variability of the disease. Basic therapy is focused on hydrating topical treatment, and avoidance of specific and unspecific provocation factors. Anti-inflammatory treatment based on topical glucocorticosteroids and topical calcineurin inhibitors (TCI) is used for exacerbation management and more recently for proactive therapy in selected cases. Topical corticosteroids remain the mainstay of therapy, but the TCI tacrolimus and pimecrolimus are preferred in certain locations. Systemic immune-suppressive treatment is an option for severe refractory cases. Microbial colonization and superinfection may induce disease exacerbation and can justify additional antimicrobial treatment. Adjuvant therapy includes UV irradiation preferably with UVA1 wavelength or UVB 311 nm. Dietary recommendations should be specific and given only in diagnosed individual food allergy. Allergen-specific immunotherapy to aeroallergens may be useful in selected cases. Stress-induced exacerbations may make psychosomatic counselling recommendable. 'Eczema school' educational programs have been proven to be helpful. Pruritus is targeted with the majority of the recommended therapies, but some patients need additional antipruritic therapies.

Biologics in atopic dermatitis

Atopic dermatitis (AD) accounts for a significant share of chronic inflammatory skin disorders. There is a niche for the development of biologics to treat recalcitrant autoinflammatory stage AD seen mostly in adults. The heterogeneity of patient response to various existing biotherapies points to involvement of various immune responses and suggests that therapies must preferably target early development of allergen-specific B- and T-cell clones. In addition to immune targets, tissue factors that help restore the normal epidermal environment constitute interesting therapeutic tools. Several approaches are needed to find the appropriate targets in a field where so many have been investigated without definitive proof of concept for human systemic therapy. The keys to success are probably (1) to influence the inflammatory skin pattern towards less pruritogenic effects, requiring us to better understand pruritogenic inflammation and (2) to limit the amplification loop of disease by attacking abnormal regulatory mechanisms which perpetuate skin autoinflammation.

What's new in atopic eczema?

IMPORTANCE OF THE FIELD

Atopic eczema (AE) is a chronic relapsing inflammatory skin condition and one of the most common, potentially debilitating diseases with increasing incidence.

AREAS COVERED IN THIS REVIEW

The complex etiology of AE with multiple systemic and local immunologic and inflammatory responses and interactions between susceptibility genes and environmental factors leading to defects in skin barrier function and eczematous skin lesions is presented. Knowledge of pathogenesis is important for understanding the more innovative treatment approaches discussed.

WHAT THE READER WILL GAIN

Basic therapy consists of hydrating topical treatment and avoidance of specific and unspecific provocation factors. For acute eczematous skin lesions, anti-inflammatory treatment consists mainly of topical glucocorticoids and topical calcineurin inhibitors (tacrolimus and pimecrolimus). Microbial colonization and superinfection may induce skin exacerbation, which can be treated by either topical or systemic antimicrobial treatment. Systemic anti-inflammatory therapy is limited to severe cases and consists of systemic steroids, cyclosporine A or mycophenolate mofetil. Novel anti-inflammatory concepts that go beyond corticosteroids are in the early phases of development. There are targeted therapeutic approaches, such as cytokine and chemokine modulators and it remains to be investigated how effective they will be and what side effects they may carry.

TAKE HOME MESSAGE

Existing treatment modalities such as barrier repair therapy, topical immunosuppressive agents, antiseptic treatment as well as systemic treatment options are discussed. The review aims to summarize the most recent findings of more innovative treatment approaches such as modulation of cytokines or chemokines, modulation of T-cell responses or anti-IgE therapy.

Alefacept: where it stands today

IMPORTANCE OF THE FIELD

The use of biologics that target a subset of immune cells in the treatment of immune-mediated ailments is an emerging field. Alefacept is one of the first biologics in the treatment of psoriasis. It selectively reduces CD45RO(+) memory T cells and inhibits T-cell activation. Clinical data support its safety and efficacy in a substantial subset of patients with psoriasis.

AREAS COVERED IN THIS REVIEW

This article reviews the mechanism of action and the pharmacokinetic and pharmacodynamic properties of alefacept. It also presents the available data about its effectiveness, modes of treatment as well as safety and efficacy in the treatment of psoriasis and other immune-based dermatologic disorders.

WHAT THE READER WILL GAIN

An overview of the published data about the clinical and adverse effects of alefacept in the treatment of psoriasis and a myriad of immunologically-based disorders.

TAKE HOME MESSAGE

Ongoing literature supports that alefacept is a safe alternative for the treatment of psoriasis. However, it remains the least prescribed medication in this group of drugs, mainly because it is only effective in a small proportion of patients. Nonetheless, its long-lasting effects and tolerability make it an excellent choice for those who do respond.

Looking ahead in dermatology: skin and allergy

The prevalence of allergic diseases has increased tremendously over the last decades. Clinically they comprise a spectrum of many different conditions caused by specific immunological hypersensitivity in response to a mostly apathogenic substance. Environmental factors such as lack of immune-stimulating contacts (infection, vaccination) and exposure to allergy-enhancing anthropogenic pollutants from tobacco smoke or traffic exhaust particles are suspected to be involved in the increase of allergies. Recently it has been shown that pollens are not only allergen carriers but also secrete highly active proinflammatory lipid mediators, pollen-associated lipid mediators (PALMs), which have proinflammatory and immuno-modulatory capacity that facilitates allergic sensitization of the skin and mucous membranes. The skin is one of the most important organs where allergic reactions manifest. Many different morphological and physiopathological entities can be observed in the skin that represent all kinds of pathogenetic immune reactions from immediate-type allergy, urticaria, angioedema, anaphylaxis, cytotoxic and immune complex reactions such as thrombocytopenic purpura or allergic leukocytoclastic vasculitis, exanthematous drug eruptions, granulomatous skin reactions to tattoos or fillers as well as a wide spectrum of dermatitis and eczema with allergic contact dermatitis being one of the most common occupational diseases in many countries. Recent progress in pathophysiology has revealed a role of epidermal barrier function as well as immunodeviation in atopic eczema giving rise to new diagnostic and therapeutic strategies. The interdisciplinary character of allergy implies a close cooperation between different disciplines where dermatology plays a major role in the management of allergic diseases, covering diagnostic, therapeutic and preventive aspects.

Anti-inflammatory and immunosuppressive effects of the enaminone E121

Asthma is a chronic inflammatory disease of the airways. The treatment of asthma is far from optimal and hence the need for novel therapeutic agents exists. The purpose of this study was to assess the anti-asthma effects of an enaminone, E121, and also its effects on human peripheral blood mononuclear cell proliferation and cytokine release. The effects of E121 were assessed in an ovalbumin-induced model of airway inflammation and airway hyperresponsiveness. In addition, the effects of E121 on phytohemagglutinin (PHA), anti-CD3 monoclonal antibody and lipopolysaccharide (LPS)-induced human peripheral blood mononuclear cell proliferation and cytokine release, respectively, were assessed. Treatment of mice with E121 significantly decreased the ovalbumin-induced increase in airway total cell influx and eosinophil infiltration and this was associated with an inhibition of ovalbumin-induced airway hyperresponsiveness. Moreover, E121 reduced PHA and anti-CD3-induced human peripheral blood mononuclear cell proliferation in vitro. E121 also inhibited PHA, anti-CD3 monoclonal antibody and LPS-induced cytokine release from human peripheral blood mononuclear cell cultures. These findings indicate that E121 exhibits anti-inflammatory and immunosuppressive activities.

Allergic skin diseases

The skin is one of the largest immunologic organs and is affected by both external and internal factors, as well as innate and adaptive immune responses. Many skin disorders, such as atopic dermatitis, contact dermatitis, urticaria, angioedema, psoriasis, and autoimmune blistering disorders, are immune mediated. Most of these diseases are chronic, inflammatory, and proliferative, in which both genetic and environmental factors play important roles. These immunologic mechanisms might have implications for potential targets of future therapeutic interventions.

Emerging drugs for atopic dermatitis

Atopic dermatitis (AD) is the most common chronic inflammatory skin disease, affecting 10-20% of children and 2% of adults worldwide. Preventive treatment of AD consists of daily skin hydration and emollient therapy; but the majority of patients still require symptomatic treatment with topical corticosteroids and/or topical calcineurin inhibitors, both of which may be associated with potential long-term side effects. With increasing evidence supporting the role of skin barrier defects in the pathogenesis of AD, there is also a parallel increase in medications that claim to assist barrier repair. The current review discusses some exciting results with these medications, as well as the challenges that lie ahead of them. While barrier repair treatments offer some promise, there continues to be a need for safer anti-inflammatory medications. Some of these medications under investigation are phosphodiesterase-4 inhibitors, urocanic acid oxidation products and IL-4/IL-13 receptor blockers. The review also discusses anti-staphylococcal treatments including nanocrystalline silver cream, silver and antimicrobial-coated fabrics, and anti-itch treatments including mu-opiod receptor antagonists, chymase inhibitors and cannabinoid receptor agonists. These medications may become an integral part of AD therapy.

Advances in allergic skin disease, anaphylaxis, and hypersensitivity reactions to foods, drugs, and insects in 2008

This review highlights some of the research advances in anaphylaxis, and hypersensitivity reactions to foods, drugs, and insects and in allergic skin disease that were reported in the Journal in 2008. Key epidemiologic observations include a rise in anaphylaxis in a population-based study and lower rates of peanut allergy in Israel, where infants consume peanut early compared with the United Kingdom, where dietary introduction is generally delayed. Advances in food allergy diagnosis include IgE epitope mapping that discloses the likelihood and severity of allergy; studies correlating likelihood of clinical reactivity on the basis of food-specific IgE to sesame, peanut, milk, and tree nuts; and an observation that a low baseline angiotensin-converting enzyme level may be associated with having pharyngeal edema during a reaction. Molecular, immunologic, and genetic studies are discerning pathways that are key in development of food allergy, identifying new modalities to interrupt mast cell degranulation, and elucidating risks associated with penicillin allergy. Regarding treatment, clinical studies show a majority of children with milk and egg allergy tolerate these proteins in modest amounts when they are extensively heated in baked goods, and studies show promise for oral immunotherapy to treat milk allergy and sublingual immunotherapy for honey bee venom hypersensitivity. The importance of skin barrier dysfunction has continued to be highlighted in the pathophysiology of atopic dermatitis (AD). Research has also continued to identify immunologic defects that contribute to the propensity of patients with AD to develop viral and bacterial infection. New therapeutic approaches to AD, urticaria, and angioedema have been reported including use of probiotics, biologics, vitamin D, and skin barrier creams.