Immunology and treatment of atopic dermatitis

Anti-inflammatory and biologic drugs for atopic dermatitis: a therapeutic approach in children and adolescents

Atopic dermatitis (AD) is a chronic inflammatory disease with a heterogeneous pathogenesis correlated with dysregulation of the immune system and a prevalence of the T2-mediated immune pathway. Recent understanding of the pathogenesis of AD has allowed the development of new drugs targeting different mechanisms and cytokines that have changed the treatment approach. The aim of this review is to update knowledge on the standard of care and recent advancements in the control of skin inflammation. In light of recent guidelines, we report on the clinical efficacy of novel treatments, with special attention to situations where biologics and small molecules are involved.

Nymphoides peltata Root Extracts Improve Atopic Dermatitis by Regulating Skin Inflammatory and Anti-Oxidative Enzymes in 2,4-Dinitrochlorobenzene (DNCB)-Induced SKH-1 Hairless Mice

Nymphoides peltata is widely used pharmacologically in Traditional Chinese Medicine and Ayurvedic medicine as a diuretic, antipyretic, or choleretic and to treat ulcers, snakebites, and edema. Previous studies have shown that phytochemicals from N. peltata have physiological activities such as anti-inflammatory, anti-tumor, and anti-wrinkle properties. Nevertheless, research on the anti-atopic dermatitis (AD) effect of N. peltata extract is limited. This study was undertaken to assess the in vitro and in vivo anti-atopic and antioxidant activities of a 95% EtOH extract of N. peltata roots (NPR). PI-induced RBL-2H3 cells and two typical hapten mice (oxazolone-induced BALB/c mice and 2,4-dinitrochlorobenzene (DNCB)-induced SKH-1 hairless mice) were used to investigate the effect of NPR extract on AD. The expressions of AD-related inflammatory cytokines, skin-related genes, and antioxidant enzymes were analyzed by ELISA, immunoblotting, and immunofluorescence, and skin hydration was measured using Aquaflux AF103 and SKIN-O-MAT instruments. The chemical composition of NPR extract was analyzed using an HPLC-PDA system. In this study, NPR extracts were shown to most efficiently inhibit IL-4 in PI-induced RBL-2H3 cells and AD-like skin symptoms in oxazolone-BALB/c mice compared to its whole and aerial extracts. NPR extract markedly reduced DNCB-induced increases in mast cells, epidermal thickness, IL-4 and IgE expressions, and atopic-like symptoms in SKH-1 hairless mice. In addition, NPR extract suppressed DNCB-induced changes in the expressions of skin-related genes and skin hydration and activated the Nrf2/HO-1 pathway. Three phenolic acids (chlorogenic acid, 3,5-dicaffeoylquinic acid, and 3,4-dicaffeoylquinic acid) were identified by HPLC-PDA in NPR extract. The study shows that NPR extract exhibits anti-atopic activities by inhibiting inflammatory and oxidative stress and improving skin barrier functions, and indicates that NPR extract has potential therapeutic use for the prevention and treatment of AD.

Narrative review on the management of moderate-severe atopic dermatitis in pediatric age of the Italian Society of Pediatric Allergology and Immunology (SIAIP), of the Italian Society of Pediatric Dermatology (SIDerP) and of the Italian Society of Pediatrics (SIP)

Currently, there are a few detailed guidelines on the overall management of children and adolescents with moderate-severe atopic dermatitis. AD ​​is a complex disease presenting with different clinical phenotypes, which require an individualized and multidisciplinary approach. Therefore, appropriate interaction between primary care pediatricians, pediatric allergists, and pediatric dermatologists is crucial to finding the best management strategy. In this manuscript, members of the Italian Society of Pediatric Allergology and Immunology (SIAIP), the Italian Society of Pediatric Dermatology (SIDerP), and the Italian Society of Pediatrics (SIP) with expertise in the management of moderate-severe atopic dermatitis have reviewed the latest scientific evidence in the field. This narrative review aims to define a pathway to appropriately managing children and adolescents with moderate-severe atopic dermatitis.

Bee Venom Within Liposomes Synergistically Inhibit Atopic Dermatitis in Mice

Background: This study was performed to determine the effects of liposome-encapsulated bee venom (BV) treatment of inflammatory factors in atopic dermatitis (AD) compared with BV treatment.Methods: AD was induced by phthalic anhydride in mice and the effects of BV liposomes were measured. Using Leica Application Suite, thickened epidermis and dermis were measured after BV liposome treatment (0.05 and 0.1 μg/mL). The number of stained mast cells and the concentration of immunoglobulin (Ig)E were measured. Serum IgE concentration was analyzed using an enzyme-linked immunosorbent assay. The serum concentrations of interleukin (IL)-1, IL-4, and IL-6 inflammatory cytokines were measured. The levels of messenger ribonucleic acid expression of proinflammatory cytokines and chemokines were measured using reverse transcription polymerase chain reaction. Inhibition of mitogen-activated protein kinase activation, was analyzed on western blot. To measure the transcriptional activity (NF-κB inhibition by BV liposomes), western blots (p65, p-IκB, p50, and IκB) were also performed.Results: The weight of lymph nodes, serum IgE concentrations, morphological changes in the skins from the backs of the mice, and mast cell numbers in inflamed tissues were noticeably lower in the BV liposome treatment group compared with the BV treatment group. The concentrations of pro-inflammatory cytokines (IL-1, IL-4, IL-6) and chemokines (TSLP, CCL22) were also reduced. Activation of mitogen-activated protein kinase (p-ERK and p-p38), and transcriptional activity (p65, p-IκB, p50, and IκB) was strongly suppressed in the BV liposome group.Conclusion: BV liposomes may have a better therapeutic effect than BV for the treatment of AD.

Microalgae as Potential Anti-Inflammatory Natural Product Against Human Inflammatory Skin Diseases

The skin is the first line of defense against pathogen and other environmental pollutant. The body is constantly exposed to reactive oxygen species (ROS) that stimulates inflammatory process in the skin. Many studies have linked ROS to various inflammatory skin diseases. Patients with skin diseases face various challenges with inefficient and inappropriate treatment in managing skin diseases. Overproduction of ROS in the body will result in oxidative stress which will lead to various cellular damage and alter normal cell function. Multiple signaling pathways are seen to have significant effects during ROS-mediated oxidative stress. In this review, microalgae have been selected as a source of natural-derived antioxidant to combat inflammatory skin diseases that are prominent in today’s society. Several studies have demonstrated that bioactive compounds isolated from microalgae have anti-inflammation and anti-oxidative properties that can help remedy various skin diseases. These compounds are able to inhibit production of pro-inflammatory cytokines and reduce the expression of inflammatory genes. Bioactive compounds from microalgae work in action by altering enzyme activities, regulating cellular activities, targeting major signaling pathways related to inflammation.

Multidose intramuscular allogeneic adipose stem cells decrease the severity of canine atopic dermatitis: A pilot study

Aim

The aim of this pilot study was to evaluate the therapeutic and safety performance of an intramuscular treatment protocol of multidose of allogeneic adipose stem cells (ASCs) isolated, characterized, and expanded ex vivo from a healthy canine donor.

Materials and Methods

Twelve dogs diagnosed with canine atopic dermatitis (CAD) were intramuscularly treated with 0.5×10⁶ of cryopreserved ASCs from a healthy immunized young canine Ehrlichia canis free donor weekly for 6 weeks. Treatment efficacy was evaluated by the pruritus index and the CAD Lesion Index (CADLI) test. Safety and adverse effects were determined by injection site reaction, weight, blood chemistry, liver function, and whole blood count.

Results

Canine ASCs obtained from a donor met the minimum qualities required for this type of cells and showed viability of 90% after thawing. The efficacy of the CADLI score and the pruritus index in 12 dogs with atopic dermatitis was statistically significant efficacy. No adverse reactions were observed at the intramuscular application site, or in relation to animal weight, blood cell populations, or liver and renal function.

Conclusion

These results suggest that intramuscular administration of cryopreserved ASCs to dogs with atopic dermatitis is a promising cellular therapeutic product for the relief of the symptoms of this disease; however, the duration of the effects obtained with this dose and with other doses should be evaluated, as well as possible immune reactions. As far as we know, this is the first report of the use of multiple intramuscular doses cryopreserved ASCs to treat atopic dermatitis.

Atopic Keratoconjunctivitis: Pharmacotherapy for the Elderly

Among the different forms of allergic conjunctivitis, atopic keratoconjunctivitis has distinct characteristics, defined by a more common onset in late adolescence or early adulthood, but also affecting the elderly, and with a higher prevalence in male individuals. However, the prevalence of atopic keratoconjunctivitis is scarcely investigated, and the data are often uncertain because other allergic nasal or respiratory disorders occur concomitantly. Mast cells, eosinophils, basophils, and T cells are involved in the pathogenesis of atopic keratoconjunctivitis. Despite its denomination as atopic, negative responses to skin tests or in-vitro immunoglobulin E tests are common. In fact, atopic keratoconjunctivitis can be attributed to a combination of T-helper-1 and T-helper-2 responses, but a higher prominence for T-helper-1 cells was found. The most common symptoms of atopic keratoconjunctivitis are bilateral ocular itching, burning, and tearing with a perennial presentation, although some patients may have seasonal exacerbations in winter or summer. Other symptoms such as photophobia, blurred vision, and mucous chewy discharge, owing to the accumulation of cells and mucin, may occur. The diagnosis of atopic keratoconjunctivitis is mainly clinical, as accepted diagnostic criteria or laboratory tests are not available. The treatment of atopic keratoconjunctivitis is aimed at controlling symptoms, decreasing relapse and exacerbations, and reducing vision loss. Therapeutic options comprise topical ophthalmic drops, including cromones, antihistamines, corticosteroids, and calcineurin inhibitors. Topical ointments are also available for corticosteroids and calcineurin inhibitors. Severe forms may require systemic medications including antihistamines, corticosteroids, and calcineurin inhibitors. Atopic keratoconjunctivitis therapy in the elderly does not differ from the adult population, but the occurrence of multi-morbidities and concomitant drug treatment, which are common in this age group, requires a careful evaluation to determine appropriate and personalized treatment.

A human and animal model-based approach to investigating the anti-inflammatory profile and potential of the 5-HT2B receptor antagonist AM1030

Background

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by highly pruritic eczematous lesions that are commonly treated with topical corticosteroids and calcineurin inhibitors. Side-effects and safety concerns associated with these agents restrict their use, and new, safe treatment options are therefore needed. Recent reports suggest that serotonin, i.e. 5-hydroxytryptamine (5-HT) and the 5-HT₂ receptor family may contribute to inflammation and pruritus in the skin. The objective of this particular study was to investigate the 5HT_2B receptor antagonist AM1030 with respect to its anti-inflammatory profile and potential.

Methods

AM1030 was tested in a set of distinct human and rodent in vitro and in vivo models, differing with respect to e.g. T cell involvement, triggering stimulus, main read-outs and route of drug administration. The in vitro systems used were staphylococcal enterotoxin A (SEA)-stimulated human peripheral blood mononuclear cells, lipopolysaccharide (LPS)-stimulated human primary monocytes, LPS-stimulated human THP-1 monocytes and LPS-stimulated mouse primary macrophages. The in vivo systems used were LPS- and SEA-induced cytokine production in the mouse, antigen-induced arthritis in the rat, glucose-6-phosphate isomerase-induced arthritis in the mouse and delayed-type hypersensitivity reaction in the mouse. In addition, different cell populations were analyzed with respect to their expression of the 5-HT_2B receptor at the mRNA level.

Results

AM1030 significantly reduced both T cell-dependent and T cell-independent inflammatory responses, in vivo and in vitro. Due to the low or absent expression of the 5-HT_2B receptor on T cell populations, the influence of AM1030 in T cell-dependent systems is suggested to be mediated via an indirect effect involving antigen-presenting cell types, such as monocytes and macrophages.

Conclusion

Based on the wide range of model systems used in this study, differing e.g. with respect to species, T cell involvement, triggering stimuli, route of drug administration and read-outs, our results suggest a broad anti-inflammatory effect of AM1030 and identify the 5-HT_2B receptor as a promising future target for anti-inflammatory intervention, e.g. in AD.

Therapeutic management of anal eczema: an evidence-based review

AIM

To conduct a systematic review of treatments for anal eczema (AE).

METHODS

We conducted a Medline search for clinical trial data for the treatment of perianal diseases including AE, including papers not published in the English language. We assessed the study reports using the system recommended by the Oxford Centre for Evidence-based Medicine. No meta-analysis was attempted.

RESULTS

The evidence base for topical treatments used to treat AE is very poor: there are very few studies and many of those that exist are of poor quality. The best evidence was found for medications that are yet to be licensed for AE. Among products with existing licences for the treatment of eczema, our assessment found some evidence to support the continued use of mild-to-moderate corticosteroids first line in most patients.

DISCUSSION

Features of the perianal region, and the fact that it is almost always occluded, mean that not all medications recommended in the general treatment guidelines for eczema are appropriate for AE. However, there are no specific treatment guidelines for these patients. This may in part be because of the lack of high-quality evidence-based medicine in this therapy area. Many frequently prescribed medications were developed and licensed many years ago, in an era when clinical trial design was not expected to be as rigorous as it is today.

CONCLUSION

This review highlights the need to conduct more high-quality clinical trials in patients with AE in order that specific guidelines for the management of this difficult proctological condition can be prepared.

Atopic keratoconjunctivitis: A review

Atopic keratoconjunctivitis is a chronic noninfectious inflammatory condition and is one of the most severe ophthalmic complications associated with atopic dermatitis. It requires prompt and effective treatment to prevent permanent vision loss. Complications of atopic keratoconjunctivitis include cataracts, keratoconus, infectious keratitis, blepharitis, tear dysfunction, and steroid-induced glaucoma. All treatment for atopic keratoconjunctivitis should be managed in conjunction with an ophthalmologist, and immediate referral is indicated when there is moderate to severe irritation, increased redness, discharge, or any visual symptoms. Treatment options include a combination of mast cell inhibitors, antihistamines, corticosteroids, and calcineurin inhibitors.

Dandruff/seborrhoeic dermatitis is characterized by an inflammatory genomic signature and possible immune dysfunction: transcriptional analysis of the condition and treatment effects of zinc pyrithione

BACKGROUND

Dandruff/seborrhoeic dermatitis is a common scalp condition that is characterized by flakes, pruritus and sometimes mild erythema. These symptoms reflect tissue level events that are poorly understood at the molecular level.

OBJECTIVES

The purpose of this work was: (i) to compare gene expression profiles in subjects with dandruff vs. those of subjects without dandruff to determine the key physiological disruptions manifest in the condition; and (ii) to determine the effect on this profile of treatment with a shampoo containing potentiated zinc pyrithione (ZPT).

METHODS

In study 1, scalp biopsies were taken from 16 normal subjects and from involved and uninvolved sites in 15 subjects with dandruff. In study 2, 30 subjects with dandruff were treated for 3 weeks with a commercial ZPT shampoo (n = 15) or a vehicle (n = 15), and scalp lesional biopsies were collected at baseline and end of study for transcriptomic analysis. RNA was extracted from all biopsies and Affymetrix gene chips were used to analyse transcriptomic profiles, followed by bioinformatic analysis.

RESULTS

Analysis of study 1 biopsies revealed more than 7000 individual probes differentially regulated in dandruff lesional skin relative to normal. Enriched Gene Ontology categories included: lipid metabolism, immune response, response to stimulus, apoptosis, cell proliferation, and epidermal development. The most striking feature of lesional skin relative to normal was the reciprocal expression of induced inflammatory genes and repressed lipid metabolism genes. Induced inflammatory genes were also enriched in dandruff uninvolved skin, suggesting the existence of predisposing factors associated with inflammation. Many genes increased in lesional skin were increased at the level of protein in stratum corneum samples (e.g. IL-1RA, S100A8, S100A9, S100A11, IL-8). Under conditions known to improve overall scalp condition, the ZPT shampoo treatment in study 2 produced a transcriptomic profile resembling that of normal scalp skin.

CONCLUSIONS

These data provide novel insights into the nature of dandruff and the therapeutic action of potentiated ZPT-containing shampoo, and provide a basis to explore many new mechanistic questions related to these topics.

Update on the management of chronic eczema: new approaches and emerging treatment options

Atopic dermatitis (AD) is a common disease with worldwide prevalence, affecting up to 20% of children and 3% of adults. Recent evidence regarding pathogenesis has implicated epidermal barrier defects deriving from filagrin mutations with resulting secondary inflammation. In this report, the authors comprehensively review the literature on atopic dermatitis therapy, including topical and systemic options. Most cases of AD will benefit from emollients to enhance the barrier function of skin. Topical corticosteroids are first-line therapy for most cases of AD. Topical calcineurin inhibitors (tacrolimus ointment, pimecrolimus cream) are considered second line therapy. Several novel barrier-enhancing prescription creams are also available. Moderate to severe cases inadequately controlled with topical therapy may require phototherapy or systemic therapy. The most commonly employed phototherapy modalites are narrow-band UVB, broadband UVB, and UVA1. Traditional systemic therapies include short-term corticosteroids, cyclosporine (considered to be the gold standard), methotrexate, azathioprine, mycophenolate mofetil, and most recently leflunamide. Biologic therapies include recombinant monoclonal antibodies acting on the immunoglobulin E / interleukin-5 pathway (omalizumab, mepolizumab), acting as tumor necrosis factor-α inhibitors (infliximab, etanercept, adalimumab), and acting as T-cell (alefacept) and B-cell (rituxumab) inhibitors, as well as interferon γ and intravenous immunoglobulin. Efficacy, safety, and tolerability are reviewed for each medication.

Pimecrolimus cream in the management of patients with atopic eczema

Atopic eczema is a common pediatric skin disorder. This review examines the use of pimecrolimus cream in the treatment of acute and chronic stages of the disease. The standard therapy is the treatment of acute flares with topical medications including pimecrolimus. The use of pimecrolimus cream for the first sign and symptoms of atopic eczema reduces the occurrence of flares as defined by the need for topical corticosteroids. The side effects of pimecrolimus cream are mild without any increase of infections or systemic immune suppression.