A systematic review of tacrolimus ointment compared with corticosteroids in the treatment of atopic dermatitis

Tacrolimus-loaded chitosan-based nanoparticles as an efficient topical therapeutic for the effective treatment of atopic dermatitis symptoms

Atopic dermatitis (AD) is a chronic cutaneous disease with a complex underlying mechanism, and it cannot be completely cured. Thus, most treatment strategies for AD aim at relieving the symptoms. Although corticosteroids are topically applied to alleviate AD, adverse side effects frequently lead to the withdrawal of AD therapy. Tacrolimus (TAC), a calcineurin inhibitor, has been used to treat AD, but its high molecular weight and insolubility in water hinder its skin permeability. Herein, we developed and optimized TAC-loaded chitosan-based nanoparticles (TAC@CNPs) to improve the skin permeability of TAC by breaking the tight junctions in the skin. The prepared nanoparticles were highly loadable and efficient and exhibited appropriate characteristics for percutaneous drug delivery. TAC@CNP was stable for 4 weeks under physiological conditions. CNP released TAC in a controlled manner, with enhanced skin penetration observed. In vitro experiments showed that CNP was non-toxic to keratinocyte (HaCaT) cells, and TAC@CNP dispersed in an aqueous solution was as anti-proliferative as TAC solubilized in a good organic solvent. Importantly, an in vivo AD mouse model revealed that topical TAC@CNP containing ~1/10 of the dose of TAC found in commercially used Protopic® Ointment exhibited similar anti-inflammatory activity to that of the commercial product. TAC@CNP represents a potential therapeutic strategy for the management of AD.

Efficacy and Safety of Topical Tacrolimus Microemulsion Applied Twice Daily in Patients with Mild to Moderate Scalp Psoriasis

INTRODUCTION

Involvement of the scalp is common in psoriasis and severely affects the quality of life of those affected. It is difficult to treat and places special demands on the galenics of a drug formulation. Tacrolimus is a calcineurin inhibitor and is approved as an ointment formulation for the treatment of atopic dermatitis. The efficacy and safety of topically applied tacrolimus have also been studied and proven for psoriasis. However, no proprietary pharmaceutical product is currently approved for this indication.

METHODS

A multicenter, double-blind, vehicle-controlled phase 3 study was conducted to evaluate the efficacy and safety of 0.1% tacrolimus microemulsion when applied topically twice daily in 128 patients independently of sex with scalp psoriasis.

RESULTS

The primary efficacy analysis showed a scalp Investigator Global Assessment (s-IGA) of 0 (absence of disease) or 1 (very mild disease) at 8 weeks in 28.6% of subjects in the tacrolimus group, indicating a significantly better response (p = 0.0476, chi-square test) versus 12.7% of subjects in the placebo group (difference of 15.9%-points). The Dermatology Life Quality Index (DLQI) improved over time and was more pronounced in the group treated with tacrolimus-containing microemulsion than in the placebo group, but showed no statistically significant difference after 8 weeks of use (p = 0.193, ANCOVA). The safety analysis revealed no evidence of cutaneous side effects other than those known. Toxicologically relevant serum levels of tacrolimus could be excluded.

CONCLUSION

The study data show that 0.1% tacrolimus microemulsion has good efficacy and safety in the treatment of scalp psoriasis.

English Version of Clinical Practice Guidelines for the Management of Atopic Dermatitis 2021

This is the English version of the Clinical Practice Guidelines for the Management of Atopic Dermatitis 2021. Atopic dermatitis (AD) is a disease characterized by relapsing eczema with pruritus as a primary lesion. In Japan, from the perspective of evidence-based medicine, the current strategies for the treatment of AD consist of three primary measures: (i) use of topical corticosteroids, tacrolimus ointment, and delgocitinib ointment as the main treatment of the inflammation; (ii) topical application of emollients to treat the cutaneous barrier dysfunction; and (iii) avoidance of apparent exacerbating factors, psychological counseling, and advice about daily life. In the present revised guidelines, descriptions of three new drugs, namely, dupilumab, delgocitinib, and baricitinib, have been added. The guidelines present recommendations to review clinical research articles, evaluate the balance between the advantages and disadvantages of medical activities, and optimize medical activity-related patient outcomes with respect to several important points requiring decision-making in clinical practice.

Management of Atopic Dermatitis: The Role of Tacrolimus

Atopic dermatitis (AD) is a long-lasting inflammatory dermatological condition characterized by itchy, eczematous, sparsely tiny blisters that hold a clear watery substance. Additionally, the diseased skin can suppurate, occasionally with weeping with thickening of the affected skin. This is considered one of the top skin disorders involving both children and adult populations globally. The principal therapeutic intervention for AD is long-standing topical glucocorticoids, which have been used for several decades. Corticosteroid therapy brings several adverse drug effects (ADRs), including irreversible skin atrophy. Tacrolimus belongs to the class of calcineurin inhibitors, which is a type of immunomodulator possessing promising efficacy in treating AD. Topical tacrolimus is an effective and safe non-corticosteroid substitute treatment for AD. We reviewed the available literature to compare and institute the safety, efficacy, and effectiveness of tacrolimus when equated to corticosteroid therapy in managing AD.

In-situ oligomerization of lactic acid within broiler skin extracted elastin/collagen matrix for the efficacy of ointment base

Elastin and collagen were isolated from waste broil skin and modified with l-lactic acid oligomer for the efficacy of substituting petroleum based ointment base matrix. Paraffin wax, which is one of the most extensively used petroleum ointment derivative is well known for its incompatibility with the skin. Chronically it clogs the skin pores, which subsequently affects the release of moisture. To mitigate this problem, a novel approach has been followed to synthesize a fully green and biocompatible ointment base matrix. The extracted Elastin and Collagen (which exists naturally in our skin) and lactic acid monomer (commonly known as a part of a body fluid) mixed at different proportion and used to synthesize a lactic acid modified elastin/collagen (OLLA-m-ELN/COL) bioconjugate matrix with lubricating characteristics via in-situ polycondensation reaction. The macromolecular interaction between Amide I group of elastin/collagen and C=O of a lactic acid oligomer was confirmed by FTIR analysis. Organoleptic analysis, spreadability, pH, and viscosity were analyzed. The six-mass loss stages which was observed in the ELN/COL matrix was changed into a single mass loss for the synthesized bioconjugate with improved thermal stability. The thermal stability improvement can be correlated with the formation of secondary macromolecular interaction.

What are the highest yielding search strategy terms for systematic reviews in atopic dermatitis? A systematic review

The impact of search strategies on systematic reviews (SR) of atopic dermatitis (AD) is unknown. The purpose of this review was to evaluate search strategies used in SR of AD and their impact on the frequency of manuscripts identified. MEDLINE and EMBASE were searched for SR related to AD. Simulations were performed by running combinations of search terms in MEDLINE and EMBASE. Overall, 250 SR met inclusion criteria, of which 225 specified search strategies. SR using 5-6 terms (20.0% to 12.1%) or ≥ 7 (40.0% to 18.8%) terms decreased, whereas SR using 3-4 terms numerically increased (18.8% to 30.2%) and 1-2 terms remained similar (37.5% to 38.9%) from 1999-2009 to 2015-2019. The most commonly searched terms were "atopic dermatitis" (n = 166), followed by "eczema" (n = 156), "dermatitis atopic'" (n = 81), "atopic eczema" (n = 74), "neurodermatitis" (n = 59), "Besniers prurigo" (n = 29), "infantile eczema" (n = 27), and "childhood eczema" (n = 19). Simulations revealed that "eczema" and "atopic dermatitis" yielded the most hits. The number of search terms that maximized hits in MEDLINE and EMBASE was 5 and 4, respectively. Search strategies for AD were heterogeneous, with high proportions of search strategies providing few search hits. Future studies should use standardized and optimized search terms.

Appraisal of Proactive Topical Therapy in Atopic Dermatitis: Pros and Cons

Atopic dermatitis is a common inflammatory skin disease that can affect both children and adults. It is a chronic disease with recurrent, highly pruritic eczematous lesions. Topical treatment with anti-inflammatory agents is the mainstay of treatment for atopic dermatitis, either in a reactive or proactive approach according to severity of the disease and always in combination with daily application of an emollient cream. Several studies have shown that proactive therapy with either topical corticosteroids or topical calcineurin inhibitors is significantly superior at reducing the number of flares and increasing the interval between flares compared with reactive therapy in patients with moderate and severe disease. The risk of side effects is considered low, and there seem to be no extra economic costs related to this treatment approach. Proactive therapy is an advisable treatment option for patients with moderate and severe atopic dermatitis to gain prolonged disease control; however, long-term safety data and data on when to stop do not yet exist.

Topical treatments in dermatology

Topical medications are key agents in treating a range of skin conditions, as they allow affected areas to be targeted while avoiding systemic side effects. Although there is a wide range of topical agents available, it is helpful to be familiar with a few commonly used formulations. This article describes how to select appropriate agents, prescribe appropriate quantities, and counsel patients on safe and effective treatment regimens.

Safety of topical corticosteroids in atopic eczema: an umbrella review

OBJECTIVE

An umbrella review summarising all safety data from systematic reviews of topical corticosteroids (TCS) in adults and children with atopic eczema.

METHODS

Embase, MEDLINE, PubMed, Cochrane Database of Systematic Reviews and the Centre of Evidence Based Dermatology map of eczema systematic reviews were searched until 7 November 2018 and Epistemonikos until 2 March 2021. Reviews were included if they assessed the safety of TCS in atopic eczema and searched >1 database using a reproducible search strategy. Review quality was assessed using version 2 of 'A MeaSurement Tool to Assess systematic Reviews' (AMSTAR 2 tool).

RESULTS

38 systematic reviews included, 34 low/critically low quality. Treatment and follow-up were usually short (2-4 weeks).

KEY FINDINGS

TCS versus emollient/vehicle: No meta-analyses identified for skin-thinning. Two 2-week randomised controlled trials (RCTs) found no significant increased risk with very potent TCS (0/196 TCS vs 0/33 vehicle in children and 6/109 TCS vs 2/50 vehicle, age unknown). Biochemical adrenal suppression (cortisol) was 3.8% (95% CI 2.4% to 5.8%) in a meta-analysis of 11 uncontrolled observational studies (any potency TCS, 522 children). Effects reversed when treatment ceased.TCS versus topical calcineurin inhibitors: Meta-analysis showed higher relative risk of skin thinning with TCS (4.86, 95% CI 1.06 to 22.28, n=4128, four RCTs, including one 5-year RCT). Eight cases in 2068 participants, 7 using potent TCS. No evidence of growth suppression.Once daily versus more frequent TCS: No meta-analyses identified. No skin-thinning in one RCT (3 weeks potent TCS, n=94) or biochemical adrenal suppression in two RCTs (up to 2 weeks very potent/moderate TCS, n=129).TCS twice/week to prevent flares ('weekend therapy') versus vehicle: No meta-analyses identified. No evidence of skin thinning in five RCTs. One RCT found biochemical adrenal suppression (2/44 children, potent TCS).

CONCLUSIONS

W e found no evidence of harm when TCS were used intermittently 'as required' to treat flares or 'weekend therapy' to prevent flares. However, long-term safety data were limited.

PROSPERO REGISTRATION NUMBER

CRD42018079409.

Practical Recommendations for the Topical Treatment of Atopic Dermatitis in South and East Asia

Introduction

There is some evidence to suggest that the prevalence of atopic dermatitis (AD) in Asia is rising. We have therefore developed an algorithm for the topical treatment of AD throughout South and East Asia for use by primary care physicians, pediatricians and dermatologists.

Methods

Nine AD experts from South and East Asia and one from Europe developed the algorithm based upon treatment guidelines, relevant literature and local treatment practices. The algorithm outlines current best practice for the use of emollients, topical corticosteroids (TCS) and topical calcineurin inhibitors (TCI), with the intention of simplifying the treatment regimen of mild-to-moderate AD in South and East Asia.

Results

Patients with AD should bathe and cleanse affected skin to remove crusts and scales daily. Emollients should also be applied daily as a maintenance treatment. When selecting appropriate topical anti-inflammatory treatment for AD flares, several factors should be taken into consideration, including the patient’s age, attitude to treatment options and site of AD lesions. Given the concerns regarding the risk of skin atrophy with use of TCS, a TCI should be used to treat AD lesions in sensitive skin areas: pimecrolimus is recommended for mild-to-moderate AD in these locations, while tacrolimus should be considered for moderate and severe cases. Either pimecrolimus or tacrolimus is recommended for flares in other, non-sensitive body locations. A proactive or intermittent maintenance treatment strategy involving regular emollient use and twice-weekly application of a TCI to previously affected areas is encouraged to reduce the risk of flares.

Conclusions

The algorithm proposed here is intended to simplify the topical treatment of mild-to-moderate AD in daily practice in South and East Asian countries.

What Is the Risk of Harm Associated With Topical Calcineurin Inhibitors?

The topical calcineurin inhibitors (TCIs), tacrolimus (Protopic) and pimecrolimus (Elidel), were approved in the early 2000s and were widely used as a nonsteroid treatment for atopic dermatitis (AD) in adult and pediatric populations. In 2005, the addition of a boxed warning was mandated for TCIs based on a potential risk of malignancy, and there was subsequently a substantial decline in their use. Since then, evidence has mounted to support the safety of this class of medications and suggests that the increased risk of malignancy remains theoretical. This review aims to dispel some of the common myths surrounding the safety of TCIs by evaluating the key evidence regarding their safety and tolerability in adult and pediatric populations. Four major themes are addressed in a practical question-and-answer format: the risk of harm associated with TCIs including common and serious adverse events; warnings and precautions for their use including the risk of systemic absorption, immunosuppression, and malignancy; the comparative safety of TCIs; and suggestions for counselling patients about the risk of harm with TCIs. Based on the available evidence, international professional dermatological organizations and regulatory authorities have concluded that the benefits of TCIs outweigh their potential risks when used in the appropriate patient populations for the recommended duration of time.

Clinical practice guidelines for the management of atopic dermatitis 2018

Atopic dermatitis (AD) is a disease characterized by relapsing eczema with pruritus as a primary lesion. The current strategies to treat AD in Japan from the perspective of evidence-based medicine consist of three primary measures: (i) the use of topical corticosteroids and tacrolimus ointment as the main treatment for the inflammation; (ii) topical application of emollients to treat the cutaneous barrier dysfunction; and (iii) avoidance of apparent exacerbating factors, psychological counseling and advice about daily life. The guidelines present recommendations to review clinical research articles, evaluate the balance between the advantages and disadvantages of medical activities, and optimize medical activity-related patient outcomes with respect to several important points requiring decision-making in clinical practice.

Childhood atopic dermatitis: current developments, treatment approaches, and future expectations

Atopic dermatitis (AD) is the most common chronic inflammatory skin disorder of childhood. Underlying factors that contribute to AD are impaired epithelial barrier, alterations in the lipid composition of the skin, immunological imbalance including increased Th2/Th1 ratio, proinflammatory cytokines, decreased T regulatory cells, genetic mutations, and epigenetic alterations. Atopic dermatitis is a multifactorial disease with a particularly complicated pathophysiology. Discoveries to date may be considered the tip of the iceberg, and the increasing number of studies in this field indicate that there are many points to be elucidated in AD pathophysiology. In this review, we aimed to illustrate the current understanding of the underlying pathogenic mechanisms in AD, to evaluate available treatment options with a focus on recently discovered therapeutic agents, and to determine the personal, familial, and economic burdens of the disease, which are frequently neglected issues in AD. Currently available therapies only provide transient solutions and cannot fully cure the disease. However, advances in the understanding of the pathogenic mechanisms of the disease have led to the production of new treatment options, while ongoing drug trials also have had promising results.

FK506 (tacrolimus) causes pain sensation through the activation of transient receptor potential ankyrin 1 (TRPA1) channels

FK506 (tacrolimus) is an immunosuppressant widely used as an ointment in the treatment of atopic dermatitis. However, local application of FK506 can evoke burning sensations in atopic dermatitis patients, and its mechanisms are unknown. In this study, we found that FK506 activates transient receptor potential ankyrin 1 (TRPA1) channels. In Ca2+-imaging experiments, increases in intracellular Ca2+ concentrations ([Ca2+]i) by FK506 were observed in HEK293T cells expressing hTRPA1 or hTRPM8. FK506-induced currents were observed in HEK293T cells expressing hTRPA1 or mTRPA1, but less or not at all in cells expressing hTRPV1 or hTRPM8 using a patch-clamp technique. FK506 also evoked single-channel opening of hTRPA1 in an inside-out configuration. FK506-induced [Ca2+]i increases were also observed in TRPA1-expressing mouse primary sensory neurons. Furthermore, injection of FK506 evoked licking or biting behaviors and these behaviors were almost abolished in TRPA1 knockout mice. These results indicate that FK506 might cause pain sensations through TRPA1 activation.

Tacrolimus ointment for the treatment of adult and pediatric atopic dermatitis: Review on safety and benefits

Atopic dermatitis (AD) requires long-term management, mainly with topical anti-inflammatory agents. Topical corticosteroids (TCS) and tacrolimus ointment (TAC-O) are recommended as first-line treatments for AD. However, the long-term use of TCS is limited by cutaneous adverse events such as skin atrophy. For TAC-O, Japanese and US labelings were updated in 2003 and 2006, respectively, to include a boxed warning about a theoretical risk of skin cancer and lymphoma in patients treated with topical calcineurin inhibitors. However, TAC-O has been used worldwide for longer than 15 years to treat adult and pediatric patients with AD. Available data suggest that TAC-O is effective and well tolerated, and can improve quality of life. TAC-O has successfully been used in the proactive management of AD consisting of long-term intermittent use to prevent, delay or reduce the occurrence of AD flares. Systemic drug absorption after TAC-O application is negligible and unlikely to result in systemic immunosuppression. There is currently no strong evidence of an increased rate of malignancy in treated patients, and observational data from postmarketing surveillance studies have shown no safety concerns. In the absence of robust evidence, the warning about the carcinogenic potential in the Japanese labeling for TAC-O does not appear justified and should be reconsidered. This mitigation of description would allow adult and pediatric patients with AD to receive the effective treatment more appropriately.

Tacrolimus nanoparticles based on chitosan combined with nicotinamide: enhancing percutaneous delivery and treatment efficacy for atopic dermatitis and reducing dose

Background

Topical application of tacrolimus (FK506) was effective in the treatment of atopic dermatitis (AD); however, adverse effects frequently occurred with the increase of FK506 dose during long–term treatment.

Objective

The objective of this project was to develop a hybrid skin targeting system encapsulating FK506 based on nicotinamide (NIC) and chitosan nanoparticles (CS–NPs), ie, FK506–NIC–CS–NPs, which took advantages of both of NIC and CS–NPs to obtain the synergetic effects of percutaneous delivery and treatment efficacy enhancement along with dose reduction.

Methods

The formulation of FK506–NIC–CS–NPs was optimized and characterized. In vitro and in vivo skin permeation studies were performed. AD–like skin lesions were constructed with BALB/c mice by 1–chloro–2, 4–dinitrobenzene (DNCB)–induced, and FK506–NIC–CS–NPs containing different dose of FK506 were topically administered to treat AD–like skin lesions in comparison with Protopic.

Results

NIC was found to significantly increase the FK506 EE to 92.2% by CS–NPs. In comparison with commercial FK506 ointment (Protopic), in vitro and in vivo skin permeation studies demonstrated that NIC–CS–NPs system significantly enhanced FK506 permeation through and into the skin, and deposited more FK506 into the skin. The treatment efficacy on clinical symptoms, histological analysis, and molecular biology of the AD–mice demonstrated that NIC–CS–NPs with ~1/3 dose of FK506 of Protopic was superior to that of Protopic, and NIC–CS–NPs vehicle exhibited the adjuvant therapy and moderate anti–AD effects.

Conclusion

The system of NIC–CS–NPs enhances the permeability of FK506, plays an adjuvant role in anti-AD, reduces the dose of FK506 in treating AD, and is therefore a promising nanoscale system of FK506 for the effective treatment of AD.

Quality assessment of atopic dermatitis clinical practice guidelines in ≤ 18 years

Atopic dermatitis (AD) is a chronic inflammatory skin disease that affects the patients' quality of life greatly often from a very young age. Its worldwide incidence in children and adults varies, but it is usually among the first ten causes of dermatological consultation worldwide. There is a wide variety of treatment options for this condition including topical and systemic regimes. The decision to choose a treatment option in dermatological diseases is greatly influenced by the personal experience of each specialist, which increases variability in the selection of available therapies. Clinical practice guidelines (CPGs) not only offer recommendations supported on the available scientific evidence, but also are intended to assist in making appropriate decisions in clinical scenarios. To standardize the way in which CPGs should be developed, an instrument called AGREE II (Appraisal of Guidelines for Research and Evaluation) is used. In this study, ten clinical practice guidelines in ≤ 18 years were evaluated. Six domains (scope and purpose, stakeholder involvement, rigor of development, clarity and presentation, applicability, and editorial independence) were assessed for each guideline, by three reviewers. Most of the domains obtained high scores except in the applicability domain. It is suggested that future atopic dermatitis CPGs should emphasize in the facilitating factors and barriers that may influence the application of guideline recommendations.

Oral administration of lactobacilli isolated from Jeotgal, a salted fermented seafood, inhibits the development of 2,4-dinitrofluorobenzene-induced atopic dermatitis in mice

Certain strains of lactobacilli have been reported to exert favorable effects on atopic dermatitis (AD). Jeotgal, a traditional Korean food, is a salted fermented seafood known to harbor many lactic acid bacteria. In the present study, two novel lactobacillus strains were isolated from Jeotgal, and their anti-AD effects were investigated. Lactobacilli isolated from Jeotgal were identified, according to conjugated linoleic acid-producing activity, as Lactobacillus plantarum (JBCC105645 and JBCC105683). AD-like skin lesions were induced in BALB/c mice using dinitrofluorobenzene (DNFB). Ear swelling, histological analysis and serum immunoglobulin E (IgE) levels in mice were evaluated to investigate the anti-AD effects of lactobacilli. Cytokine production of ex vivo cluster of differentiation (CD)4⁺ T cells, and interleukin (IL)-12 production of in vitro macrophages were also evaluated to establish a putative mechanism of the action of lactobacilli. Administration of JBCC105645 or JBCC105683 suppressed ear swelling and serum IgE levels in DNFB-treated mice (P<0.05). Notably, JBCC105645 was more effective than JBCC105683 (P<0.05). Treatment with the lactobacilli also induced a significant decrease in IL-4 production with concomitant increase in interferon (IFN)-γ production in DNFB-exposed CD4⁺ T cells, and an increase in IL-12 production in macrophages (P<0.05). Taken together, the lactobacilli isolated from Jeotgal may suppress the development of AD-like skin inflammation in mice by modulating IL-4 and IFN-γ production in CD4⁺ T cells, presumably via enhancing IL-12 production by macrophages.

Clinical Practice Guidelines for the Management of Atopic Dermatitis 2016

Atopic dermatitis (AD) is a disease characterized by relapsing eczema with pruritus as a primary lesion. Most patients have an atopic predisposition. The definitive diagnosis of AD requires the presence of all three features: (i) pruritus; (ii) typical morphology and distribution of the eczema; and (iii) chronic and chronically relapsing course. The current strategies to treat AD in Japan from the perspective of evidence-based medicine consist of three primary measures: (i) the use of topical corticosteroids and tacrolimus ointment as the main treatment for the inflammation; (ii) topical application of emollients to treat the cutaneous barrier dysfunction; and (iii) avoidance of apparent exacerbating factors, psychological counseling and advice about daily life. The guidelines present recommendations to review clinical research articles, evaluate the balance between the advantages and disadvantages of medical activities, and optimize medical activity-related patient outcomes with respect to several important points requiring decision-making in clinical practice.

Differences in therapeutic effects of topically applied corticosteroid and tacrolimus on atopic dermatitis-like symptoms in NC/Nga mice

BACKGROUND

Topical corticosteroid and calcineurin inhibitor have similar therapeutic benefits in atopic dermatitis (AD), but the differences in therapeutic mechanisms of action of these agents against AD symptoms are not fully understood.

OBJECTIVE

This study was performed to examine the different effects of topical betamethasone valerate (BMV), clobetasol propionate (CBP), and tacrolimus (TAC) on itch-related behavior and dermatitis in NC/Nga mice with AD-like symptoms.

METHODS

AD-like dermatitis was induced in the dorsal skin of NC/Nga mice by repeated topical application of Dermatophagoides farinae body (Dfb) ointment twice weekly for three weeks. Mice with dermatitis scores over 5 were divided into five groups with equal dermatitis scores and treated with BMV, CBP, TAC, or Vaseline (Vas) once daily for two consecutive days, or were not treated (NT). Scratching behavior was analyzed using a SCLABA^®-Real system. Transepidermal water loss (TEWL) before and after treatment was measured using a Tewameter^® TM210. Skin collected from each group was analyzed histologically.

RESULTS

After the second treatment, dermatitis showed significantly greater improvement in the CBP and TAC-treated groups than in the Vas-treated and NT groups. The numbers of scratching bouts were significantly lower in CBP and TAC-treated mice than in Vas-treated mice. TEWL was significantly lower in TAC-, but not in CBP-, treated mice than in Vas-treated mice. Immunohistochemical examination showed that BMV, CBP and TAC did not reduce the increased densities of epidermal protein gene product 9.5- and substance P-immunoreactive fibers. The numbers of dermal CD4-immunoreactive T cells were significantly lower in BMV and CBP-treated mice than in Vas-treated and NT mice. The numbers of dermal eosinophils were significantly lower in BMV, CBP and TAC-treated mice than in Vas-treated and NT mice, with CBP showing the strongest effect. CBP significantly reduced epidermal thickness compared with Vas and NT. There were no significant differences in the numbers of interleukin-31-immunoreactive cells and mast cells, or in expression of epidermal thymic stromal lymphopoietin among all five groups.

CONCLUSION

The therapeutic potency of TAC against AD-like symptoms, including pruritus, is equal to that of the corticosteroid CBP. Epidermal innervation of sensory nerves itself might not be related to the therapeutic effects of topical tacrolimus and corticosteroids in its early phase.

A programme of research to set priorities and reduce uncertainties for the prevention and treatment of skin disease

Background

Skin diseases are very common and can have a large impact on the quality of life of patients and caregivers. This programme addressed four diseases: (1) eczema, (2) vitiligo, (3) squamous cell skin cancer (SCC) and (4) pyoderma gangrenosum (PG).

Objective

To set priorities and reduce uncertainties for the treatment and prevention of skin disease in our four chosen diseases.

Design

Mixed methods including eight systematic reviews, three prioritisation exercises, two pilot randomised controlled trials (RCTs), three feasibility studies, two core outcome initiatives, four funding proposals for national RCTs and one completed national RCT.

Setting

Secondary care, primary care and the general population.

Participants

Patients (and their caregivers) with eczema, vitiligo, SCC and PG, plus health-care professionals with an interest in skin disease.

Interventions

Our three intervention studies included (1) barrier enhancement using emollients from birth to prevent eczema (pilot RCT); (2) handheld narrowband ultraviolet light B therapy for treating vitiligo (pilot RCT); and (3) oral ciclosporin (Neoral®, Novartis Pharmaceuticals) compared with oral prednisolone for managing PG (pragmatic national RCT).

Results

Systematic reviews included two overarching systematic reviews of RCTs of treatments for eczema and vitiligo, an umbrella review of systematic reviews of interventions for the prevention of eczema, two reviews of treatments for SCC (one included RCTs and the second included observational studies), and three reviews of outcome measures and outcome reporting. Three prioritisation partnership exercises identified 26 priority areas for future research in eczema, vitiligo and SCC. Two international consensus initiatives identified four core domains for future eczema trials and seven core domains for vitiligo trials. Two pilot RCTs and three feasibility studies critically informed development of four trial proposals for external funding, three of which are now funded and one is pending consideration by funders. Our pragmatic RCT tested the two commonly used systemic treatments for PG (prednisolone vs. ciclosporin) and found no difference in their clinical effectiveness or cost-effectiveness. Both drugs showed limited benefit. Only half of the participants’ ulcers had healed by 6 months. For those with healed ulcers, recurrence was common (30%). Different side effect profiles were noted for each drug, which can inform clinical decisions on an individual patient basis. Three researchers were trained to PhD level and a dermatology patient panel was established to ensure patient involvement in all aspects of the programme.

Conclusions

Findings from this programme of work have already informed clinical guidelines and patient information resources. Feasibility studies have ensured that large national pragmatic trials will now be conducted on important areas of treatment uncertainty that address the needs of patients and the NHS. There is scope for considerable improvement in terms of trial design, conduct and reporting for RCTs of skin disease, which can be improved through wider collaboration, registration of trial protocols and complete reporting and international consensus over core outcome sets. Three national trials have now been funded as a result of this work. Two international initiatives to establish how best to measure the core outcome domains for eczema and vitiligo are ongoing.

Trial registration

Current Controlled Trials Barrier Enhancement for Eczema Prevention (BEEP) (ISRCTN84854178 and NCT01142999), Study of Treatments fOr Pyoderma GAngrenosum Patients (STOP GAP) (ISRCTN35898459) and Hand Held NB-UVB for Early or Focal Vitiligo at Home (HI-Light Pilot Trial) (NCT01478945).

Funding

This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full inProgramme Grants for Applied Research; Vol. 4, No. 18. See the NIHR Journals Library website for further project information.

Systematic review and meta-analysis of randomized clinical trials (RCTs) comparing topical calcineurin inhibitors with topical corticosteroids for atopic dermatitis: A 15-year experience

BACKGROUND

Calcineurin inhibitors are alternatives to corticosteroid for treatment of atopic dermatitis.

OBJECTIVES

We sought to compare the beneficial effects and adverse events associated with these therapies in treating patients with atopic dermatitis.

METHODS

Four databases were searched for randomized clinical trials comparing topical calcineurin inhibitors versus corticosteroids in children and adults. Methodological quality was evaluated to assess bias risk. Clinical outcome and costs were compared.

RESULTS

Twelve independent randomized clinical trials comparing calcineurin inhibitors (n = 3492) versus corticosteroids (n = 3462) were identified. Calcineurin inhibitors and corticosteroids had similar rates of improvement of dermatitis (81% vs 71%; risk ratio [RR] 1.18; 95% confidence interval [CI] 1.04-1.34; P = .01) and treatment success (72% vs 68%; RR 1.15; 95% CI 1.00-1.31; P = .04). Calcineurin inhibitors were associated with higher costs and had more adverse events (74% vs 64%; RR 1.28; 95% CI 1.05-1.58; P = .02) including a higher rate of skin burning (30% vs 9%; RR 3.27; 95% CI 2.48-4.31; P < .00001) and pruritus (12% vs 8%; RR 1.49; 95% CI 1.24-1.79; P < .00001). There were no differences in atrophy, skin infections, or adverse events that were serious or required discontinuation of therapy.

LIMITATIONS

Only a small number of trials reported costs.

CONCLUSION

Calcineurin inhibitors and corticosteroids have similar efficacy. Calcineurin inhibitors are associated with higher costs and have more adverse events, such as skin burning and pruritus. These results provide level-1a support for the use of corticosteroids as the therapy of choice for atopic dermatitis.

Systematic review on the efficacy, safety, and cost-effectiveness of topical calcineurin inhibitors in atopic dermatitis

BACKGROUND

Topical calcineurin inhibitors (TCIs) are widely used as an alternative to topical corticosteroids (TCSs) in treating of atopic dermatitis, but their risk versus benefit compared with TCSs remains unclear.

OBJECTIVE

We performed a systematic review of the efficacy, safety, and cost-effectiveness of TCI compared with TCS and emollients.

METHODS

Published meta-analysis, systematic reviews, and individual studies from January 2005 to January 2015 on the comparative efficacy, safety, and cost-effectiveness of TCI against emollients and TCS were included.

RESULTS

Tacrolimus is comparable to TCS in efficacy, safety profile, and cost-effectiveness. Pimecrolimus has a similar safety profile compared with TCS, emollients, and tacrolimus. It is superior to emollients but inferior to TCS and tacrolimus in efficacy and cost-effectiveness. The association of tacrolimus with malignancy remains uncertain.

CONCLUSIONS

Tacrolimus is an efficacious and cost-effective alternative to TCS, but its benefits need to be weighed against its still uncertain risk for malignancy. Pimecrolimus is appropriate for mild atopic dermatitis when TCS or tacrolimus is unsuitable.

What is the discrepancy between drug permeation into/across intact and diseased skins? Atopic dermatitis as a model

The discrepancy in drug absorption between healthy and diseased skins is an issue that needs to be elucidated. The present study attempted to explore the percutaneous absorption of drugs via lesional skin by using atopic dermatitis (AD) as a model. Tape-stripping and ovalbumin (OVA) sensitization induced AD-like skin. The lesions were evaluated by physiological parameters, histology, cytokines, and differentiation proteins. The permeants of tacrolimus, 8-methoxypsoralen, methotrexate, and dextran were used to examine in vitro and in vivo cutaneous permeation. Transepidermal water loss (TEWL) increased from 5.2 to 27.4 g/m(2)/h by OVA treatment. AD-like lesions were characterized by hyperplasia, skin redness, desquamation, and infiltration of inflammatory cells. Repeated OVA challenge produced a T-helper 2 (Th2) hypersensitivity accompanied by downregulation of filaggrin, involucrin, and integrin β. Tacrolimus, the most lipophilic permeant, revealed an increase of cutaneous deposition by 2.7-fold in AD-like skin compared to intact skin. The transdermal flux of methotrexate and dextran, the hydrophilic permeants, across AD-like skin increased about 18 times compared to the control skin. Surprisingly, AD-like skin showed less skin deposition of 8-methoxypsoralen than intact skin. This may be because the deficient lipids in the atopic-affected stratum corneum (SC) diminished drug partitioning into the superficial skin layer. The fluorescence and confocal microscopic images demonstrated a broad and deep passage of small-molecular and macromolecular dyes into AD-like skin. The results obtained from this report were advantageous for showing how the lesional skin influenced percutaneous absorption.

Phagocytosis-dependent activation of a TLR9-BTK-calcineurin-NFAT pathway co-ordinates innate immunity to Aspergillus fumigatus

Transplant recipients on calcineurin inhibitors are at high risk of invasive fungal infection. Understanding how calcineurin inhibitors impair fungal immunity is a key priority for defining risk of infection. Here, we show that the calcineurin inhibitor tacrolimus impairs clearance of the major mould pathogen Aspergillus fumigatus from the airway, by inhibiting macrophage inflammatory responses. This leads to defective early neutrophil recruitment and fungal clearance. We confirm these findings in zebrafish, showing an evolutionarily conserved role for calcineurin signalling in neutrophil recruitment during inflammation. We find that calcineurin–NFAT activation is phagocytosis dependent and collaborates with NF-κB for TNF-α production. For yeast zymosan particles, activation of macrophage calcineurin–NFAT occurs via the phagocytic Dectin-1–spleen tyrosine kinase pathway, but for A. fumigatus, activation occurs via a phagosomal TLR9-dependent and Bruton's tyrosine kinase-dependent signalling pathway that is independent of MyD88. We confirm the collaboration between NFAT and NF-κB for TNF-α production in primary alveolar macrophages. These observations identify inhibition of a newly discovered macrophage TLR9–BTK–calcineurin–NFAT signalling pathway as a key immune defect that leads to organ transplant-related invasive aspergillosis.

Topical tacrolimus for atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) (or atopic eczema) is a chronic inflammatory skin condition that affects children and adults and has an important impact on quality of life. Topical corticosteroids (TCS) are the first-line therapy for this condition; however, they can be associated with significant adverse effects when used chronically. Tacrolimus ointment (in its 2 manufactured strengths of 0.1% and 0.03%) might be an alternative treatment. Tacrolimus, together with pimecrolimus, are drugs called topical calcineurin inhibitors (TCIs).

OBJECTIVES

To assess the efficacy and safety of topical tacrolimus for moderate and severe atopic dermatitis compared with other active treatments.

SEARCH METHODS

We searched the following databases up to 3 June 2015: the Cochrane Skin Group Specialised Register, CENTRAL in the Cochrane Library (Issue 5, 2015), MEDLINE (from 1946), EMBASE (from 1974), LILACS (from 1982), and the Global Resource of Eczema Trials (GREAT database). We searched six trials registers and checked the bibliographies of included studies for further references to relevant trials. We contacted specialists in the field for unpublished data.A separate search for adverse effects of topical tacrolimus was undertaken in MEDLINE and EMBASE on 30 July 2013. We also scrutinised the U.S. Food and Drug Administration (FDA) websites for adverse effects information.

SELECTION CRITERIA

All randomised controlled trials (RCTs) of participants with moderate to severe atopic dermatitis (both children and adults) using topical tacrolimus at any dose, course duration, and follow-up time compared with other active treatments.

DATA COLLECTION AND ANALYSIS

Two authors independently screened and examined the full text of selected studies for compliance with eligibility criteria, risk of bias, and data extraction. Our three prespecified primary outcomes were physician's assessment, participant's self-assessment of improvement, and adverse effects. Our secondary outcomes included assessment of improvement of the disease by validated or objective measures, such as SCORAD (SCORing Atopic Dermatitis), the EASI (Eczema Area and Severity Index), and BSA (Body Surface Area) scores.

MAIN RESULTS

We included 20 studies, with 5885 participants. The variability of drug doses, outcomes, and follow-up periods made it difficult to carry out meta-analyses.A single trial showed that tacrolimus 0.1% was better than low-potency TCS by the physician's assessment (risk ratio (RR) 3.09, 95% confidence interval (CI) 2.14 to 4.45, 1 study, n = 371, moderate-quality evidence). It was also marginally better than low-potency TCS on face and neck areas and moderate-potency TCS on the trunk and extremities by the physician's assessment (RR 1.32, 95% CI 1.17 to 1.49, 1 study, n = 972, moderate level of evidence) and for some of the secondary outcomes. Compared with pimecrolimus 1%, people treated with tacrolimus were almost twice as likely to improve by the physician's assessment (RR 1.80, 95% CI 1.34 to 2.42, 2 studies, n = 506, moderate quality of evidence). Compared with the lower concentration of 0.03%, the tacrolimus 0.1% formulation reduced the risk of not having an improvement by 18% as evaluated by the physician's assessment (RR 0.82, 95% CI 0.72 to 0.92, 6 studies, n = 1640, high-quality evidence). Tacrolimus 0.1% compared with moderate-to-potent TCS showed no difference by the physician's assessment, and 2 secondary outcomes (1 study, 377 participants) and a marginal benefit favouring tacrolimus 0.1% was found by the participant's assessment (RR 1.21, 95% CI 1.13 to 1.29, 1 study, n = 974, low quality of evidence) and SCORAD.Based on data from 2 trials, tacrolimus 0.03% was superior to mild TCS for the physician's assessment (RR 2.58, 95% CI 1.96 to 3.38, 2 studies, n = 790, moderate-quality evidence) and the participant's self-assessment (RR 1.64, 95% CI 1.41 to 1.90, 1 study, n = 416, moderate quality of evidence). One trial showed moderate benefit of tacrolimus 0.03% compared with pimecrolimus 1% on the physician's assessment (RR 1.42, 95% CI 1.02 to 1.98, 1 study, n = 139, low-quality evidence), but the effects were equivocal when evaluating BSA. In the comparison of tacrolimus 0.03% with moderate-to-potent corticosteroids, no difference was found in most of the outcomes measured (including physician's and participant's assessment and also for the secondary outcomes), but in two studies, a marginal benefit favouring the corticosteroid group was found for the EASI and BSA scores.Burning was more frequent in those using calcineurin inhibitors than those using corticosteroid tacrolimus 0.03% (RR 2.48, 95% CI 1.96 to 3.14, 5 studies, 1883 participants, high-quality evidence), but no difference was found for skin infections. Symptoms observed were mild and transient. The comparison between the two calcineurin inhibitors (pimecrolimus and tacrolimus) showed the same overall incidence of adverse events, but with a small difference in the frequency of local effects.Serious adverse events were rare; occurred in both the tacrolimus and corticosteroid groups; and in most cases, were considered to be unrelated to the treatment. No cases of lymphoma were noted in the included studies nor in the non-comparative studies. Cases were only noted in spontaneous reports, cohorts, and case-control studies. Systemic absorption was rarely detectable, only in low levels, and this decreased with time. Exception is made for diseases with severe barrier defects, such as Netherton's syndrome, lamellar ichthyosis, and a few others, with case reports of a higher absorption. We evaluated clinical trials; case reports; and in vivo, in vitro, and animal studies; and didn't find any evidence that topical tacrolimus could cause skin atrophy.

AUTHORS' CONCLUSIONS

Tacrolimus 0.1% was better than low-potency corticosteroids, pimecrolimus 1%, and tacrolimus 0.03%. Results were equivocal when comparing both dose formulations to moderate-to-potent corticosteroids. Tacrolimus 0.03% was superior to mild corticosteroids and pimecrolimus. Both tacrolimus formulations seemed to be safe, and no evidence was found to support the possible increased risk of malignancies or skin atrophy with their use. The reliability and strength of the evidence was limited by the lack of data; thus, findings of this review should be interpreted with caution. We did not evaluate costs.

The effect of tacrolimus compared with betamethasone valerate on the skin barrier in volunteers with quiescent atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is an inflammatory skin disease arising as a result of immune system and skin barrier defects. Topical corticosteroids are safe and effective treatments for AD, when used in short courses. Prolonged use is associated with skin barrier damage. Topical calcineurin inhibitors are alternative immune-modulating treatments for AD purported to have no negative effects on the skin barrier.

OBJECTIVES

To compare the effects of betamethasone valerate 0·1% cream (BMVc) and tacrolimus 0·1% ointment (TACo) on the skin barrier.

METHODS

Twenty volunteers with quiescent AD (no active signs for 6 months) participated in a randomized observer-blind study, wherein BMVc was applied to one forearm and TACo to the other, twice daily for 4 weeks. The biophysical/biological properties of the stratum corneum were assessed before and after treatment. Nine volunteers with active disease and 10 with healthy skin were assessed at untreated sites.

RESULTS

BMVc significantly reduced skin barrier function, integrity and cohesion, and the levels of pyrrolidone carboxylic acid (PCA) and urocanic acid (UCA) towards the subclinical barrier defect observed in patients with AD (nonlesional sites). TACo preserved skin barrier function, integrity, cohesion and PCA and UCA levels, while significantly increasing skin hydration to levels comparable with healthy skin. Both treatments reduced skin surface pH and trypsin-like protease activity, with TACo doing so to a significantly greater degree.

CONCLUSION

In quiescent AD, 4 weeks of BMVc treatment adversely affected the biophysical properties of the skin and reduced the levels of natural moisturizing factor, whereas TACo improved the condition of the skin barrier.

Validation of the global resource of eczema trials (GREAT database)

Background

Eczema (syn. Atopic Eczema or Atopic Dermatitis) is a chronic, relapsing, itchy skin condition which probably results from a combination of genetic and environmental factors. The Global Resource of EczemA Trials (GREAT) is a collection of records of randomised controlled trials (RCTs) for eczema treatment produced from a highly sensitive search of six reference databases. We sought to assess the sensitivity of the GREAT database as a tool to save future researchers repeating extensive bibliographic searches.

Methods

All Cochrane systematic review on treatments for eczema and five non-Cochrane systematic reviews on eczema were identified as a reference set to assess the utility of the GREAT database in identifying randomised controlled trials (RCTs). RCTs included in the systematic reviews were checked for inclusion in the GREAT database by two independent authors. A third author resolved any disagreements.

Results

Five Cochrane and six non-Cochrane systematic reviews containing a total of 105 RCTs of eczema treatments were included. Of these, 95 fitted the inclusion criteria for the GREAT database and 88 were published from 2000 onwards. Of the 88 eligible studies, 92% were found in the GREAT database. Seven trials were not included in the GREAT database - two of these were reported within a review paper and one as an abstract with no trial results.

Conclusions

The sensitivity of the GREAT database for trials from 2000 onwards was high (75/88 trials, 94%). Sensitivity for the period prior to 2000 was less sensitive, due to differences in how the trials were identified prior to this time.

‘Dual’ filtering for new records has recently become part of the GREAT database methodology and should further improve the sensitivity of the database in time. The GREAT database can be considered as a primary source for future systematic reviews including randomised controlled trials of eczema treatments, but searches should be supplemented by checking reference lists for eligible trials, searching trial registries and contacting pharmaceutical companies for unpublished studies.

Functional interpretation of metabolomics data as a new method for predicting long-term side effects: treatment of atopic dermatitis in infants

Topical steroids are used for the treatment of primary atopic dermatitis (AD); however, their associated risk of serious complications is great due to the presence of vulnerable lesions in young children with AD. Topical calcineurin inhibitors (TCIs) are steroid-free, anti-inflammatory agents used for topical AD therapy. However, their use is prohibited in infants <2 years of age because of their carcinogenic potential. We conducted a randomized, double-blind trial to evaluate the efficacy of TCIs as a secondary AD treatment for children <2 years of age by comparing 1% pimecrolimus cream with 0.05% desonide cream. We performed urinary metabolomics to predict long-term side effects. The 1% pimecrolimus cream displayed similar efficacy and exceptional safety compared with the 0.05% desonide cream. Metabolomics-based long-term toxicity tests effectively predicted long-term side effects using short-term clinical models. This applicable method for the functional interpretation of metabolomics data sets the foundation for future studies involving the prediction of the toxicity and systemic reactions caused by long-term medication administration.

Atopic dermatitis: an evidence-based treatment update

BACKGROUND

Atopic dermatitis (AD) is a common inflammatory disorder of skin with significant comorbidities. AD care often requires a combination of treatment approaches, including emollients, topical steroids, systemic immunosuppressants and/or phototherapy.

PURPOSE

Our purpose was to review recent randomized controlled trials (RCT) and systematic reviews of AD treatments.

METHODS

A MEDLINE search was performed focusing on RCTs of AD treatments, with a sample size ≥ 15, and systematic reviews published from 2011 to 2013, limited to the English language. A total of 53 manuscripts met the inclusion/exclusion criteria, including 44 RCTs and nine systematic reviews.

RESULTS

Investigator-initiated RCTs support the use of the systemic agents cyclosporine, methotrexate, azathioprine and mycophenolate mofetil. In one RCT, petrolatum was found to be as effective as creams containing ceramides or glycyrrhetinic acid. Additional therapeutic approaches supported by RCTs include balneotherapy, oral and/or topical probiotics, nutritional interventions, vitamin D with or without vitamin E supplementation, as well as several new topical and complementary medicines.

CONCLUSIONS

Advances have been made with respect to AD treatment in the past few years through the use of well designed RCTs and comparative efficacy studies. However, more well designed RCTs and investigator-initiated studies are needed in order to improve the care of AD patients.

Topical calcineurin inhibitors for atopic dermatitis: review and treatment recommendations

Atopic dermatitis (AD) is an inflammatory skin disease commonly affecting children and managed by pediatricians, primary care physicians, allergists, and dermatologists alike. For many years, the only available topical pharmacological treatment was topical corticosteroids. This changed in 2000-2001, when topical formulations of two calcineurin inhibitors (tacrolimus and pimecrolimus) were approved for short-term or chronic intermittent treatment of AD in patients ≥ 2 years of age, in whom other treatments have been ineffective or contraindicated. These topical calcineurin inhibitors (TCIs) quickly became a popular treatment option due at least in part to concerns over adverse events associated with prolonged topical corticosteroid use, especially in children. However, based on theoretical concerns about a possible risk of lymphoma associated with TCI use, a Boxed Warning was placed on both products in 2006. Since then, despite an extensive body of evidence, no causal relationship has been demonstrated between TCI use and an increased risk of lymphoma; however, the US FDA has concluded that a link cannot be ruled out. In fact, based on post-marketing surveillance of spontaneous, literature, and solicited reports, we report here that the lymphoma incidence in the topical pimecrolimus-exposed population is up to approximately 54-fold less than that seen in the general US population. This review summarizes the mechanism of action of TCIs, the factors that prompted the Boxed Warning, and recent TCI safety and efficacy data. Based on these data, both topical corticosteroids and TCIs should have defined roles in AD management, with TCIs favored for sensitive skin areas (e.g., face) and instances where topical corticosteroids have proven ineffective, thereby minimizing the risk of adverse effects with both drug classes.

Targeting tacrolimus to deeper layers of skin with improved safety for treatment of atopic dermatitis-Part II: in vivo assessment of dermatopharmacokinetics, biodistribution and efficacy

The objective of present investigation was to study in vivo behavior of tacrolimus-loaded lipid-nanoparticles (T-LN) to understand its targeting potential for treatment of atopic-dermatitis-(AD). T-LN have shown significantly improved drug penetration to deeper epidermal and dermal skin-layers than commercial ointment-Protopic(®) and effectively reached target dendritic-immune-cells, responsible for immunopathogenesis of AD. Due to enhanced penetrability of T-LN, it became necessary to evaluate the toxicity of the nanocarrier and the drug at non-target tissues. This paper evaluates dermatopharmacokinetics (DPK), biodistribution, efficacy and safety of T-LN in comparison to Protopic(®) as reference. In vivo DPK in guinea pigs showed 3.02-fold higher bioavailability while γ-scintigraphy in albino-rats demonstrated 1.5-fold rapid penetration of radioactivity in skin for T-LN. Biodistribution in albino-rats revealed restricted localization at the target-skin-area with no general spreading to other body organs suggesting targeting potential of T-LN. In vivo efficacy studies in BALB/c mice showed highly efficient suppression of inflammatory AD-like skin-lesions with T-LN than reference and placebo. Dermal toxicity-studies revealed keratosis and collagenous mass-infiltration with repeated application of reference however interestingly, T-LN treated group showed no evident toxicity demonstrating significantly improved safety. Thus T-LN offered improved penetration to the target site without any toxic-effects and would represent an efficient and commercially viable alternative for AD treatment.

Streptavidin suppresses T cell activation and inhibits IL-2 production and CD25 expression

Streptavidin is widely used as a detection tool in biology research because of its high affinity and specificity binding to biotin. Biotin-streptavidin system has also been explored for detection of infection and tumor in clinical medicine. Here, we show immunosuppressive property of streptavidin on T cell activation and proliferation. Upon CD3 and CD28 stimulation, CD4(+) T cells produce interleukin 2 (IL-2) and express IL-2 receptor α chain (CD25). Addition of streptavidin in T cell culture suppressed IL-2 synthesis and CD25 expression with no cytotoxicity. The immunosuppressive effect of streptavidin was reversed by excessive biotin. Conjugated to a single chain anti-CD7 variable fragment (scFvCD7), streptavidin was directly delivered to T cells and showed substantially more profound suppressive effect on T cell activation. These results suggest that streptavidin could potentially be used as a novel immunomodulator.