The ascomycin macrolactam pimecrolimus (Elidel, SDZ ASM 981) is a potent inhibitor of mediator release from human dermal mast cells and peripheral blood basophils

Pimecrolimus protects neuron-like SH-SY5Y cells against anti-inflammatory and anti-oxidant effects of both microglial secretome and hydrogen peroxide

Calcineurin inhibitors have been found to exhibit a preventive role against neuroinflammation, which represents a crucial underlying mechanism in neurodegenerative diseases (ND). Additionally, they possess suppressive effects on the activation of apoptotic pathways, which constitute another mechanism underlying such diseases. Given that pimecrolimus, a calcineurin inhibitor, impedes the synthesis of pro-inflammatory cytokines, such as interleukin (IL)-2, IL-4, and IL-10, and influences apoptotic processes, it is noteworthy to test its potential neuroprotective properties. Thus, the objective of this investigation was to assess the potential protective effects of pimecrolimus against the degenerative consequences of both microglial secretomes and hydrogen peroxide (H2O2), an oxidant agent. The survival rates of HMC3 microglia cells, neuron-like differentiated SH-SY5Y (d-SH-SY5Y) cells, and their co-culture were determined using the 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) method. Furthermore, the levels of pro-inflammatory cytokines IL-1β and IL-6, and anti-inflammatory cytokine IL-10 were measured using ELISA kits, besides total antioxidant and oxidant capacities in conditioned media of cells. Additionally, the effect of pimecrolimus on neurite length in these cell groups was evaluated through morphological observations. This study revealed, for the first time, that pimecrolimus exerts preventive effects on neurodegenerative processes by virtue of its anti-inflammatory and -antioxidant activities. It holds promise as a potential treatment option for ND.

Selected recent advances in understanding the role of human mast cells in health and disease

Mast cells are highly granular tissue-resident cells and key drivers of inflammation, particularly in allergies as well as in other inflammatory diseases. Most mast cell research was initially conducted in rodents but has increasingly shifted to the human system, with the advancement of research technologies and methodologies. Today we can analyze primary human cells including rare subpopulations, we can produce and maintain mast cells isolated from human tissues, and there are several human mast cell lines. These tools have substantially facilitated our understanding of their role and function in different organs in both health and disease. We can now define more clearly where human mast cells originate from, how they develop, which mediators they store, produce de novo, and release, how they are activated and by which receptors, and which neighbouring cells they interact with and by which mechanisms. Considerable progress has also been made regarding the potential contribution of mast cells to disease, which, in turn, has led to the development of novel approaches for preventing key pathogenic effects of mast cells, heralding the era of mast cell-targeted therapeutics. In this review, we present and discuss a selection of some of the most significant advancements and remaining gaps in our understanding of human mast cells during the last 25 years, with a focus on clinical relevance.

Practical algorithm to inform clinical decision-making in the topical treatment of atopic dermatitis

Atopic dermatitis is a chronic relapsing, inflammatory skin disorder associated with skin barrier dysfunction, the prevalence of which has increased dramatically in developing countries. In this article, we propose a treatment algorithm for patients with mild-to-moderate and severe atopic dermatitis flares in daily clinical practice. An international panel of 15 dermatology and allergy experts from eight countries was formed to develop a practical algorithm for the treatment of patients with atopic dermatitis, with a particular focus on topical therapies. In cases of mild-to-moderate atopic dermatitis involving sensitive skin areas, the topical calcineurin inhibitor pimecrolimus should be applied twice daily at the first signs of atopic dermatitis. For other body locations, patients should apply a topical calcineurin inhibitor, either pimecrolimus or tacrolimus, twice daily at the first signs of atopic dermatitis, such as pruritus, or twice weekly in previously affected skin areas. Emollients should be used regularly. Patients experiencing acute atopic dermatitis flares in sensitive skin areas should apply a topical corticosteroid twice daily or alternate once-daily topical corticosteroid/topical calcineurin inhibitor until symptoms improve. Following improvement, topical corticosteroid therapy should be discontinued and patients switched to a topical calcineurin inhibitor. Maintenance therapy should include the use of pimecrolimus once daily for sensitive areas and tacrolimus for other body locations. This treatment algorithm can help guide clinical decision-making in the treatment of atopic dermatitis.

Aloe-emodin, a naturally occurring anthraquinone, is a highly potent mast cell stabilizer through activating mitochondrial calcium uniporter

Mast cells play a fundamental role in immune system. Upon stimulation, they are activated via IgE dependent or independent pathway and then release granules which contain plenty of preformed constituents. Mast cell stabilizers are commonly used clinically for inhibiting the degranulation of mast cells. In the current study, we firstly identified aloe-emodin, a naturally occurring anthraquinone, was a prominent mast cell stabilizer. It could strikingly dampen IgE/FcεRI- and MAS-related G protein coupled receptor (Mrgpr)-mediated mast cell degranulation in vitro and in vivo. Mechanism study indicated that aloe-emodin rapidly and reversibly decreased cytosolic Ca²⁺ (Ca²⁺_[c]) concentration through enhancing the mitochondrial Ca²⁺ (Ca²⁺_[m]) uptake. After genetically silencing or pharmacologic inhibiting mitochondrial calcium uniporter (MCU), the effects of aloe-emodin on the Ca²⁺_[c] level and mast cell degranulation were significantly weakened. In contrast to six clinical drugs with mast cell stabilizing properties (amlexanox, tranilast, ketotifen, cromolyn disodium salt, dexamethasone and pimecrolimus), aloe-emodin showed an impressive and potent inhibitory action on the mast cell degranulation. Collectively, aloe-emodin is a highly potent mast cell stabilizer. By directly activating MCU, it decreases Ca²⁺_[c] level to suppress mast cell degranulation. Our study may provide a promising candidate for the treatment of mast cell activation-related diseases.

Bioprocess and genetic engineering aspects of ascomycin production: a review

BACKGROUND

Ascomycin is a highly valuable multifunctional drug which exhibits numerous biological properties. Being an immunosuppressant, it is known to prevent graft rejection in humans and has potential to treat varying skin ailments. Its derivatives represent a novel class of anti-inflammatory macrolactams. But the biosynthetic machinery of ascomycin is still unclear. Due to the structural complexity, there occurs difficulty in its chemical synthesis; therefore, microbial production has been preferred by using Streptomyces hygroscopicus subsp. ascomyceticus. Through several genetic manipulation and mutagenesis techniques, the yield can be increased by several folds without any difficulties. Genetic engineering has played a significant role in understanding the biosynthetic pathway of ascomycin.

SHORT CONCLUSION

Recently, many efforts have been made to utilize the therapeutic effects of ascomycin and its derivatives. This article covers concepts related to the production kinetics of ascomycin including an update of the ongoing yield improvement techniques as well as screening method of novel strains for ascomycin production.

Targeting of Basophil and Mast Cell Pro-Allergic Reactivity Using Functionalised Gold Nanoparticles

Calcineurin inhibitors potentially prevent pro-allergic mediator release from basophils and mast cells but are rarely used systemically due to ubiquitous expressions of target signaling proteins. However, specific targeting of allergic effector cells with these inhibitors could circumvent unwanted side effects. We recently demonstrated the biocompatibility of gold nanoparticles (AuNPs) as a platform for non-toxic delivery of signaling inhibitors due to unique physicochemical properties of these nanomaterials. Since AuNPs can be conjugated with both anti-allergic drugs and antibodies or other proteins that specifically recognize basophils and mast cells, our aims were to assess specific targeting of allergic effector cell function using AuNPs conjugated with the calcineurin inhibitor ascomycin. Purified human basophils and LAD2 human mast cells were used for investigations with AuNPs conjugated either to CD203c antibodies or containing stem cell factor (SCF), respectively, which were amine-coupled to acidic groups of reduced glutathione (GSH). GSH was also used as a spacer for immobilization of ascomycin on the gold surface. AuNPs conjugated with anti-CD203c and ascomycin strikingly blocked IgE-dependent degranulation of both purified basophils and those present in mixed leukocyte preparations, suggesting specific targeting of these cells. In contrast, LAD2 mast cell responses were not inhibited using anti-CD203c-containing nanoconjugates but were when the conjugates contained SCF. Successful targeting of allergic effector cells using gold nanoconjugates indicates that this technology may have therapeutic potential for the treatment of allergies by specifically delivering highly effective signaling inhibitors with reduced side effects.

Scoping systematic review of treatments for eczema

Background

Eczema is a very common chronic inflammatory skin condition.

Objectives

To update the National Institute for Health Research (NIHR) Health Technology Assessment (HTA) systematic review of treatments for atopic eczema, published in 2000, and to inform health-care professionals, commissioners and patients about key treatment developments and research gaps.

Data sources

Electronic databases including MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Skin Group Specialised Register, Latin American and Caribbean Health Sciences Literature (LILACS), Allied and Complementary Medicine Database (AMED) and Cumulative Index to Nursing and Allied Health Literature (CINAHL) were searched from the end of 2000 to 31 August 2013. Retrieved articles were used to identify further randomised controlled trials (RCTs).

Review methods

Studies were filtered according to inclusion criteria and agreed by consensus in cases of uncertainty. Abstracts were excluded and non-English-language papers were screened by international colleagues and data were extracted. Only RCTs of treatments for eczema were included, as other forms of evidence are associated with higher risks of bias. Inclusion criteria for studies included availability of data relevant to the therapeutic management of eczema; mention of randomisation; comparison of two or more treatments; and prospective data collection. Participants of all ages were included. Eczema diagnosis was determined by a clinician or according to published diagnostic criteria. The risk of bias was assessed using the Cochrane Collaboration risk-of-bias tool. We used a standardised approach to summarising the data and the assessment of risk of bias and we made a clear distinction between what the studies found and our own interpretation of study findings.

Results

Of 7198 references screened, 287 new trials were identified spanning 92 treatments. Trial reporting was generally poor (randomisation method: 2% high, 36% low, 62% unclear risk of bias; allocation concealment: 3% high, 15% low, 82% unclear risk of bias; blinding of the intervention: 15% high, 28% low, 57% unclear risk of bias). Only 22 (8%) trials were considered to be at low risk of bias for all three criteria. There was reasonable evidence of benefit for the topical medications tacrolimus, pimecrolimus and various corticosteroids (with tacrolimus superior to pimecrolimus and corticosteroids) for both treatment and flare prevention; oral ciclosporin; oral azathioprine; narrow band ultraviolet B (UVB) light; Atopiclair™ and education. There was reasonable evidence to suggest no clinically useful benefit for twice-daily compared with once-daily topical corticosteroids; corticosteroids containing antibiotics for non-infected eczema; probiotics; evening primrose and borage oil; ion-exchange water softeners; protease inhibitor SRD441 (Serentis Ltd); furfuryl palmitate in emollient; cipamfylline cream; andMycobacterium vaccaevaccine. Additional research evidence is needed for emollients, bath additives, antibacterials, specialist clothing and complementary and alternative therapies. There was no RCT evidence for topical corticosteroid dilution, impregnated bandages, soap avoidance, bathing frequency or allergy testing.

Limitations

The large scope of the review coupled with the heterogeneity of outcomes precluded formal meta-analyses. Our conclusions are still limited by a profusion of small, poorly reported studies.

Conclusions

Although the evidence base of RCTs has increased considerably since the last NIHR HTA systematic review, the field is still severely hampered by poor design and reporting problems including failure to register trials and declare primary outcomes, small sample size, short follow-up duration and poor reporting of risk of bias. Key areas for further research identified by the review include the optimum use of emollients, bathing frequency, wash products, allergy testing and antiseptic treatments. Perhaps the greatest benefit identified is the use of twice weekly anti-inflammatory treatment to maintain disease remission. More studies need to be conducted in a primary care setting where most people with eczema are seen in the UK. Future studies need to use the same core set of outcomes that capture patient symptoms, clinical signs, quality of life and the chronic nature of the disease.

Funding

The National Institute for Health Research Programme Grants for Applied Research programme.

Phenotypic variability in human skin mast cells

Mast cells (MCs) are unique constituents of the human body. While inter-individual differences may influence the ways by which MCs operate in their skin habitat, they have not been surveyed in a comprehensive manner so far. We therefore set out to quantify skin MC variability in a large cohort of subjects. Pathophysiologically relevant key features were quantified and correlated: transcripts of c-kit, FcεRIα, FcεRIβ, FcεRIγ, histidine decarboxylase, tryptase, and chymase; surface expression of c-Kit, FcεRIα; activity of tryptase, and chymase; histamine content and release triggered by FcεRI and Ca(2+) ionophore. While there was substantial variability among subjects, it strongly depended on the feature under study (coefficient of variation 33-386%). Surface expression of FcεRI was positively associated with FcεRIα mRNA content, histamine content with HDC mRNA, and chymase activity with chymase mRNA. Also, MC signature genes were co-regulated in distinct patterns. Intriguingly, histamine levels were positively linked to tryptase and chymase activity, whereas tryptase and chymase activity appeared to be uncorrelated. FcεRI triggered histamine release was highly variable and was unrelated to FcεRI expression but unexpectedly tightly correlated with histamine release elicited by Ca(2+) ionophore. This most comprehensive and systematic work of its kind provides not only detailed insights into inter-individual variability in MCs, but also uncovers unexpected patterns of co-regulation among signature attributes of the lineage. Differences in MCs among humans may well underlie clinical responses in settings of allergic reactions and complex skin disorders alike.

Pimecrolimus Is a Potent Inhibitor of Allergic Reactions to Hymenopteran Venom Extracts and Birch Pollen Allergen In Vitro

Pimecrolimus (Elidel, SDZ ASM 981) is an anti-inflammatory and immunomodulatory 33-epichloro-derivative of macrolactam ascomycin, with low potential for affecting systemic immune responses compared with other calcineurin inhibitors, cyclosporin A and tacrolimus. Despite numerous studies focused on the mechanism of pimecrolimus action on mast cells, only the single report has addressed pimecrolimus effects on other typical FcεRI-expressing cells, the basophils. Patients allergic to birch pollen (n = 20), hymenopteran venoms (n = 23) and 10 non-allergic volunteers were examined. Primary human basophils pre-treated or not with 0.5-50 μMol pimecrolimus were exposed to various concentrations of recombinant Bet v 1a allergen, bee or wasp venom extracts and anti-IgE for 20 min, and then examined for the expression of CD45, CD193, CD203c, CD63 and CD164 using flow cytometry. The externalization of basophil activation markers (CD63 and CD164) was equally inhibited through pimecrolimus in cells activated by recombinant pollen allergen, hymenopteran venom extracts and anti-IgE. Although the individual response rate was subject to strong variation, importantly, pre-treatment with pimecrolimus lowered the number of activated basophils in response to any of the stimuli in the basophils from all patients. The inhibition was concentration-dependent; approximately half of the basophils were inhibited in the presence of 2.5 mMol pimecrolimus. Pimecrolimus is a valuable new tool for the inhibition of hyper-reactive basophils in patients with pollen allergy and a history of anaphylactic reactions to bee or wasp venoms. Further research should address short-term use of pimecrolimus in vivo in a wide spectrum of allergic diseases.

Tryptase and protease-activated receptor-2 stimulate scratching behavior in a murine model of ovalbumin-induced atopic-like dermatitis

The aim of the current study was to investigate the involvement of tryptase and protease-activated receptor-2 (PAR2) in the pathogenesis of itch using a recently developed murine model of atopic dermatitis (AD) elicited by epicutaneous sensitization with ovalbumin (OVA). We also examined whether tacrolimus exerts an antipruritic effect. Epicutaneous sensitization of BALB/c mice with OVA led to a significant increase in the number of scratches. Notably, PAR2 mRNA and protein levels as well as cutaneous levels of tryptase were significantly enhanced in epicutaneously sensitized mice. Pretreatment with the protease inhibitor, leupeptin, PAR2 antibody, and tacrolimus significantly reduced the number of degranulated mast cells and tryptase content, and consequently alleviated scratching behavior. Cetirizine (10mg/kg) exerted a significant inhibitory effect on the scratching behavior of mice, but did not affect the number of degranulated mast cells and induction of tryptase. Our results collectively suggest that tryptase and PAR2 are involved in OVA allergy-induced scratching behavior.

Two Cases of Telangiectasia Macularis Eruptiva Perstans Demonstrated by Immunohistochemistry for C-Kit (CD 117)

Telangiectasia macularis eruptiva perstans (TMEP) is an uncommon form of cutaneous mastocytosis that occurs exclusively in adults. Histologically, TMEP presents with scattered mast cells lined up around the dilated capillaries and venules of the superficial vascular plexus. In some cases, the number of mast cells falls within the range observed in normal skin and therefore cannot be detected by routine histologic examination. We used immunohistochemical staining for c-kit (CD 117) for the definitive diagnosis in two patients with TMEP. One of them was successfully treated with topical application of pimecrolimus.

Macrolactam Immunomodulators (Tacrolimus and Pimecrolimus): New Horizons in the Topical Treatment of Inflammatory Skin Diseases

Tacrolimus and pimecrolimus are new macrolactam immunomodulators which were developed for the treatment of inflammatory skin diseases, mainly atopic dermatitis. In this article, we review the pharmacologic properties of the drugs, their side effects, and their clinical uses.

Topical Pimecrolimus as a New Optional Treatment in Cutaneous Sarcoidosis of Lichenoid Type

We report the case of cutaneous sarcoidosis of lichenoid type successfully treated with pimecrolimus. For the first time in the literature, we propose the use of this topical calcineurin inhibitor for the treatment of the cases refractory to common therapy regimens.

Atopic dermatitis: a practice parameter update 2012

This parameter was developed by the Joint Task Force on Practice Parameters, representing the American Academy of Allergy, Asthma & Immunology (AAAAI); the American College of Allergy, Asthma & Immunology (ACAAI); and the Joint Council of Allergy, Asthma and Immunology. The AAAAI and the ACAAI have jointly accepted responsibility for establishing "Atopic dermatitis: a practice parameter update 2012." This is a complete and comprehensive document at the current time. The medical environment is a changing environment, and not all recommendations will be appropriate for all patients. Because this document incorporated the efforts of many participants, no single individual, including those who served on the Joint Task Force, is authorized to provide an official AAAAI or ACAAI interpretation of these practice parameters. Any request for information about or an interpretation of these practice parameters by the AAAAI or ACAAI should be directed to the Executive Offices of the AAAAI, the ACAAI, and the Joint Council of Allergy, Asthma & Immunology. These parameters are not designed for use by pharmaceutical companies in drug promotion. Published practice parameters of the Joint Task Force on Practice Parameters for Allergy & Immunology are available online at http://www.jcaai.org.

Long-term cultured human skin mast cells are suitable for pharmacological studies of anti-allergic drugs due to high responsiveness to FcεRI cross-linking

Human skin mast cells proliferated in the presence of interleukin (IL)-4+SCF (expanding 18-fold in 8 weeks) and acquired profound responsiveness towards high affinity IgE receptor (FcεRI) cross-linking, liberating about 75% of their histamine. In a proof-of-concept, we found that these cells are useful for pharmacological testing. Even a subtle inhibition of degranulation can be visualized. This model might prove valuable in tests of novel anti-allergic drugs.

Topical pimecrolimus: a review of its use in the management of pediatric atopic dermatitis

Topical pimecrolimus 1% cream (Elidel) [hereafter referred to as topical pimecrolimus] is a nonsteroidal alternative in the treatment of pediatric atopic dermatitis. In vehicle-controlled, short-term, continuous-use trials in pediatric patients with mild to moderate atopic dermatitis, topical pimecrolimus was effective in treating disease symptoms. Topical pimecrolimus was effective in preventing disease flares and reducing the need for topical corticosteroids in longer term, intermittent-use trials. In addition, topical pimecrolimus was associated with improvements in the health-related quality of life (HR-QOL) of pediatric patients with atopic dermatitis and their parents. In vehicle-controlled trials, topical pimecrolimus was generally as well tolerated as vehicle. Topical pimecrolimus showed similar efficacy to topical tacrolimus 0.03% ointment (hereafter topical tacrolimus) in a short-term, continuous-use trial and the two agents had a generally similar tolerability profile. Although comparative data between topical pimecrolimus and topical corticosteroids are lacking in pediatric patients, and the long-term tolerability (beyond 1-2 years) of topical pimecrolimus is yet to be established, topical pimecrolimus is a useful agent in the management of pediatric patients with mild to moderate atopic dermatitis who do not achieve satisfactory treatment with other topical pharmacologic treatments, including topical corticosteroids.

Canadian practical guide for the treatment and management of atopic dermatitis

BACKGROUND

Atopic dermatitis is a common condition, with a lifetime prevalence of approximately 10% to 20% among the Canadian population. A clear, practical, Canadian guideline for the management of these patients has been lacking.

OBJECTIVE

To provide primary-care physicians, pediatricians and dermatologists with the first practical and comprehensive set of Canadian recommendations for the management of atopic dermatitis.

METHODS

A group of Canadian dermatologists convened to review the current issues of diagnosis, treatment and international guidelines and adapt them to the Canadian context. The reviewers used the latest clinical trial data on atopic dermatitis, complemented by clinical experience, to develop the consensus recommendations found in this review.

RESULTS

In the present report, following a brief review of the epidemiology of and clinical diagnosis criteria for atopic dermatitis, the recommendations for treatment and management are detailed. These recommendations, which are intended to provide clinicians with a useful and valuable tool to help manage their patients with atopic dermatitis, are divided into the following sections: epidemiology, diagnosis, general measures/skin care, acute management of atopic dermatitis, long-term management/disease control, adjunct therapies, and considerations for switching between antiinflammatory therapies/handling treatment failure. General measures discussed include hydration with bathing and the use of moisturizers. Management strategies discussed include topical corticosteroids, topical calcineurin inhibitors, antihistamines and anti-infectives. A management algorithm is also presented.

A randomized study of the safety, absorption and efficacy of pimecrolimus cream 1% applied twice or four times daily in patients with atopic dermatitis

BACKGROUND

Pimecrolimus cream 1% (Elidel), a non-steroid inhibitor of inflammatory cytokines, is effective in the treatment of atopic dermatitis, without corticosteroid-related side effects such as skin atrophy. It is indicated for twice-daily application. More frequent applications might be expected either to enhance efficacy or increase toxicity. This study compared the safety, efficacy and systemic absorption of pimecrolimus administered twice daily (recommended dose) and four times daily early in the treatment of patients with moderate to severe atopic dermatitis.

METHODS

Adolescent and adult patients with moderate to severe atopic dermatitis were randomly assigned to a twice daily (BID) treatment group (n = 24) or a four times daily (QID) group (n = 25). During days 1-7, patients in the QID group applied pimecrolimus four times daily, and patients in the BID group applied pimecrolimus twice daily plus vehicle equivalent twice daily. During days 8-21, all patients were required to use pimecrolimus twice daily and had the option to use up to two further daily treatments (pimecrolimus in the QID group and vehicle equivalent in the BID group). Blood sampling occurred 2, 4, and 6 hours after the first morning application on days 1 and 5 and then prior to the first morning application on days 8 and 15, and any time on day 22.

RESULTS

Only 3 (12%) QID patients and 4 (17%) BID patients reported adverse events (primarily mild, transient application-site burning) with no significant difference between treatment groups in the frequency, type, or severity of adverse events. The median daily number of applications in the QID group during days 8-21 when two additional doses were optional remained at four. Pimecrolimus blood levels from a subgroup of 22 patients showed no difference in systemic exposure between the two dosing regimens. All but three (one in the QID group, two in the BID group) patients had blood levels below the limit of quantification; the highest single blood level of pimecrolimus measured in any patient was 1.37 ng/ml (QID group). Both the QID and BID regimens improved the signs and symptoms of atopic dermatitis similarly as measured by improvements in pruritus severity score, Investigator's Global Assessment, Eczema Area and Severity Index, percentage of body surface area affected, and patient's self-assessment of disease control.

CONCLUSIONS

The data suggest that increasing pimecrolimus application from twice daily to four times daily to treat moderate to severe atopic dermatitis for up to 3 weeks does not alter the safety profile nor does it increase the efficacy of treatment. Systemic absorption of pimecrolimus applied BID and QID is minimal and is not different between dosing regimens. Patients and physicians familiar with the potential hazards of overuse of topical corticosteroids should be reassured that if pimecrolimus is applied at twice the recommended BID dose for short periods of time, there is no effect on safety, tolerability, or systemic absorption.

Dexamethasone and FK506 inhibit expression of distinct subsets of chemokines in human mast cells

Mast cells produce a large amount of several chemokines after cross-linking of FcepsilonRI and participate in the pathogenesis of allergic diseases. The objective of this study was to comprehensively investigate FcepsilonRI-mediated chemokine induction in human mast cells and the effect of a corticosteroid (dexamethasone) and a calcineurin inhibitor (FK506). Human peripheral blood-derived mast cells were stimulated with anti-IgE Ab in the presence of dexamethasone or FK506. Gene expression profiles were evaluated using GeneChip and confirmed by real-time PCR, and chemokine concentrations were measured by cytometric bead arrays and ELISA. Expression of eight chemokines was significantly induced in mast cells by anti-IgE stimulation. Induction of CCL2, CCL7, CXCL3, and CXCL8 by anti-IgE was significantly inhibited by dexamethasone but was enhanced by FK506. In contrast, induction of CCL1, CCL3, CCL4, and CCL18 was significantly inhibited by FK506 but, with the exception of CCL1, was enhanced by dexamethasone. Combination of dexamethasone and FK506 suppressed production of all chemokines by anti-IgE stimulation. Studies using protease inhibitors indicate that mast cell proteases may degrade several of the chemokines. These results suggest that corticosteroids and calcineurin inhibitors inhibit expression of distinct subsets of chemokines, and a combination of these drugs almost completely suppresses the induction of all chemokine genes in human mast cells in response to FcepsilonRI-dependent stimulation. This implies that a combination of a corticosteroid and a calcineurin inhibitor may be more effective than each single agent for the treatment of allergic diseases in which mast cell-derived chemokines play a major role.

Pimecrolimus reduces eosinophil activation associated with calcium mobilization

BACKGROUND

Pimecrolimus is a calcineurin inhibitor that inhibits T cell and mast cell activation and effectively treats atopic dermatitis. However, its effects on eosinophils, a cell type implicated in allergic disease pathology, are unknown. Therefore, we examined the effects of pimecrolimus on eosinophil superoxide anion production, degranulation and survival.

METHODS

Purified eosinophils from normal or atopic donors were incubated with serial dilutions of pimecrolimus (microM to nM) and then stimulated with platelet activating factor (PAF), interleukin 5 (IL5), secretory immunoglobulin A (sIgA) or Alternaria alternata (Alt) fungus extract. Eosinophil activation was monitored by cytochrome c reduction resulting from superoxide anion production and by a 2-site immunoassay for eosinophil-derived neurotoxin (EDN) in cellular supernatants, as a marker of degranulation. Eosinophil survival was measured by propidium iodide exclusion using flow cytometry after 4 days in culture.

RESULTS

Normal and atopic eosinophil superoxide anion production induced by PAF, and associated with increased intracellular calcium, was inhibited up to 37% with 1 microM pimecrolimus. However, superoxide anion production induced by IL5 and sIgA was not consistently inhibited. EDN release, which ultimately depends on calcium, was inhibited about 30% with PAF, IL5 and sIgA stimulation for normal and atopic donor eosinophils. Furthermore, calcium-dependent Alt-induced EDN release was inhibited up to 49% with nanomolar pimecrolimus. Finally, increased eosinophil survival promoted by IL5 and sIgA was not influenced by pimecrolimus.

CONCLUSION

Pimecrolimus moderately inhibits eosinophil superoxide anion production and EDN release associated with calcium mobilization, which may contribute to its efficacy in treating atopic dermatitis.

Sustained efficacy and safety of pimecrolimus cream 1% when used long-term (up to 26 weeks) to treat children with atopic dermatitis

Atopic dermatitis is a chronic, inflammatory condition affecting up to 20% of children. Here, we report the long-term extension study of previously published pivotal phase III studies with pimecrolimus cream 1%. Two identical, 26-week studies (6-week, double-blind, followed by 20-week, open-label phases) were conducted in children aged 2 to 17 years with atopic dermatitis. Pooled efficacy and safety analyses were performed. At day 43, 34.8% pimecrolimus-treated patients versus 18.4% in the vehicle group (p < 0.001) were clear/almost clear (Investigators' Global Assessment 0/1) of disease, with significant differences (p < 0.05) between treatment groups for all double-blind visits in all parameters. Pimecrolimus was significantly more effective (based on the Eczema Area and Severity Index) in treating the face and neck versus the rest of the body (p < 0.0001) and versus vehicle (p < 0.0001) in the double-blind phase. Disease control was sustained in the pimecrolimus group throughout the whole study. Patients treated with vehicle during the double-blind phase experienced rapid, marked improvement when switched to pimecrolimus in the open-label phase. The incidence of adverse events was low and comparable between treatment groups. In conclusion, pimecrolimus cream 1% is effective and well tolerated in the long-term control of children with mild to moderately severe atopic dermatitis.

Clinical correlations of recent developments in the pathogenesis of atopic dermatitis

Atopic dermatitis is a chronic inflammatory skin disease with a steadily increasing prevalence affecting 10-20 of infants and 1-3 of adults globally. It is often the first clinical manifestation of atopic disease preceding asthma and allergic rhinitis. Probably half of the children with atopic dermatitis develop some other form of atopic disease later in life. The pathogenesis involves a complex interplay of factors including genetic predisposition due to altered immune or skin barrier function, interactions with the environment such as food and allergen exposures, and infectious triggers of inflammation. In this review, we summarize the recent advances in understanding the contribution of different factors in the pathophysiology of atopic dermatitis and how insights provide new therapeutic potential for its treatment.

Systemic ciclosporin and tacrolimus in dermatology

Ciclosporin and tacrolimus are calcineurin inhibiting immunosuppressant agents useful in the treatment of immune-mediated inflammatory dermatoses. Available data and clinical experience demonstrate ciclosporin's efficacy in treating psoriasis, atopic dermatitis, pyoderma gangrenosum, lichen planus, autoimmune bullous disease (in combination with corticosteroids), recalcitrant chronic idiopathic urticaria, and chronic dermatitis of the hands and feet. Although the role of topical tacrolimus in atopic dermatitis is well established, such experience with the oral formulation of tacrolimus has been limited. However, there are several case studies and anecdotal reports of the successful use of oral tacrolimus in various dermatoses. In this article we discuss the utility of systemic ciclosporin and tacrolimus in dermatology.

An exploratory study to evaluate the efficacy of pimecrolimus cream 1% for the treatment of pityriasis alba

BACKGROUND

Use of topical corticosteroids for the treatment of pityriasis alba is limited by their potential side-effects, such as skin atrophy especially with long-term use on the face. Pimecrolimus cream 1% is a topical calcineurin inhibitor that has anti-inflammatory properties, lacks the cutaneous side-effects associated with steroids, and provide a potential benefit for the treatment of pityriasis alba.

METHODS

This 10-patient, prospective, single-arm, open-label, single-center, 12-week, investigator-initiated proof of concept study assessed the efficacy, safety, and patient acceptance of pimecrolimus cream 1% twice daily. In addition to pimecrolimus cream, patients used facial emollient containing SPF 15 sunscreen and mild soap-free cleanser. Efficacy assessments were Investigator Global Assessment (IGA) of disease severity and evaluation of uneven skin color, scaling, eczema, follicular keratosis, and pruritus. All efficacy assessments were reported on a 4-point scale (0 = none to 3 = severe).

RESULTS

Of the 10 patients enrolled (aged: 12-35 years), all had intensive sun-exposure, 90% had skin type IV-V, and 80% completed the 12-week treatment. At baseline, mean IGA was 1.20 (mild-moderate), uneven skin color was 2.3 (moderate-severe) and scaling was 1.2 (mild). IGA decreased to 0.25 by week 12, uneven skin color improved by week 3 with near complete resolution by week 12 (mean = 0.38) and scaling resolved at week 3. Pruritus, eczema, and follicular keratosis remained at low levels from baseline throughout the course of the study. Patients consistently reported satisfaction with the treatment ("satisfied" or "very satisfied"). No adverse events were reported.

CONCLUSIONS

Pimecrolimus cream 1% may represent an alternative for the treatment of pityriasis alba.

Results of a randomized, double-blind, vehicle-controlled efficacy trial of pimecrolimus cream 1% for the treatment of moderate to severe facial seborrheic dermatitis

BACKGROUND

Seborrheic dermatitis is commonly treated with anti-inflammatory products, including topical corticosteroids. Pimecrolimus cream 1% also exerts anti-inflammatory activity by inhibiting T-cell cytokine production.

OBJECTIVE

We sought to compare the efficacy and safety of twice-daily pimecrolimus for treatment of moderate to severe facial seborrheic dermatitis.

METHODS

This double-blind, vehicle-controlled, 4-week trial randomized patients with seborrheic dermatitis to pimecrolimus or vehicle (1:1). Clinical assessments (erythema [0-3] and scaling [0-3] combined for a total area score [0-6]) were performed at weeks 0, 2, and 4. Inclusion criteria included total area score 4 or greater and erythema 2 or greater. The prespecified primary variable, change from baseline in total area score at week 4, was analyzed using a two-sample t test for intent-to-treat and per protocol populations.

RESULTS

In all, 96 adults of mean age 59.6 years, 88.5% male, were randomized (n = 47 pimecrolimus; 49 vehicle). At week 4, the mean change from baseline in total area score was 3.7 versus 3.3 for pimecrolimus and vehicle groups, respectively (intent-to-treat: P = .1913; 95% confidence interval (CI) for difference [-0.195, 0.961]). Per protocol analysis (n = 41 pimecrolimus; 46 vehicle) indicated a significant difference between groups (mean change 3.9 pimecrolimus vs 3.2 vehicle; P = .0156; CI [0.129, 1.197]). The superiority of pimecrolimus was observed as early as week 2 (intent-to-treat: P = .0062; CI [0.132, 0.777]; per protocol: P = .0012; CI [0.410, 1.593]). No drug-related serious adverse events occurred. The most frequent drug-related adverse events were local, mild, and transient (pimecrolimus = 26%; vehicle = 12%).

LIMITATIONS

Generalizability is limited by the elderly male study population.

CONCLUSION

This study suggests that pimecrolimus cream 1% is an effective and well-tolerated treatment for moderate to severe facial seborrheic dermatitis.

Pimecrolimus Cream 1% for Treatment of Vulvar Lichen Simplex Chronicus: An Open-Label, Preliminary Trial

BACKGROUND

To evaluate efficacy and safety of pimecrolimus cream 1% twice daily for treatment of vulvar lichen simplex chronicus (LSC).

METHODS

Patients in this 12-week, open-label study had biopsy-proven vulvar LSC. Inclusion criteria were patient-reported Visual Analog Scale for Pruritus Relief > or = 3 (VAS-PR, 0 cm = no itching to 10 cm = severe itching) and Investigator's Global Assessment > or = 2 (IGA, 0 = no disease to 3 = severe disease). Safety was evaluated by adverse event reports and pimecrolimus blood level measurements.

RESULTS

Twelve women aged 25-53 years were enrolled. The median pruritus score (VAS-PR) decreased from 6 (min. 4.9, max. 9.0) at baseline to 0 cm at week 4 (max. 4.2), week 8 (max. 3.1) and week 12 (max. 2.1). Seven patients reported complete resolution of pruritus by week 4. Median IGA decreased from 2.5 (min. 2, max. 3) at baseline to 0 (min. 0, max. 2) at week 12. Erythema, excoriation, and lichenification improved for all patients. Pimecrolimus blood concentration for all samples was below the limit of quantification, 0.3 ng/ml. No adverse events were reported.

CONCLUSIONS

In this exploratory study, signs and symptoms of vulvar LSC improved for all women and pimecrolimus cream showed a favorable safety profile. Larger prospective studies are needed to further evaluate pimecrolimus for treatment of vulvar LSC.

Calcineurin inhibitors and rapamycin: cancer protection or promotion?

Since the introduction of cyclosporin A (CsA) in the early 1980s, the use of immunosuppressants has markedly increased. Already established drugs have proved effective in the treatment of a wide range of diseases outside transplantation medicine and new immunosuppressants have been developed for more specific indications such as psoriasis and atopic dermatitis. Patients in transplantation medicine as well as in dermatology have benefited significantly from systemic and topical application of both new and established drugs. But are these drugs without risks? Cancer-protecting effects have been reported for some of the available immunosuppressants. Conversely, other publications and the issue of a black box warning by the US Food and Drug Administration have increased concerns about cancer-promoting effects. Knowledge of the specific effects as well as adverse effects is paramount to ensure an application that is safe and beneficial for the patient. Here we review the mechanisms of action and therapeutic potential, and critically review recent literature with respect to possible carcinogenic side effects of systemic and topical CsA, tacrolimus, pimecrolimus and rapamycin.

Topical pimecrolimus and tacrolimus transiently induce neuropeptide release and mast cell degranulation in murine skin

BACKGROUND

The topical calcineurin inhibitors pimecrolimus and tacrolimus have been demonstrated to be an effective new anti-inflammatory therapy. The only clinically relevant side-effect reported is transient application site burning and stinging itch at the beginning of topical therapy.

OBJECTIVES

In order to understand the underlying mechanism of this effect, we examined whether or not the compounds are able to stimulate neuropeptide release in normal murine skin as well as in a mouse model of experimentally induced irritant contact dermatitis.

METHODS

Balb/c mice were treated with 1% pimecrolimus cream or 0.1% tacrolimus ointment. Untreated and corresponding vehicle-treated mice served as controls. Skin specimens were investigated by light, immunofluorescence and electron microscopy as well as enzyme-linked immunosorbent assay and polymerase chain reaction.

RESULTS

Topical application of pimecrolimus and tacrolimus was followed by an initial release of substance P and calcitonin gene-related peptide from primary afferent nerve fibres in murine skin during the early inflammatory response. The release of the neuropeptides and their binding to mast cells (MCs) led to MC degranulation. Mediators of MCs such as histamine and tryptase may induce pruritus and burning by binding to the corresponding receptors (histamine receptor 1, proteinase-activated receptor 2) on sensory nerve fibres, which explains the initial side-effects during therapy with calcineurin inhibitors.

CONCLUSIONS

It may be speculated that calcineurin inhibitors directly stimulate intracellular signalling pathways or bind to ion channels such as transient receptor potential vanilloid 1 or receptors involved in nociception.

Review of pimecrolimus cream 1% for the treatment of mild to moderate atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is a pruritic and inflammatory skin disease affecting at least 28 million people in the United States. During an AD flare, the skin becomes inflamed and intensely pruritic. A "major flare" is characterized by persistent or uncontrollable pruritus, intense erythema, extensive excoriation, and potential oozing and crusting. The overall goal of AD treatment is to minimize the frequency and severity of disease flares. Long-term management involves multiple treatment strategies, including identifying and eliminating triggers, routine moisturization, antipruritic therapy, and use of topical anti-inflammatory agents (topical corticosteroids and topical calcineurin inhibitors). Pimecrolimus cream 1% is a topical calcineurin inhibitor developed specifically for patients with AD.

OBJECTIVE

The aim of this review was to assess the current literature (clinical trials and postapproval studies) on the efficacy and safety of pimecrolimus cream 1% in the treatment of AD.

METHODS

A literature search was performed using the National Library of Medicine (MEDLINE), EMBASE, International Pharmaceutical Abstracts, Current Contents, and SciSearch databases (1980-2006) with the search term pimecrolimus. Selected studies comprised randomized, vehicle-controlled trials of topical pimecrolimus cream 1%, focused on efficacy and safety, and complied with the pimecrolimus cream 1% indication (study participants were aged >or=2 years with mild to moderate AD).

RESULTS

When used in appropriately identified pediatric and adult patients with mild to moderate AD, pimecrolimus cream 1% improved the signs and symptoms of AD and delayed time to a major flare. The most commonly seen adverse events in clinical trials were application-site reactions (10.4%-14.5%) and nasopharyngitis (10.1%-28.9%), headache (13.9%-23.0%), cough (11.6%-19.3%), pyrexia (7.5%-15.4%), influenza (3.0%-14.6%), and bronchitis (0.4%-13.2%), which overall were not significantly different from patients treated with vehicle cream. Pimecrolimus cream 1% was not associated with skin atrophy (supporting its use on sensitive areas of the skin such as the face, neck, and skinfolds). In addition, a review of the literature identified no reports of cumulative irritation or photosensitivity potential, no substantial increases in the incidence of common bacterial and viral skin infections compared with vehicle cream (placebo), and no effects on the systemic immune system, including delayed-type hypersensitivity.

CONCLUSION

Pimecrolimus cream 1% is a valuable treatment option for mild to moderate AD in adults and children aged >or=2 years.

Atopic eczema: what's new?

Atopic eczema (AE) is a chronic inflammatory skin disease characterized by recurrent intense pruritus and a typical age-related distribution of skin lesions. Several new aspects with regard to the pathogenetic background as well as strategies for prevention, diagnosis and treatment of AE have emerged. There are ongoing studies on genetic susceptibility loci, as well as environmental and nutritional factors associated with an increase or a decrease of AE lesions. The atopy patch test is now available for identification of allergens in aeroallergen-triggered AE. New topical therapies, such as the calcineurin inhibitors, have broadened the therapeutic armamentarium substantially. In order to increase knowledge and coping strategies, patient education programs have been launched. Learning objective Upon completing this paper, the reader should be aware of new developments in AE, especially on nomenclature, prevention strategies, diagnostic tests, as well as therapeutic options.

Discovery of Topical Calcineurin Inhibitors and Pharmacological Profile of Pimecrolimus

Using a newly developed model of allergic contact dermatitis in pigs, calcineurin inhibitors of the tacrolimus and ascomycin type were shown to have a highly anti-inflammatory action after topical application. These findings provided the first pharmacological evidence of the efficacy of this novel class of topical agents in the treatment of inflammatory skin diseases, and, thus, their potential to become the first alternative to corticosteroids in more than 40 years. As a result of a large research program into ascomycins, pimecrolimus (Elidel(R), SDZ ASM 981) was selected for development due to its favorable pharmacology and safety profile, alongside tacrolimus (Protopic(R), FK 506). In vitro, pimecrolimus inhibits the transcription and release of pro-inflammatory cytokines in T cells. Similar to the corticosteroids, betamethasone-17-valerate and dexamethasone, pimecrolimus is effective at nanomolar concentrations. Targeting mainly T cells, pimecrolimus has, however, a more specific mode of action. Moreover, in contrast to corticosteroids, pimecrolimus has no effect on Langerhans' cells, the professional antigen- presenting dendritic cells of the skin that are crucial for local immunosurveillance. When applied topically, pimecrolimus exerts a high and selective anti-inflammatory activity in the skin, shows minimal percutaneous absorption, and has a low potential to affect systemic immunoreactions. Pimecrolimus cream 1% has proven to be well tolerated, safe, and highly effective in clinical studies in patients with atopic dermatitis.

Modulation of Atopy Patch Test and Skin Prick Test by Pretreatment with 1% Pimecrolimus Cream

BACKGROUND

In a subgroup of patients with atopic eczema (AE), aeroallergens are relevant eliciting factors. The atopy patch test (APT) was proposed as inflammation model for AE.

OBJECTIVE

It was the aim of this study to investigate the effect of pretreatment with 1% pimecrolimus cream (Elidel) on the APT and skin prick test (SPT).

METHODS

In a randomized, controlled, double-blind study, 20 patients with AE and positive SPT and APT screening reaction to house dust mite Dermatophagoides pteronyssinus, cat dander, grass or birch pollen were enrolled (age 20 +/- 11 years, 55% males). For 2 weeks, patients twice daily applied pimecrolimus and vehicle control to marked fields on their backs and forearms. Then, APT was performed (200 index of reactivity/g extracts in petrolatum; Stallergènes, France) on both fields on the back and SPT was performed on the pretreated forearms.

RESULTS

Including only patients with different readings (n = 13), stronger APT suppression of at least 1 ETFAD (European Task Force on Atopic Dermatitis) grade in the pimecrolimus area versus intraindividual control was observed in 10 of these patients after 48 and 72 h (p < 0.05; 90% CI 50.5-93.4). Including all 20 subjects, the analysis still showed a borderline significance compared with the vehicle (p = 0.0564). SPT with histamine and aeroallergens showed a median 7.5-10% reduction in actively pretreated areas (p = 0.086). Immunohistochemical analysis in 2 patients revealed an induction of interferon-gamma in primecrolimus-pretreated skin.

CONCLUSION

APT can be used as a model for AE skin inflammation. It was shown for the first time that pimecrolimus pretreatment has a potential to suppress the development of lesions induced by aeroallergen exposure in patients with AE.

Dermal microdialysis in the dog: in vivo assessment of the effect of cyclosporin A on cutaneous histamine and prostaglandin D2 release

Dermal microdialysis, a relatively noninvasive technique, allows investigation of the changes in cellular mediators released during cutaneous allergic responses. This technique was used to evaluate the effect of cyclosporin A, an immunosuppressive drug used for treatment of canine atopic dermatitis, on the cutaneous release of two pro-inflammatory mediators following intradermal allergen challenge. Four beagle dogs spontaneously sensitized to Ascaris suum were treated for 1 month with oral cyclosporin A. At days 0, 15 and 30 of the treatment, dialysis probes were inserted into the skin of the back, and 20 microL of A. suum antigen was injected intradermally at each site. At timed intervals, dialysate was collected and assayed for histamine and prostaglandin D(2) and the wheal area was measured. Mean histamine concentration and wheal area were significantly lower at days 15 and 30 of treatment, compared with day 0. However, prostaglandin D(2) concentration was not significantly reduced. The inhibition in histamine release after intradermal challenge, by cyclosporin, confirms its anti-inflammatory action in the dog. Dermal microdialysis provides a useful tool for investigating canine allergic reactions and their modulation by drugs.

Penetration of ASM 981 in canine skin: a comparative study

ASM 981 has been developed for topical treatment of inflammatory skin diseases. It specifically inhibits the production and release of pro-inflammatory cytokines. We measured the skin penetration of ASM 981 in canine skin and compared penetration in living and frozen skin. To make penetration of ASM 981 visible in dog skin, tritium labelled ASM 981 was applied to a living dog and to defrosted skin of the same dog. Using qualitative autoradiography the radioactive molecules were detected in the lumen of the hair follicles until the infundibulum, around the superficial parts of the hair follicles and into a depth of the dermis of 200 to 500 microm. Activity could not be found in deeper parts of the hair follicles, the dermis or in the sebaceous glands. Penetration of ASM 981 is low in canine skin and is only equally spread in the upper third of the dermis 24 hours after application. Penetration in frozen skin takes even longer than in living canine skin but shows the same distribution.

Onset of pruritus relief with pimecrolimus cream 1% in adult patients with atopic dermatitis: a randomized trial

BACKGROUND

Pimecrolimus cream 1% (Elidel, Novartis Pharmaceuticals AG) effectively improves/relieves pruritus associated with atopic dermatitis (AD), but few data are available regarding the timing of relief. The purpose of this study was to investigate the timing of pruritus relief produced with pimecrolimus in adults with mild/moderate AD and moderate/severe pruritus.

METHODS

Patients were randomized to 7 days of treatment with pimecrolimus (n = 100) or vehicle (n = 98). Pruritus severity was assessed daily on a 4-point scale (0 = absent, 3 = severe), reflecting the previous 24 h experience. Patients who completed this core study were eligible to enter a voluntary 5-week, open-label extension study.

RESULTS

A significant effect was noted within 48 h of treatment, with pruritus improving in 56% of pimecrolimus-treated patients and 34% of vehicle-treated patients (P = 0.003). Pruritus relief was maintained during the remainder of the core and extension phases, and was accompanied by an improvement in the Investigator's Global Assessment score.

CONCLUSION

Pimecrolimus cream 1% significantly reduced pruritus within 48 h.

Role of topical therapies in the management of cutaneous disease

Within the last decade, healthcare providers have had a larger selection of effective novel topical immunomodulatory agents to treat many dermatologic conditions. Novel mechanisms of action of newer topical agents have facilitated differentiation from well-established topical agents such as corticosteroids and 5-fluorouracil. Further, because of a growing understanding of the immune mechanisms within the skin, the opportunity has arisen to use the body's immune system to effectively treat many dermatologic conditions, such as condyloma acuminata, actinic keratosis, basal cell carcinoma, and atopic dermatitis, while maintaining a favorable safety profile. Imiquimod 5% cream, an immune response modifier, is safe and effective in the treatment of condyloma acuminata, actinic keratosis, and primary superficial basal cell carcinoma (sBCC). Pimecrolimus cream 1% and tacrolimus ointment (0.1% and 0.03%) are safe and effective in the treatment of atopic dermatitis. This review highlights newer data on approved and investigational indications for these topical immunomodulatory agents.

Atopic dermatitis: beyond the itch that rashes

The prevalence of atopic dermatitis is increasing, and more than 50% of children with atopic dermatitis go on to develop asthma and allergies. A better understanding of the underlying immune abnormalities of this complex chronic relapsing skin disease is needed. Although the optimal treatment approach remains to be defined, several recent studies suggest a rationale for using topical calcineurin inhibitors as early intervention and adding topical corticosteroids as rescue therapy if needed.

Effects of calcineurin inhibitors on an in vitro assay for chronic urticaria

BACKGROUND

Chronic urticaria is a common skin disorder, which causes considerable morbidity. In approximately 40% of cases, patients have an autoimmune disorder in which functional antibodies cause degranulation of mast cells and basophils, and C5a complement augments this in varying amounts from patient to patient. Since the calcineurin inhibitor ciclosporin has been used in chronic autoimmune urticaria, we examined the effect of ciclosporin and other drugs on the release of histamine from basophils when stimulated by sera from patients with chronic autoimmune urticaria.

METHODS

Leucocytes from healthy donors were isolated and incubated in varying concentrations of ciclosporin, ascomycin, methotrexate, diphenhydramine or hydroxyzine for 30 min prior to stimulation with serum from urticaria patients known to have functional immunoglobulin (Ig)G antibodies directed against the alpha subunit of the IgE receptor. Histamine release was then measured.

RESULTS

Pre-incubating cells with ciclosporin and ascomycin produced dose-dependent inhibition of histamine release when cells were stimulated by sera of urticaria patients, by purified IgG from these sera, but not by C5a. Inhibition was not prevented by C5a receptor blocking antibodies. No inhibition was seen with methotrexate, diphenhydramine or hydroxyzine.

CONCLUSIONS

This is the first demonstration of inhibition of histamine release by calcineurin inhibitors employing sera of patients with chronic autoimmune urticaria. These drugs may work by interfering with intracellular signalling in cells following cross-linking of the IgE receptor, but not following stimulation of the C5a receptor.

Wirksamkeit von Tacrolimus-0,1-%-Salbe bei Prurigoerkrankungen. Efficacy of tacrolimus 0.1 % ointment in prurigo

BACKGROUND

Potent topical corticosteroids are used the intense pruritus in prurigo diseases. Their long-term application leads to local side effects such as atrophy and telangiectasia.

PATIENTS AND METHODS

We treated 6 women (average age 64 years) with chronic prurigo with tacrolimus 0.1 % ointment (Protopic) to evaluate its efficacy in this clinical setting. Tacrolimus 0.1% ointment was applied twice a day for 4 weeks.

RESULTS

After one week, both clinical improvement and reduced pruritus were observed in all patients.

CONCLUSION

Tacrolimus 0.1% ointment represents a therapeutic option for the treatment of prurigo.

Treatment of infants with atopic eczema with pimecrolimus cream 1% improves parents' quality of life: a multicenter, randomized trial

Atopic eczema begins primarily in infancy or early childhood, and sleep loss due to night-time pruritus can have a considerable impact on patients' and parents' quality of life (QoL). In this study, infants (n = 196) with mild to severe atopic eczema were randomized 2:1, double-blind, to receive either pimecrolimus cream 1% (Elidel, Novartis Pharma, Nürnberg, Germany) or the corresponding vehicle bid for 4 wk, followed by a 12 wk, open-label phase and a 4 wk, treatment-free, follow-up period. The parents' QoL was measured at baseline and at the end of the double-blind phase, using the questionnaire 'QoL in Parents of Children with Atopic Dermatitis' (PQoL-AD), thus data presented here refer to the initial 4-wk treatment phase only. After 4 wk of double-blind treatment, an increase in the mean percentage change from baseline in eczema area and severity index of 71.5% was observed with pimecrolimus, compared with 19.4% with vehicle. The increase in efficacy was paralleled by the following mean percentage changes from baseline in the five domains of the questionnaire in pimecrolimus and vehicle, respectively: psychosomatic well-being: 14.6% vs. 6.2%; effects on social life: 6.7% vs. 2.3%; confidence in medical treatment: 10.0% vs. 3.7%; emotional coping: 16.1% vs. 6.5%; acceptance of disease: 19.6% vs. 7.0%. Analysis (ancova) of the dependent variable difference from baseline and the covariate baseline value revealed values of p < 0.05 for all five domains, despite the very short duration of the study. It is concluded that improvements in atopic eczema in infants achieved by treatment with pimecrolimus have a significant beneficial effect on the QoL of parents.

Safety and efficacy of topical calcineurin inhibitors in the treatment of childhood atopic dermatitis

Approximately 10-20% of infants in industrialized countries experience atopic dermatitis. In recent decades topical corticosteroids have been the first-choice therapy for treatment of flares. However, this form of therapy may induce skin atrophy, especially after application to facial lesions or with long-term use. Thus, development of new anti-inflammatory topical agents for the treatment of childhood atopic dermatitis was needed. The topical calcineurin inhibitors tacrolimus and pimecrolimus have an effect on various cells of the cutaneous immune system, specifically on T cells, by inhibiting the phosphatase calcineurin and preventing the transcription of proinflammatory cytokines. In several clinical studies of children and adults with atopic dermatitis, topical calcineurin inhibitors were found to be effective both on the face and the trunk and extremities, in both short- and long-term treatment regimens. Tachyphylaxis or rebound were not observed. In most patients an improvement of their eczema occurred during the first week of treatment, as measured by subjective and objective clinical signs of atopic dermatitis. Treatment significantly reduced the incidence of flares and the need for corticosteroids in children and adults. Treatment success, commonly defined as 'excellent improvement' or 'clearing of all lesions', was observed in more than one-third of all children treated with 0.03% or 0.1% tacrolimus or 1% pimecrolimus. Topical application of pimecrolimus and tacrolimus does not lead to significant blood concentrations of these agents in the majority of children with atopic dermatitis, and any increase in blood concentrations decreases after a few days of therapy. No changes in laboratory parameters were observed in short- and long-term studies in patients with atopic dermatitis. The most common adverse effect following the application of topical calcineurin inhibitors is mild to moderate symptoms of irritation such as burning, erythema and pruritus, which occurred in up to 20% of all children treated with tacrolimus and 10% of children treated with pimecrolimus, and usually faded after a few days. In contrast to topical corticosteroids, calcineurin inhibitors do not induce skin atrophy, even after long-term use. Topical calcineurin inhibitors have been proven to be effective and have a good safety profile during short-term and long-term use for up to 1 year with pimecrolimus and up to 4 years with tacrolimus. Given the lack of extensive experience with use of topical calcineurin inhibitors over longer periods, regular use of these agents, particularly in children, should be undertaken only after careful consideration of individual cases. Sun protection should also be advised.

Inflammatory cell numbers and cytokine expression in atopic dermatitis after topical pimecrolimus treatment

BACKGROUND

In several clinical trials the topical application of pimecrolimus was shown to be effective in the treatment of atopic dermatitis (AD). By targeting calcineurin-dependent signaling pathways, pimecrolimus controls cytokine gene expression. The purpose of this study was to investigate the effect of pimecrolimus on the inflammatory infiltrate and cytokine expression pattern in AD upon topical therapy.

METHODS

From 10 patients with acute AD, skin biopsies as well as immunophenotype and cytokine production of peripheral blood mononuclear cells (PBMC) were examined before and 3 weeks after therapy.

RESULTS

The clinical improvement was associated with a marked regression of histopathological features. In particular, the density of the inflammatory infiltrate mostly containing lymphocytes and eosinophils declined. By double immunofluorescent staining, a reduced expression of the T helper (Th) 2 cytokines interleukin (IL)-5, IL-10, and IL-13 in both CD4+ and CD8+ T cells was demonstrated after therapy. Pimecrolimus therapy was also associated with a reduced expression of the Th1 cytokine interferon (IFN)-gamma. Interestingly, the numbers of epidermal CD1a+ dendritic cells increased following treatment. In the peripheral blood, a decrease of lymphocytes and eosinophils was noticed, but the distribution of lymphocyte subpopulations and their capacity of cytokine production did not change.

CONCLUSIONS

Topical pimecrolimus exhibits anti-inflammatory effects in AD by reducing the inflammatory cell infiltrate and cytokine expression in the dermis.

Topical Immunotherapy: What's New

Further understanding of the pathogenesis of dermatologic conditions at a molecular level has led to targeted therapies. The topical immune response modifiers have contributed significantly to the treatment of cutaneous diseases. New topical remedies, particularly the Toll-like receptor agonists and calcineurin inhibitors, have added to the clinical armamentarium and have further advanced clinicians' ability to treat a wide variety of benign, premalignant, and malignant conditions. Furthermore, these agents have contributed to the understanding of the disease process. The next decade will witness even greater advances in targeted immunotherapies for dermatologic disease.

Pimecrolimus for the treatment of inflammatory skin disease

Pimecrolimus (SDZ ASM 981, Elidel ) is an ascomycin macrolactam derivative and a cell-selective inhibitor of inflammatory cytokines specifically developed to treat inflammatory skin diseases. Pimecrolimus combines high anti-inflammatory activity in the skin with a low potential to impair systemic immune reactions. Multi-centre studies have proved the efficacy and safety of pimecrolimus cream in patients with atopic dermatitis (AD) and confirmed that it is suitable for short-term treatment and long-term management of AD in adults, children and infants as young as 3 months. Topical application in humans is not associated with the atrophogenic side effects observed with corticosteroids. Pimecrolimus blood levels remained consistently low after repeated topical application and no clinically relevant drug-related systemic adverse events have been reported among the 8000 patients treated in clinical trials so far. Short-term, Phase I/II and Phase II trials of pimecrolimus administered orally in psoriasis and AD have shown that this drug is highly effective in a dose-dependent manner in patients with these diseases and has high safety profile. This finding is confirmed by pharmacogenomic blood analysis. Available data thus indicates that pimecrolimus, in both the cream and oral formulations, may represent a new option for the treatment of inflammatory skin diseases.