Novel immune-based therapies for psoriasis

Biologic Therapeutics in the Treatment of Psoriasis. Part 1: Review

Background:

Psoriasis is a chronic inflammatory skin disease principally mediated by activated T cells, which release proinflammatory cytokines with reactive epidermal changes in the skin, producing the characteristic lesions of psoriasis. New research into possible treatment options has been inspired by increased understanding of the pathophysiology of psoriasis and advances in immunology and molecular biology permitting the development of targeted, highly active biologic agents.

Objective:

The aim of this article is to review the efficacy and safety of five biologic therapeutics in the treatment of moderate to severe psoriasis and to provide practical guidelines for integration of these agents in the management of psoriasis.

Methods:

We searched MEDLINE (1966–2005) for articles containing the key words: alefacept, efalizumab, etanercept, infliximab, and adalimumab and searched recent conference abstracts.

Results:

Emerging immunotherapeutic agents (fusion proteins, recombinant cytokines, fusion toxins, or antibodies) target T cells or cytokines responsible for plaque formation that is characteristic of psoriasis. Alefacept is the first biologic to be approved in both the United States and Canada. More recently, efalizumab and etanercept and infliximab have been approved in the United States and Canada for plaque-type psoriasis. Adalimumab is currently in phase III clinical trials.

Conclusion:

These novel biologics offer an intriguing and effective treatment option for patients with moderate to severe psoriasis.

Celiac disease and autoimmunity: review and controversies

Celiac disease (CD) is an autoimmune condition affecting the small intestine, triggered by the ingestion of gluten, the protein fraction of wheat, barley, and rye. There is a strong linkage between CD and HLA-DQ2 and HLA-DQ8 haplotypes. Multiple case reports and small series suggest concordance between CD and other autoimmune disorders. This paper provides a brief overview of the pathogenesis of CD and reviews the literature regarding associations between CD and other autoimmune diseases, including the potential effects of gluten-free diet therapy on the prevention or amelioration of associated diseases.

Coeliac disease-associated antibodies in psoriasis

Background

The possible relationship between psoriasis and coeliac disease (CD) has been attributed to the common pathogenic mechanisms of the two diseases and the presence of antigliadin antibodies in patients has been reported to increase the incidence of CD.

Objective

The aim of this report was to study CD-associated antibodies serum antigliadin antibody immunoglobulin (Ig)A, IgG, anti-endomysial antibody IgA and anti-transglutaminase antibody IgA and to demonstrate whether there is an increase in the frequency of those markers of CD in patients with psoriasis.

Methods

Serum antigliadin antibody IgG and IgA, antiendomysial antibody IgA and anti-transglutaminase antibody IgA were studied in 37 (19 males) patients with psoriasis and 50 (23 males) healthy controls. Upper gastrointestinal endoscopy and duodenal biopsies were performed in patients with at least one positive marker.

Results

Antigliadin IgA was statistically higher in the psoriasis group than in the controls (p<0.05). Serological markers were found positive in 6 patients with psoriasis and 1 person from the control group. Upper gastrointestinal endoscopy was performed in all these persons, with biopsies collected from the duodenum. The diagnosis of CD was reported in only one patient with psoriasis following the pathological examination of the biopsies. Whereas one person of the control group was found to be positive for antigliadin antibody IgA, pathological examination of the duodenal biopsies obtain from this patient were found to be normal.

Conclusion

Antigliadin IgA prominently increases in patients diagnosed with psoriasis. Patients with psoriasis should be investigated for latent CD and should be followed up.

Estimation of (IgA) anti-gliadin, anti-endomysium and tissue transglutaminase in the serum of patients with psoriasis

Studies have indicated an association between psoriasis and coeliac disease (CD), an immune-mediated gluten-dependent enteropathy; however, the precise relationship between psoriasis and CD remains controversial. We aimed to assess the prevalence of the CD-associated IgA antibodies antigliadin antibody (AGA), tissue transglutaminase (tTG) and antiendomysium antibody (EMA) in patients with psoriasis. In total, 41 patients with psoriasis and 41 healthy controls were enrolled in this study. Blood samples were taken from all participants, and screened for AGA, tTG and EMA. We found a significantly higher level of AGA in patients with psoriasis than in controls, but levels of tTG and EMA were not significant. There was also a significantly higher prevalence of AGA, tTG and EMA in the patient group (34.1%, 34.1% and 14.6%, respectively) than in the control group (2.4%, 22% and 4.9%, respectively). We conclude that the significantly high prevalence of AGA antibodies in patients with psoriasis supports the possibility of a link between psoriasis and gluten-sensitive enteropathies, especially CD.

Clinical improvement of psoriasis in an AIDS patient effectively treated with combination antiretroviral therapy

Psoriasis has been classified as a T-cell-mediated inflammatory disease. The paradoxical exacerbation of psoriasis in AIDS has not been fully explained. We describe a case of a 45-y-old male with AIDS whose coincidental psoriasis resolved following antiretroviral therapy. Dramatic improvement was seen 4 weeks after combination antiretroviral therapy including enfuvirtide was started. In advanced HIV disease psoriasis could represent a clinical index of progression of HIV disease. Several pathogenetic factors involved in the clinical manifestations of psoriasis in the HIV-infected population are discussed.

Cyclosporins from Mycelium sterilae MS 2929

The structures of two new cyclosporins were elucidated by NMR and MS methods as cyclo[-MeBmt(1)-Abu(2)-Sar(3)-MeLeu(4)-Val(5)-MeLeu(6)-Ala(7)-d-Ala(8)-MeLeu(9)-MeNva(10)-MeVal(11)-] and cyclo[-MeBmt(1)-Abu(2)-Sar(3)-MeLeu(4)-Abu(5)-MeLeu(6)-Ala(7)-d-Ala(8)-MeLeu(9)-MeLeu(10)-MeVal(11)-].

Increased Expression of the Orphan Nuclear Receptor NURR1 in Psoriasis and Modulation following TNF-α Inhibition

The orphan nuclear receptor NURR1 belongs to the NR4A subfamily of transcription factors which are emerging as important mediators of cytokine and growth factor signaling. The transcriptional function of these ligand-independent and constitutively active receptors is controlled at the level of expression and nuclear localization. This study examines the expression of NURR1 in psoriasis and biological effects on this receptor following inhibition of tumor necrosis factor-alpha (TNF-alpha) signaling. We report increased expression of NURR1 mRNA and protein in involved psoriasis skin compared with uninvolved and normal skin, which correlates significantly (P=0.0055) with clinical measures of the psoriasis area and severity index. Enhanced NURR1 expression localizes to both nucleus and cytoplasm of cells of involved epidermis, blood vessels, and inflammatory infiltrates, in contrast to predominant cytoplasmic distribution in uninvolved and normal skin. Endogenous NURR1 levels are rapidly and selectively increased in response to proinflammatory agonists and growth factors in normal dermal endothelial cells. Following TNF-alpha inhibition with infliximab or etanercept, NURR1 mRNA and protein levels in involved skin are significantly decreased and cytoplasmic distribution is restored. These findings establish the aberrant expression and distribution of NURR1 in psoriasis and suggest that clinical benefits of TNF-alpha inhibition may be mediated through altered NURR1 activity.

Altered claudin expression is a feature of chronic plaque psoriasis

Epithelial tight junctions play a central role in cell-cell adhesion and are necessary for the selective paracellular movement of ions. Claudins are key components of tight junctions and their expression is altered in gut epithelia in a variety of inflammatory enteropathies, including ulcerative colitis and Crohn's disease. Psoriasis is a chronic inflammatory skin disease affecting approximately 2% of the western population, with significantly increased occurrence in individuals with Crohn's disease. Initial studies investigated the expression of claudins in skin of healthy volunteers and patients with chronic plaque psoriasis. We report here that claudins-1 and -3 are the major protein species present in the epidermis of healthy skin; they are expressed on the surface of epidermal keratinocytes, consistent with their localization to tight junctions. In plaques of psoriasis, claudin-1 was not identifiable in the epidermis, although typical staining patterns were observed in clinically normal, uninvolved skin of patients with psoriasis. Claudin-3 was present in the epidermal granular cell layer in normal skin, but was only identified within the cytosol of epidermal keratinocytes in both involved and uninvolved skin of psoriasis patients. We examined further whether exposure of keratinocytes in vitro to pro-inflammatory cytokines mimicked the observed changes in claudin expression seen in chronic plaque psoriasis; lipopolysaccharide, interferon-gamma and tumour necrosis factor-alpha had no effect on claudin protein expression or distribution. Addition of interleukin-1beta, however, resulted in down-regulation of claudins-1 and -3. Tumour necrosis factor-alpha and interleukin-1beta were further used in an in vivo model of skin inflammation; interleukin-1beta alone modulated claudin protein expression in this system. These data demonstrate that epidermal claudin expression is altered in chronic plaque psoriasis and that expression is in part modulated by interleukin-1beta.

Cutaneous manifestations in celiac disease

Celiac disease (CD) is an autoimmune gluten-dependent enteropathy characterized by atrophy of intestinal villi that improves after gluten-free diet (GFD). CD is often associated with extra-intestinal manifestations; among them, several skin diseases are described in CD patients. The present review reports all CD-associated skin manifestations described in the literature and tries to analyze the possible mechanisms involved in this association. The opportunity to evaluate the possible presence of CD in patients affected by skin disorders is discussed.

Challenges in developing therapies for rare diseases including pachyonychia congenita

The ability to attract sufficient resources to effectively develop therapeutics for rare diseases is a daunting task. This review summarizes existing resources for rare diseases and discusses some of the challenges and strategies associated with developing therapies for small patient populations with an emphasis on pachyonychia congenita.

Alefacept: an expert review concerning the treatment of psoriasis

Psoriasis is a chronic, inflammatory skin disease. Historically, phototherapy or immunosuppressive agents have been the first line of treatment for patients with severe psoriasis; however, the long-term use of these agents is limited by dose-dependent toxicities. Alefacept was the first biological agent approved in both the US and Canada for the treatment of adults with moderate-to-severe chronic plaque psoriasis. Alefacept is a remittive therapy that selectively reduces memory T cells. The efficacy and safety of up to two courses of alefacept have been demonstrated in clinical trials, and thus, this review focuses on new data to optimise the use of this biological agent. Emerging data indicates that multiple courses of alefacept for the long-term treatment of psoriasis are safe and effective. In addition, data are reviewed on the use of alefacept in combination with other agents and in other diseases, including psoriatic arthritis.

Novel biologic therapies for psoriasis

There has been a recent explosion in knowledge regarding the central role of the immune system in the pathogenesis of psoriasis. Originally felt to be primarily a disorder of keratinocyte hyperproliferation, it has recently been classified as a T cell-mediated, autoimmune disease. Type 1 cytokines released predominantly from activated T lymphocytes are now considered to cause the psoriatic phenotype, including the epidermal and vascular changes. Armed with this new knowledge, pharmaceutical and biotechnology companies have developed more specific, immunologically directed interventions. These newer agents aim to be both more effective in clearing a condition that is associated with much morbidity and to be more selective, resulting in fewer toxic side effects than current therapies. This article gives an overview of the newer immunotherapeutic approaches from the points of view of safety, efficacy and mechanisms of action. The review also outlines the steps involved in the immune response leading to psoriasis and considers how each step could offer a target for therapeutic intervention. Infliximab, etanercept, alefacept and efalizumab are considered in detail.

Fos and Jun Proteins Are Specifically Expressed During Differentiation of Human Keratinocytes

Activator protein 1 (AP-1) proteins play key roles in the regulation of cell proliferation and differentiation. In this study we investigated the expression of Fos and Jun proteins in different models of terminal differentiation of human keratinocytes and in skin from psoriasis patients. All Jun and Fos proteins, with the exception of FosB, were efficiently expressed in keratinocytes in monolayer cultures. In contrast, in normal epidermis as well as in organotypic epidermal cultures, the expression pattern of AP-1 proteins was dependent on the differentiation stage. Fos proteins were readily detected in nuclei of keratinocytes of basal and suprabasal layers. JunB and JunD were expressed in all layers of normal epidermis. Interestingly, expression of c-Jun started suprabasally, then disappeared and became detectable again in distinct cells of the outermost granular layer directly at the transition zone to the stratum corneum. In psoriatic epidermis, c-Jun expression was prominent in both hyperproliferating basal and suprabasal keratinocytes, whereas c-Fos expression was unchanged. These data indicate that AP-1 proteins are expressed in a highly specific manner during terminal differentiation of keratinocytes and that the enhanced expression of c-Jun in basal and suprabasal keratinocytes might contribute to the pathogenesis of psoriasis.

Psoriasis vulgaris: an interplay of T lymphocytes, dendritic cells, and inflammatory cytokines in pathogenesis

PURPOSE OF REVIEW

Discuss and update concepts and hypotheses for the pathogenesis of psoriasis based on new research reports (primarily from 2003 and early 2004).

RECENT FINDINGS

Increases in newly defined dendritic cell subsets, cytokines, and chemokines have been identified in psoriasis lesions and have modified views of T-cell-mediated pathogenesis. In addition, the psoriasis transcriptome has been defined by large-scale genomic expression studies, and these data suggest distinct molecular mechanisms of type 1 T-cell-mediated inflammation. Somewhat surprisingly, therapeutic clinical trials suggest that tumor necrosis factor is a major pathogenic cytokine in psoriasis, whereas translational studies point to roles of other innate pathways mediated by heat shock proteins, glycolipids, natural killer T cells, or dendritic cells in disease pathogenesis.

SUMMARY

An interactive network of inflammatory cytokines, chemokines, dendritic cells, and type 1 T cells or natural killer T cells potentially drives pathogenic inflammation in psoriasis vulgaris. Continued clinical studies with defined immune antagonists provide a critical means to dissect the contribution of different cell subsets and genomic pathways to the pathogenesis of psoriasis vulgaris.

Biological therapies in the systemic management of psoriasis: International Consensus Conference

Psoriasis is a chronic, immune-mediated disorder that usually requires long-term treatment for control. Approximately 25% of patients have moderate to severe disease and require phototherapy, systemic therapy or both. Despite the availability of numerous therapeutic options, the long-term management of psoriasis can be complicated by treatment-related limitations. With advances in molecular research and technology, several biological therapies are in various stages of development and approval for psoriasis. Biological therapies are designed to modulate key steps in the pathogenesis of psoriasis. Collectively, biologicals have been evaluated in thousands of patients with psoriasis and have demonstrated significant benefit with favourable safety and tolerability profiles. The limitations of current psoriasis therapies, the value of biological therapies for psoriasis, and guidance regarding the incorporation of biological therapies into clinical practice are discussed.

Tratamento sistêmico da psoríase - Parte II: Imunomoduladores biológicos

Em continuidade ao capítulo da edição anterior dos Anais Brasileiros de Dermatologia, nesta segunda parte da EMC-D serão discutidas as novas drogas, os imunomoduladores biológicos, que agem em determinadas fases da imunopatogênese da doença, modificando fenotipicamente sua evolução. Também serão discutidos alguns aspectos imunológicos que, atualmente, são responsáveis pelo desencadeamento da doença

Psoriasis and the new biologic agents: interrupting a T-AP dance

Psoriasis is an immune-mediated skin disease in which chronic T-cell stimulation by antigen-presenting cells (APC) occurs in the skin. This interplay between the T-cell and APC has been likened to a "T-AP dance" where specific steps must occur in sequence to result in T-cell activation and the disease phenotype; otherwise T-cell anergy would occur. Several novel engineered proteins designed to block specific steps in immune activation (biologic agents) have demonstrated efficacy in the treatment of psoriasis. These agents include fusion proteins, monoclonal antibodies and recombinant cytokines. These medications act at specific steps during the T-AP dance either to inhibit T-cell activation, costimulation and subsequent proliferation of T-cells, lead to immune deviation or induce specific cytokine blockades. The potential increased selectivity for specific pathways in immune activation, clinical efficacy and relative safety of these new agents offers an alternative for the treatment of moderate to severe psoriasis.

Rapid regression of psoriasis in a coeliac patient after gluten-free diet. A case report and review of the literature

BACKGROUND

Several skin disorders are present in patients affected by coeliac disease (CD) - among them, psoriasis has been described. However, at present the relationship between CD and psoriasis remains controversial since there are few and contrasting data on this topic.

METHOD

Here we describe a case of psoriasis in a CD patient not responding to specific therapies for psoriasis.

RESULT

The regression of skin lesions after gluten-free diet (GFD) was evident in a short time.

CONCLUSION

The present case supports the association between CD and psoriasis and the concept that psoriasis in CD patients can be improved by GFD. Future studies are needed to clarify the possible mechanisms involved in this association.

Therapy of alopecia areata: on the cusp and in the future

Over the past decade, basic research has established alopecia areata as a T cell-mediated autoimmune disease and has clarified many of its genetic, cellular, and molecular aspects. Perifollicular and intrafollicular mononuclear cell infiltrates directed at anagen hair bulbs are characteristic and striking histologic features in early alopecia areata. The inflammatory infiltrate is composed predominantly of activated CD4+ and CD8+ T cells, together with macrophages and Langerhans cells. The initiation phase of alopecia areata is mediated by type 1 cytokines, including interleukin-2, interferon-gamma, and tumor necrosis factor-alpha. Like other diseases with a strong autoimmune component, alopecia areata has associated with it specific human leukocyte antigens, which determine susceptibility, severity, chronicity, and resistance. New topical immunomodulating drugs and biologic therapies that have been developed, or that are in development, for the treatment of other immune-mediated inflammatory skin diseases will likely be effective in alopecia areata as well. The present discussion addresses the treatment of alopecia areata within the framework of these new modalities.

Novel biological immunotherapies for psoriasis

Psoriasis is a common skin disease affecting 1 - 3% of the white population. Although its physiopathogenesis still remains poorly understood, recent data suggest a key role played by memory T cells in the genesis of skin and joint lesions. Recent developments in the understanding of cellular mechanisms underlying psoriasis and in biotechnologies have given rise to a generation of biological agents that have shown clinical efficacy in treating psoriasis. These agents, including chimeric antibodies, fusion proteins and recombinant interleukins, specifically target the activated memory T cells directly involved in the development of psoriasis lesions and inhibit their action either directly or through inhibition of pro-inflammatory cytokines. Compared with conventional systemic treatments, they show a better safety profile and allow durable remissions. Some of these agents were very recently marketed for the treatment of psoriasis and hopefully others will follow. These biologicals have opened a new era for the management of this disease; they are reviewed in this article, based on data available in the literature.

Modulating T cell responses for the treatment of psoriasis: a focus on efalizumab

An improved understanding regarding the pathophysiology of psoriasis, coupled with advances in molecular research, has prompted the development of targeted biologic treatments for patients with plaque psoriasis. T lymphocytes play an important role in initiating the immune system and the inflammatory responses that result in the development and maintenance of psoriatic plaques. Efalizumab (anti-CD11a, Raptiva; Genentech, Inc.) is a mAb that targets the T cell adhesion molecule, leukocyte function-associated antigen-1 (LFA-1). By binding to CD11a - the alpha-subunit of LFA-1 - LFA-1 is prevented from binding with its ligand, intercellular adhesion molecule-1 (ICAM-1). This inhibits various T cell processes believed to be important in the pathogenesis of psoriasis, including T cell activation, T cell adhesion to endothelial cells and T cell migration. Clinical trials demonstrate that efalizumab, given subcutaneously once-weekly, provides clinical benefit, including improved quality of life, in patients with moderate-to-severe plaque psoriasis. Efalizumab is associated with an early onset of action, with improvement noted as early as 14 days. Studies with extended treatment suggest that continuing efalizumab therapy is more beneficial in maintaining and improving responses. Relapse of psoriasis is usually seen within 60 - 70 days after discontinuation of therapy, and rebound in approximately 5% of patients (i.e., flare to > 125% of baseline) is noted. Efalizumab is associated with acute adverse events during the first and second injections, which decrease in incidence with each subsequent injection. Data indicate that efalizumab can be safely administered for extended periods of time. Given the efficacy, early onset of clinical benefit, the safety profile and the convenience of once-weekly subcutaneous home dosing, efalizumab offers an interesting new therapeutic option for the treatment of psoriasis and the potential for improved and potentially safer long-term, continuous 'maintenance' therapy.

DNA photodamage stimulates melanogenesis and other photoprotective responses

Ultraviolet (UV) irradiation is a major source of environmental damage to skin. Melanin pigmentation protects against this damage by absorbing UV photons and UV-generated free radicals before they can react with DNA and other critical cellular components; and UV-induced melanogenesis or tanning is widely recognized as exposed skin's major defense against further UV damage. This article reviews extensive data suggesting DNA damage or DNA repair intermediates directly triggers tanning and other photoprotective responses. Evidence includes the observations that tanning is enhanced in cultured pigment cells by accelerating repair of UV-induced cyclobutane pyrimidine dimers or by treating the cells with UV-mimetic DNA-damaging chemicals. Moreover, small single stranded DNA fragments such as thymidine dinucleotides (pTpT), the substrate for almost all DNA photoproducts, also stimulates tanning when added to cultured pigment cells or applied topically to intact skin. In bacteria, single stranded DNA generated by DNA damage or its repair activates a protease that in turn derepresses over 20 genes whose protein products enhance DNA repair and otherwise promote cell survival, a phenomenon termed the SOS response. Interestingly, pTpT also enhances repair of UV-induced DNA damage in human cells and animal skin, at least in part by activating the tumor suppressor protein and transcription factor p53 and thus upregulating a variety of gene products involved in DNA repair and cell cycle regulation. Together, these data suggest that human cells have an evolutionarily conserved SOS-like response in which UV-induced DNA damage serves as signal to induce photoprotective responses such as tanning and increased DNA repair capacity. The responses can also be triggered in the absence of DNA damage by addition of small single-stranded DNA fragments such as pTpT.