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

Loss of TIPE2 Has Opposing Effects on the Pathogenesis of Autoimmune Diseases

Autoimmune diseases are a physiological state wherein immune responses are directed against and damage the body's own tissues. Cytokines secreted by infiltrated inflammatory cells contribute to the pathogenesis of autoimmune diseases. TIPE2, one of the four family members of Tumor necrosis factor-α induced protein-8 (TNFAIP8), is a negative regulator of innate and adaptive immunity and plays essential roles in the maintenance of immune tolerance. However, studies on the role of TIPE2 during the development of autoimmune diseases have generated contradictory results. In the current study, we sought to determine the role of TIPE2 during the development of IMQ-induced psoriasis and Experimental Autoimmune Uveitis (EAU) in mice. Our study revealed that, while TIPE2-deficiency alleviates psoriasis, it exacerbates the development of EAU. Further studies demonstrated that, although TIPE2-deficient T cells produced more IL-17A, they do not migrate efficiently to the local inflammatory site, i.e., the skin. This in turn led to the decreased IL-17A production in the skin and consequently reduced the severity of psoriasis in TIPE2-deficient mice. However, although TIPE2-deficient T cells still produced more IL-17A in EAU model, they migrate into the inflamed eye as efficient as TIPE2-sufficient T cells, and consequently exacerbates the development of EAU in TIPE2-deficient mice. Taken together, these results indicate that TIPE2 may either promote or suppress autoimmunity depending on the specific inflammatory microenvironment in different types of autoimmune diseases.

Anti-inflammatory effect of naringin and sericin combination on human peripheral blood mononuclear cells (hPBMCs) from patient with psoriasis

BACKGROUND

Several immunological pathways, particularly skin inflammation via various pro-inflammatory cytokines have been reported to be involved in the pathogenesis and clinical manifestations of psoriasis. The aim of the study was to investigate the potential role of naringin from Citrus maxima (Burm.) Merr and sericin from Bombyx mori combination in the treatment of psoriasis. Inhibitory effects on the expression of mRNA and the production of pro-inflammatory cytokines (TNF-α, IL-6, IL-23, and IL-12p40) were investigated.

METHODS

Human peripheral blood mononuclear cells (hPBMCs) were isolated from 10 healthy subjects and 10 patients with psoriasis. The hPBMCs from each group were exposed to naringin or sericin alone, and the combination of naringin and sericin. The expression levels of mRNA and the production of all cytokines were determined using quantitative RT-PCR and ELISA, respectively.

RESULTS

Naringin/sericin combination significantly decreased the expression of mRNA and the production of all pro-inflammatory cytokines in hPBMCs from patients with psoriasis. The potency of inhibitory activity was markedly higher than naringin or sericin alone.

CONCLUSION

The activity of naringin/sericin combination on down-regulation of these pro-inflammatory cytokines suggested its potential clinical use in psoriasis as well as other inflammation-associated diseases. The combination might be used as a complementary therapy with conventional treatment in psoriasis to improve clinical efficacy and tolerability.

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.

High Cytokine Levels in Tonsillitis Secretions Regardless of Presence of Beta-Hemolytic Streptococci

Acute pharyngotonsillitis denotes tonsillar inflammation caused by bacteria or viruses. Here, we investigated if beta-hemolytic streptococci (β-HS) tonsillitis would differ in inflammatory mediator response from tonsillitis of other causes. Tonsillar secretions were obtained from 36 acute pharyngotonsillitis patients and 16 controls. Bacteria were cultured quantitatively and 18 different viruses were quantified by real-time polymerase chain reaction. Cytokine and prostaglandin E2 (PGE2) levels were determined by enzyme-linked immunosorbent assays. Almost half of the patients' tonsillar secretions yielded high counts of β-HS, and most samples contained viruses, irrespective of whether β-HS were present or not. The Epstein-Barr virus (EBV) was the most common virus (patients 62% and controls 13%). Compared to controls, patients' secretions had higher levels of interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor (TNF), and PGE2, while few samples contained IL-12, IL-10, or interferon-gamma (IFN-γ). The presence of β-HS in tonsillitis secretions could not be distinguished by any of the measured mediators, while the presence of EBV DNA tended to be associated with enhanced levels of IL-1β and IL-8. The results suggest a common inflammatory response in acute pharyngotonsillitis, regardless of causative agent. The suggested correlation between intense inflammation and the presence of EBV DNA in tonsillitis secretions may be due to reactivation of the virus and/or the EBV-containing B cells.

Plant-made pharmaceuticals for the prevention and treatment of autoimmune diseases: where are we?

Molecular farming in plants or plant cell cultures represents a viable alternative technology that holds great promise for the low-cost and large-scale production of recombinant proteins. The particular case of plant-based vaccines for the prevention of autoimmune diseases is addressed here, presenting a comprehensive overview of the different molecules and expression technologies that have been investigated so far in both academia and industry. The potential of plants not only as bioreactors but also as delivery systems for pharmaceuticals is discussed, and the advantages of oral delivery of autoantigens for the induction of immune tolerance are highlighted.

Update on Alefacept Safety

Background:

Alefacept has been demonstrated in clinical trials to be an effective, safe, and well-tolerated treatment strategy when used alone or in combination with other antipsoriatic therapies in patients with chronic plaque psoriasis.

Objective:

AWARE (Amevive Wisdom Acquired from Real-World Evidence) is a multicenter, observational, Canadian phase IV registry evaluating the efficacy and safety of alefacept, alone or in combination with other antipsoriatic therapies, in patients with psoriasis.

Methods:

Patients with chronic plaque psoriasis were treated with at least one course of alefacept followed by an off-treatment period, typically lasting 12 or more weeks. Prospective follow-up was at least 60 weeks, depending on when patients presented for retreatment. Safety data collected throughout the study included the incidence of serious adverse events (SAEs), dosing suspensions, and withdrawals owing to adverse events.

Results:

Twelve SAEs were reported in psoriasis patients treated with at least one course of alefacept, with only one considered to be possibly related to the study drug. Approximately one-quarter of patients missed at least one dose of alefacept during the course of the study. A total of 291 doses of alefacept were missed, representing almost 4% of the total doses administered in this group of patients. Low CD4+ count was the most frequent reason for missed doses; however, no patient had persistently low CD4+ counts requiring permanent discontinuation of alefacept treatment. Seven patients in the AWARE registry discontinued treatment with alefacept, with the most common reason being patient request.

Conclusion:

The AWARE study supports the safety of alefacept used alone or in combination with other antipsoriatic therapies, in a broad population of real-world chronic plaque psoriasis patients in Canada.

Immunologic changes in TNF-alpha, sE-selectin, sP-selectin, sICAM-1, and IL-8 in pediatric patients treated for psoriasis with the Goeckerman regimen

Psoriasis is a chronic inflammatory skin disease which is often manifested during childhood. The present study investigated changes in the serum levels of proinflammatory cytokines and soluble forms of adhesion molecules in children with psoriasis. The observed patient group of 26 children was treated with the Goeckerman regimen. This therapy combines dermal application of crude coal tar with ultraviolet radiation. The Psoriasis Area Severity Index decreased significantly after treatment by with the Goeckerman regimen (p < 0.001). Serum levels of the proinflammatory cytokine TNF-alpha and adhesion molecules sICAM-1, sP-selectin and sE-selectin decreased after the Goeckerman regimen. The TNF-alpha and sICAM-1 decreased significantly (p < 0.05). Our findings support the complex role of these immune parameters in the immunopathogenesis of psoriasis in children. The serum level of IL-8 increased after the Goeckerman regimen. This fact indicates that the chemokine pathway of IL-8 activity could be modulated by this treatment, most likely by polycyclic aromatic hydrocarbons.

Psoriasis of the nail: anatomy, pathology, clinical presentation, and a review of the literature on therapy

Psoriasis is a chronic skin disease that affects millions of people throughout the world. Even though cutaneous signs and symptoms are the most common clinical manifestations, the nails can be involved in up to 50% of cases, and their involvement remains an important yet often overlooked aspect of the disease. There is a broad spectrum of nail dystrophies associated with psoriasis, ranging from the common pitting and loosening of the nail plate to the less frequent discoloration and splinter hemorrhages seen in the nail bed. This article discusses the normal anatomy and embryology of the nail unit as well as the current understanding of the pathogenesis of the disease. It also provides an extensive review of the existing literature with respect to psoriatic nail therapy. Although there have been many recent advances in the treatment of the cutaneous form of the disease-most notably in the field of immunotherapies-the options for nail psoriasis are far more limited. While a number of treatment alternatives currently exist for nail disease, the general paucity of clear evidence regarding these choices often makes it difficult to select the most efficient, safe, and optimal treatment for the patient. Even though the current literature has shown some support for the use of topical, intralesional, radiation, systemic, and combination therapies for nail psoriasis, the available studies lack sufficient power to extrapolate a standardized therapeutic regimen. Therefore, until better-documented evidence validating the treatment options emerges within the literature, clinicians and patients are left with a vague and relatively unproven approach to psoriatic nail disease.

The CD11a Binding Site of Efalizumab in Psoriatic Skin Tissue as Analyzed by Multi-Epitope Ligand Cartography Robot Technology

Efalizumab (Raptiva) is an immunomodulating recombinant humanized IgG1 monoclonal antibody that binds to CD11a, the alpha-subunit of leukocyte function antigen-1 (LFA-1). By blocking the binding of LFA-1 to ICAM-1, efalizumab inhibits the adhesion of leukocytes to other cell types and interferes with the migration of T lymphocytes to sites of inflammation (including psoriatic skin plaques). Analysis of the response in patients treated with efalizumab to date shows that distinct groups of responders and nonresponders to the drug exist. It would therefore be of great practical value to be able to predict which patients are most likely to respond to treatment, by identifying key parameters in the mechanism of action of efalizumab. Detailed investigation and detection of multiple epitopes in microcompartments of skin tissue has until recently been restricted by the available technology. However, the newly developed technique of Multi-Epitope Ligand Cartography (MELC) robot technology combines proteomics and biomathematical tools to visualize protein networks at the cellular and subcellular levels in situ, and to decipher cell functions. The MELC technique, which is outlined in this paper, was used to help characterize the binding of efalizumab to affected and unaffected psoriatic skin as compared to normal control skin under ex vivomodel conditions. Efalizumab was labeled with fluorescein isothiocyanate and integrated into a MELC library of more than 40 antibodies. These antibodies were selected for their potential to detect epitopes which may be indicative of (a) various cell types, (b) structural components of the extracellular matrix, or (c) the processes of cell proliferation, activation and adhesion. Efalizumab bound to CD11a in affected psoriatic skin by a factor 15x and 32x higher than in unaffected psoriatic skin and normal control skin, respectively. CD11a and the efalizumab binding site were primarily expressed in the extravascular dermis, whereas CD54 (ICAM-1) as its ligand was most prevalent in the dermal vessels. T lymphocytes (for which the markers were CD3, CD8, CD4, and CD45R0) were the major cellular targets of efalizumab. In contrast, NK cells were only a minor target of efalizumab. Our study demonstrated that efalizumab represents a treatment for psoriasis that primarily targets memory CD4+ and CD8+ T cells and has a high specificity for psoriatic disease activity. Moreover, we hereby introduce the novel principle of a biological drug-binding biochip assay being especially useful for the future monitoring of psoriatic skin lesions under efalizumab treatment conditions.

Efalizumab, a reversible T-cell modulator for psoriasis

The humanized monoclonal antibody (MAb) efalizumab (Raptiva) was developed to meet a longstanding need for specific, safe, and effective anti-psoriatic treatments. Efalizumab, which is directed at the lymphocyte surface protein LFA-1, prevents multiple interactions between T cells and other cell types. Here, we review the inflammatory pathway that drives the development of psoriasis, and we discuss several mechanisms by which efalizumab suppresses skin inflammation in psoriasis. Efalizumab reversibly increases circulating T-cell counts, as T cells--including pathogenic CD8 memory T cells that are prominent in psoriatic lesions-- are specifically restrained from leaving the bloodstream and entering the skin. Within two weeks of the onset of efalizumab treatment, cell surface and intracellular LFA-1 pools are substantially cleared by lysosomal degradation. Residual surface LFA-1 molecules remain saturated with bound efalizumab for some weeks following cessation of treatment. Efalizumab's pharmacodynamic properties are consistent with its profound and reversible beneficial effects on the histopathology of psoriatic skin.

What have we learned in dermatology from the biologic therapies?

Recent advances in our basic understanding of immunology, specifically the roles of various cell types involved in immune response and the action of cytokines they produce, has radically changed our understanding of the origin of inflammatory dermatoses, and other autoimmune diseases. Broadened comprehension of the immune response on a molecular level has facilitated the development of biologic therapeutics for the treatment of psoriasis, atopic dermatosis, and other inflammatory conditions. However, despite major advances in development and use of targeted biologics for controlling autoimmune disease, effective cures for these conditions remain to be developed and genetic determinants of predisposition to such diseases remain to be identified. Here, we review the history of our understanding of inflammatory dermatoses, traditional and new treatment approaches, and future directions for research and therapy in this area.

Terapia biológica y psoriasis

Psoriasis is a common, persistent, inflammatory skin disorder that can have a major effect on patient quality of life. Conventional psoriasis treatment fail to meet the clinical needs for a save and remittive therapy. The implication of an immunological lymphocyte T phenomena in the pathogenesis of psoriasis has led to research for new treatment options over the past few years. With advances in molecular research and technology, several biological therapies may be employed in the treatment of psoriasis. Biological treatments are designed to modulate key steps in the pathogenesis of psoriasis. They act by: inhibition of activation of antigen-presenting cells, inhibition of activation and proliferation of lymphocytes, immune deviation (from a T1 immune response to a T2 immune response) and reduction of pathogenic T cells and blocking the activity of inflammatory cytokines. Different biological treatments are discussed in this article.

Fulfilling an Unmet Need in Psoriasis

Psoriasis is a chronic inflammatory disease of the skin affecting approximately 2% of the world's population. Traditional systemic treatments, including methotrexate, ciclosporin, psoralen plus UVA (PUVA), oral retinoids and fumaric acid esters, are widely used for severe disease and are effective in the short term. Severe psoriasis is a chronic disease and patients and physicians have expressed concerns about possible harm from organ toxicity, such as skin cancer (PUVA), hyperlipidaemia (retinoids), renal (ciclosporin) or hepatotoxicity (methotrexate). Long-term monitoring is required and may not detect early organ damage. The pathophysiology of psoriasis remains to be clarified, but advances toward the understanding of the immunological basis of psoriasis have uncovered the involvement of immunological pathways; for example, the role of tumour necrosis factor (TNF)-alpha, T cell proliferation and T cell activation, and migration to the epidermis. This advancement in knowledge combined with developments in recombinant technologies has led to the development of target-specific therapies. Biological agents are defined as proteins that can be extracted from animal tissue or produced via recombinant DNA technologies and possess pharmacological activity. Adalimumab, alefacept, infliximab, efalizumab and etanercept are examples of biological agents currently used for the treatment of psoriasis. Some of these are also therapy for other autoimmune conditions, such as rheumatoid arthritis and Crohn's disease. These biological agents are effective in psoriasis but raise new safety concerns. Information on the safety of biological agents in conditions such as rheumatoid arthritis and Crohn's disease can not be directly extrapolated to psoriasis. An increased incidence of lymphomas has been postulated to be associated with etanercept, infliximab and adalimumab; serious infections, such as tuberculosis, have also been reported with these three biologicals, all of which target TNF-alpha. Demyelinating disorders, such as multiple sclerosis, have been reported with some biologicals as has congestive heart failure. Alefacept, because of its mechanism of action of lowering the number of active T cells, is associated with low T cell counts. Efalizumab has been associated with thrombocytopenia and haemolytic anaemia. Data on the safety of >2.5 years' continuous treatment with efalizumab are reassuring and a valuable beginning to understanding the role and risk of harm of long-term therapy for a chronic disease. Longer follow-up studies and safety databases, for each of the biologicals used in psoriasis, are needed to ensure both prolonged efficacy and minimal risk of harm.

Enhancement of antibacterial superoxide-anion generation in human monocytes by fumaric acid esters

Fumaric acid esters (FAE) are used for the systemic therapy of psoriasis with high clinical efficacy. Among the potential side effects of FAE therapy, lymphocytopenia is sometimes observed. We have investigated the effect of dimethylfumarate (DMF) and its main metabolite methylhydrogenfumarate (MHF) as well as dexamethasone on superoxide anion generation by human monocytes and neutrophils after stimulation with bacteria (Staphylococcus aureus and Escherichia coli) and the yeast Candida albicans in addition with zymosan particles and with the tripeptide fMLP. Expression of mannose receptors on monocytes and neutrophils was also analyzed. The results showed that dexamethasone significantly inhibited superoxide anion generation from monocytes in response to bacteria and C. albicans, whereas DMF as well as MHF dose dependently increased the production of superoxide anion in monocytes in response to zymosan, fMLP and bacteria. Dexamethasone, DMF or MHF did not modulate superoxide anion generation of neutrophils. Expression of mannose receptors on monocytes was not regulated by DMF or MHF. Our data provide evidence that DMF and MHF do not alter the production of superoxide anions as an important mechanism of innate defense against microorganisms.

Efalizumab for the Treatment of Moderate to Severe Plaque Psoriasis

OBJECTIVE:

To review the pharmacology, efficacy, and safety of efalizumab for the treatment of moderate to severe plaque psoriasis.

DATA SOURCES:

A MEDLINE search (1966–May 2005%) using the key words hu1124, anti-CD11a, efalizumab, Raptiva, Xanelim, and psoriasis was conducted. References of identified articles were reviewed for additional citations.

STUDY SELECTION AND DATA EXTRACTION:

Clinical trials evaluating the pharmacology, efficacy, and safety of efalizumab for treatment of moderate to severe plaque psoriasis in adults were included in our review.

DATA SYNTHESIS:

Efalizumab's ability to inhibit the binding of CD11a, a subunit of leukocyte function–associated antigen type 1, to intracellular adhesion molecule 1 results in decreased T-cell activation and migration, 2 key steps in the immunopathogenesis of psoriasis. Results of clinical trials have demonstrated that efalizumab administered subcutaneously is a safe and effective treatment for moderate to severe plaque psoriasis. Efalizumab was well tolerated in trials, with the majority of adverse events arising with the first dose and decreasing with subsequent doses. The high cost of this agent and lack of head-to-head trials with other drugs will likely restrict its use to patients who have failed prior systemic therapy or phototherapy.

CONCLUSIONS:

Efalizumab is a safe and effective therapy for treatment of moderate to severe plaque psoriasis in patients who have failed prior systemic therapy or phototherapy.