The antipsoriatic agent dimethylfumarate immunomodulates T-cell cytokine secretion and inhibits cytokines of the psoriatic cytokine network

Psoriasis: emerging therapeutic strategies

Psoriasis is a chronic inflammatory skin disorder that is characterized by thickened, scaly plaques, and is estimated to affect approximately 1-3% of the Caucasian population. Traditional treatments, although effective in patients with limited disease, have numerous shortcomings, including inconvenience and toxicity. These drawbacks mean that many patients experience cycles of disease clearance, in which normal quality of life alternates with active disease and poor quality of life. However, as this review discusses, recent advances have highlighted the key role of the immune system in the pathogenesis of psoriasis, and have provided new defined targets for therapeutic intervention, offering hope for safe and effective psoriasis treatment.

[Successful treatment of skin and lung sarcoidosis with fumaric acid ester]

A 61-year old female patient with cutaneous sarcoidosis was treated with fumaric acid esters (Fumaderm). After 12 months of therapy, lesions were markedly improved and treatment was discontinued. 18 months later, the cutaneous lesions recurred, angiotensin converting enzyme (ACE) serum levels were increased and a chest X-ray demonstrated pulmonary involvement. Therapy with fumaric acid esters was again started. The skin showed improvement after 2 months and completely cleared within 17 months, within 4 months ACE levels normalized, and within 10 months radiologic changes markedly resolved. This case demonstrates a possible role for fumaric acid esters not only in the treatment of cutaneous but also systemic sarcoidosis.

Fumaric acid esters in severe psoriasis, including experience of use in combination with other systemic modalities

BACKGROUND

Fumaric acid esters (FAE) are used as a systemic treatment for severe psoriasis in Germany but there has been only very little published experience from the U.K. The potential for use in combination with other systemic drugs has not been explored.

OBJECTIVES

To present data relating to the efficacy of FAE in severe psoriasis and to examine the potential dose-sparing effect and safety issues when FAE are combined with other systemic agents.

METHODS

We retrospectively analysed the records of patients who had received FAE for severe psoriasis either alone (in two cases) or along with other systemic medications (in 10 cases). We reviewed the efficacy of FAE and assessed whether dose reductions were achieved for other systemic drugs. Patients were monitored carefully for possible adverse effects.

RESULTS

Of 12 patients treated with FAE one discontinued the drug very early, due to flushing, while on a very low dose. The other 11 patients all demonstrated an improvement in psoriasis after starting FAE. Nine patients received FAE in combination with other systemic therapies including ciclosporin, acitretin, hydroxyurea and methotrexate. Seven achieved useful overall reductions in the dose of the other drugs. In two patients severe psoriasis was controlled using FAE alone. The side-effect profile of FAE was similar to that previously reported. There was no evidence of drug interactions.

CONCLUSIONS

FAE appear effective and less toxic than other systemic treatments for psoriasis. FAE were used successfully in combination with other systemic agents and generally enabled the doses of the more hazardous drugs to be reduced. Extremely careful monitoring is required when using FAE in such combined regimens as experience is currently very limited.

Fumaric acid esters in the treatment of psoriasis: an Italian experience

BACKGROUND

Psoriasis is a common, chronic, cell-mediated, inflammatory skin disease. Treatment limitations and a developing understanding of its pathogenesis on a molecular level have encouraged much interest in the field of immunomodulatory therapy.

OBJECTIVE

To evaluate the efficacy and safety of fumaric acid esters, in particular dimethylfumarate (DMF), in the treatment of moderate to severe plaque psoriasis intolerant and/or resistant to other conventional systemic therapies.

METHODS

A total of 40 patients were enrolled in this study. DMF was orally administered at the daily dose of 30 mg up to 360 mg for a minimum of 6 months treatment. Patients were followed-up with psoriasis area and severity index (PASI) score assessment, and clinical and photographic documentation.

RESULTS

A total of 33 (82.5%) patients achieved complete clinical remission with DMF treatment: eight after 3 months and 25 after 6 months. Adverse events, such as intolerable abdominal cramps and incoercible diarrhoea, occurred in four patients who, for this reason, interrupted therapy.

CONCLUSION

The findings suggest that DMF is a safe, effective and well-tolerated long-term oral treatment worthy of consideration for selective patients.

Ultraviolet B 308-nm excimer laser treatment of psoriasis: a new phototherapeutic approach

BACKGROUND

Excimer laser-derived 308-nm ultraviolet (UV) B therapy is a new alternative for treating psoriasis by phototherapy. Some studies have been made showing the effectiveness of intralesional phototherapy technology in treating psoriasis. However, there has been no information available so far with regard to the cumulative dosage on a larger group of patients and on therapy optimized treatment strategies.

OBJECTIVES

One hundred and twenty psoriatic patients were treated according to standard protocol to define the effectiveness. Our aim was to develop new parameters and determine whether effectiveness could be improved and whether treatment exposure, the cumulative UVB dose and adverse effects could be minimized.

METHODS

Initially, the excimer laser's effectiveness in treating psoriasis was evaluated in an open prospective study according to standard protocol. This included 120 adult patients (67 female/53 male) with chronic plaque psoriasis and < 20% involved body surface. The initial dose was based on three multiples of a predetermined minimal erythema dose (MED). Patients were treated twice a week for the first 3 weeks, then once a week until clearance was achieved. The main parameters were the initial starting dose, psoriasis area and severity index (PASI), the number of treatments needed, the time in treatment and the cumulative dose needed to clear psoriatic plaques. Thereafter, 43 patients were treated as a second comparable group. Therapy began with a starter dose, defined as MED-I. MED-I was defined as a UVB 308-nm dose which provoked a visible increase in erythema after 24 h. In addition, the epidermal thickness of the plaques was measured on an individual basis by 20-MHz ultrasound and correlated to the MED-I.

RESULTS

Of the patients who met the standard protocol, 65.7% were at least 90% clear after a maximum of 10 treatments; an even greater number (85.3%) showed a > or = 90% improvement in PASI after 13 sessions, while 14.7% of patients had only a < or = 50% PASI improvement. The cumulative UVB dose was 11.25 +/- 4.21 J cm-2 and the average treatment time was 7.2 weeks. Patients treated individually with the MED-I starter dose showed nearly identical rates of clearance (83.7%), but were clear in 7.07 +/- 2.15 sessions with a cumulative dose of 6.25 +/- 4.02 J cm-2.

CONCLUSIONS

The majority of our patients benefited greatly from laser-derived 308-nm UVB therapy, which cleared skin lesions faster than conventional phototherapy. As this therapy targets only the involved skin, the thickness of the plaques and individual MED-I should determine the initial dose, thus increasing the effectiveness of the therapy. We propose that light therapy sparing uninvolved skin will become predominant in the future.

Long-term safety aspects of systemic therapy with fumaric acid esters in severe psoriasis

BACKGROUND

Therapy with fumaric acid esters (FAE) has been shown to be safe and effective in patients with severe psoriasis in several clinical studies with limited follow-up periods. In view of the chronic character of psoriasis, long-term safety aspects are of major importance in determining the suitability of a drug during prolonged periods of treatment.

OBJECTIVES

To investigate adverse events of therapy with systemic FAE with follow-up periods of up to 14 years, in order to determine safety aspects of their long-term use in patients with severe psoriasis.

METHODS

Current and/or past therapeutic use of FAE was reviewed in 66 patients with severe psoriasis.

RESULTS

Forty-one of 66 patients had received FAE for at least 1 year, and 12 of these 41 patients had received FAE for between 10 and 14 years. Adverse events were reported in 73% of the patients. These were usually mild and mainly consisting of flushing (55%), diarrhoea (42%), nausea (14%), tiredness (14%) and stomach complaints (12%). A relative lymphocytopenia was observed in 76% of patients during therapy with FAE, resulting in a permanent discontinuation of therapy with FAE in four patients. A transient eosinophilia and moderate liver enzyme elevations were observed in 14% and 25% of patients, respectively.

CONCLUSIONS

The present study indicates that FAE can be considered as a safe long-term treatment in patients with severe psoriasis.

Current concepts in psoriasis and its treatment

Many advances have been made in our understanding of the biology of psoriasis over the past 20 years. We are close to knowing the genetic determinants of psoriasis. There is now greater insight into the immunological mechanisms that produce the phenotype, and the possibility of intervening selectively to antagonise some of these mechanisms is becoming a reality. Nevertheless, psoriasis remains an enigmatic disease, and much of the suffering it produces is not adequately addressed. The sheer number of treatments that are used therapeutically suggests a lack of efficacy and/or toxicity of many of these approaches. In this review, we aim to briefly describe the biology of psoriasis, document the key features of treatments that are available or under development, and explain how these treatments can be used effectively to manage this chronic relapsing disease.

Macular exanthema due to fumaric acid esters

OBJECTIVE

To report a case of an unusual skin reaction to fumaric acid esters (FAE).

CASE SUMMARY

A 68-year-old white woman who was treated with FAE for 4 days for lichen planus developed generalized pruritic exanthema. This was suspected to be an allergic drug reaction to FAE, and the treatment was discontinued. After 48-72 hours, the exanthema resolved completely. An objective causality assessment revealed that the adverse drug event was probable. As skin testing for diagnostic purposes is not feasible with FAE, the drug-related origin of the exanthema was confirmed by oral rechallenge with FAE.

DISCUSSION

The effectiveness of FAE in the systemic treatment of psoriasis vulgaris has been proven by controlled clinical trials. The compound has been shown to be tolerable and safe even during prolonged treatment. The most frequent adverse effects are gastrointestinal symptoms and flushing, which typically occur 4-6 hours after administration of the drug. Allergic reactions to FAE have not yet been reported. Since the patient was rechallenged with the suspected drug, we could confirm the allergic origin of the exanthema.

CONCLUSIONS

The occurrence of allergic skin reaction should be considered in patients receiving treatment with FAE.

IgG class antibodies to heat shock-induced streptococcal antigens in psoriatic patients

BACKGROUND

Psoriasis is a chronic inflammatory skin disease. Probably autoimmune in nature, and associated with streptococcal throat infections as a triggering factor. Although many groups have associated the disease with other pathogens, Streptococcus pyogenes seems to be the most important microorganism related to this disease. Therefore, it is necessary to identify the streptococcal antigens involved in the process.

METHODS

In this work IgG class antibodies to soluble antigens obtained from Staphyloccus aureus, Candica albicans or S. pyogenes before and after heat shock induction, were analyzed by ELISA in 28 psoriatic patients and 30 healthy donors.

RESULTS

In all cases, the patients and the controls had IgG class antibodies to the four antigens. Nevertheless, the IgG levels to the heat shock-induced S. pyognes were statistically different between the patients and the controls (P < 0.001). There was no difference between the groups when the IgG antibodies to the other antigens, including the noninduced streptococcal extract, were analyzed. Additionally, anti-streptolysin O titers and throat cultures were carried out in all patients and controls. No differences between ASO titers were found but the patients were more frequently colonized by pyogenes.

CONCLUSION

Results obtained in this study suggest that heat shock-induced proteins from S. pyogenes are associated with psoriasis.

Dimethylfumarate inhibits TNF-induced nuclear entry of NF-kappa B/p65 in human endothelial cells

Fumaric acid esters, mainly dimethylfumarate (DMF), have been successfully used to treat psoriasis. Based on previous observations that DMF inhibited expression of several TNF-induced genes in endothelial cells, we wished to explore the molecular basis of DMF function in greater detail. In first experiments we analyzed DMF effects on tissue factor expression in human endothelial cells in culture, because tissue factor is expressed by two independent sets of transcription factors, by NF-kappa B via TNF and by early gene response-1 transcription factor via vascular endothelial growth factor (VEGF). We show that DMF inhibits TNF-induced tissue factor mRNA and protein expression as well as TNF-induced DNA binding of NF-kappa B proteins, but not VEGF-induced tissue factor protein, mRNA expression, or VEGF-induced early gene response-1 transcription factor/DNA binding. To determine where DMF interferes with the TNF/NF-kappa B signaling cascade, we next analyzed DMF effects on I kappa B and on the subcellular distribution of NF-kappa B. DMF does not inhibit TNF-induced I kappa B alpha phosphorylation and I kappa B degradation; thus, NF-kappa B is properly released from I kappa B complexes even in the presence of DMF. Importantly, DMF inhibits the TNF-induced nuclear entry of NF-kappa B proteins, and this effect appears selective for NF-kappa B after the release from I kappa B, because the constitutive shuttling of inactive NF-kappa B/I kappa B complexes into and out from the nucleus is not blocked by DMF. Moreover, DMF does not block NF-kappa B/DNA binding. In conclusion, DMF appears to selectively prevent the nuclear entry of activated NF-kappa B, and this may be the basis of its beneficial effect in psoriasis.

Dimethylfumarate inhibits tumor-necrosis-factor-induced CD62E expression in an NF-kappa B-dependent manner

Fumaric acid esters are thought to improve psoriasis by altering leukocyte, keratinocyte, and/or endothelial functions. To determine specificity, kinetics, and molecular mechanisms of different fumaric acid esters in their ability to inhibit endothelial cell activation, we analyzed CD62E and CD54 expression in endothelial cells in vivo and in vitro. In lesional skin of psoriatic patients, oral fumaric acid ester treatment resulted in a marked reduction of CD62E but not CD54 expression on dermal microvessels. Using human umbilical vein endothelial cells, dimethylfumarate almost completely inhibited tumor-necrosis-factor-induced CD62E, but not CD54 expression at concentrations < or = 70 microM, mimicking the situation in vivo. A 60 min dimethylfumarate preincubation was sufficient to block tumor-necrosis-factor-induced CD62E expression for up to 24 h. In contrast, equimolar concentrations of methylhydrogenfumarate, the hydrolysis product of dimethylfumarate, did not suppress tumor-necrosis-factor-induced CD62E expression. Likewise, all fumaric acid esters other than dimethylfumarate were ineffective. Using CD62E, NF-kappa B, or AP-1-responsive promoter constructs, dimethylfumarate inhibited tumor-necrosis-factor-induced activation of the CD62E and the NF-kappa B but not the AP-1 promoter construct. In summary, at a dose range < or = 70 microM, dimethylfumarate appeared to be a specific inhibitor of CD62E expression in an NF-kappa B-dependent manner.

IL-10 improves skin disease and modulates endothelial activation and leukocyte effector function in patients with psoriatic arthritis

Psoriatic arthritis (PsA) provides an ideal disease model in which to investigate the bioactivities of potentially therapeutic cytokines at multiple sites of tissue inflammation. We investigated the effects of IL-10, an antiinflammatory cytokine, given s.c. for 28 days in a double-blind, placebo-controlled study in PsA patients. Synovial/skin biopsies, peripheral blood leukocytes, articular magnetic resonance images, and clinical disease activity scores were obtained sequentially. Modest, but significant clinical improvement in skin, but not articular disease activity scores with only minor adverse effects was observed. Type 1, but not type 2 T cell cytokine production in vitro was suppressed in human rIL-10 compared with placebo recipients. Similarly, monokine production in vitro was reduced, whereas serum soluble TNFRII levels were elevated, indicating suppression of monocyte function. Decreased T cell and macrophage infiltration in synovial tissues was accompanied by reduced P-selectin expression. Moreover, suppressed synovial enhancement on magnetic resonance imaging and reduced alpha(v)beta(3) integrin expression on von Willebrand factor(+) vessels were observed. Together these data demonstrate that a short course of IL-10 modulates immune responses in vivo via diverse effects on endothelial activation, and leukocyte recruitment and effector function. Such biological changes may result in clinically meaningful improvement in disease activity.

Inhibition of dendritic cell differentiation by fumaric acid esters

Fumaric acid esters have proved to be effective for the systemic treatment of severe psoriasis vulgaris. These compounds have been shown to induce a Th2-like cytokine secretion pattern in T cells and to reduce keratinocyte proliferation in vitro. Dendritic cells seem to be of major importance as regulatory cells driving the psoriatic tissue reaction. Monocytes or CD34-positive myeloid progenitor cells are precursors of dendritic cells that can be generated in vitro by culture with granulocyte-macrophage colony-stimulating factor and interleukin-4. Using this model the effect of fumaric acid esters on granulocyte-macrophage colony-stimulating factor/interleukin-4-induced differentiation of monocyte-derived dendritic cells was investigated. The results of this study show that dimethylfumarate as well as methylhydrogenfumarate-calcium-salt (0.01-100 microg per ml) concentration-dependently inhibit monocyte-derived dendritic cell differentiation. This was reflected by an inhibition of CD1a, CD40, CD80, CD86, and HLA-DR expression as well as by a reduced capacity of dimethylfumarate-treated monocyte-derived dendritic cells to stimulate lymphocytes in the allogeneic mixed lymphocyte reaction. Other fumaric acid esters showed no effect on monocyte-derived dendritic cell-differentiation. At higher concentrations (30-100 microg per ml) dimethylfumarate, but not methylhydrogenfumarate calcium-salt induced apoptosis in monocyte-derived dendritic cells as measured by expression of Apo 2.7 and DNA fragmentation (TUNEL assay). These data point to a high susceptibility of the monocyte/dendritic cell system to dimethylfumarate and its main metabolite methylhydrogenfumarate. Other fumaric acid esters investigated were without effect. As the effects of fumarates on monocyte-derived dendritic cells observed occur at concentrations 20-fold lower compared with lymphocytes, our data seem to be of relevance in explaining the possible mode of action of these compounds in psoriasis.

Dimethylfumarate is an inhibitor of cytokine-induced nuclear translocation of NF-kappa B1, but not RelA in normal human dermal fibroblast cells

We previously demonstrated that the oral antipsoriatic dimethylfumarate is an inhibitor of cytokine-induced adhesion molecule expression in endothelial HUVEC cells. We now report the inhibitory effect of dimethylfumarate on tumor-necrosis-factor-alpha- or interleukin-1 alpha-induced intercellular adhesion molecule 1 expression in normal human dermal fibroblasts. Western blots of normal human dermal fibroblast cytoplasmic extracts showed that dimethylfumarate has minor effects on the I kappa B alpha, beta and epsilon proteins: their cytokine-induced degradation and resynthesis is only slowed down, an effect most prominently observed for I kappa B beta. No inhibitory effect of dimethylfumarate was observed on cytokine-induced RelA/p65 or c-Rel accumulation in nuclear extracts of cytokine-treated normal human dermal fibroblast cells. In contrast, cytokine-induced nuclear factor kappa B1/p50 nuclear accumulation was specifically inhibited by dimethylfumarate. This inhibitory effect on nuclear factor kappa B1 nuclear localization in normal human dermal fibroblasts proved sufficient to inhibit nuclear factor kappa B1-RelA binding to nuclear factor kappa B consensus oligonucleotides in DNA binding assays. Likewise, cytokine-induced activation of a pNF kappa B::luciferase reporter construct in transiently transfected normal human dermal fibroblasts was inhibited by dimethylfumarate. The observations support a mechanistic model for the oral antipsoriatic dimethylfumarate in which lowering of nuclear factor kappa B1 leads to changes in the nuclear factor kappa B1-RelA nuclear balance and inhibition of cytokine-induced adhesion molecule expression in normal human dermal fibroblasts.

Treatment of severe psoriasis with fumaric acid esters: scientific background and guidelines for therapeutic use. The German Fumaric Acid Ester Consensus Conference

Fumaric acid ester (FAE) therapy has proved to be safe and effective in patients with severe psoriasis vulgaris. This treatment was introduced nearly 30 years ago, but is only now gaining renewed interest among dermatologists. FAE therapy is licensed in Germany and registration is pending in many European countries. Multicentre trials have confirmed the beneficial effect of FAE in psoriasis and have defined the spectrum of its adverse effects. Although the mode of action of FAEs in the treatment of psoriasis is not fully understood, recent experimental data point towards a skewing of the Th1-dominated T-cell response in psoriasis to a Th2-like pattern, and inhibition of proliferation of keratinocytes. This article reviews the experimental and clinical information on FAEs in psoriasis and provides guidelines for the clinical use of FAEs derived from a consensus meeting of leading experts.

Fumaric acid esters: an alternative systemic treatment for psoriasis

We report the successful clearance of severe chronic plaque psoriasis following treatment with fumaric acid esters (FAE) in two patients who had failed previous systemic therapy. FAE is gaining increasing acceptance for the treatment of psoriasis in countries such as Germany and the Netherlands, but at present remains unlicensed in Britain.