Mycophenolate mofetil as a systemic antipsoriatic agent: positive experience in 11 patients

Mycophenolate mofetil and skin diseases

Mycophenolate mofetil (MMF) is an immunosuppressive drug the efficiency of which has been established in renal transplantation. Recent studies suggest that it may also be effective in the treatment of variant skin diseases especially if the skin lesions are triggered by lymphocytes. Studies have shown efficacy in autoimmune bullous dermatoses, atopic dermatitis and psoriasis. However, there are no placebo-controlled trials that support the use of MMF as first line therapy in these skin diseases.

Mycophenolate mofetil and skin diseases

Mycophenolate mofetil (MMF) is an immunosuppressive drug the efficiency of which has been established in renal transplantation. Recent studies suggest that it may also be effective in the treatment of variant skin diseases especially if the skin lesions are triggered by lymphocytes. Studies have shown efficacy in autoimmune bullous dermatoses, atopic dermatitis and psoriasis. However, there are no placebo-controlled trials that support the use of MMF as first line therapy in these skin diseases.

Erythrodermic psoriasis: pathophysiology and current treatment perspectives

Erythrodermic psoriasis (EP) is a rare and severe variant of psoriasis vulgaris, with an estimated prevalence of 1%-2.25% among psoriatic patients. The condition presents with distinct histopathologic and clinical findings, which include a generalized inflammatory erythema involving at least 75% of the body surface area. The pathogenesis of EP is not well understood; however, several studies suggest that the disease is associated with a predominantly T helper 2 (Th2) phenotype. Given the morbidity and potential mortality associated with the condition, there is a need for a better understanding of its pathophysiology. The management of EP begins with a comprehensive assessment of the patient's presentation and often requires multidisciplinary supportive measures. In 2010, the medical board of the US National Psoriasis Foundation published consensus guidelines advocating the use of cyclosporine or infliximab as first-line therapy in unstable cases, with acitretin and methotrexate reserved for more stable cases. Since the time of that publication, additional information regarding the efficacy of newer agents has emerged. We review the latest data with regard to the treatment of EP, which includes biologic therapies such as ustekinumab and ixekizumab.

Psoriasis treatment: Unconventional and non-standard modalities in the era of biologics

Psoriasis is a potentially debilitating inflammatory dermatosis affecting 0.2%-4.8% of the population worldwide causing a significant occupational, personal or psychosocial morbidity to these patients for life. The basic aim of psoriasis therapy is to control the disease to maximum possible extent and improve the patient’s quality of life. Management of triggers for flare-ups, lifestyle modifications, and dietary supplements are often recommended. Intermittent or rotational therapy with frequent alterations in treatment options is usually needed to reduce toxicity of anti-psoriatic drugs in the absence of safer alternatives. Currently, several biological agents categorized as either T-cell targeted (e.g., Alefacept, Efalizumab) or cytokine modulating (e.g., Adalimumab, Infliximab, Etanercept) are available for treating severe psoriasis. However, their high cost is often precluding for most patients. The usefulness of systemic (methotrexate, cyclosporine, acitretin or several other therapeutic agents) or topical (tar, anthralin, corticosteroids or calcipotriol ointments, phototherapy with or without psoralens) therapies has been well established for the management of psoriasis. The literature is also replete with benefits of less used non-standard and unconventional treatment modalities (hydroxycarbamide, azathioprine, leflunomide, mycophenolate mofetil, isotretinoin, fumarates, topical calcineurin inhibitors, peroxisome proliferator-activated receptors agonists, statins, sulfasalazine, pentoxifylline, colchicine, grenz ray therapy, excimer laser, climatotherapy and balneophototherapy, peritoneal dialysis, tonsillectomy, ichthyotherapy, etc.). These can be used alternatively to treat psoriasis patients who have mild/minimal lesions, are intolerant to conventional drugs, have developed side effects or achieved recommended cumulative dose, where comorbidities pose unusual therapeutic challenges, or may be as intermittent, rotational or combination treatment alternatives.

Enteric-coated mycophenolate sodium in psoriasis vulgaris: an open pilot study

BACKGROUND

Mycophenolate mofetil is a well-known immunosuppressive agent in transplantation medicine. The efficacy of enteric-coated mycophenolate sodium (EC-MPS) was confirmed in other inflammatory skin diseases, including atopic dermatitis and SCLE.

OBJECTIVE

To investigate the efficacy and the tolerability/short-term safety of EC-MPS in patients with moderate to severe chronic plaque psoriasis.

PATIENTS AND METHODS

An open-label pilot study in which 20 patients with a PASI >10 received EC-MPS 720 mg twice daily for 6 weeks followed by 360 mg twice daily for another 6 weeks. Patients who completed 12 weeks of treatment were followed-up for an additional 12 weeks. Treatment outcomes were assessed with PASI50% and PASI75%.

RESULTS

Eighteen men and two women (mean age 46 years) entered the study. Sixty-five percent (13/20) finished the treatment period. By week 6, no patient achieved PASI 75% and 8/20 patients achieved a PASI 50%. Compared to week 6, 4/13 showed a deterioration of their psoriasis at week 12. Twenty-five percent (2/8) achieved a PASI 75% in week 24. The most-reported adverse events were itching (30%), diarrhea (10%), and a reversible elevation of the triglycerides level.

CONCLUSION

EC-MPS does not seem effective as monotherapy for moderate to severe psoriasis, but might be used at a dosage of 1440 mg daily in well-selected patients with treatment-resistant psoriasis.

Retrospective analysis of the treatment of psoriasis of the palms and soles

In this retrospective analysis, the effect of currently used treatments in 26 patients with psoriasis of the palms and soles were analyzed. In general, patients are treated initially with topical medications including superpotent topical corticosteroids in combination with calcipotriene ointment or tazarotene gel or both. If satisfactory improvement is not achieved in 4-8 weeks, systemic retinoids are added, formerly etretinate and currently acitretin, except in women of childbearing potential. If the latter regimen is not effective within two months, soak PUVA is added to the regimen of oral retinoids and topical medications. If improvement is inadequate, or if the treatment regimen is not tolerated, methotrexate or cyclosporine have been added in the past. The availability of the excimer laser has recently modified our approach so that this therapy is used in combination with acitretin before soak PUVA. With the availability of biologic agents, methotrexate is avoided because of its hepatotoxicity and bone marrow toxicity and cyclosporine is avoided because of its nephrotoxicity. If oral acitretin plus topical therapy is not adequate to control the disease and the excimer laser is not an option because of its limited availability, alefacept, etanercept and infliximab are added when possible. Other biologic agents are likely to be added to this list in the future.

Mycophenolate in dermatology

Originally used to treat psoriasis nearly three decades ago, mycophenolic acid, reformulated as mycophenolate mofetil (MMF), has been rediscovered by the world of dermatology. As a relatively well-tolerated immunosuppressive used in organ transplant recipients, MMF has recently been reported to show promise for several dermatologic conditions, including psoriasis, pemphigus vulgaris, pyoderma gangrenosum, bullous lichen planus, and even connective tissue diseases such as lupus erythematosus and dermatomyositis. Although not intended to be exhaustive, this review discusses MMF with regard to its basic pharmacology, its side effects, and its reported efficacy in a variety of dermatologic indications. Relevant literature was retrieved by a Medline search combining the terms "mycophenolate" or "mycophenolic acid" and "skin" or "skin disease" or a number of specific conditions ("psoriasis", "dermatitis", "eczema", "pemphigoid", "pemphigus", "vasculitis", "pyoderma gangrenosum", "Crohn's disease", "graft-versus-host disease", "lichen planus"). As MMF has only been recently re-introduced for dermatologic application, the nature of much of the literature is admittedly that of case reports or case series. Nevertheless, the results are sufficiently promising to warrant further larger, control studies.

Guidelines of care for the management of psoriasis and psoriatic arthritis: section 4. Guidelines of care for the management and treatment of psoriasis with traditional systemic agents

Psoriasis is a common, chronic, inflammatory, multisystem disease with predominantly skin and joint manifestations affecting approximately 2% of the population. In this fourth of 6 sections of the guidelines of care for psoriasis, we discuss the use of traditional systemic medications for the treatment of patients with psoriasis. Treatment should be tailored to meet individual patients' needs. We will discuss in detail the efficacy and safety, and offer recommendations for the use of the 3 most commonly used, and approved, traditional systemic agents: methotrexate, cyclosporine, and acitretin. We will also briefly discuss the available data for the use of azathioprine, fumaric acid esters, hydroxyurea, leflunomide, mycophenolate mofetil, sulfasalazine, tacrolimus, and 6-thioguanine in psoriasis.

Nonstandard and off-label therapies for psoriasis

Although most psoriasis patients respond to standard therapies, many circumstances warrant the use of nonstandard or off-label treatments. For instance, patients with treatment-resistant psoriasis or those who have had multiple adverse effects to other therapies may be good candidates for off-label treatments. Similarly, patients with unusual and hard-to-treat forms of psoriasis such as pustular psoriasis and palmoplantar psoriasis or specific comorbidities may benefit from certain nonstandard therapies. Drugs that may be used as alternatives to standard therapies include mycophenolate mofetil, tacrolimus or pimecrolimus, isotretinoin, colchicine, sulfasalazine, paclitaxel, dapsone, azathioprine, and hydroxyurea. Other unconventional therapies include climatotherapy at the Dead Sea and grenz ray therapy.

[Medically induced myopathia]

Muscular side effects of various anesthetics, analgetics, antibiotics, antihistaminic drugs, antiretrovirals, cardiotropics, immunosuppressants, lipid-lowering drugs, psychotropic drugs, anticancer drugs, and other substances are more frequent than assumed and are easily overlooked. Clinically, muscular side effects manifest as fatigue, myalgias, persistent or transient weakness, stiffness, intolerance to exercise, psychomotor slowing, muscle cramps, wasting, dyspnea, dysphagia, fasciculations, reduced tendon reflexes, impaired consciousness, myoglobinuria, renal failure, or hyperthermia. Diagnosis of these drug-induced myopathies is based on history, clinical neurologic examination, blood work, urine analysis, repetitive stimulation, electromyography, and muscle biopsy. A drug which induces muscular side effects should never be given again. Particularly in patients suffering from primary myopathy, myotoxic drugs should be applied with caution. The drugs which most frequently induce muscular side effects are steroids, statins, fibrates, antiretrovirals, immunosuppressants, colchicine, amiodarone, and anticancer drugs. Many drugs exhibit their myotoxic potential only in combination with other drugs or premorbid pathologic myogenic conditions.

Sequential study on the treatment of moderate-to-severe chronic plaque psoriasis with mycophenolate mofetil and cyclosporin

BACKGROUND

There are numerous studies that individually evaluate the efficacy/effectiveness and toxicity of drugs in the systemic treatment of psoriasis. On the contrary, we can hardly find studies that compare each other.

OBJECTIVE

To evaluate and compare the effectiveness and toxicity of mycophenolate mofetil and cyclosporin in chronic plaque psoriasis through a prospective, sequential, cross-over, non-randomized, two-phase, open-label study.

PATIENTS/METHODS

Eight patients (five women and three men; mean age 57, range 35-78) with moderate-to-severe chronic plaque psoriasis were included in the study. They were treated with oral mycophenolate mofetil (30 mg/kg/day) over a period of 16 weeks. Following a variable washout period and after a new outbreak of the disease, oral cyclosporin was introduced at a dose of 4 mg/kg/day. During both treatment regimens, follow-up visits were performed at 3, 8 and 16 weeks.

RESULTS

In both groups, the PASI started to decrease once treatment was begun. Cyclosporin was faster and statistically a lot more effective than mycophenolate mofetil, reaching a higher number of complete remissions and better percentages of PASI improvement from baseline (45.7%, 60.2% and 60.5% at 3, 8 and 16 weeks respectively for mycophenolate mofetil, and 89.7%, 95.3% and 95.3% respectively at the same intervals for cyclosporin). Cyclosporin was also more predictable in its action as the percentage of improvement along the follow-up visits had a much wider range for mycophenolate mofetil. Overall, the tolerability of both drugs was good. None of the patients had to discontinue treatment because of an adverse event. Two patients treated with cyclosporin showed increased plasma levels of creatinine.

CONCLUSIONS

Cyclosporin is more effective, fast, and predictable in its effect than mycophenolate mofetil to control moderate-to-severe chronic plaque psoriasis. Both drugs are well tolerated in short courses of treatment.

Optimal management of severe plaque form of psoriasis

Psoriasis is a chronic, inflammatory, hyperproliferative skin disease that affects 1-2% of the general population in the UK and US. Plaque psoriasis is the most common form, accounting for approximately 90% of cases. The disease is usually chronic and persistent, although up to 50% of patients may enter spontaneous remission for varying periods of time. There is no cure for psoriasis; therefore, the aim of treatment is to minimize the extent and severity of the disease to the point at which it no longer substantially disrupts the patient's quality of life. First-line therapy of psoriasis usually consists of topical agents, such as emollients, tar, dithranol, and vitamin D3 analogs. In cases of severe, extensive psoriasis, where topical therapy is either impractical or not sufficiently effective, systemic treatment may be warranted at the outset. In these circumstances, the therapeutic options include: (i) intensive inpatient or day center topical therapy; (ii) phototherapy; and/or (iii) systemic agents. There are now a number of systemic agents available for the treatment of severe psoriasis, but all have potential adverse effects. We review the current treatment options, which include the use of phototherapy and systemic agents, and provide recommendations on their use in clinical practice. Importantly, treatment should be tailored to each individual patient depending on concurrent medical problems (which might preclude certain agents), patient choice and acceptance of the risk of adverse effects.

Use of Mycophenolate Mofetil in Autoimmune and Renal Diseases

Progress in understanding the pathogenesis and treatment of rheumatologic and glomerular diseases such as systemic lupus erythematosus and particularly lupus nephritis has been closely linked with the development of newer immunosuppressive agents. With improved patient survival following the institution of cyclophosphamide and corticosteroid therapy, longer-term management issues came to the forefront, especially how to decrease adverse effects of the immunosuppressive regimen. Many of the immunosuppressive regimens used in lupus patients were first established as efficacious and safe through their use in solid organ transplantation. Mycophenolate mofetil (MMF) is now widely used in the field of transplantation. Following anecdotal reports describing benefits of MMF in lupus and lupus nephritis patients, small studies and finally large randomized, controlled trials have established the use of MMF in these patients, particularly those with lupus nephritis. MMF use in other rheumatologic and renal diseases has been evaluated in only smaller studies and very few randomized controlled trials. Nevertheless, many studies currently are ongoing with this immunosuppressive agent. This article will review the published data and the experience of two major New York medical centers with the use of MMF in autoimmune and renal diseases.

Emerging drugs for moderate-to-severe psoriasis

Psoriasis is a chronic, incurable, disabling skin disease characterised by red, scaly plaques. Approximately 23% of psoriasis patients also have an accompanying arthritis that can become debilitating. Psoriasis has a stigmatising effect on its victims, who often feel socially isolated. Although the exact aetiology of psoriasis is still unknown, it is clearly an immune-mediated disease. Traditional therapies for psoriasis include topical drugs, such as corticosteroids, retinoids and vitamin D3 analogues; systemic drugs, such as methotrexate, ciclosporin and retinoids; and phototherapy. These mainstays of treatment are efficacious for the treatment of severe disease; however, most are associated with toxicities or are inconvenient. Recent advances in biotechnology have produced new pharmaceuticals that interfere with immune responses thought to be involved in the pathogenesis of psoriasis and other inflammatory diseases. The immunobiologicals, one new family of drugs, consist of monoclonal antibodies and fusion proteins. Many have demonstrated efficacy in treating psoriasis. Some appear to offer safety benefits over traditional therapies; further monitoring and surveillance of these agents is required to adequately establish safety profiles. This article discusses existing and emerging treatments for moderate-to-severe psoriasis.

The Use of Systemic Immune Moderators in Dermatology: An Update

In addition to corticosteroids, dermatologists have access to an array of immunomodulatory therapies. Azathioprine, cyclophosphamide, methotrexate, cyclosporine, and mycophenolate mofetil are the systemic immunosuppressive agents most commonly used by dermatologists. In addition, new developments in biotechnology have spurred the development of immunobiologic agents that are able to target the immunologic process of many inflammatory disorders at specific points along the inflammatory cascade. Alefacept, efalizumab, etanercept, and infliximab are the immunobiologic agents that are currently the most well known and most commonly used by dermatologists. This article reviews the pharmacology, mechanism of action, side effects, and clinical applications of these therapies.

Novel pharmacological approaches in the treatment of psoriasis

Progress in the understanding of psoriasis as a T-cell mediated inflammatory disease has led to the development of new immunomodulatory therapies. Currently the main focus is on the so-called biologics (or biological agents), including fusion proteins, monoclonal antibodies, cytokines and selective receptors. They mainly target single steps in the complex cascade of humoral and cellular inflammatory immuno-mechanisms that finally lead to the accelerated growth of epidermal and vascular cells in the psoriatic lesions. The most promising and advanced biological agents are discussed along with their influence on the critical pathophysiological steps in psoriasis, including depletion of T cells, blockade of initial T-cell activation and T-cell receptor (TCR) stimulation, blockade of costimulatory signals and T-cell proliferative signals as well as restoration of the T helper type 1 (Th1)/Th2 balance by diminishing type 1 cytokines and administration of type 2 cytokines. In addition to the biological agents, further development of 'classical' dermatological therapies, such as retinoids, or the discovery of new indications for non-dermatological agents contribute to the novel pharmacological approaches in the treatment of psoriasis.

Rethinking the Psoriasis Area and Severity Index: the impact of area should be increased

BACKGROUND

The Psoriasis Area and Severity Index (PASI) is the most frequently used clinical severity scale in clinical trials. Drug approval often depends on a 75% improvement in the baseline PASI score, also known as a PASI 75 or Delta PASI 75. This benchmark may be an overly stringent way to determine the success of psoriasis treatments as Delta PASIs appear to under-represent true clinical improvement. This discrepancy may relate to the way numerical values are assigned to the degree of body surface area (BSA) involvement.

OBJECTIVES

To assess whether altering the BSA component of the PASI formula so that it is weighted more heavily will result in a calculated change in psoriasis severity that more closely reflects patient assessment of improvement. Models developed included the Psoriasis Log-based Area and Severity Index (PLASI), which assigns values to the BSA score based on a linear scale using logarithms to define the intervals, and the Psoriasis Exact Area and Severity Index (PEASI), which uses the actual BSA as the multiplicative factor in the area score.

METHODS

Data were abstracted retrospectively from two clinical trials involving psoriasis treatments that used the PASI. The same trained psoriasis graders were involved in both trials. In these trials, baseline and end-point PASI worksheets were completed that included the actual clinician-estimated BSA involvement (0-100%) for each of the four areas (head, upper extremities, trunk and lower extremities). In one of the trials, patients were asked to assess the percentage improvement in their psoriasis at the end of the treatment window. PASIs and Delta PASIs were recalculated based on the new models and all scoring systems were validated by analysing their relationship to patients' self-assessments.

RESULTS

Clinical improvements under the new grading systems translated into greater percentage changes than calculated using the Delta PASI formula. Specifically, the Delta PASI 50 translated to a Delta PLASI 57.2 and Delta PEASI 61.1; Delta PASI 75 was equivalent to Delta PLASI 85.7 and Delta PEASI 91.7. Importantly, Delta PASI tended to be systematically lower than patients' self-assessment, while Delta PLASI and Delta PEASI better matched patients' self-assessments using a best-fit model.

CONCLUSIONS

These results suggest that the Delta PASI underestimates percentage improvement when compared with measures of patient's self-assessment, while Delta PLASI and Delta PEASI correlate better. Prospective studies will have to be performed to confirm these relationships, but weighting BSA more heavily in the severity score may result in a more accurate reflection of clinical status.

Mycophenolate mofetil for remission maintenance in the treatment of Wegener's granulomatosis

OBJECTIVE

To examine the safety of mycophenolate mofetil (MMF) for remission maintenance in patients with Wegener's granulomatosis (WG) who had been treated with daily cyclophosphamide (CYC) and glucocorticoids to induce remission.

METHODS

Fourteen patients were treated for active WG using a standardized regimen of CYC and glucocorticoids for induction of remission and MMF for remission maintenance. Outcome was assessed using predetermined definitions based on clinical characteristics and pathologic, laboratory, and radiographic findings.

RESULTS

Remission occurred in all 14 patients (100%) at a median time of 3 months. The median time to discontinuation of glucocorticoids was 8 months. No patients died during protocol treatment and 6 patients (43%) relapsed at a median of 10 months after achieving remission. MMF was well tolerated and no patients had to be withdrawn as a result of medication toxicity.

CONCLUSION

The use of CYC and glucocorticoids for induction of remission and MMF for remission maintenance was well tolerated, but disease relapses were observed.

Plasma trough levels of mycophenolic acid do not correlate with efficacy and safety of mycophenolate mofetil in psoriasis

BACKGROUND

Mycophenolate mofetil (MMF) has been shown to be effective for systemic treatment of psoriasis. MMF is the prodrug of mycophenolic acid (MPA), the pharmacologically active compound. The measurement of plasma MPA levels could be useful for optimizing therapeutic management using MMF.

OBJECTIVES

To investigate whether plasma trough levels of MPA correlate with the efficacy and safety of oral MMF in the treatment of patients with psoriasis.

METHODS

Six patients (four women and two men, mean age 58 years) with severe chronic plaque-type psoriasis were treated with oral MMF 1 g twice daily. The Psoriasis Area and Severity Index (PASI), routine laboratory examinations and plasma MPA trough levels, measured by an enzyme-multiplied immunoassay (EMIT), were determined at 2 weeks and 1, 3, 5 and 7 months.

RESULTS

All the patients experienced a marked improvement within the first 15 days and continued to do so for 5-7 months. Two patients achieved complete remission. MMF was well tolerated. MPA levels showed a wide intra- and interindividual variability. There was no significant correlation between MPA trough levels and the reduction of the PASI or the presence of adverse effects, but a good correlation with therapeutic compliance.

CONCLUSIONS

The monitoring of MPA trough levels with EMIT appears to be a poor predictor of efficacy or toxicity. In contrast, it is a useful tool to evaluate the degree of therapeutic compliance.

Position Paper: Oral Features of Mucocutaneous Disorders

Part of periodontology involves the diagnosis and treatment of a variety of non-plaque-related diseases of the periodontium. The International Workshop for a Classification of Periodontal Diseases and Conditions noted that the periodontist may be called upon to manage non-plaque-related mucocutaneous disorders either alone, or as part of a treatment team consisting of physicians, dentists or other allied health care professionals. This informational paper will review the etiology, clinical manifestations, diagnosis, and treatment of the most common chronic mucocutaneous diseases, including those that may present as desquamative gingivitis or intraoral vesiculobullous lesions. This paper is intended for the use of periodontists and other members of the dental profession.

Current systemic therapies for psoriasis: where are we now?

Many systemic agents are used in the treatment of psoriasis. They provide good control of psoriasis in the majority of patients and have improved their life quality indices. Frequently, combination therapy is utilized to synergize the efficacy of these medications. Many dermatologists are hesitant in prescribing systemic agents because of their adverse effects. However, such potential toxicities arising from these medications can largely be avoided if proper patient selection and close monitoring are performed.

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.

Connections between psoriasis and Crohn's disease

The prevalence of psoriasis in patients with Crohn's disease (CD) is higher than chance would allow if they were mutually exclusive diseases. A close examination reveals genetic and pathologic connections between these diseases. An appreciation for the role of tumor necrosis factor-alpha in both diseases has proven very important. Increased levels of this inflammatory cytokine have been measured in CD lesions, and in 1997 a clinical trial demonstrated the response of this disease to infliximab, a monoclonal antibody specific for tumor necrosis factor-alpha. A subsequent clinical trial evaluated infliximab in a patient with CD and psoriasis, another disease in which increased levels of tumor necrosis factor-alpha are seen in lesions. Scientists noticed the marked skin improvement of this patient and later demonstrated the efficacy of infliximab for psoriasis in a randomized, double-blind, placebo-controlled trial. Thus, an appreciation for connections between psoriasis and CD can suggest novel therapeutic strategies with ensuing benefits to patients. This article reviews epidemiologic, genetic, and pathologic connections between psoriasis and CD and discusses pharmaceuticals targeting inflammatory mediators common to each disease. (J Am Acad Dermatol 2003;48:805-21.)

LEARNING OBJECTIVE

At the completion of this learning activity, participants should understand how psoriasis and Crohn's disease are related at epidemiologic, genetic, and pathological levels and should appreciate how to use this knowledge to treat these diseases.

[New immunosuppressive agents for treating psoriasis]

Accumulative evidence suggests that psoriasis may be a genetically determined immunologenic inflammatory disorder based on an ongoing autoreactive Th-1 response. Various cytokines (e.g. IL-2, interferon-gamma etc.) are released and exert proliferative signals on to keratinocytes, which start proliferation that finally results in an incomplete differentiation. During this pathobiological process keratinocytes themselves express receptors that make them sensitive for growth inducing stimulation and also start the production of a set of cytokines that contribute to and maintain inflammation. Immunosuppressive agents, mostly by affecting T-cells may interfere with or even disrupt by rather unspecific mechanisms, this complex process of mutual stimulation of leucocytes and keratinocytes. In this manuscript we show mode of action, efficacy and side effects of Methotrexate, Ciclosporin A, Tacrolimus and Pimecrolimus, and discuss therapeutic options with mycophenolate mofetil and fumaric acid esters.

Mycophenolate mofetil and leflunomide: promising compounds for the treatment of skin diseases

In the past decade, there has been enormous progress in the understanding of the pathomechanisms of immune-mediated diseases, which has led to major advances in immunotherapeutic strategies. As a consequence, the armamentarium of specific and nonspecific immune-modulating and immunosuppressive drugs for the treatment of skin diseases has been widely extended. Among the nonspecific immunomodulators, mycophenolate mofetil and leflunomide show promising effects in a variety of autoimmune and inflammatory skin disorders. Both compounds inhibit a key enzyme in nucleotide biosynthesis, a step that is pivotal for the production of cytotoxic T cells and antibody formation. They do not act in the nucleus, which may explain their advantageous side-effect profile.

Novel immunotherapies for psoriasis

New insights into the pathophysiology of psoriasis have suggested possibilities for targeted therapeutic intervention. Several novel, systemic immunomodulatory therapies are currently in clinical development and results of recent clinical trials are remarkable. These include approaches targeting antigen presentation and costimulation, T-cell activation and leukocyte adhesion, the action of proinflammatory mediators and the administration of anti-inflammatory cytokines. These trials contribute to our further understanding of the disease, indicating which mechanisms play a greater or lesser part in its development. Moreover, they will lead to new therapeutic options. If psoriasis is considered as a visible model disease for T-cell-mediated disorders characterized by a type-1 cytokine pattern these recent findings might have a more general impact on the treatment of autoimmune disorders.