Psoriasis and psoriatic arthritis are inflammatory diseases that respond well to anti-tumour necrosis factor-α therapy. To evaluate the effects of anti-tumour necrosis factor-α treatment on expression of adhesion molecules and angiogenesis in psoriatic lesional skin and synovial tissue, we performed a prospective single-centre study with infliximab therapy combined with stable methotrexate therapy. Eleven patients with both active psoriasis and psoriatic arthritis received infusions of infliximab (3 mg/kg) at baseline, and at weeks 2, 6, 14 and 22 in an open-label study. In addition, patients continued to receive stable methotrexate therapy in dosages ranging from 5 to 20 mg/week. Clinical assessments, including Psoriasis Area and Severity Index (PASI) and Disease Activity Score (DAS), were performed at baseline and every 2 weeks afterward. In addition, skin biopsies from a target psoriatic plaque and synovial tissue biopsies from a target joint were taken before treatment and at week 4. Immunohistochemical analysis was performed to detect the number of blood vessels, the expression of adhesion molecules and the presence of vascular growth factors. Stained sections were evaluated by digital image analysis. At week 16, the mean PASI was reduced from 12.3 ± 2.4 at baseline to 1.8 ± 0.4 (P ≤ 0.02). The mean DAS was reduced from 6.0 ± 0.5 to 3.6 ± 0.6 (P ≤ 0.02). We found some fluctuations in DAS response as compared with the change in PASI, with the latter exhibiting a steady decrease over time. After 4 weeks the cell infiltrate was reduced in both skin and synovium. There was a significant reduction in the number of blood vessels in dermis and synovium at week 4. A significant reduction in the expression of αvβ3 integrin, a marker of neovascularization, was also found in both skin and synovium at week 4. In addition, a significant reduction in the expression of adhesion molecules was observed in both skin and synovium at week 4. We also observed a trend toward reduced expression of vascular endothelial growth factor in both skin and synovium. In conclusion, low-dose infliximab treatment leads to decreased neoangiogenesis and deactivation of the endothelium, resulting in decreased cell infiltration and clinical improvement in psoriasis and psoriatic arthritis.
Angiogenesis; immunotherapy; inflammation; psoriasis; psoriatic arthritis
Psoriasis is a chronic and immunomediated skin disease characterized by erythematous scaly plaques. Psoriasis affects approximately 1% to 3% of the Caucasian population. Tumor necrosis factor alpha (TNF-α) is a proinflammatory cytokine that plays a critical role in the pathogenesis of psoriasis. Infliximab is an anti-TNF-α drug widely used for the treatment of plaque type psoriasis and psoriatic arthritis. Controlled clinical trials demonstrated that infliximab is characterized by a high degree of clinical response in moderate to severe plaque psoriasis. Moreover infliximab showed rapid efficacy in nail psoriasis which represents a therapeutic challenge for dermatologists and a relevant source of distress for patients with plaque psoriasis. This anti-TNF-α has an encouraging safety profile, especially as long as physicians are watchful in prevention and early diagnosis of infections and infuse reactions. The efficacy, tolerability and safety profiles suggest infliximab as a suitable anti-psoriatic drug in the long-term treatment of a chronic disease such as plaque-type psoriasis.
psoriasis; nail psoriasis; infliximab; long-term treatment
The cellular events underlying the pathogenesis of psoriatic arthritis (PsA) and psoriasis have not yet been fully elucidated. Nevertheless, some clues to these conditions are beginning to emerge. In particular, a growing body of data supports the role of proinflammatory cytokines, such as tumour necrosis factor (TNF), in the pathophysiology of PsA and psoriasis. Raised levels of these cytokines are found in the joints of patients with PsA, as well as in psoriatic skin lesions. Physiotherapy, non-steroidal anti-inflammatory agents, corticosteroids, and disease modifying antirheumatic agents, such as methotrexate, are the most commonly used treatments for PsA. However, the data supporting the effectiveness of these treatments are limited, and disease resolution is usually incomplete. This study examined the effects of etanercept, a TNF inhibitor, in patients with PsA. Etanercept treatment was well tolerated and resulted in significant improvement in the signs and symptoms of PsA and in psoriatic skin lesions. Infliximab, another TNF inhibitor, has also been shown to be effective in patients with PsA. Such studies confirm the importance of proinflammatory cytokines in PsA, and hold out hope for patients who require new options for the treatment of their disease.
Elucidation of the cellular immunopathology and cytokine profile of psoriatic arthritis (PsA), a chronic inflammatory disease associated with psoriasis, has resulted in the development of a number of novel biologic therapies. Among these biologics, tumor necrosis factor-alpha (TNF-α) inhibitors have been used successfully to treat patients suffering from rheumatoid arthritis or psoriasis. The pivotal role of TNF-α in the pathogenesis and progression of PsA suggested that anti-TNF-α agents could be effective in controlling PsA. The results from two large, randomized, double-blind, placebo-controlled trials in patients with moderate to severe PsA indicated that the anti-TNF-inhibitor, infliximab, can control both the joint and skin manifestations of the disease. This review focuses on the clinical development of infliximab as a treatment for PsA. The development of other anti-TNF-α biologics is also discussed.
psoriatic arthritis; psoriasis; spondyloarthropathies; TNF inhibition; biologics
We evaluated the incidence of and the main risk factors associated with cutaneous adverse events in patients with chronic inflammatory arthritis following anti-TNF-α therapy.
A total of 257 patients with active arthritis who were taking TNF-α blockers, including 158 patients with rheumatoid arthritis, 87 with ankylosing spondylitis and 12 with psoriatic arthritis, were enrolled in a 5-year prospective analysis. Patients with overlapping or other rheumatic diseases were excluded. Anthropometric, socioeconomic, demographic and clinical data were evaluated, including the Disease Activity Score-28, Bath Ankylosing Spondylitis Disease Activity Index and Psoriasis Area Severity Index. Skin conditions were evaluated by two dermatology experts, and in doubtful cases, skin lesion biopsies were performed. Associations between adverse cutaneous events and clinical, demographic and epidemiological variables were determined using the chi-square test, and logistic regression analyses were performed to identify risk factors. The significance level was set at p<0.05.
After 60 months of follow-up, 71 adverse events (73.85/1000 patient-years) were observed, of which allergic and immune-mediated phenomena were the most frequent events, followed by infectious conditions involving bacterial (47.1%), parasitic (23.5%), fungal (20.6%) and viral (8.8%) agents.
The skin is significantly affected by adverse reactions resulting from the use of TNF-α blockers, and the main risk factors for cutaneous events were advanced age, female sex, a diagnosis of rheumatoid arthritis, disease activity and the use of infliximab.
TNF-alpha Blockers; Skin; Adverse Events; Rheumatoid Arthritis; Ankylosing Spondylitis
Psoriatic arthritis (PsA) is a chronic inflammatory skin disease that causes enthesitis and destructive arthritis and significantly lowers patient quality of life. Recognition of the two target organs (the skin and joints) involved in the immunopathophysiology of PsA helped in elucidating the pathology of various systemic autoimmune diseases targeting multiple organs. Recent advances in immunology and genetics have made it clear that acquired immunity, especially that mediated by the Th17/IL-23 axis, plays an important role in the inflammatory pathology observed in psoriasis and PsA. Additionally, involvement of natural immunity has also been suggested. Microbial infection has been known to trigger psoriasis and PsA. Recent clinical studies using biopharmaceuticals, such as tumor-necrosis-factor- (TNF-) α inhibitors and IL-12/23 p40 antibodies, indicate that studies need not be based only on the immunological phenomena observed in PsA pathology since disease pathology can now be verified using human-based science. Considering this aspect, this paper discusses the immunopathology of PsA compared to psoriasis (cutaneous) and rheumatoid arthritis in humans and immunopathology of PsA with respect to the Th17/IL-23 axis and microbial infection.
Gelatinases A and B (matrix metalloproteinase 2 [MMP-2] and MMP-9, respectively) can induce basal membrane breakdown and leukocyte migration, but their role in leprosy skin inflammation remains unclear. In this study, we analyzed clinical specimens from leprosy patients taken from stable, untreated skin lesions and during reactional episodes (reversal reaction [RR] and erythema nodosum leprosum [ENL]). The participation of MMPs in disease was suggested by (i) increased MMP mRNA expression levels in skin biopsy specimens correlating with the expression of gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α), (ii) the detection of the MMP protein and enzymatic activity within the inflammatory infiltrate, (iii) increased MMP levels in patient sera, and (iv) the in vitro induction of MMP-9 by Mycobacterium leprae and/or TNF-α. It was observed that IFN-γ, TNF-α, MMP-2, and MMP-9 mRNA levels were higher in tuberculoid than lepromatous lesions. In contrast, interleukin-10 and tissue inhibitor of MMP (TIMP-1) message were not differentially modulated. These data correlated with the detection of the MMP protein evidenced by immunohistochemistry and confocal microscopy. When RR and ENL lesions were analyzed, an increase in TNF-α, MMP-2, and MMP-9, but not TIMP-1, mRNA levels was observed together with stronger MMP activity (zymography/in situ zymography). Moreover, following in vitro stimulation of peripheral blood cells, M. leprae induced the expression of MMP-9 (mRNA and protein) in cultured cells. Overall, the present data demonstrate an enhanced MMP/TIMP-1 ratio in the inflammatory states of leprosy and point to potential mechanisms for tissue damage. These results pave the way toward the application of new therapeutic interventions for leprosy reactions.
TNF inhibitors have revolutionized the treatment of psoriasis vulgaris, as well as psoriatic and rheumatoid arthritis, and Crohns disease. Despite our understanding that these agents block TNF, their complex mechanism of action in disease resolution is still unclear.
To globally analyze the genomic effects of TNF inhibition in psoriasis patients, and compare genomic profiles of patients who responded or did not respond to treatment.
In a clinical trial using etanercept TNF inhibitor to treat psoriasis vulgaris (n=15), Affymetrix gene arrays were used to analyze gene profiles in lesional skin at multiple time-points during drug treatment (baseline, and weeks 1, 2, 4 and 12) compared to non-lesional skin. Patients were stratified as responders (n=11) or non-responders (n=4) based on histological disease resolution. Cluster analysis was used to define gene sets that were modulated with similar magnitude and velocity over time.
In responders, 4 clusters of down-regulated genes and 3 clusters of up-regulated genes were identified. Genes down-modulated most rapidly reflected direct inhibition of myeloid lineage immune genes. Up-regulated genes included stable dendritic cell population genes CD1c and CD207 (Langerin). Comparison of responders and non-responders revealed rapid down-modulation of innate IL-1β and IL-8 “sepsis cascade” cytokines in both groups, but only responders down-regulated IL-17 pathway genes to baseline levels.
While both responders and non-responders to etanercept inactivated “sepsis cascade” cytokines, response to etanercept is dependent on inactivation of myeloid dendritic cell genes and inactivation of Th17 immune response.
Cutaneous genes regulated during psoriasis treatment by etanercept provide a global view of response in disease tissue. Only responders down-regulated IL-17 pathway genes.
TNF; psoriasis; etanercept; gene; Th17; Th1
In recent years there has been a surge of interest in the treatment of chronic inflammatory disorders as a result of the development and application of targeted biological therapies. The elucidation of the overlapping cellular and cytokine immunopathology of such diverse conditions as rheumatoid arthritis (RA), Crohn's disease, and psoriasis points to specific targets for bioengineered proteins or small molecules.
Similar to clinical trials in RA, trials in psoriatic arthritis (PsA) have shown excellent clinical results with the tumour necrosis factor (TNF) blockers, etanercept, infliximab, and adalimumab in a variety of domains including the joints, quality of life, function, and slowing of disease progress as evidenced radiologically. In addition, these agents have shown benefit in domains more unique to PsA, such as the skin lesions of psoriasis, enthesitis, and dactylitis, pointing out the similar pathogenesis of the disease in the skin, the tendons, and the synovial membrane. This therapy has been generally safe and well tolerated in clinical trials of PsA.
Other logical candidates for targeted therapy in development include other anti-TNF agents, costimulatory blockade agents that affect T cell function, blockers of other cytokines such as interleukin (IL)-1, 6, 12, 15, or 18, and B cell modulatory medicines. Also, it will be useful to learn more about the effects of combining traditional disease modifying drugs and the newer biologicals.
Chronic plaque psoriasis affects more than 2% of world population, has a chronic recurrent behavior, gives a heavy burden to the patients’ quality of life, and hence remains a huge medical and social problem. The clinical results of conventional therapies of psoriasis are not satisfactory. According to the current knowledge of the molecular and cellular basis of psoriasis, it is defined as an immune-mediated chronic inflammatory and hyperproliferative skin disease. A new generation of biological drugs, targeting molecules and cells involved into perturbed pro-inflammatory immune response in the psoriatic skin and joints, has been recently designed and applied clinically. These biological agents are bioengineered proteins such as chimeric and humanized antibodies and fusion proteins. In particular, they comprise the antitumor necrosis factor-α agents etanercept, infliximab, and adalimumab, with clinical efficacy in both moderate-severe psoriasis and psoriatic arthritis, and the anti-CD11a efalizumab with selective therapeutic action exclusively in the skin. Here, we overview recent findings on the molecular pathways relevant to the inflammatory response in psoriasis and present our clinical experience with the drugs currently employed in the dermatologic manifestations, namely etanercept, infliximab, and efalizumab. The growing body of clinical data on the efficacy and safety of antipsoriasis biological drugs is reviewed as well. Particular focus is given to long-term safety concerns and feasibility of combined therapeutic protocols to ameliorate clinical results.
psoriasis; immune-mediated inflammation; etanercept; infliximab; efalizumab
Psoriatic arthritis (PsA) is a rheumatoid factor (RF)-seronegative systemic inflammatory disorder associated with psoriasis. Current treatment for PsA in China is still focused on disease modifying anti-rheumatic drugs (DMARDs). In this paper, we report two Chinese patients with active longstanding PsA treated with infliximab, a human-mouse chimeric monoclonal antibody against tumor necrosis factor alpha (TNF-α). The results show that infliximab acted quickly and effectively in relieving peripheral and axial symptoms and refractory skin lesions, even in recombinant human TNF-α receptor (rhTNFR)-resistant case. The take-home message from our cases is that infliximab is a useful therapeutic option for refractory PsA, especially when a patient has a combination of psoriasis and psoriatic arthritis. Further local evidence and experience must be accumulated in order to make anti-TNF-α therapy more accessible to PsA patients in China.
Refractory psoriatic arthritis; Skin lesions; Infliximab; Anti-tumor necrosis factor alpha (TNF-α) treatment
Psoriatic arthritis (PsA) is commonly associated with bone pathology, including entheseal new bone formation and osteolysis. On MRI, areas of active clinical involvement are represented by bone oedema and synovitis.
To assess the impact of infliximab on bone oedema in PsA as shown by MRI.
18 patients with joint swelling, psoriasis and seronegativity for rheumatoid factor received four infusions of infliximab, 3 mg/kg, in combination with methotrexate. MRI of the affected hand (12 patients) or knee joints (6 patients) was performed before and after treatment. The primary outcome was the assessment of bone oedema and synovitis at 20 weeks as shown by MRI. Secondary outcomes included the American College of Rheumatology (ACR) response criteria, psoriasis skin scores (Psoriasis Area and Severity Index (PASI)) and a quality of life measure (Psoriatic Arthritis Quality of Life (PsAQoL)).
At baseline, bone oedema was seen in 50% of patients (seven hands and two knees) in 30% of scanned joints, and this improved or resolved in all cases in the hand joints (p = 0.018) and in one knee joint at 20 weeks. Synovitis was found to be reduced in 90% of cases on MRI. Likewise, a significant improvement in all clinical outcomes, including PASI (p = 0.003) and PsAQoL (p = 0.006) was seen at week 20. 65% (n = 11) of the patients achieved an ACR response, of whom 45% had ACR70 or above and 54% had ACR20 or ACR50.
Infliximab treatment is associated with dramatic improvements in MRI‐determined bone oedema in PsA in the short term. It remains to be determined whether infliiximib treatment is the cause for prevention of new bone formation, bone fusion or osteolysis in PsA as shown by radiography.
Psoriatic arthritis (PsA) is a chronic inflammatory arthropathy associated with psoriasis and included in seronegative spondyloarthropathy. PsA has several unique characteristics different from rheumatoid arthritis (RA), such as enthesopathy, dactylitis, and abnormal bone remodeling. As compared with synovitis of RA (pannus), proliferation of PsA synovium is mild and characterized by hypervascularity and increased infiltration of polymorphonuclear leukocytes in the synovial tissues. Angiogenesis plays a crucial role in cutaneous psoriasis, and several angiogenic factors such as vascular endothelial growth factor, interleukin-8, angiopoietin, tumor necrosis factor-α and transforming growth factor-β, are suggested to play an important role also in the pathophysiology of PsA. Further, IL-17 has various functions such as upregulation of proinflammatory cytokines, attraction of neutrophils, stimulation of keratinocytes, endothelial cell migration, and osteoclast formation via RANKL from activated synovial fibroblasts. Thus, IL-17 may be important in angiogenesis, fibrogenesis, and osteoclastogenesis in PsA. In this paper, roles of angiogenesis in the psoriatic synovium are discussed, which may strengthen the understanding of the pathogenesis of PsA.
Psoriatic arthritis (PsA) is an inflammatory joint disease associated with psoriasis. Alefacept (a lymphocyte function-associated antigen (LFA)-3 Ig fusion protein that binds to CD2 and functions as an antagonist to T-cell activation) has been shown to result in improvement in psoriasis but has limited effectiveness in PsA. Interleukin-20 (IL-20) is a key proinflammatory cytokine involved in the pathogenesis of psoriasis. The effects of alefacept treatment on IL-20 expression in the synovium of patients with psoriasis and PsA are currently unknown.
Eleven patients with active PsA and chronic plaque psoriasis were treated with alefacept (7.5 mg per week for 12 weeks) in an open-label study. Skin biopsies were taken before and after 1 and 6 weeks, whereas synovial biopsies were obtained before and 4 and 12 weeks after treatment. Synovial biopsies from patients with rheumatoid arthritis (RA) (n = 10) were used as disease controls. Immunohistochemical analysis was performed to detect IL-20 expression, and stained synovial tissue sections were evaluated with digital image analysis. Double staining was performed with IL-20 and CD68 (macrophages), and conversely with CD55 (fibroblast-like synoviocytes, FLSs) to determine the phenotype of IL-20-positive cells in PsA synovium. IL-20 expression in skin sections (n = 6) was analyzed semiquantitatively.
IL-20 was abundantly expressed in both PsA and RA synovial tissues. In inflamed PsA synovium, CD68+ macrophages and CD55+ FLSs coexpressed IL-20, and its expression correlated with the numbers of FLSs. IL-20 expression in lesional skin of PsA patients decreased significantly (P = 0.04) 6 weeks after treatment and correlated positively with the Psoriasis Area and Severity Index (PASI). IL-20 expression in PsA synovium was not affected by alefacept.
Conceivably, the relatively limited effectiveness of alefacept in PsA patients (compared with anti-tumor necrosis factor (TNF) therapy) might be explained in part by persistent FLS-derived IL-20 expression.
Tumor necrosis factor-alpha (TNF-α) inhibitors, such as etanercept, infliximab, and adalimumab, bind to TNF-α and thereby act as anti-inflammatory agents. This group of drugs has been approved for the treatment of rheumatoid arthritis, psoriatic arthritis, moderate to severe plaque psoriasis, ankylosing spodylitis, Crohn disease, and juvenile idiopathic arthritis. We describe a 56-year-old woman who developed an erythematous pruritic rash on both arms—diagnosed as granuloma annulare by skin biopsy—approximately 22 months after initiating adalimumab for treatment of rheumatoid arthritis. On stopping adalimumab there was total clearance of the skin lesions, but a similar rash developed again when her treatment was switched to another anti-TNF agent (etanercept). This clinical observation supports a link between TNF inhibition and the development of granuloma annulare.
Adverse effect; anti-TNF therapy; granuloma annulare
Psoriasis is characterized by hyperproliferation of keratinocytes and by
infiltration of activated Th1 and Th17 cells in the (epi)dermis. By expression
microarray, we previously found the GATA3 transcription factor significantly
downregulated in lesional psoriatic skin. Since GATA3 serves as a key switch in
both epidermal and T helper cell differentiation, we investigated its function
in psoriasis. Because psoriatic skin inflammation shares many characteristics of
epidermal regeneration during wound healing, we also studied GATA3 expression
under such conditions.
Psoriatic lesional skin showed decreased GATA3 mRNA and protein expression
compared to non-lesional skin. GATA3 expression was also markedly decreased in
inflamed skin of mice with a psoriasiform dermatitis induced with imiquimod.
Tape-stripping of non-lesional skin of patients with psoriasis, a standardized
psoriasis-triggering and skin regeneration-inducing technique, reduced the
expression of GATA3. In wounded skin of mice, low GATA3 mRNA and protein
expression was detected. Taken together, GATA3 expression is downregulated under
regenerative and inflammatory hyperproliferative skin conditions. GATA3
expression could be re-induced by successful narrow-band UVB treatment of both
human psoriasis and imiquimod-induced psoriasiform dermatitis in mice. The
prototypic Th2 cytokine IL-4 was the only cytokine capable of inducing GATA3 in
skin explants from healthy donors. Based on these findings we argue that GATA3
serves as a key regulator in psoriatic inflammation, keratinocyte
hyperproliferation and skin barrier dysfunction.
Psoriasis is a chronic inflammatory disease of the skin characterized by epidermal hyperplasia, dermal angiogenesis, infiltration of activated T cells, and increased cytokine levels. One of these cytokines, IL-15, triggers inflammatory cell recruitment, angiogenesis, and production of other inflammatory cytokines, including IFN-γ, TNF-α, and IL-17, which are all upregulated in psoriatic lesions. To investigate the role of IL-15 in psoriasis, we generated mAb’s using human immunoglobulin-transgenic mice. One of the IL-15–specific antibodies we generated, 146B7, did not compete with IL-15 for binding to its receptor but potently interfered with the assembly of the IL-15 receptor α, β, γ complex. This antibody effectively blocked IL-15–induced T cell proliferation and monocyte TNF-α release in vitro. In a human psoriasis xenograft model, antibody 146B7 reduced the severity of psoriasis, as measured by epidermal thickness, grade of parakeratosis, and numbers of inflammatory cells and cycling keratinocytes. These results obtained with this IL-15–specific mAb support an important role for IL-15 in the pathogenesis of psoriasis.
Observation of the Koebner response was used in the clinical evaluation, determination of prognosis and management of seven patients with psoriasis. The Koebner response may be observed in patients with progressive and eruptive psoriasis; it is not the etiological factor but determines the localization of lesions when a psoriatic reaction is active. The eliciting stimuli for response are varied and non-specific; a common factor is cutaneous injury. Other skin diseases may provoke suitable eliciting cutaneous injury and determine the distribution patterns of sebo-psoriasis, psoriasis inversus, and psoriasiform neurodermatitis. Cutaneous injury is followed by repair or an attempt at repair. Psoriasis is a reaction pattern to non-specific stimuli in which psoriatic defect is brought to light by the increased rate of metabolism in cells regenerating after injury.
The development of psoriasis and psoriatic arthritis is a multistep process that leads to chronic or recurrent inflammation. Recent studies have suggested the importance of T helper (TH)1 and TH17 cells, accessory cells, and proinflammatory cytokines in the pathogenesis of the enthesis, synovium, and skin involvement in psoriasis in the presence of susceptibility genes that remain quiescent until triggered. Biologics, such as soluble CTLA-4 immunoglobulin, tumor necrosis factor (TNF) inhibitors, and ustekinumab, inhibit T cell activation which eventually leads to further stimulation of the interleukin 12, 17, and 23 axis, TNF-α, and lymphotoxin-α. Treatment with TNF-α blockers has been effective in refractory psoriasis and psoriatic arthritis, but there is still a subgroup of patients who do not respond to TNF inhibitors and, paradoxically, when treated, may develop TNF-induced psoriasis. Ustekinumab, because of its different mechanism of action at the level of the interleukin 12, 17, and 23 pathways, is an alternative treatment for this group of patients.
psoriasis; psoriatic arthritis; biologics; ustekinumab; tumor necrosis factor inhibitors
Psoriasis is a common chronic skin disease mediated by cellular immune mechanisms and characterized by an intense neutrophil cell infiltrate and proliferative activation of epidermal keratinocytes. We have previously described the expression of the inducible nitric oxide synthase (iNOS) in epidermal keratinocytes of psoriatic skin lesions. In this study, the role of iNOS in psoriatic inflammation was explored ex vivo in psoriatic skin biopsies and in vitro in primary cultures of human keratinocytes. Messenger RNA for the iNOS enzyme (iNOS mRNA) was detected by reverse transcriptase polymerase chain reaction in skin biopsies from patients with psoriasis, but not in skin specimens from patients with atopic eczema or from healthy volunteers. As demonstrated by in situ hybridization and immunohistochemistry, expression of iNOS mRNA and its gene product was localized to the epidermal keratinocytes of psoriatic skin lesions. In situ hybridization further revealed a complete colocalization of mRNA expression for iNOS with interleukin (IL) 8 receptor-specific mRNA either in the basal germinative cell layer or at focal sites of ongoing neutrophil inflammation in suprabasal cell layers. Because psoriatic keratinocytes have previously been shown to express mRNA transcripts for IL-8, it seemed reasonable to hypothesize that iNOS expression could be induced in an autocrine loop by IL-8. This hypothesis was substantiated by our in vitro experiments showing that a combination of IL-8 and interferon gamma induces the expression of iNOS-specific mRNA and of the functional enzyme in cultured human keratinocytes. These results suggest an important role for iNOS in concert with IL-8 and its receptor early during the formation of psoriatic lesions.
Psoriasis is a chronic inflammatory skin disease, most commonly resulting in the occurrence of red and silver scaly plaques. About 30% of psoriasis sufferers develop psoriatic arthritis (PsA), a disorder that presents with additional joint inflammation and other clinical features. At present, the most effective treatment for moderate and severe psoriasis and PsA are biologics such as antitumor necrosis factor alpha therapy. Biologics are costly and typically require repeated injections; hence, the development of novel, orally available, small molecular inhibitors that are less expensive to produce is highly desirable. The phosphodiesterase 4 inhibitor apremilast is a small molecular inhibitor that acts by increasing cyclic adenosine monophosphate levels, ultimately suppressing tumor necrosis alpha production. Apremilast has been tested in a number of psoriasis and PsA pilot and Phase II trials to evaluate its efficacy and safety. More recently, three larger double-blinded, and randomized multicenter studies demonstrate that apremilast is efficacious in the treatment of psoriasis and PsA, with significantly higher numbers of apremilast-treated patients achieving endpoints of a 75% reduction compared to baseline in Psoriasis Area and Severity Index (PASI-75) or American College of Rheumatology-20 scores, relative to placebo. This encouraging data, along with a tolerable incidence of mild to moderate adverse events, has led to the initiation of several large Phase III trials that aim to further validate apremilast as a treatment for psoriasis and PsA. Here, we provide an overview of the current treatments for psoriasis and PsA, and summarize the findings from multiple Phase II clinical trials where the effects of apremilast in the treatment of psoriasis and PsA patients have been investigated.
apremilast; psoriasis; psoriatic arthritis; phosphodiesterase inhibitor
Psoriatic arthritis (PsA) is a seronegative spondyloarthropathy that commonly appears after the onset of the characteristic cutaneous lesions. This complication affects about 40% of patients with moderate to severe cutaneous disease. Analysis of synovial fluid and tissue in patients with PsA demonstrates a profile of high levels of tumor necrosis factor (TNF) plus other cytokines similar to those seen in patients with rheumatoid arthritis (RA). In the past, medical management of patients with this disease consisted of treatment with nonsteroidal anti-inflammatory agents. Patients with more severe disease have tried a number of different disease-modifying drugs including methotrexate, azathioprine, and gold salts. However, there is no evidence that these agents can arrest the progress of structural joint damage. Infliximab and etanercept are TNF antagonists that have demonstrated significant efficacy and safety in patients with RA. Clinical trials with these two agents in patients with PsA have shown significant improvement in the rheumatologic and cutaneous manifestations of the disease.
arthritis; etanercept; infliximab; psoriasis; spondyloarthropathies; tumor necrosis factor
Psoriasis is a chronic inflammatory disease affecting 2% to 3% of the population in Western countries. Psoriasis is associated with limited quality of life, cardiovascular disease, and depression. The approval of injectable biological agents has revolutionized the management of moderate to severe psoriasis. Adalimumab is a human monoclonal antibody against tumor necrosis factor (TNF) alpha approved for moderate-to-severe plaque-type psoriasis and psoriatic arthritis (PsA). This systematic review summarizes the evidence concerning the efficacy, clinical effectiveness, safety, and cost-effectiveness of adalimumab in the treatment of psoriasis. Five randomized controlled trials demonstrated the efficacy of adalimumab in moderate-to-severe plaque-type psoriasis and PsA with PASI-75 response rates of 53% to 80% and ACR-20 response rates of 39% to 58% after 12 to 16 weeks of treatment. In clinical practice patients who have not responded to one TNF antagonist may respond to another TNF antagonist. Adalimumab has similar or better cost-effectiveness than other biologics, but is less efficient than methotrexate and cyclosporine. Adalimumab is generally well tolerated. Patients should be evaluated for active/latent tuberculosis, serious infections, and other contraindications prior to initiation of adalimumab therapy. Future studies should investigate the comparative efficacy of adalimumab and other biologic and prebiologic agents. Recently established registries will yield additional data on the effectiveness and long-term safety of adalimumab.
adalimumab; biologic; efficacy; effectiveness; efficiency; psoriasis; treatment; safety
Infliximab is a monoclonal antibody directed against TNF-α. It has been approved for use in rheumatoid arthritis, ankylosing spondylitis, inflammatory bowel disease, psoriatic arthritis and plaque-type psoriasis. In case reports, positive effects on pustular variants of psoriasis have also been reported. However, paradoxically, manifestation of pustular psoriasis and plaque-type psoriasis has been reported in patients treated with TNF antagonists including infliximab for other indications. Here, we report on 5 patients with chronic plaque-type psoriasis who developed palmoplantar pustulosis during or after discontinuation of infliximab therapy. In two of the five cases, manifestation of palmoplantar pustulosis was not accompanied by worsening of plaque-type psoriasis. Possibly, site-specific factors or a differential contribution of immunological processes modulated by TNF inhibitors to palmoplantar pustulosis and plaque-type psoriasis may have played a role.
TNF; Antagonist; Infliximab; Pustulosis; Psoriasis
Psoriatic arthritis (PsA) is an inflammatory arthritis that affects many psoriasis patients and can often have a debilitating disease progression. Golimumab is a new tumor necrosis factor (TNF) antagonist recently approved by the FDA for controlling signs and symptoms of psoriatic arthritis. In a Phase III clinical trial in patients with PsA, patients receiving golimumab showed significant improvement in the signs and symptoms of disease. It was usually well tolerated, but adverse events generally occurred more in patients receiving golimumab compared to placebo. Golimumab has also recently shown efficacy in slowing structural damage in PsA. This new biologic therapy provides physicians with another option in the treatment of this inflammatory arthritis while offering patients certain advantages over other TNF antagonists.
golimumab; psoriatic arthritis; TNF-alpha inhibitor