Role of novel biological therapies in psoriatic arthritis: effects on joints and skin

The risk of organ-based comorbidities in psoriasis: a systematic review and meta-analysis

Background

The close relationship between psoriasis and concomitant diseases is widely accepted. However, a comprehensive analysis of organ-based comorbidities in psoriasis is still lacking.

Objective

The authors aimed to present the risk of organ-based comorbidities in psoriasis by comparing the general population.

Methods

The authors retrieved a search of Pubmed, EMBASE, and Cochrane databases for studies reporting organ-based comorbidities in psoriasis versus the general population. Observational studies that met the following criteria were assessed: 1) Psoriasis diagnosis; 2) Cardiovascular or kidney or liver or respiratory or cerebrovascular outcomes; 3) Comparison group of individuals without psoriasis. Pooled Relative Risks (pRRs) and 95% Confidence Intervals (CIs) were calculated by using the random-effect model.

Results

Fifteen observational studies with 216,348 psoriatic patients and 9,896,962 individuals from the general population were included. Psoriasis showed a greater risk of organ-based comorbidities. Compared to the general population, pRR for all organ-based comorbidities was 1.20 (95% CI 1.11‒1.31) in psoriasis, and pRR was lower in mild 0.61 (95% CI 0.46‒0.81) than in moderate/severe patients. pRR was 1.20 (95% CI 1.11‒1.30) for cardiovascular, 1.56 (95% CI 1.20‒2.04), and 1.75 (95% CI 1.33‒2.29) for cerebrovascular and liver diseases, respectively. pRR for coexisting renal and cardiovascular events was 1.09 (95% CI 1.01‒1.18). pRR for coexisting renal and cerebrovascular events was 1.28 (95% CI 0.99‒1.66). pRR for coexisting renal and liver diseases was 1.46 (95% CI 1.10‒1.94). pRR for coexisting cardiovascular and liver diseases was 1.41 (95% CI 1.11‒1.80).

Study limitations

There is heterogeneity.

Conclusion

Psoriasis has a higher risk of single and multiple organ-based comorbidities than the general population. The present study will further improve attention to psoriasis as a systemic inflammatory disease.

Phenylpyridine-2-ylguanidines and rigid mimetics as novel inhibitors of TNFα overproduction: Beneficial action in models of neuropathic pain and of acute lung inflammation

4-phenylpyridin-2-yl-guanidine (5b): a new inhibitor of the overproduction of pro-inflammatory cytokines (TNFα and Il1β) was identified from a high-throughput screening of a chemical library on human peripheral blood mononuclear cells (PBMCs) after LPS stimulation. Derivatives, homologues and rigid mimetics of 5b were designed and synthesized, and their cytotoxicity and ability to inhibit TNFα overproduction were evaluated. Among them, compound 5b and its mimetic 12 (2-aminodihydroquinazoline) showed similar inhibitory activities, and were evaluated in vivo in models of lung inflammation and neuropathic pain in mice. In particular, compound 12 proved to be active (5 mg/kg, ip) in both models.

MDcons: Intermolecular contact maps as a tool to analyze the interface of protein complexes from molecular dynamics trajectories

Background

Molecular Dynamics (MD) simulations of protein complexes suffer from the lack of specific tools in the analysis step. Analyses of MD trajectories of protein complexes indeed generally rely on classical measures, such as the RMSD, RMSF and gyration radius, conceived and developed for single macromolecules. As a matter of fact, instead, researchers engaged in simulating the dynamics of a protein complex are mainly interested in characterizing the conservation/variation of its biological interface.

Results

On these bases, herein we propose a novel approach to the analysis of MD trajectories or other conformational ensembles of protein complexes, MDcons, which uses the conservation of inter-residue contacts at the interface as a measure of the similarity between different snapshots. A "consensus contact map" is also provided, where the conservation of the different contacts is drawn in a grey scale. Finally, the interface area of the complex is monitored during the simulations. To show its utility, we used this novel approach to study two protein-protein complexes with interfaces of comparable size and both dominated by hydrophilic interactions, but having binding affinities at the extremes of the experimental range. MDcons is demonstrated to be extremely useful to analyse the MD trajectories of the investigated complexes, adding important insight into the dynamic behavior of their biological interface.

Conclusions

MDcons specifically allows the user to highlight and characterize the dynamics of the interface in protein complexes and can thus be used as a complementary tool for the analysis of MD simulations of both experimental and predicted structures of protein complexes.

Mitogen-activated protein kinase-activated protein kinase 2 (MAPKAP-K2) as an antiinflammatory target: discovery and in vivo activity of selective pyrazolo[1,5-a]pyrimidine inhibitors using a focused library and structure-based optimization approach

A novel class of mitogen-activated protein kinase-activated protein kinase 2 (MAPKAP-K2) inhibitors was discovered through screening a kinase-focused library. A homology model of MAPKAP-K2 was generated and used to guide the initial SAR studies and to rationalize the observed selectivity over CDK2. An X-ray crystal structure of a compound from the active series bound to crystalline MAPKAP-K2 confirmed the predicted binding mode. This has enabled the discovery of a series of pyrazolo[1,5-a]pyrimidine derivatives showing good in vitro cellular potency as anti-TNF-α agents and in vivo efficacy in a mouse model of endotoxin shock.

Conformationally constrained peptides from CD2 to modulate protein-protein interactions between CD2 and CD58

Cell adhesion molecule CD2 and its ligand CD58 provide good examples of protein-protein interactions in cells that participate in the immune response. To modulate the cell adhesion interaction, peptides were designed from the discontinuous epitopes of the β-strand region of CD2 protein. The two strands were linked by a peptide bond. β-Strands in the peptides were nucleated by inserting a β-sheet-inducing (D)-Pro-Pro sequence or a dibenzofuran (DBF) turn mimetic with key amino acid sequences from CD2 protein that binds to CD58. The solution structures of the peptides (5-10) were studied by NMR and molecular dynamics simulations. The ability of these peptides to inhibit cell adhesion interaction was studied by E-rosetting and lymphocyte epithelial assays. Peptides 6 and 7 inhibit the cell adhesion activity with an IC(50) of 7 and 11 nM, respectively, in lymphocyte epithelial adhesion assay. NMR and molecular modeling results indicated that peptides 6 and 7 exhibited β-hairpin structure in solution.

Infliximab (Remicade) in the treatment of psoriatic arthritis

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-alpha) inhibitors have been used successfully to treat patients suffering from rheumatoid arthritis or psoriasis. The pivotal role of TNF-alpha in the pathogenesis and progression of PsA suggested that anti-TNF-alpha 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-alpha biologics is also discussed.

Heterotypic cell adhesion assay for the study of cell adhesion inhibition

CD2 is a cell adhesion molecule that mediates T-cell activation by binding to its ligand CD58 on antigen-presenting cells. Interaction between CD2 and CD58 or leukocyte function-associated antigen-3 (LFA-3) helps to optimize immune recognition facilitating contact between T lymphocytes and antigen-presenting cells. Modulation or inhibition of this interaction has been shown to be therapeutically useful in the treatment of autoimmune diseases. Antibodies and small molecules including peptides have been designed to modulate or disrupt the cell adhesion interactions due to CD2 and CD58. E-rosetting assay is a widely used method applied in the study of the modulation of CD2-CD58 interaction, which is either labor-intensive or radio-hazardous. In this chapter, we describe two methods that are used to study cell adhesion inhibition: (a) E-rosetting Assay and (b) Lymphocyte-epithelial assay. The second method, lymphocyte-epithelial assay, is a rapid and sensitive heterotypic cell adhesion assay for studying cell adhesion inhibition. The method relies on the CD2 expression on the surface of Jurkat cells and the CD58 expression on the surface of Caco-2 cells, which were confirmed by flow cytometry and ELISA studies respectively. This heterotypic cell adhesion assay described typically takes less than 4 h to perform, allows the evaluation of inhibitory activity of peptides/small molecules to modulate CD2-CD58 interaction in real cell system.

A peptide from the beta-strand region of CD2 protein that inhibits cell adhesion and suppresses arthritis in a mouse model

Cell adhesion molecules play a central role at every step of the immune response. The function of leukocytes can be regulated by modulating adhesion interactions between cell adhesion molecules to develop therapeutic agents against autoimmune diseases. Among the different cell adhesion molecules that participate in the immunologic response, CD2 and its ligand CD58 (LFA-3) are two of the best-characterized adhesion molecules mediating the immune response. To modulate the cell adhesion interaction, peptides were designed from the discontinuous epitopes of the beta-strand region of CD2 protein. The two strands were linked by a peptide bond. beta-Strands in the peptides were nucleated by inserting a beta-sheet-inducing Pro-Gly sequence with key amino acid sequences from CD2 protein that binds to CD58. Using a fluorescence assay, peptides that exhibited potential inhibitory activity in cell adhesion were evaluated for their ability to bind to CD58 protein. A model for peptide binding to CD58 protein was proposed based on docking studies. Administration of one of the peptides, P3 in collagen-induced arthritis in the mouse model, indicated that peptide P3 was able to suppress rheumatoid arthritis in mice.

Design of beta-hairpin peptides for modulation of cell adhesion by beta-turn constraint

The CD2-CD58 interaction in immune regulation and disease pathology has provided new targets for developing potential immunosuppressive agents. In the present study, we report the introduction of constraints to generate beta-hairpin structures from the strand sequences of CD2 protein. The beta-hairpin structures were induced in the designed peptides by introducing Pro-Gly sequences in the peptides. Results from NMR and MD simulation indicated that the peptides exhibited beta-turn structure at the X-Pro-Gly-Y sequence and formed the beta-hairpin structure in solution. The ability of these peptides to inhibit cell adhesion was evaluated by two cell adhesion assays. Among the peptides studied (1-4) (P1-P4), peptides 2-4 were able to inhibit cell adhesion between Jurkat cells and SRBC nearly 50% at 180 microM, and 80% inhibition between Jurkat cells and Caco-2 cells was seen at 90 microM. Peptide 1 did not show significant inhibition activity compared to control.

Efficacy and safety of etanercept in psoriasis/psoriatic arthritis: an updated review

The introduction in recent years of biologic medicines has greatly changed the treatment of psoriasis and psoriatic arthropathy (PsA). These drugs have been effective in the treatment of these chronic, physically weakening disorders, offering good efficacy and a safety profile that differs from those of all other systemic therapies and medications available to date. Different studies have assessed the efficacy and safety of etanercept in the treatment of psoriasis and PsA. Etanercept therapy for up to 144 weeks in psoriasis has shown maintenance of efficacy over time, recapture of initial clinical responses in patients who interrupted their etanercept therapy and were re-treated, an increased percentage of clinical responses in medium-dose non-responding patients who switched to higher dosages, good responses on quality-of-life tests, and an adverse event-adjusted rate similar to placebo. In PsA, etanercept therapy for up to 96 weeks was associated with inhibition of radiologic progression of the disease in addition to maintenance of efficacy over time and good responses on quality-of-life tests. In studies of patients with psoriasis, the adverse effects of etanercept were mostly mild, did not require discontinuation of treatment, and were not associated with cumulative toxicity over time. However, safety concerns about etanercept therapy are well known, and include injection-site reactions, infections, congestive heart failure, demyelinating diseases, lupus-like syndromes, and neoplasms. There are no data about any new safety concerns when etanercept is combined with systemic traditional therapies, although use of this therapy has been reported in only a small number of patients to date.Non-neutralizing anti-etanercept antibodies are not related to a decreased response to therapy and neutralizing antibodies have not been described to date. Treatment of patients infected with hepatitis C virus or HIV does not increase viral load in either case, affect liver function tests, or increase the risk of infections. To date, the available data suggest that use of etanercept during pregnancy or in breast-feeding women should be avoided. Children and the elderly may be treated with similar efficacy and safety profiles as have been observed in adults. Non-live vaccines can be administered to patients taking etanercept. Because of its long-term efficacy and safety, etanercept is likely to become a treatment option for consideration in the long-term management of patients with psoriasis and PsA.

Novel tetrahydro-β-carboline-1-carboxylic acids as inhibitors of mitogen activated protein kinase-activated protein kinase 2 (MK-2)

A structure-activity relationship study was conducted on a series of tetrahydro-beta-carboline-1-carboxylic acid analogs in order to identify the key functionality responsible for activity against the mitogen-activated protein kinase-activated protein kinase 2 enzyme (MK-2). The compounds were further evaluated for their ability to inhibit TNFalpha production in U937 cells and in vivo. These compounds represent a novel structural class of compounds capable of inhibiting MK-2 with remarkable selectivity.

Structure-based rational design of beta-hairpin peptides from discontinuous epitopes of cluster of differentiation 2 (CD2) protein to modulate cell adhesion interaction

Modulation or inhibition of interaction of cluster of differentiation (CD) adhesion molecules CD2-CD58 has been shown to be therapeutically useful. The analysis of the crystal structure of CD2 complexed with CD58 was carried out to define the epitopes that are important for the interaction of the two proteins. The crystal structure of CD2 indicated that the interaction surface of CD2 with CD58 has two beta-strand structures (F and C strands) with charged residues. On the basis of the crystal structure of the complex CD2-CD58, we have designed beta-hairpin peptides from the beta-strand region of CD2 by conjugating the discontinuous sequences in the protein. The peptides were modeled by molecular dynamics simulation, and their inhibitory activities were evaluated in vitro using two heterotypic cell adhesion assays, E-rosetting and lymphocyte-epithelial cell adhesion assays. Results indicated that 12- and 14-residue conjugate cyclic peptides cKS12 and cDD14 exhibited 60% and 50% inhibition activity, respectively, at 90 microM.

Pyrrolopyridine Inhibitors of Mitogen-Activated Protein Kinase-Activated Protein Kinase 2 (MK-2)

A new class of potent kinase inhibitors selective for mitogen-activated protein kinase-activated protein kinase 2 (MAPKAP-K2 or MK-2) for the treatment of rheumatoid arthritis has been prepared and evaluated. These inhibitors have IC50 values as low as 10 nM against the target and have good selectivity profiles against a number of kinases including CDK2, ERK, JNK, and p38. These MK-2 inhibitors have been shown to suppress TNFalpha production in U397 cells and to be efficacious in an acute inflammation model. The structure-activity relationships of this series, the selectivity for MK-2 and their activity in both in vitro and in vivo models are discussed. The observed selectivity is discussed with the aid of an MK-2/inhibitor crystal structure.

Cutaneous side-effects in patients with rheumatic diseases during application of tumour necrosis factor-? antagonists

BACKGROUND

Patients with rheumatic diseases receiving antitumour necrosis factor (TNF)-alpha-based treatment may develop cutaneous reactions.

OBJECTIVES

To analyse the new onset or aggravation of skin lesions in patients with a rheumatic disease during treatment with TNF-alpha antagonists.

METHODS

We conducted a prospective analysis of 35 of 150 patients with a long history of rheumatic disease, including rheumatoid arthritis, ankylosing spondylitis (Bechterew's disease) and psoriatic arthritis, to test for the development of cutaneous manifestations during anti-TNF-alpha (infliximab, adalimumab or etanercept) treatment.

RESULTS

Chronic inflammatory skin diseases such as psoriasis and eczema-like manifestations represented the majority of cases (16 of 35). Cutaneous infections caused by viral, bacterial and fungal agents were also observed in many patients (13 of 35). Skin diseases such as dermatitis herpetiformis, leucocytoclastic vasculitis and alopecia occurred in single cases only.

CONCLUSIONS

We observed a broad, diverse clinical spectrum with a majority of chronic inflammatory and infectious skin diseases. However, we did not identify individual risk factors and a discontinuation of the anti-TNF-alpha treatment was not necessary if adequate dermatological treatment was performed. The onset of cutaneous side-effects in anti-TNF-alpha-based treatments should be determined by nationwide registries.

Outcome-Parameter bei Psoriasisarthritis

The most important and most commonly occurring form of psoriasis is psoriasis vulgaris. In the specialism of rheumatology palmoplantar pustulosis is also important. The outcome is influenced mainly by how severe and how widespread the manifestations affecting the skin and nails are. All manifestations affecting the joints and occurring in association with psoriasis are subsumed under the term 'psoriatic arthritis' (PsA). Asymmetric oligoarthritis, enthesitis and inflammatory spinal manifestations are especially frequent. PsA is a rheumatic illness with widely varying clinical pictures, most patients having signs and symptoms resembling those of spondyloarthritides (SpA) and other features of rheumatoid arthritis (RA) and/or of arthrosis/osteoarthritis (OA). Clinical features that are particularly typical of PsA are ray-wise joint involvement, dactylitis and osteodestructive and osteoproliferative joint destruction. Dactylitis, asymmetric joint involvement and enthesitis also occur in other SpA. It is becoming increasingly important to define outcome parameters for use in PsA against the backdrop of new forms of treatment. In the case of clinical outcome basic distinctions must be made between clinical signs and symptoms, function and structure. In PsA the sometimes significant manifestations affecting skin and nails must also be considered. The outcome parameters used thus far have varied very widely. The extent and intensity of involvement of the peripheral joints and insertions of tendons and of spinal involvement are particularly important in PsA. In addition, functional impairments, quality of life and parameters concerned with work must be considered. There are hardly any measuring instruments specific to PsA; many have been developed and used primarily for SpA or RA.

Therapy of ankylosing spondylitis. Part II: biological therapies in the spondyloarthritides

Therapeutic options for patients with active and severe spondylarthritis (SpA) have been fairly limited in the past decades. There is now accumulating evidence that biological therapy with agents directed against tumour necrosis factor-alpha (TNF-alpha) is highly efficacious in the spondyloarthritides, especially in ankylosing spondylitis (AS) and psoriatic arthritis (PsA). The TNF blocking agents currently available, infliximab (Remicade), etanercept (Enbrel), and adalimumab (Humira), are approved for the treatment of rheumatoid arthritis (RA) in Europe and the USA. In contrast to rheumatoid arthritis (RA) disease-modifying anti-rheumatic drugs (DMARDs) have limited efficacy in SpA. No DMARDs are available for AS patients with active spinal disease. Thus, for AS patients whose condition is not sufficiently controlled with non-steroidal anti-inflammatory drugs (NSAIDs), therapy with TNF blockers may be considered as a first-line treatment. For infliximab, a dose of 3-5 mg/kg seems to be required, and intervals between 6 and 12 weeks are necessary to suppress disease activity continually. The standard dosage of etanercept is 2 x 25 mg subcutaneously (s.c.) per week. There are very few studies with adalimumab (standard dose in RA 20-40 mg s.c. every 1-2 weeks) in SpA. Infliximab and etanercept are now both approved for AS in Europe. There is some evidence that both agents also work in other SpA, especially in PsA. Withdrawal of long-term therapy in AS patients led to relapses of disease after several months. Less radiographic progression after 2 years of continuous treatment with infliximab compared to conventional therapy has been suggested in a small study. Serious adverse events on anti-TNF therapy have remained rare. However, severe infections, including tuberculosis, have been reported. These can be largely prevented by appropriate screening. The benefits of anti-TNF therapy in AS seem to outweigh these shortcomings.

Psoriatic arthritis: pathogenesis and novel immunomodulatory approaches to treatment

Psoriatic arthritis (PsA) is a chronic inflammatory arthropathy characterized by the association of arthritis and psoriasis. PsA runs a variable course, from mild synovitis to severe, progressive, erosive arthropathy. The pathogenesis of PsA involves alteration in the components of the immune response, although the exact cause of PsA is unknown. A number of patients with severe peripheral arthritis fail to respond to standard conventional therapy. Advances in biotechnology and in our understanding of the immunopathogenesis of PsA have led to great interest and progress in regards to biologic treatments for PsA. Notable success achieved with recently introduced biologic therapies has paved the way for further research and development of additional therapies that should improve outcomes for affected patients.

Aggressive cutaneous T-cell lymphomas after TNFalpha blockade

Pharmacologic blockade of TNFalpha has been a highly effective approach to treating several immunologically mediated diseases, including rheumatoid arthritis, Crohn's disease, and psoriatic arthritis. 1,2,3 Both etanercept, the recombinant extracellular domain of the tumor necrosis factor receptor 2 (TNFR2), and infliximab, a humanized murine antibody, bind TNFalpha and block its interaction with cell surface receptors. Recently, it has become clear that blockade of TNFalpha action is profoundly immunosuppressive, and may result in reactivation of tuberculosis and histoplasmosis, as well as the emergence of B-cell lymphomas. 4,5,6 In this report, we describe two cases of cutaneous and systemic T-cell lymphoma that progressed rapidly in the setting of TNFalpha blockade. Both cases were characterized by rapid onset, a fulminant clinical course with extensive cutaneous and systemic involvement, and death within months of diagnosis.

Aminocyanopyridine inhibitors of mitogen activated protein kinase-activated protein kinase 2 (MK-2)

A class of inhibitors of mitogen-activated protein kinase-activated protein kinase 2 (MK-2) was discovered. These compounds have demonstrated activity against the enzyme with IC50 values as low as 130 nM and suppress the expression of TNFalpha in U937 cells. These represent the first small molecule inhibitors of MK-2 to be reported.

Psoriatic arthritis and psoriasis: Need for a multidisciplinary approach

Psoriatic arthritis is a progressive and often destructive form of seronegative inflammatory arthritis that is associated with psoriasis. It can be difficult to diagnose because it can present in a number of different ways, often indistinguishable from noninflammatory arthropathies such as osteoarthritis as well as inflammatory arthritis such as gout. Severe arthritis may be observed in the absence of psoriasis, or mild arthritis may be seen in the presence of moderate-to-severe psoriasis. A high index of suspicion, screening of psoriasis patients, and close follow-up and evaluation with rheumatology often is needed to make the diagnosis. Early recognition of the disorder and timely therapy can prevent long-term complications, such as permanent joint destruction and disability. With the advent of biologic agents, we are better equipped to manage psoriatic arthritis today. Because dermatologists are on the front-line of psoriasis management, we are perfectly poised to identify and help improve care for patients who suffer from both psoriasis and psoriatic arthritis.

Novel approaches in the treatment of ankylosing spondylitis and other spondyloarthritides

The therapeutic options for patients suffering from severe forms of spondyloarthritis (SpA) have been rather limited in recent decades. There is now accumulating evidence that anti-TNF therapy is highly effective in SpA, especially in ankylosing spondylitis (AS) and psoriatic arthritis (PsA). Based on the data recently published on what is now several hundred AS and PsA patients, this treatment seems to be even more effective than the same therapy in rheumatoid arthritis (RA). The anti-TNF-alpha agents currently available, infliximab (Remicade); Centocor), etanercept (Enbrel); Amgen) and adalimumab (Humira; Abbott), are approved for the treatment of RA in the US; infliximab and etanercept are approved in Europe. The situation in SpA is different to RA because there is an unmet medical need, especially in AS, since no therapies with disease-controlling antirheumatic drugs are available for severely affected patients, especially with spinal disease. Thus, TNF blockers might even be considered as first-line immunosuppressive agents in patients with active AS and PsA who are not sufficiently treated by non-steroidal anti-inflammatory drugs and sulfasalazine, if peripheral arthritis is present. For infliximab, a dosage of 5 mg/kg at intervals between 6 and 12 weeks was necessary to constantly suppress disease activity; this is also a major aim of long-term treatment. No dose-finding studies have yet been performed. The standard dose of etanercept is 25 mg s.c. twice-weekly. No studies on adalimumab (standard RA dose 20 - 40 mg s.c. every 2 weeks) have yet been conducted in SpA. The efficacy of etanercept was first demonstrated in PsA and etanercept is now approved for this indication. A double-blind study has also been performed in AS, with similarly clearcut efficacy. There is preliminary evidence that both agents do also work in other SpA such as undifferentiated SpA. Infliximab has recently been approved for short-term treatment of severe uncontrolled AS; the approval for etanercept is pending. Studies should be performed to document the long-term efficacy of this treatment. There is hope that ankylosis might be preventable but it remains to be shown whether patients benefit from long-term anti-TNF therapy and whether radiological progression and ankylosis can be stopped. Severe adverse events have remained rare. Complicated infections including tuberculosis have been reported. Tuberculosis can be mostly prevented if patients are checked for previous contact with tuberculosis. Currently, the benefits of anti-TNF therapy in AS seem to outweigh these shortcomings.