Alefacept treatment in psoriatic arthritis: reduction of the effector T cell population in peripheral blood and synovial tissue is associated with improvement of clinical signs of arthritis

Will rheumatologists ever pick up the arthroscope again?

Conditions prompting physicians and surgeons first adapting endoscopes to peer into joints were mainly the sort of synovial conditions that would concern today's rheumatologists. Rheumatologists were among the pre-World War II pioneers developing and documenting arthroscopy. The post-War father of modern arthroscopy, Watanabe, found rheumatologists among his early students, who took back the technique to their home countries, teaching orthopedists and rheumatologists alike. Rheumatologists described and analyzed the intra-articular features of their common diseases in the '60s and '70s. A groundswell of interest from academic rheumatologists in adapting arthroscopy grew considerably in the '90s with development of "needle scopes" that could be used in an office setting. Rheumatologists helped conduct the very trials the findings of which reduced demand for their arthroscopic services by questioning the efficacy of arthroscopic debridement in osteoarthritis (OA) and also developing biological compounds that greatly reduced the call for any resective intervention in inflammatory arthropathies. The arthroscope has proven an excellent tool for viewing and sampling synovium and continues to serve this purpose at several international research centers. While cartilage is now imaged mainly by magnetic resonance imaging, some OA features - such as a high prevalence of visible calcinosis - beg further arthroscopy-directed investigation. A new generation of "needle scopes" with far superior optics awaits future investigators, should they develop interest.

Ultrasound-Guided Synovial Biopsies of Wrists, Metacarpophalangeal, Metatarsophalangeal, Interphalangeal Joints, and Tendon Sheaths

Ultrasound-guided synovial biopsy (UGSB) is a minimally-invasive procedure which allows quality synovial tissue retrieval. In this article, we will discuss overarching principles of the procedure performed in wrists, metacarpophalangeal (MCP), metatarsophalangeal (MTP), interphalangeal joints (IP), and tendon sheaths, including basic sonoanatomy, entry site and biopsy technique, as well as special considerations for each structure whenever relevant.

Japanese guidelines for the management and treatment of generalized pustular psoriasis: The new pathogenesis and treatment of GPP

Generalized pustular psoriasis (GPP) is a rare disease characterized by recurrent fever and systemic flushing accompanied by extensive sterile pustules. The committee of the guidelines was founded as a collaborative project between the Japanese Dermatological Association and the Study Group for Rare Intractable Skin Diseases under the Ministry of Health, Labour, and Welfare Research Project on Overcoming Intractable Diseases. The aim of the guidelines was to provide current information to aid in the treatment of patients with GPP in Japan. Its contents include the diagnostic and severity classification criteria for GPP, its pathogenesis, and recommendations for the treatment of GPP. Since there are few clinical trial data with high levels of evidence for this rare disease, recommendations by the committee are described in the present guidelines.

Biologic Therapeutics in the Treatment of Psoriasis. Part 1: Review

Background:

Psoriasis is a chronic inflammatory skin disease principally mediated by activated T cells, which release proinflammatory cytokines with reactive epidermal changes in the skin, producing the characteristic lesions of psoriasis. New research into possible treatment options has been inspired by increased understanding of the pathophysiology of psoriasis and advances in immunology and molecular biology permitting the development of targeted, highly active biologic agents.

Objective:

The aim of this article is to review the efficacy and safety of five biologic therapeutics in the treatment of moderate to severe psoriasis and to provide practical guidelines for integration of these agents in the management of psoriasis.

Methods:

We searched MEDLINE (1966–2005) for articles containing the key words: alefacept, efalizumab, etanercept, infliximab, and adalimumab and searched recent conference abstracts.

Results:

Emerging immunotherapeutic agents (fusion proteins, recombinant cytokines, fusion toxins, or antibodies) target T cells or cytokines responsible for plaque formation that is characteristic of psoriasis. Alefacept is the first biologic to be approved in both the United States and Canada. More recently, efalizumab and etanercept and infliximab have been approved in the United States and Canada for plaque-type psoriasis. Adalimumab is currently in phase III clinical trials.

Conclusion:

These novel biologics offer an intriguing and effective treatment option for patients with moderate to severe psoriasis.

Biologic Therapeutics in the Treatment of Psoriasis. Part 2: Practical Considerations

Background:

Psoriasis is a chronic inflammatory skin disease principally mediated by activated T cells, which release proinflammatory cytokines with reactive epidermal changes in the skin, producing the characteristic lesions of psoriasis. New research into possible treatment options has been inspired by increased understanding of the pathophysiology of psoriasis and advances in immunology and molecular biology permitting the development of targeted, highly active biologic agents.

Objective:

The aim of this article is to provide practical guidelines for integration of these agents in the management of psoriasis.

Neutrophils and arthritis: Role in disease and pharmacological perspectives

The inflammatory response in the joint can induce an intense accumulation of leukocytes in the tissue that frequently results in severe local damage and loss of function. Neutrophils are essential cells to combat many pathogens, but their arsenal can contribute or aggravate articular inflammation. Here we summarized some aspects of neutrophil biology, their role in inflammation and indicated how the modulation of neutrophil functions could be useful for the treatment of different forms of arthritis.

Computational drug repositioning for peripheral arterial disease: prediction of anti-inflammatory and pro-angiogenic therapeutics

Peripheral arterial disease (PAD) results from atherosclerosis that leads to blocked arteries and reduced blood flow, most commonly in the arteries of the legs. PAD clinical trials to induce angiogenesis to improve blood flow conducted in the last decade have not succeeded. We have recently constructed PADPIN, protein-protein interaction network (PIN) of PAD, and here we combine it with the drug-target relations to identify potential drug targets for PAD. Specifically, the proteins in the PADPIN were classified as belonging to the angiome, immunome, and arteriome, characterizing the processes of angiogenesis, immune response/inflammation, and arteriogenesis, respectively. Using the network-based approach we predict the candidate drugs for repositioning that have potential applications to PAD. By compiling the drug information in two drug databases DrugBank and PharmGKB, we predict FDA-approved drugs whose targets are the proteins annotated as anti-angiogenic and pro-inflammatory, respectively. Examples of pro-angiogenic drugs are carvedilol and urokinase. Examples of anti-inflammatory drugs are ACE inhibitors and maraviroc. This is the first computational drug repositioning study for PAD.

Immunosuppression by co-stimulatory molecules: inhibition of CD2-CD48/CD58 interaction by peptides from CD2 to suppress progression of collagen-induced arthritis in mice

Targeting co-stimulatory molecules to modulate the immune response has been shown to have useful therapeutic effects for autoimmune diseases. Among the co-stimulatory molecules, CD2 and CD58 are very important in the early stages of generation of an immune response. Our goal was to utilize CD2-derived peptides to modulate protein-protein interactions between CD2 and CD58, thereby modulating the immune response. Several peptides were designed based on the structure of the CD58-binding domain of CD2 protein. Among the CD2-derived peptides, peptide 6 from the F and C β-strand region of CD2 protein exhibited inhibition of cell-cell adhesion in the nanomolar concentration range. Peptide 6 was evaluated for its ability to bind to CD58 in Caco-2 cells and to CD48 in T cells from rodents. A molecular model was proposed for binding a peptide to CD58 and CD48 using docking studies. Furthermore, in vivo studies were carried out to evaluate the therapeutic ability of the peptide to modulate the immune response in the collagen-induced arthritis (CIA) mouse model. In vivo studies indicated that peptide 6 was able to suppress the progression of CIA. Evaluation of the antigenicity of peptides in CIA and transgenic animal models indicated that this peptide is not immunogenic.

The Th17 axis in psoriatic disease: pathogenetic and therapeutic implications

Psoriasis and psoriatic arthritis represent two paradigmatic conditions characterized by chronic inflammation and possibly autoimmunity, despite the absence of known serum autoantibodies. The two diseases, albeit strongly correlated from clinical, genetic, and epidemiogical standpoints, manifest significant differences in terms of etiology and pathogenetic mechanisms. Nonetheless, Th17 cells appear crucial to both diseases, and IL23 is the cytokine involved in determining the fate of naive CD4+ cells to differentiate into a pathogenic phenotype. This basic experimental observation led to a clear understanding of the immune dysfunction causing psoriasis and psoriatic arthritis but, more importantly, also led to new therapeutic approaches. In recent years, monoclonal antibodies directed to IL12/IL23 (ustekinumab) or IL17 (secukinumab, ixekizumab, brodalumab) are being investigated or have proven to be beneficial for patients with psoriatic disease, thus further supporting the view that Th17 cells play a pivotal role in disease onset and perpetuation. These most recent reports indeed represent significant developments that may allow overcoming the TNFα pathway as the major therapeutic target in chronic inflammation.

Light and electron microscopic features of synovium in patients with psoriatic arthritis

INTRODUCTION

Few ultrastructural studies have been reported in psoriatic arthritis (PsA). The authors report a series of synovial biopsies with emphasis on patients with early disease to look for distinctive light (LM) and electron microscopic (EM) features of possible importance.

METHODS

The authors examined synovial biopsies obtained primarily by needle biopsy from 13 PsA patients using LM and/or EM. Sections from 12 patients were evaluated by LM for vascularity, synovial lining thickness, fibrin deposition, and inflammation via a semi-quantitative scale. Nine EM specimens were descriptively analyzed. Clinical, synovial fluid (SF), and radiographic characteristics were recorded.

RESULTS

Patients were mostly male, with mean disease duration before biopsy of 2.19 ± 2.60 years; 7 patients had arthritis for less than 1 year. All patients had peripheral arthritis, 2 had axial involvement. SFs disclosed predominance of polymorphonuclear leukocytes. LM demonstrated proliferation of synovial lining cells, lymphocyte and plasma cell infiltration, as well as dramatic clusters of small vessels in the superficial synovium. EMs showed more detailed vascular changes, including small, subendothelial, electron-dense deposits and scattered microparticles in vessel lumens and walls.

CONCLUSIONS

Prominent vascularity is confirmed as an important feature of some PsA. Vascular changes and other features, including the first EM demonstration of microparticles in PsA (identified as potent factors in other inflammatory joint diseases), are potential targets for therapy.

Novel targeted therapies for eosinophilic disorders

Hypereosinophilic syndromes (HESs) are a diverse group of conditions characterized by clinical manifestations attributable to eosinophilia and eosinophilic infiltration of tissues. HESs are chronic disorders with significant morbidity and mortality. Although the availability of targeted chemotherapeutic agents, including imatinib, has improved quality of life and survival in some patients with HESs, additional agents with increased efficacy and decreased toxicity are sorely needed. The purpose of this review is to provide an overview of eosinophil biology with an emphasis on potential targets of pharmacotherapy and to provide a summary of potential eosinophil-targeting agents, including those in development, in clinical trials, or approved for other disorders.

Expression of IL-20 in synovium and lesional skin of patients with psoriatic arthritis: differential response to alefacept treatment

Introduction

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.

Methods

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.

Results

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.

Conclusions

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.

Pathogenesis of spondyloarthritis: autoimmune or autoinflammatory?

PURPOSE OF REVIEW

Spondyloarthritis (SpA) is a chronic immune-mediated inflammatory disease of unknown origin. Here we aim to review whether SpA is driven by T-cell and/or B-cell autoreactivity or by abnormal innate immune responses.

RECENT FINDINGS

SpA does not share genetic risk factors, female predominance, presence of disease-specific autoantibodies and response to T-cell or B-cell-targeted therapies with prototypical autoimmune diseases like rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). Growing evidence indicates that increased responsiveness of innate immune cells such as macrophages, mast cells and neutrophils drives inflammation in SpA. The altered innate immune response may be related to nonantigen-presenting functions of HLA-B27, including the induction of an unfolded protein response, and can be triggered by bacterial and mechanical stress. Innate immune cells appear to be the main producers of both pro-inflammatory (tumor necrosis factor, IL-1, IL-23, IL-17) and anti-inflammatory (IL-10) cytokines in SpA.

SUMMARY

The predominance of myeloid above lymphoid alterations suggests an autoinflammatory rather than autoimmune origin of inflammation in SpA. Therefore, targeting innate cells or their inflammatory mediators may be more effective than T-cell or B-cell-directed therapies.

Synovial tissue response to treatment in psoriatic arthritis

Following its validation and wide application in rheumatoid arthritis (RA), synovial tissue analysis has recently been applied to studies on Psoriatic Arthritis (PsA). Such studies aim to thereby clarify its distinctive features and the nature of specific responses upon administration of disease modifying anti-rheumatic drug (DMARD) or biologic agents. In consequence, insights to disease pathogenesis, drugs' mechanisms of action (MOA) and biomarkers of response have emerged. Data from pilot and open-label studies, and recently from randomized controlled trials, have helped in refining the therapeutic approaches to PsA patients, by improving understanding of MOA and in provision of biomarkers of response. The availability of less invasive and reproducible analysis techniques to obtain and evaluate synovial biopsies will further enhance the utility of this approach in due course.

Synovitis in psoriatic arthritis: immunohistochemistry, comparisons with rheumatoid arthritis, and effects of therapy

Psoriatic arthritis (PsA) is a chronic inflammatory arthropathy associated with psoriasis that affects the peripheral joints, spine, and entheses. Most patients with PsA present with peripheral synovitis of the oligoarticular or polyarticular subtype. As one of the targets of this disease, studies on the synovium may provide insight into the mechanisms involved in this condition. Key findings from the available studies comparing synovial tissue of PsA and rheumatoid arthritis patients are discussed in this review. Also, changes in the synovial infiltrate, expression of proinflammatory cytokines and adhesion molecules, and vascularity in synovial tissue after treatment with various medications are addressed. Finally, a model for proof-of-principle study design using serial synovial biopsies is described, which could be used to predict clinical (in)efficacy in early clinical trial design in PsA.

Change in CD3 positive T-cell expression in psoriatic arthritis synovium correlates with change in DAS28 and magnetic resonance imaging synovitis scores following initiation of biologic therapy--a single centre, open-label study

INTRODUCTION

With the development of increasing numbers of potential therapeutic agents in inflammatory disease comes the need for effective biomarkers to help screen for drug efficacy and optimal dosing regimens early in the clinical trial process. This need has been recognized by the Outcome Measures in Rheumatology Clinical Trials (OMERACT) group, which has established guidelines for biomarker validation. To seek a candidate synovial biomarker of treatment response in psoriatic arthritis (PsA), we determined whether changes in immunohistochemical markers of synovial inflammation correlate with changes in disease activity scores assessing 28 joints (ΔDAS28) or magnetic resonance imaging synovitis scores (ΔMRI) in patients with PsA treated with a biologic agent.

METHODS

Twenty-five consecutive patients with PsA underwent arthroscopic synovial biopsies and MRI scans of an inflamed knee joint at baseline and 12 weeks after starting treatment with either anakinra (first 10 patients) or etanercept (subsequent 15 patients) in two sequential studies of identical design. DAS28 scores were measured at both time points. Immunohistochemical staining for CD3, CD68 and Factor VIII (FVIII) was performed on synovial samples and scored by digital image analysis (DIA). MRI scans performed at baseline and at 12 weeks were scored for synovitis semi-quantitatively. The ΔDAS28 of the European League Against Rheumatism good response definition (>1.2) was chosen to divide patients into responder and non-responder groups. Differences between groups (Mann Whitney U test) and correlations between ΔDAS28 with change in immunohistochemical and MRI synovitis scores (Spearman's rho test) were calculated.

RESULTS

Paired synovial samples and MRI scans were available for 21 patients (8 anakinra, 13 etanercept) and 23 patients (8 anakinra, 15 etanercept) respectively. Change in CD3 (ΔCD3) and CD68 expression in the synovial sublining layer (ΔCD68sl) was significantly greater in the disease responders compared to non-responders following treatment (P = 0.005 and 0.013 respectively). ΔCD3, but not ΔCD68 or ΔFVIII, correlated with both ΔDAS28 (r = 0.49, P = 0.025) and ΔMRI (r = 0.58, P = 0.009).

CONCLUSIONS

The correlation of ΔCD3 with ΔDAS28 and ΔMRI following biologic treatment in this cohort contributes to the validation of ΔCD3 as a synovial biomarker of disease response in PsA, and supports the further evaluation of ΔCD3 for predictive properties of future clinical outcomes.

Evaluation of a range of anti-proliferative assays for the preclinical screening of anti-psoriatic drugs: a comparison of colorimetric and fluorimetric assays with the thymidine incorporation assay

Established treatments for psoriasis are generally based on antiproliferative, anti-inflammatory, or differentiation-modifying activity, or a combination of these effects. New agents for the treatment of psoriasis could be identified by high-throughput screening (HTS) of large compound libraries using keratinocyte proliferation models. Although several new proliferation assays have been developed, the radioactive [(3)H]-thymidine incorporation assay is still considered to be the gold standard for the evaluation of keratinocyte proliferation in vitro. In this study, we compare a number of simple, and reliable, colorimetric (MTT, NRU, SRB, and CVS), and fluorimetric (CAM and AB) methods with the [(3)H]-thymidine incorporation assay for the measurement of keratinocyte proliferation in the exponential growth phase in 96-well formats. The concentrations that induced 50% growth inhibition (GI(50)) were determined by each assay for the established antipsoriatics, dithranol, and methotrexate. Strong correlations were observed between the percentage growth inhibitions determined by the radioactive and the colorimetric assays, with no significant differences (P > 0.05) between their GI(50) values. The colorimetric assays are thus suitable alternatives to the radioactive assay for quantifying keratinocyte growth inhibition. We have also validated the use of the HaCaT cell line as a representative of the hyperproliferative psoriatic epidermis, in the preclinical screening of experimental anti-psoriatic agents.

Update on the epidemiology and systemic treatment of psoriasis

Recent epidemiological observations reveal that the prevalence of psoriasis increases more rapidly in young women compared with young men, and that the prevalence of psoriasis may decrease in the elderly. Emerging evidence suggests that some potentially modifiable exposures, such as smoking, stress and obesity, may increase a patient's risk of developing psoriasis. The evolving literature suggests that psoriasis is associated with multiple other diseases, including cancer, cardiovascular disease, diabetes and psychiatric disease, and that psoriasis itself may be an independent risk factor for developing atherosclerosis and myocardial infarction. The treatment of moderate-to-severe psoriasis is undergoing a revolution with the advent of biological therapies that target the immunopathogenesis of psoriasis, such as tumor necrosis factor-alpha and T-cell function. The pharmacokinetics, pharmacodynamics, efficacy and safety profiles vary among biologicals and, therefore, drug and patient factors are important in selecting the optimum therapy. In this article, we focus on recent developments in the epidemiology and systemic treatment of psoriasis.

Alefacept: where it stands today

IMPORTANCE OF THE FIELD

The use of biologics that target a subset of immune cells in the treatment of immune-mediated ailments is an emerging field. Alefacept is one of the first biologics in the treatment of psoriasis. It selectively reduces CD45RO(+) memory T cells and inhibits T-cell activation. Clinical data support its safety and efficacy in a substantial subset of patients with psoriasis.

AREAS COVERED IN THIS REVIEW

This article reviews the mechanism of action and the pharmacokinetic and pharmacodynamic properties of alefacept. It also presents the available data about its effectiveness, modes of treatment as well as safety and efficacy in the treatment of psoriasis and other immune-based dermatologic disorders.

WHAT THE READER WILL GAIN

An overview of the published data about the clinical and adverse effects of alefacept in the treatment of psoriasis and a myriad of immunologically-based disorders.

TAKE HOME MESSAGE

Ongoing literature supports that alefacept is a safe alternative for the treatment of psoriasis. However, it remains the least prescribed medication in this group of drugs, mainly because it is only effective in a small proportion of patients. Nonetheless, its long-lasting effects and tolerability make it an excellent choice for those who do respond.

[Biologic therapies different from the anti-TNFα therapy in psoriasis and psoriatic arthritis]

Psoriasis and psoriatic arthritis (PsA) are common conditions in the clinical practice of both dermatologists and rheumatologists. Both entities may cause an important loss in quality of life, and in the case of PsA, joint structural damage may arise over time. For these reasons, clinicians may be faced with the need for treating these cases with highly effective therapies, such as TNFα blocking agents, although these drugs may be paradoxically related with de novo onset (or exacerbation of previous lesions) of psoriasis or psoriasiform lesions. In spite of the clinical efficacy of these therapies, recent registry studies show that up to 25% of PsA cases exposed to anti-TNF therapies are withdrawn from these drugs within the first year of therapy. Therefore, there is a need for the use of alternative biologic therapies in this context. The present review deals with this subject.

The effect of topical corticosteroids in combination with alefacept on circulating T‐cell subsets in psoriasis

BACKGROUND

Novel therapies against psoriasis are emerging. Alefacept is such a treatment. It selectively targets the memory effector population of T cells and thereby diminishes the psoriatic plaques. In some cases, however, the use of alefacept as a monotherapy is not sufficient.

OBJECTIVE

In the present study we investigate the safety and efficacy of adding topical steroids to alefacept treatment during the initial 4 weeks.

METHODS

Peripheral blood was obtained from all patients and the presence of specific T-cell subsets was assessed by flow cytometry. Fourteen patients were included and treated with 15 mg alefacept intramuscularly for a period of 12 weeks. Each of them was randomized to use either betamethasone-dipropionate cream or a vehicle cream during the first 4 weeks of the alefacept course.

RESULTS

Additional topical corticosteroid treatment during the first 4 weeks of alefacept treatment does not have a beneficial effect on the clinical efficacy. Marked changes were seen in the absolute cell counts of various of the analysed T-cell subsets in peripheral blood after 12 weeks of alefacept, either with or without additional local steroid application. The CD45RO+, CD8+CD45RO+, CD8+CD161+, CD4+CD25+, CD4+CLA+ and CD8+CLA+ populations showed a statistically significant decrease immediately after the treatment period. Further analysis revealed that the addition of local steroid therapy to alefacept results in marked decreases of all T-cell subsets analysed in this study, in contrast to the addition of the vehiculum only.

CONCLUSION

Alefacept selectively targets the CD45RO+ lymphocyte population, as well as some other subpopulations of lymphocytes. This effect is independent of the use of additional topical therapy during the first 4 weeks. The extent of the decrease, on the contrary, is dependent on the use of corticosteroids.

Evaluation of arthroscopy and macroscopic scoring

INTRODUCTION

Arthroscopy is a minimally invasive technique for retrieving synovial biopsies in rheumatology during the past 20 years. Vital for its use is continual evaluation of its safety and efficacy. Important for sampling is the fact of intraarticular variation for synovial markers. For microscopic measurements scoring systems have been developed and validated, but for macroscopic evaluations there is a need for further comprehensive description and validation of equivalent scoring systems.

METHODS

We studied the complication rate and yield of arthroscopies performed at our clinic between 1998 and 2005. We also created and evaluated a macroscopic score set of instructions for synovitis.

RESULTS

Of 408 procedures, we had two major and one minor complication; two haemarthrosis and one wound infection, respectively. Pain was most often not a problem, but 12 procedures had to be prematurely ended due to pain. Yield of biopsies adequate for histology were 83% over all, 94% for knee joints and 34% for smaller joints. Video printer photographs of synovium taken during arthroscopy were jointly and individually reviewed by seven raters in several settings, and intra and inter rater variation was calculated. A macroscopic synovial scoring system for arthroscopy was created (Macro-score), based upon hypertrophy, vascularity and global synovitis. These written instructions were evaluated by five control-raters, and when evaluated individual parameters were without greater intra or inter rater variability, indicating that the score is reliable and easy to use.

CONCLUSIONS

In our hands rheumatologic arthroscopy is a safe method with very few complications. For knee joints it is a reliable method to retrieve representative tissue in clinical longitudinal studies. We also created an easy to use macroscopic score, that needs to be validated against other methodologies. We hope it will be of value in further developing international standards in this area.

Psoriatic arthritis

Although there is still some controversy about the existence of psoriatic arthritis (PsA) as a specific form of inflammatory arthritis associated with psoriasis, epidemiological and clinical studies support the unique features of PsA. Because of lack of diagnostic or classification criteria, the disease has been thought of as uncommon. New classification criteria should facilitate case definition of PsA. Over the past several decades, it has become clear that the disease leads to serious disability and even increased mortality. Traditional medications have not been effective in preventing the progression of joint damage. New medications, including biologics, have emerged with potential to controlling the inflammation and arresting the progression of joint damage.

A prospective, randomised, placebo-controlled study to identify biomarkers associated with active treatment in psoriatic arthritis: effects of adalimumab treatment on synovial tissue

OBJECTIVE

To determine which of the changes in synovial tissue correlates best with clinical response associated with effective therapy (adalimumab) to facilitate the planning of future studies with therapeutic agents for psoriatic arthritis (PsA).

METHODS

A total of 24 patients with active PsA were randomised to receive adalimumab (n = 12) or placebo (n = 12) for 4 weeks. Synovial biopsies were obtained before and after 4 weeks of treatment. Immunohistochemical analysis was performed to characterise the cell infiltrate, expression of cytokines and matrix metalloproteinases (MMPs) and vascularity. Sections were analysed by digital image analysis. Statistical analysis was performed using covariance analysis.

RESULTS

The mean Disease Activity Score in 28 joints (DAS28) after 4 weeks was 1.92 units lower (95% confidence interval (CI) 1.07 to 2.77) after adalimumab therapy compared with placebo. Paired pretreatment and post-treatment synovial samples were available from 19 patients. Many cell types were reduced after adalimumab treatment compared to placebo. After applying a ranked analysis of covariance (ANCOVA) model to correct for baseline imbalances, a significant effect of treatment was observed on CD3-positive cells: there was a median reduction of 248 cells/mm(2) after adalimumab versus placebo treatment (p = 0.035). In addition, the expression of MMP13 was significantly reduced after active treatment: the integrated optical density (IOD)/mm(2) was 18 190 lower after adalimumab treatment as compared to placebo (p = 0.033).

CONCLUSION

Adalimumab therapy in PsA is associated with a marked reduction in T cell infiltration and MMP13 expression in synovial tissue, suggesting that these parameters could be used as biomarkers that are sensitive to change after active treatment in small proof of concept studies in PsA.

T cells in psoriatic arthritis

Psoriatic arthritis is characterized by chronic inflammation of the skin and synovial joint. T cells are abundant in the inflamed joint and skin. Disease susceptibility is associated with major histocompatibility complex, which presents antigens to T cells. T cells in the synovial joints have an activated phenotype and demonstrate selective T-cell receptor usage suggestive of oligoclonal expansions. Taken together, these facts suggest that psoriatic arthritis is driven by antigen or autoantigen-driven T-cell activation. The therapeutic benefit of anti-T-cell agents further supports an important pathogenic role for T cells in persistent synovial inflammation and joint damage in psoriatic arthritis.

Update on the natural history and systemic treatment of psoriasis

The onset of psoriatic disease and its associated comorbidities involves the interplay among a myriad of genetic and environmental risk factors. As we gain further insight into the immunopathogenesis of psoriasis, we hope it will provide the basis for the development of safer, more efficacious, and more durable therapeutics in the future. Given its enormous toll on patient health and quality of life, steps should be taken to prevent or decrease the risk for psoriasis-associated comorbidities through behavior modification and use of preventative health screenings and treatments. Future studies will need to be performed to determine if successful treatment of psoriasis will lead to a decreased risk for developing psoriasis-associated comorbidities over time.

Cost-effectiveness and impact on quality of life of alefacept in the treatment of psoriasis

Although alefacept was the first biologic agent approved to treat psoriasis, it is used less frequently than other biologic therapies. Alefacept decreases the Psoriasis Area and Severity Index (PASI) score and enhances the quality of life of patients with psoriasis. Unlike other biologics, alefacept can also induce remission of psoriasis. If reports in Pubmed and the package insert are considered to be surrogates for side effects, alefacept appears to be safer than other biologics. Alefacept can be effective against psoriatic arthritis, especially in combination with methotrexate. The response of psoriatics to alefacept, however, is inconsistent and often incomplete. Alefacept also has the highest cost of any biologic agent as measured by patients achieving PASI-75 and cost per patient achieving Dermatology Life Quality Index Minimal Important Difference. Traditional systemic therapies such as spriatane, ciclosporine, as well as phototherapy and TNF-alpha, possess firmer and superior pharmacoeconomic foundations, although some of these apparent cost-benefit disadvantages may take into account the ability of alefacept to induce remission after cessation of treatment.

The added therapeutic efficacy and safety of alefacept in combination with other (systemic) anti-psoriatics in refractory psoriasis

OBJECTIVE

Alefacept is a biologic treatment for psoriasis, with a selective effect on memory effector T cells. Few data are available on the combination of alefacept with either topical or systemic anti-psoriatics. We studied the effect of alefacept combination treatment on clinical disease severity scores and on circulating T-cell subsets.

METHODS

Twelve patients with moderate-to-severe psoriasis were included and treated with alefacept for a period of 12 weeks. Patients were allowed to continue the anti-psoriatic therapies they used prior to the study. Severity of disease and expression of T-cell markers CD4, CD8, CD45RA, CD45RO, CD94, CD161, CD25, and CLA were assessed at baseline and after treatment.

RESULTS

Seven of 12 included patients used a concomitant systemic therapy: either methotrexate (n = 4), acitretin (n = 2) or cyclosporine (n = 1). PASI reductions in this group after 12 and 24 weeks were 40% and 55%, respectively. Several lymphocyte subsets showed a reduction in circulating numbers. These decreases were independent of the use of an additional systemic psoriasis therapy.

CONCLUSIONS

The concomitant use of systemic anti-psoriatic medication in combination with alefacept has a noteworthy impact on efficacy results. No differences in circulating psoriasis-relevant T-cell populations between patients with or without an additional systemic treatment were seen.

Structure-function studies of peptides for cell adhesion inhibition: identification of key residues by alanine mutation and peptide-truncation approach

Blockage of the interaction of CD2 with its ligand CD58 is expected to bring out potential therapeutic value for autoimmune diseases and organ transplantation. Three series of peptides (cVL, cIL and cAQ series) were designed from ratCD2 and humanCD2 to modulate CD2-CD58 interaction. To determine the specific segments in parent peptides responsible for inhibitory activity as lead sequence, we generated shorter fragments of the parent peptides and evaluated their biological activity with cell adhesion assay. The structure-activity relationship studies indicated that small cyclic peptides derived from CD2 ligand binding epitopes could mimic native beta-turn structure, and thus modulate CD2-CD58 interaction.

Targeting effector memory T cells with the small molecule Kv1.3 blocker PAP-1 suppresses allergic contact dermatitis

The voltage-gated potassium channel Kv1.3 has been recently identified as a molecular target that allows for selective pharmacological suppression of effector memory T (T(EM)) cells without affecting the function of naïve and central memory T cells. We here investigated whether PAP-1, a small molecule Kv1.3 blocker (EC50=2 nM), could suppress allergic contact dermatitis (ACD). In a rat model of ACD, we first confirmed that the infiltrating cells in the elicitation phase are indeed CD8+ CD45RC- memory T cells with high Kv1.3 expression. In accordance with its selective effect on T(EM) cells, PAP-1 did not impair sensitization, but potently suppressed oxazolone-induced inflammation by inhibiting the infiltration of CD8+ T cells and reducing the production of the inflammatory cytokines IFN-gamma, IL-2, and IL-17 when administered intraperitoneally or orally during the elicitation phase. PAP-1 was equally effective when applied topically, demonstrating that it effectively penetrates skin. We further show that PAP-1 is not a sensitizer or an irritant and exhibits no toxicity in a 28-day toxicity study. Based on these results we propose that PAP-1 could potentially be developed into a drug for the topical treatment of inflammatory skin diseases such as psoriasis.

The Disease Activity Score in 28 joints in rheumatoid arthritis and psoriatic arthritis patients

OBJECTIVE

To assess the factorial structure of the Disease Activity Score including a 28-joint count (DAS28) if applied in patients with rheumatoid arthritis (RA) and psoriatic arthritis (PsA).

METHODS

DAS28 values from 85 consecutive PsA outpatients and 2 RA patient cohorts comprising 85 patients each were compared. The first RA cohort (RA1) consisted of age- and sex-matched patients seen during the same period as the patients with PsA. The first 85 RA outpatients from September 2003 were included in the second cohort (RA2). Item weighting, factor loading, and internal consistency were assessed by factor analysis, principal component analysis, and calculation of Cronbach's alpha.

RESULTS

The mean +/- SD DAS28 scores of patients in the PsA, RA1, and RA2 cohorts were 3.2 +/- 1.31, 3.21 +/- 1.45, and 3.79 +/- 1.44, respectively. A significant difference between the PsA and RA2 cohorts was found for DAS28 (P = 0.0063), swollen joint count (P = 0.007), and patient's global assessment (P < 0.001), but not for erythrocyte sedimentation rate. Internal consistency of the DAS28 in patients with PsA was considerably lower, item weighting showed remarkable differences, and factor analysis revealed that the DAS28 constitutes a bidimensional instrument in patients with PsA, whereas in both RA cohorts it appeared to be monodimensional.

CONCLUSION

With respect to its statistical properties, the DAS28 proved to be considerably different in PsA compared with RA. Therefore its application for disease activity assessment in patients with PsA cannot be recommended without a formal validation procedure.

Management of psoriatic arthritis: the therapeutic interface between rheumatology and dermatology

Psoriatic arthritis is an inflammatory arthritis, which occurs in up to 30% of individuals with psoriasis. Dermatologists and other physicians treating psoriasis are in an ideal position to screen for the condition, and with rheumatologists, strategize optimal therapy. Mild skin and joint manifestations may be treated effectively with topical agents, ultraviolet light therapy, and nonsteroidal anti-inflammatory drugs. More severe manifestations of the disease, including progressive peripheral joint damage, spine disease, enthesitis, dactylitis, and severe skin changes, require systemic therapy. Traditional systemic agents include methotrexate, sulfasalazine, and cyclosporine. When these agents are not adequate or not tolerated, new biologic agents, particularly anti-tumor necrosis factor (TNF) compounds, have shown significant and enduring benefit in all disease domains, improvement in quality of life and function, and inhibition of progressive joint damage.

Spondyloarthropathy: disease at the crossroads of immunity

Up until recently, the prevailing paradigm relating to spondyloarthropathy (SpA) pathogenesis was that they were human leukocyte antigen (HLA)-associated, T-cell-driven autoimmune diseases. This view is now being questioned. Careful studies of well-characterised cohorts of patients with SpA, including detailed analysis of involved tissue, together with clinical trials of targeted treatments, in particular anti-tumour necrosis factor (TNF) therapies, have contributed enormously to both interest in and understanding of disease pathogenesis. In this chapter, our current knowledge and understanding of the relative contributions of the components of the innate and adaptive arms of the immune response to SpA pathogenesis is reviewed. It is clear that both arms of the immune response are involved and inter-dependent in SpA. With continued emphasis on discovery research, including detailed analysis of novel therapeutic interventions, significant additional breakthroughs in SpA are likely to be forthcoming.

Identification of synovial biomarkers of response to experimental treatment in early-phase clinical trials in spondylarthritis

OBJECTIVE

To identify biomarkers for effective treatment in early-phase clinical trials of spondylarthritis (SpA), by analyzing which synovial features can be reliably identified in patients with SpA.

METHODS

Synovial biopsies were performed at weeks 0 and 12 in 20 SpA patients treated with infliximab, 20 treated with etanercept, and 12 who were not treated. Primary clinical outcome measures were patient and physician global assessment of disease activity. Extensive histologic evaluation included assessment of lining layer hyperplasia, vascularity, markers of cellular infiltration, and metalloproteinases (MMPs) in the lining and sublining layers.

RESULTS

Changes in levels of CD163 (resident tissue macrophages) in the lining, and CD163, MMP-3, and myeloid-related protein 14 (MRP-14; infiltrating myeloid cells) in the sublining correlated significantly with changes in the primary clinical outcomes. Comparison between responders (n = 35) and nonresponders (n = 17) showed differences in the degree of change in the levels of CD163 in the lining and CD163, MMP-3, and CD3 in the sublining, whereas trends in change in the levels of MRP-8 and MRP-14 in the lining and sublining were similar in the 2 groups. Accordingly, the highest differences in standardized response means (SRMs) between the 2 groups were found for CD163 in the lining, MMP-3, CD163, CD3, and MRP-8 in the sublining, and the level of polymorphonuclear cells (PMNs). When comparing treated and untreated patients, high differences in SRMs were again found for CD163 in the lining, MMP-3, CD163, and MRP-8 in the sublining, and PMNs. These parameters performed prognostically as well as the erythrocyte sedimentation rate and better than the C-reactive protein level. Class prediction analysis yielded a 90% correct prediction using 8 synovial parameters, as follows: lining and sublining CD163, MRP-8, and MRP-14, sublining MMP-3, and PMNs. In validation analyses with independent samples, effective treatment was correctly predicted in 24 of 30 SpA patients and in 2 of 2 placebo-treated patients.

CONCLUSION

Changes in synovial macrophage subsets, PMN levels, and MMP-3 expression reflect response to treatment in SpA. The ability of these parameters to correctly identify effective therapy makes them interesting biomarkers for use in early-phase clinical trials in SpA.

Pathogenesis of spondyloarthritis: Insights from synovial membrane studies

Here, we review histopathologic studies of the cellular and molecular pathways of spondyloarthritis (SpA) synovial inflammation. In contrast with lymphocytes, specific macrophage subsets and polymorphonuclear cells selectively increase in SpA synovitis, correlate with global disease activity, decrease rapidly upon effective treatment with tumor necrosis factor (TNF)-alpha blockers, and serve as valuable biomarkers for treatment response in SpA. Functionally, increased Toll-like receptor triggering may be responsible for the proinflammatory response of these cells. Therefore, we propose that an exaggerated response of the innate immune system in genetically susceptible patients rather than a classic, lymphocyte-mediated autoimmune process is involved in the pathogenesis of SpA.

Detailed analysis of the cell infiltrate and the expression of mediators of synovial inflammation and joint destruction in the synovium of patients with psoriatic arthritis: implications for treatment

BACKGROUND

The synovial tissue is a primary target of many inflammatory arthropathies, including psoriatic arthritis (PsA). Identification of proinflammatory molecules in the synovium may help to identify potentially therapeutic targets.

OBJECTIVE

To investigate extensively the features of cell infiltration and expression of mediators of inflammation and joint destruction in the synovium of patients with PsA compared with patients with rheumatoid arthritis matched for disease duration and use of drugs.

METHODS

Multiple synovial tissue biopsy specimens were obtained by arthroscopy from an inflamed joint in 19 patients with PsA (eight oligoarthritis, 11 polyarthritis) and 24 patients with rheumatoid arthritis. Biopsy specimens were analysed by immunohistochemistry to detect T cells, plasma cells, fibroblast-like synoviocytes, macrophages, proinflammatory cytokines, matrix metalloproteinases and tissue inhibitor metalloproteinase-1, adhesion molecules and vascular markers. Stained sections were evaluated by digital image analysis.

RESULTS

The synovial infiltrate of patients with PsA and rheumatoid arthritis was comparable with regard to numbers of fibroblast-like synoviocytes and macrophages. T cell numbers were considerably lower in the synovium of patients with PsA. The number of plasma cells also tended to be lower in PsA. The expression of tumour necrosis factor alpha (TNFalpha), interleukin (IL) 1beta, IL6 and IL18 was as high in PsA as in rheumatoid arthritis. The expression of matrix metalloproteinases, adhesion molecules and vascular markers was comparable for PsA and rheumatoid arthritis.

CONCLUSION

These data show increased proinflammatory cytokine expression in PsA synovium, comparable to results obtained for rheumatoid arthritis, and support the notion that, in addition to TNFalpha blockade, there may be a rationale for treatments directed at IL1beta, IL6 and IL18.