Drug Insight: anti-tumor-necrosis-factor therapy for ankylosing spondylitis

Ankylosing spondylitis and mesenchymal stromal/stem cell therapy: a new therapeutic approach

Ankylosing spondylitis (AS) is an inflammatory rheumatoid disease categorized within spondyloarthropathies (SpA) and manifested by chronic spinal arthritis. Several innate and adaptive immune cells and secreted-mediators have been indicated to play a role in AS pathogenesis. Considering the limitations of current therapeutic approaches (NSAIDs, glucocorticoids, DMARDs and biologic drugs), finding new treatments with fewer side effects and high therapeutic potentials are required in AS. Mesenchymal stem cells (MSCs) with considerable immunomodulatory and regenerative properties could be able to attenuate the inflammatory responses and help tissue repair by cell-to-cell contact and secretion of soluble factors. Moreover, MSCs do not express HLA-DR, which renders them a favorable therapeutic choice for transplantation in immune-mediated disorders. In the present review, we describe immunopathogenesis and current treatments restrictions of AS. Afterwards, immunomodulatory properties and applications of MSCs in immune-mediated disorders, as well as recent findings of clinical trials involving mesenchymal stem cell therapy (MSCT) in ankylosing spondylitis, will be discussed in detail. Additional studies are required to investigate several features of MSCT such as cell origin, dosage, administration route and, specifically, the most suitable stage of disease for ideal intervention.

Inhibition of Runx2 signaling by TNF-α in ST2 murine bone marrow stromal cells undergoing osteogenic differentiation

Tumor necrosis factor-alpha (TNF-α) inhibits osteogenic differentiation of murine bone marrow stromal cells, and transcription factor Runx2 serves as an essential regulation target in the process. The underlying mechanism may involve the regulation of Runx2 expression and the Runx2 activity in downstream gene transcription, which has not been fully elucidated. In this study, ST2 murine bone marrow-derived stromal cells were treated with bone morphogenetic protein-2 (BMP-2) and/or TNF-α in osteogenic medium, and the expression of Runx2 was estimated. Cells were transfected with Runx2, p65, inhibitor of κBα (IκBα), 9.0 kb bone sialoprotein (BSP) promoter-luciferase or osteoblast-specific cis-acting element 2 (OSE2)-luciferase reporter vectors, and then real time-PCR and dual luciferase analysis were used to investigate the effect of TNF-α on Runx2-activated osteogenic gene transcription and the molecular mechanism. We found that TNF-α inhibited BMP-2-induced osteogenic marker expression and both the spontaneous and BMP-2-induced Runx2 expression. TNF-α stimulation or overexpression of nuclear factor-kappa B (NF-κB) p65 subunit repressed the Runx2-activated BSP and osteocalcin (OC) transcriptions. The Runx2-induced 9.0 kb BSP promoter activity was attenuated by TNF-α or p65, while the OSE2 activity was not affected. Besides, blockage of NF-κB by IκBα overexpression eliminated these inhibitory effects of TNF-α on Runx2 signaling. These results suggest that in murine bone marrow stromal cells undergoing osteogenic differentiation, TNF-α and it activated NF-κB pathway inhibit the expression of Runx2 gene, and suppress the Runx2-mediated osteogenic gene transcription via the 9.0 kb BSP promoter.

Consensus development on eligibility of government subsidisation of biologic disease modifying anti-rheumatic agents for treatment of ankylosing spondylitis: The Singapore experience

INTRODUCTION

The beneficial effects of biologic disease-modifying anti-rheumatic drugs (bDMARDs), such as tumour necrosis factor inhibitors (anti-TNF) in active ankylosing spondylitis (AS) are well established. The significant costs on patients in the absence of financial subsidization can limit their use. The objective was to describe a consensus development process on recommendations for government-assisted funding of biologic therapy for AS patients in Singapore.

METHODS

Evidence synthesis followed by a modified RAND/UCLA Appropriateness Method (RAM) was used. Eleven rheumatologists rated indications for therapies for different proposed clinical scenarios. Points reflecting the output from the formal group consensus were used to formulate 10 practice recommendations.

RESULTS

It was agreed that a bDMARD (anti-TNF) is indicated if a patient has active AS with a Bath Ankylosing Spondylitis Activity Index (BASDAI) ≥ 4 and spinal pain of ≥ 4 cm on visual analogue scale (VAS) on two occasions at least 12 weeks apart, despite being on a minimum of two sequential non-steroidal anti-inflammatory drugs at maximal tolerated dose for at least 4 weeks, in addition to adherence to an appropriate physiotherapy program for at least 3 months. To qualify for continued biologic therapy, a patient must have documentation of response every 3 months and at least 50% improvement in BASDAI and reduction of spinal pain VAS ≥ 2 cm.

CONCLUSION

A validated and feasible consensus process can enable pragmatic standardized recommendations to be developed for bDMARD subsidization for AS patients in a local Asian context.

Role of IL-17 in psoriasis and psoriatic arthritis

The role of T cell subpopulations in human disease is in a transition phase due to continuous discovery of new subsets of T cell, one of which is Th17, characterized by the production of signature cytokine IL-17. In the last couple of years, many articles are coming out on the role of Th17 and its signature cytokine IL-17 in different autoimmune diseases like rheumatoid arthritis, psoriasis, psoriatic arthritis (PsA), SLE and multiple sclerosis. Psoriasis and PsA are immune-mediated diseases, affecting the skin and joints, respectively. Initially, it was thought that psoriasis and PsA were Th1-mediated diseases; however, studies in knockout animal models (IL-17 knockout mice) as well as human experimental data indicate that Th17 and its signature cytokine IL-17 have a critical role in the pathogenesis of psoriatic disease. Th17 cells have been identified from the dermal extracts of psoriatic lesions. Subsequently, our research group has substantiated this observation that Th17 cells are enriched in the papillary dermis of psoriatic plaques and in freshly isolated effector T lymphocytes from the synovial fluid of PsA patients, and we have reported that the majority of these CD4 + IL-17+ T cells are of memory phenotype (CD4RO(+)CD45RA(-)CD11a(+)). Recent reports also suggest that the synovial tissue in psoriatic arthritis is enriched with IL-17R, and its most well recognized receptor IL-17RA is functionally active in psoriatic arthritis. In this review article, we have discussed the role of IL-17 in psoriatic disease and have narrated about the novel IL17/IL-17R antibodies currently in preparation for its therapeutic uses in autoimmune diseases.

How to translate basic knowledge into clinical application of biologic therapy in spondyloarthritis

Spondyloarthritis (SpA) is a family of many diseases, and these diseases share some clinical, genetic, and radiologic features. The disease process in the spine at the beginning is spinal inflammation, in which TNFα is the principal cytokine involved. Therefore, the dramatic clinical and pathologic response of anti-TNFα therapy in SpA is based upon the presence of increased TNFα in synovial tissues and sacroiliac joints, which perpetuates chronic inflammation. The increased Toll-like receptors (TCR) 2 and 4 in the serum, peripheral blood mononuclear cells, or synovial tissues of ankylosing spondyloarthritis (AS) or SpA patients suggest that SpA is highly associated with innate immunity. Any drug including anti-TNFα blocker which can downregulate the TCR, infiltrated neutrophils, or CD163+ macrophages in the synovial tissue is the rationale for the management of SpA. Like rheumatoid arthritis, the increased TH22 and TH17 cells either in blood, synovial fluid, or synovial tissues were also demonstrated in SpA. Thus, TH17 and TH22 may be reasonable cellular targets for therapeutic intervention. Drugs (anti-IL6R or anti-IL6) which can reduce the binding of IL6 and IL6R to the cell surface may be beneficial in SpA. Many proteins are implicated in the new bone formation (syndesmophyte) or ankylosis in AS or SpA. The enhanced BMP and Wnt pathway will activate osteoblasts which promote the new bone formation. However, no drug including anti-TNFα can stop or prevent the syndesmophyte in AS. In summary, looking for new targeting therapies for either anti-inflammation (beyond anti-TNF) or anti-bone formation (including anti-TGFβ or PDGF) is warranted in the future.

Physical activity and body composition in patients with ankylosing spondylitis

OBJECTIVE

Patients with ankylosing spondylitis (AS) are at risk for accelerated muscle loss and reduced physical activity. Accurate data are needed on body composition and physical activity in this patient group. The purpose of this study was to investigate body composition and objectively assessed physical activity in patients with AS.

METHODS

Twenty-five AS patients (15 men, mean ± SD age 48 ± 11 years) were compared with 25 healthy adults matched for age, sex, and body mass index. Body composition was measured using a 3-compartment model based on air-displacement plethysmography to assess body volume and deuterium dilution to assess total body water. The fat-free mass index (FFMI; fat-free mass divided by height squared) and the percent fat mass (%FM) were calculated. Daily physical activity was assessed for 7 days using a triaxial accelerometer and physical fitness with an incremental test until exertion on a bicycle ergometer. Blood samples were taken to determine C-reactive protein (CRP) level and tumor necrosis factor α.

RESULTS

Accelerometer output (kilocounts/day) showed the same physical activity level for patients and controls (mean ± SD 319 ± 105 versus 326 ± 66). There was no difference in the FFMI or %FM between the patients and controls. Physical activity was positively related to the FFMI (partial R = 0.38, P = 0.01) and inversely related to CRP level (R = -0.39, P < 0.01), independent of group. CRP level was inversely related to the FFMI, but the effect was less strong than with physical activity (partial R = -0.31, P = 0.03).

CONCLUSION

Daily physical activity may help preserve fat-free mass in patients with AS.

ASAS/EULAR recommendations for the management of ankylosing spondylitis: the patient version

BACKGROUND

The ASAS/EULAR (Assessment of SpondyloArthritis International Society/European League Against Rheumatism) recommendations for the management of ankylosing spondylitis (AS) have been developed by rheumatologists for a target population of health professionals.

OBJECTIVE

To extend the cooperation between ASAS and EULAR by translating the recommendations into a language that can be easily understood by patients in order to further disseminate and evaluate the recommendations.

METHODS

In cooperation with patient organisations 18 patients with AS (17 European, one Canadian) were invited to attend a meeting in February 2008. As a starting point the original publication and a version created by Canadian patients with AS were used. To improve the understanding of potential problems, data on the evaluation of a recent German translation were presented. After intensive discussions the wording was adjusted and a vote was held on the new wording of the recommendations aiming for >80% agreement on each sentence. Finally, patients were asked to indicate their level of agreement with the content of the recommendations.

RESULTS

Ten recommendations were successfully translated into a patient-understandable version. The original text was changed in most cases. In all but one case (recommendation No 4) there was broad agreement with the proposed translation. The overall agreement with the content of the recommendations was high: 8.7 (0.6).

CONCLUSION

For the first time, EULAR recommendations were successfully converted into a patient-understandable language version by a large international group of patients in collaboration with rheumatologists. The evaluation showed broad agreement. Translations into different languages and further dissemination in individual countries will be performed.

Activation of the protective Survivor Activating Factor Enhancement (SAFE) pathway against reperfusion injury: Does it go beyond the RISK pathway?

Lethal reperfusion injury is now recognized as a major limitation of current reperfusion therapy by primary percutaneous coronary intervention for acute myocardial infarction. Interestingly, the heart itself is capable of activating an intrinsic protective signaling programme to limit cell death during reperfusion. Tumor necrosis factor alpha (TNFalpha) is a cytokine generally thought to contribute to myocardial dysfunction in ischemia/reperfusion or heart failure. We review evidence that TNFalpha can paradoxically initiate the activation of a novel protective pathway against reperfusion injuries that we have named the Survivor Activating Factor Enhancement (SAFE) pathway. This path requires the activation of the signal transducer and activator of transcription 3 (STAT-3) and it can successfully lessen cardiomyocyte death at the time of reperfusion, independently of the activation of the already well-described Reperfusion Injury Salvage Kinase (RISK) pathway (which includes activation of Akt and Erk 1/2). Emerging knowledge on this novel protective path is presented here with the aim of unravelling its interaction with the RISK pathway and its potential human application to protect against lethal reperfusion injury.

Enhancement of human adaptive immune responses by administration of a high-molecular-weight polysaccharide extract from the cyanobacterium Arthrospira platensis

The effect of consumption of Immulina, a high-molecular-weight polysaccharide extract from the cyanobacterium Arthrospira platensis, on adaptive immune responses was investigated by evaluation of changes in leukocyte responsiveness to two foreign recall antigens, Candida albicans (CA) and tetanus toxoid (TT), in vitro. Consumption of Immulina by 11 healthy male volunteers caused an immediate, but temporary, increase of CA-induced CD4+ T-helper (Th) cell proliferation (P < .02). TT-induced Th cell proliferation was increased in individuals over 50 years of age (P < .05) and correlated with age (P < .02). Consumption for 8 days enhanced the CA-induced B cell proliferation (P < .02), but after 56 days a diminution was seen (P < .03). The CA-elicited production of the Th1 cytokines tumor necrosis factor (TNF)-alpha, interleukin (IL)-2, and interferon (IFN)-gamma was increased after Immunlina administration for 3 days (P < .001, < .03, and < .007, respectively), and increased IL-2 production persisted after 56 days (P < .004). The TNF-alpha, IFN-gamma, and IL-6 responses to TT were enhanced after 8 and 14 days (P < .002-.05), while IL-5 responses increased significantly within 3 days (P < .04) and fell below baseline levels after 14 days (P < .008). Conversely, consumption for 3 days inhibited the IL-4 responses to both CA and TT (P < .008 and P < .03, respectively). No effects on IL-10 responses were observed. Upon addition to normal mononuclear cells in vitro, Immulina elicited strong TNF-alpha, IL-1beta, and IL-6 responses, indicating that it acts by inducing a pro-inflammatory state. Taken together, the data suggest that Immulina causes an age-dependent, temporary enhancement of adaptive immune responses.

Increased numbers of circulating polyfunctional Th17 memory cells in patients with seronegative spondylarthritides

OBJECTIVE

A distinct subset of proinflammatory CD4+ T cells that produce interleukin-17 was recently identified. These cells are implicated in different autoimmune disease models, such as experimental autoimmune encephalomyelitis and collagen-induced arthritis, but their involvement in human autoimmune disease has not yet been clearly established. The purpose of this study was to assess the frequency and functional properties of Th17 cells in healthy donors and in patients with different autoimmune diseases.

METHODS

Peripheral blood was obtained from 10 psoriatic arthritis (PsA), 10 ankylosing spondylitis (AS), 10 rheumatoid arthritis (RA), and 5 vitiligo patients, as well as from 25 healthy donors. Synovial tissue samples from a separate group of patients were also evaluated (obtained as paraffin-embedded sections). Peripheral blood cells were analyzed by multiparameter flow cytometry and immunohistochemistry. Cytokine production was examined by enzyme-linked immunosorbent assay and intracellular cytokine staining using specific monoclonal antibodies. Synovial tissue was examined for infiltrating T cells by immunohistochemical analysis.

RESULTS

We found increased numbers of circulating Th17 cells in the peripheral blood of patients with seronegative spondylarthritides (PsA and AS), but not in patients with RA or vitiligo. In addition, Th17 cells from the spondylarthritis patients showed advanced differentiation and were polyfunctional in terms of T cell receptor-driven cytokine production.

CONCLUSION

These observations suggest a role of Th17 cells in the pathogenesis of certain human autoimmune disorders, in particular the seronegative spondylarthritides.

Circulating levels of TNF-like cytokine 1A (TL1A) and its decoy receptor 3 (DcR3) in rheumatoid arthritis

TL1A is a novel TNF-like cytokine, which provides co-stimulatory and Th1-polarizing signals to activated lymphocytes, via binding to death-domain receptor 3 (DR3). These functions are inhibited when TL1A associates to decoy receptor 3 (DcR3). We investigated the serum expression of TL1A and DcR3 in 81 patients with RA and 51 healthy controls. TL1A concentrations were elevated in patients by 5-fold (P<0.00001). This increase was more prominent in RFactor-positive patients and correlated with clinical activity in this subgroup. DcR3 was detected more frequently and in significantly higher values in RA-derived sera, correlated strongly with TL1A, and was present in inflammatory synovial fluid. Severe RA stage was associated with highly elevated TL1A and DcR3 serum levels. Treatment with an anti-TNF agent significantly decreased TL1A serum levels. We conclude that TL1A may serve as an inflammatory marker in RA. Interactions between TL1A and its receptors may be important in the pathogenesis of RA.

The role of physical activity in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory auto-immune disease, causing progressive damage to the musculoskeletal system. Many patients with RA also suffer from accelerated muscle loss or cachexia, which contributes to the loss of physical function and quality of life. Physical activity plays a central role in the management of the disease as it is essential to maintain muscle strength and endurance, range of motion and the ability to perform activities of daily life. On the other hand, given the nature of the disease, there is always an increased risk for injury. There is a large amount of literature investigating the effect of exercise interventions on muscle function and disease activity. These studies show that exercise clearly improves muscle function without affecting disease activity. Studies including radiographic evaluation of joint damage as an endpoint also show that there is no evidence that exercise, even high-intensity exercise, increases inflammation or joint damage, although care should be taken with patients with severe baseline damage. Regarding daily physical activity (exercise is only one component of physical activity) there is hardly any research done showing either that physical activity is indeed decreased in patients or whether or not there is a relation between daily physical activity and disease activity. The results from studies looking at the effect of exercise on muscle mass or the ability to prevent or reverse cachexia are somewhat contradictory, but it seems that when the training dose is sufficiently large, gains in muscle mass can be achieved.