Interrelationships between interleukin (IL)-1, IL-6 and IL-8 in synovial fluid of various arthropathies

Effects of externally-applied, non-pharmacological Interventions on short- and long-term symptoms and inflammatory cytokine levels in patients with knee osteoarthritis: a systematic review and network meta-analysis

Background

With the continuous development of clinical medicine, an increasing number of non-pharmacological interventions have been applied for the treatment of knee osteoarthritis (KOA), with the results of several recent randomized controlled trials (RCTs) showing that a variety of externally-applied, non-pharmacological interventions (EANPI) can improve symptoms and inflammation in patients with KOA. However, the relative benefits and disadvantages of non-drug therapies remain uncertain, and an optimal treatment strategy has not yet been determined.

Objective

This study applied network meta-analysis (NMA) to compare and rank the effectiveness of EANPI on the short- and long-term clinical symptoms and inflammatory cytokine levels in patients with KOA.

Methods

Two independent researchers searched online databases and performed manual retrieval of related citations to identify RCTs that met the selection criteria for the network meta-analysis. These researchers retrieved studies indexed from database inception to August 2023 and performed data extraction and assessment of the risk of bias.

Results

The analysis included 80 RCTs involving 8440 participants and nine externally-applied, non-pharmacological therapies, namely extracorporeal shock wave, radiofrequency, acupotomy, laser therapy, Tuina therapy, kinesio taping, electroacupuncture, platelet-rich plasma injection, and ozone therapy. The treatment courses ranged from 1 to 12 weeks, with follow-up periods ranging from 4 to 24 weeks. The results of the NMA indicated that each non-drug therapy was superior to sham intervention in improving all outcome indicators. Except for the visual analog scale (VAS) and Western Ontario MacMaster (WOMAC) pain outcomes, all non-drug therapies had better efficacy than pharmacological treatments. For short-term VAS and tumor necrosis factor-alpha (TNF-α), extracorporeal shock wave performed better than other therapies (90.2% and 85.2% respectively). Radiofrequency therapy may be the most promising method to reduce long-term VAS, short- and long-term WOMAC pain, and interleukin (IL)-1β level (84.8%, 97.8%, 90.1%, 94.8% respectively). Tuina therapy may be a significant choice for short- and long-term outcomes of WOMAC function and range of motion (ROM).

Conclusions

The results of the comprehensive comparison of the outcome indicators in 9 different EANPI indicated that radiofrequency and Tuina therapy were more effective and consistently ranked high in improving clinical symptoms in the short and long term. Radiofrequency is effective at relieving pain, and Tuina therapy can be given priority for treatment when hypofunction is the main symptom. EANPI to improve pain symptoms may be related to the regulation of inflammatory cytokine levels, which may be a potential mechanism of action.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?, identifier CRD42023464177.

Engineering Closed-Loop, Autoregulatory Gene Circuits for Osteoarthritis Cell-Based Therapies

PURPOSE OF REVIEW

Genetic engineering offers the possibility to simultaneously target multiple cellular pathways in the joints affected by osteoarthritis (OA). The purpose of this review is to summarize the ongoing efforts to develop disease-modifying osteoarthritis drugs (DMOADs) using genetic engineering, including targeting approaches, genome editing techniques, and delivery methods.

RECENT FINDINGS

Several gene circuits have been developed that reprogram cells to autonomously target inflammation, and their efficacy has been demonstrated in chondrocytes and stem cells. Gene circuits developed for metabolic disorders, such as those targeting insulin resistance and obesity, also have the potential to mitigate the impact of these conditions on OA onset and/or progression. Despite the strides made in characterizing the inflammatory environment of the OA joint, our incomplete understanding of how the multiple regulators interact to control signal transduction, gene transcription, and translation to protein limits the development of targeted disease-modifying therapeutics. Continuous advances in targeted genome editing, combined with online toolkits that simplify the design and production of gene circuits, have the potential to accelerate the discovery and clinical application of multi-target gene circuits with disease-modifying properties for the treatment of OA.

The Importance of CXCL1 in Physiology and Noncancerous Diseases of Bone, Bone Marrow, Muscle and the Nervous System

This review describes the role of CXCL1, a chemokine crucial in inflammation as a chemoattractant for neutrophils, in physiology and in selected major non-cancer diseases. Due to the vast amount of available information, we focus on the role CXCL1 plays in the physiology of bones, bone marrow, muscle and the nervous system. For this reason, we describe its effects on hematopoietic stem cells, myoblasts, oligodendrocyte progenitors and osteoclast precursors. We also present the involvement of CXCL1 in diseases of selected tissues and organs including Alzheimer’s disease, epilepsy, herpes simplex virus type 1 (HSV-1) encephalitis, ischemic stroke, major depression, multiple sclerosis, neuromyelitis optica, neuropathic pain, osteoporosis, prion diseases, rheumatoid arthritis, tick-borne encephalitis (TBE), traumatic spinal cord injury and West Nile fever.

Interleukin 6 Concentration in Synovial Fluid of Patients with Inflammatory and Degenerative Arthritis

AIM

The present study aims to compare interleukin 6 (IL-6) concentration in synovial fluid in patients with known types of arthritis.

BACKGROUND

Persistent synovitis without known markers such as Rheumatoid Factor (RF), Anti-Citrullinated Protein Antibodies (ACPA), and genetic markers as HLA-B27 is not uncommon. It is valuable to determine the presence of chronic inflammation and put it in correlation with age-related changes, which are especially relevant for middle-aged patients with mono- or oligoarthritis, when the dilemma to start disease-modifying drugs for inflammatory disease often is present. INTERLEUKIN 6 (IL-6) plays a significant role in chronic inflammation.

OBJECTIVES

IL-6 concentration in synovial fluid reflects the presence and activity of joint inflammation.

METHODS

Synovial fluid was obtained from 101 patients with chronic synovitis. IL-6 concentration was determined by the immunochemical luminescence method.

RESULTS

The median IL-6 concentration in synovial fluid in patients with osteoarthritis (OA) was 138.0 pg/ml (interquartile range [IQR] 43.4 to 296.0); in patients with rheumatoid arthritis was 2516.5 pg/ml, (IQR 1136.0 to 25058.0); in reactive arthritis 2281.0 pg/ml (IQR 1392.0 to 8652.0); psoriatic arthritis 1964.0 pg/ml (IQR 754.0 to 7300.0); ankylosing spondylitis 2776.0 pg/ml (IQR 514.7, 3944.0); in a group with negative RF, ACPA and HLA-B27 inflammatory arthritis 2163.0 pg/ml (IQR 822.0 to 7875.0). There is statistically significant difference of IL-6 concentration comparing OA and each inflammatory arthritis group, p<0.0001.

CONCLUSION

IL-6 detection in the synovial fluid is helpful in arthritis evaluation. The results show that an IL-6 level over 1000 pg/ml suggests the diagnosis of inflammatory arthritis.

Long non-coding RNA musculin antisense RNA 1 promotes proliferation and suppresses apoptosis in osteoarthritic chondrocytes via the microRNA-369-3p/Janus kinase-2/ signal transducers and activators of transcription 3 axis

Increasing evidence indicates that long non-coding RNAs (lncRNAs) play critical roles in osteoarthritis (OA). The present study aimed to investigate the underlying molecular mechanism of lncRNA musculin antisense RNA 1 (MSC-AS1) in OA. RT-qPCR was used to detect MSC-AS1 levels in cartilage tissues from patients with OA. The effects of MSC-AS1 knockdown on the viability and apoptosis in OA were evaluated via CCK-8 and TUNEL assays. The StarBase database was used to predict the binding sites between microRNA (miR)-369-3p and MSC-AS1 or JAK2, which were confirmed via the dual-luciferase reporter assay. The results demonstrated that MSC-AS1 expression was downregulated in OA. Functional analysis indicated that the addition of MSC-AS1 promoted viability and inhibited inflammation and the apoptosis of chondrocytes. In addition, MSC-AS1 regulated the survival of OA chondrocytes by sponging miR-369-3p. JAK2 was confirmed as a direct target of miR-369-3p, and MSC-AS1 regulated JAK2/STAT3 signaling via miR-369-3p in OA chondrocytes. Taken together, our results suggest that MSC-AS1 may regulate the miR-369-3p/JAK2/STAT3 signaling pathway to accelerate the viability, and inhibit inflammation and cell apoptosis in OA chondrocytes.

Cytokines and Chemokines Involved in Osteoarthritis Pathogenesis

Osteoarthritis is a common cause of disability worldwide. Although commonly referred to as a disease of the joint cartilage, osteoarthritis affects all joint tissues equally. The pathogenesis of this degenerative process is not completely understood; however, a low-grade inflammation leading to an imbalance between anabolic and katabolic processes is a well-established factor. The complex network of cytokines regulating these processes and cell communication has a central role in the development and progression of osteoarthritis. Concentrations of both proinflammatory and anti-inflammatory cytokines were found to be altered depending on the osteoarthritis stage and activity. In this review, we analyzed individual cytokines involved in the immune processes with an emphasis on their function in osteoarthritis.

IgA Immune Complexes Induce Osteoclast-Mediated Bone Resorption

Objective

Autoantibodies are detected in most patients with rheumatoid arthritis (RA) and can be of the IgM, IgG or IgA subclass. Correlations between IgA autoantibodies and more severe disease activity have been previously reported, but the functional role of IgA autoantibodies in the pathogenesis of RA is ill understood. In this study, we explored the effect of IgA immune complexes on osteoclast mediated bone resorption.

Methods

Anti-citrullinated peptide antibody (ACPA) and anti-carbamylated protein (anti-CarP) antibody levels of the IgA and IgG isotype and rheumatoid factor (RF) IgA were determined in synovial fluid (SF) of RA patients. Monocytes, neutrophils, and osteoclasts were stimulated with precipitated immune complexes from SF of RA patients or IgA- and IgG-coated beads. Activation was determined by neutrophil extracellular trap (NET) release, cytokine secretion, and bone resorption.

Results

NET formation by neutrophils was enhanced by SF immune complexes compared to immune complexes from healthy or RA serum. Monocytes stimulated with isolated SF immune complexes released IL-6 and IL-8, which correlated with the levels of ACPA IgA levels in SF. Osteoclasts cultured in the presence of supernatant of IgA-activated monocytes resorbed significantly more bone compared to osteoclasts that were cultured in supernatant of IgG-activated monocytes (p=0.0233). Osteoclasts expressed the Fc receptor for IgA (FcαRI; CD89) and Fc gamma receptors. IgA-activated osteoclasts however produced significantly increased levels of IL-6 (p<0.0001) and IL-8 (p=0.0007) compared to IgG-activated osteoclasts. Both IL-6 (p=0.03) and IL-8 (p=0.0054) significantly enhanced bone resorption by osteoclasts.

Conclusion

IgA autoantibodies induce release of IL-6 and IL-8 by immune cells as well as osteoclasts, which enhances bone resorption by osteoclasts. We anticipate that this will result in more severe disease activity in RA patients. Targeting IgA-FcαRI interactions therefore represents a promising novel therapeutic strategy for RA patients with IgA autoantibodies.

Compressive mechanical stress enhances susceptibility to interleukin-1 by increasing interleukin-1 receptor expression in 3D-cultured ATDC5 cells

Background

Mechanical overload applied on the articular cartilage may play an important role in the pathogenesis of osteoarthritis. However, the mechanism of chondrocyte mechanotransduction is not fully understood. The purpose of this study was to assess the effects of compressive mechanical stress on interleukin-1 receptor (IL-1R) and matrix-degrading enzyme expression by three-dimensional (3D) cultured ATDC5 cells. In addition, the implications of transient receptor potential vanilloid 4 (TRPV4) channel regulation in promoting effects of compressive mechanical loading were elucidated.

Methods

ATDC5 cells were cultured in alginate beads with the growth medium containing insulin-transferrin-selenium and BMP-2 for 6 days. The cultured cell pellet was seeded in collagen scaffolds to produce 3D-cultured constructs. Cyclic compressive loading was applied on the 3D-cultured constructs at 0.5 Hz for 3 h. The mRNA expressions of a disintegrin and metalloproteinases with thrombospondin motifs 4 (ADAMTS4) and IL-1R were determined with or without compressive loading, and effects of TRPV4 agonist/antagonist on mRNA expressions were examined. Immunoreactivities of reactive oxygen species (ROS), TRPV4 and IL-1R were assessed in 3D-cultured ATDC5 cells.

Results

In 3D-cultured ATDC5 cells, ROS was induced by cyclic compressive loading stress. The mRNA expression levels of ADAMTS4 and IL-1R were increased by cyclic compressive loading, which was mostly prevented by pyrollidine dithiocarbamate. Small amounts of IL-1β upregulated ADAMTS4 and IL-1R mRNA expressions only when combined with compressive loading. TRPV4 agonist suppressed ADAMTS4 and IL-1R mRNA levels induced by the compressive loading, whereas TRPV4 antagonist enhanced these levels. Immunoreactivities to TRPV4 and IL-1R significantly increased in constructs with cyclic compressive loading.

Conclusion

Cyclic compressive loading induced mRNA expressions of ADAMTS4 and IL-1R through reactive oxygen species. TRPV4 regulated these mRNA expressions, but excessive compressive loading may impair TRPV4 regulation. These findings suggested that TRPV4 regulates the expression level of IL-1R and subsequent IL-1 signaling induced by cyclic compressive loading and participates in cartilage homeostasis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04095-x.

Regenerative Potential and Inflammation-Induced Secretion Profile of Human Adipose-Derived Stromal Vascular Cells Are Influenced by Donor Variability and Prior Breast Cancer Diagnosis

Adipose tissue contains a heterogeneous population of stromal vascular fraction (SVF) cells that work synergistically with resident cell types to enhance tissue healing. Ease of access and processing paired with therapeutic promise make SVF cells an attractive option for autologous applications in regenerative medicine. However, inherent variability in SVF cell therapeutic potential from one patient to another hinders prognosis determination for any one person. This study investigated the regenerative properties and inflammation responses of thirteen, medically diverse human donors. Using non-expanded primary lipoaspirate samples, SVF cells were assessed for robustness of several parameters integral to tissue regeneration, including yield, viability, self-renewal capacity, proliferation, differentiation potential, and immunomodulatory cytokine secretion. Each parameter was selected either for its role in regenerative potential, defined here as the ability to heal tissues through stem cell repopulation and subsequent multipotent differentiation, or for its potential role in wound healing through trophic immunomodulatory activity. These data were then analyzed for consistent and predictable patterns between and across measurements, while also investigating the influence of the donors' relevant medical histories, particularly if the donor was in remission following breast cancer treatment. Analyses identified positive correlations among the expression of three cytokines: interleukin (IL)-6, IL-8, and monocyte chemoattractant protein (MCP)-1. The expression of these cytokines also positively related to self-renewal capacity. These results are potentially relevant for establishing expectations in both preclinical experiments and targeted clinical treatment strategies that use stem cells from patients with diverse medical histories.

Anti-arthritic potential of marine macroalgae Turbinaria ornata in Complete Freund's Adjuvant induced rats

T. ornata a macroalgae rich in bioactive molecules possess various biological activities. Herein, the aim of the study is to evaluate the aqueous extract and the sulphated polysaccharide isolated from T. ornata for its anti-arthritic potential in Complete Freund's Adjuvant (CFA) induced arthritis in rats. Anti-arthritic potential of aqueous T. ornata (ATO) and T. ornata sulphated polysaccharide (TSP) was evidenced by the significant reduction in paw volume and arthritic score. Inflammatory and antioxidant markers were found to be restored in the drug treated groups which was found to be in line with dexamethasone a standard anti-inflammatory drug. The histopathological and radiological examination adds on the support to the above findings confirming the anti-arthritic potential of ATO and TSP. It is interesting to note that the sulphated polysaccharide inhibits inflammation and bone damage at very low dose itself. Hence, TSP could be considered as a better candidate in the management of chronic inflammatory diseases like rheumatoid arthritis.

Efficacy of arthrocentesis versus arthrocentesis with sodium hyaluronic acid in temporomandibular joint osteoarthritis: A comparison

INTRODUCTION

Temporomandibular joint osteoarthritis (TMJ OA) is a degenerative disease characterized by deterioration of articular tissue with concomitant osseous changes in the condyle and/or articular eminence, joint positive for TMJ noise with jaw movement or function, crepitus detected on palpation on opening, closing, right/left lateral, or protrusive movement. Hyaluronic acid (HA) is a polysaccharide of the family of glycosaminoglycans. HA has been shown to improve and restore normal lubrication in joint, provide nutrition to the avascular articulating disc, and stabilize the joint.

MATERIALS AND METHODS

Twenty patients with OA of TMJ with age limit between 18 and 60 years of age were enrolled in this study. Patients were randomly divided into two groups, in which one group received arthrocentesis only, and another group received arthrocentesis plus intra-articular injection of sodium HA (0.5 ml) in superior joint space in a cycle of 5 weekly arthrocentesis (one per week). Patients were followed at regular interval of 1^st day, 5^th day, 7^th day, 4 weeks, 6 weeks, and 12 weeks. Assessment of clinical outcome was done in terms of reduction in pain (visual analog scale score), maximum mouth opening (MMO) in millimeters, painful/pain-free lateral or protrusive jaw movement, and clicking/crepitus in joint.

RESULTS

Significant reduction in pain was observed in both the groups. MMO, lateral and protrusive movements improved significantly in both groups; however, arthrocentesis with sodium HA was superior to arthrocentesis alone.

CONCLUSION

Combination of arthrocentesis with HA injection showed much better outcome than arthrocentesis alone.

Mesenchymal stromal cells for cartilage repair in osteoarthritis

Treatment for articular cartilage damage is quite challenging as it shows limited repair and regeneration following injury. Non-operative and classical surgical techniques are inefficient in restoring normal anatomy and function of cartilage in osteoarthritis (OA). Thus, investigating new and effective strategies for OA are necessary to establish feasible therapeutic solutions. The emergence of the new discipline of regenerative medicine, having cell-based therapy as its primary focus, may enable us to achieve repair and restore the damaged articular cartilage. This review describes progress and development of employing mesenchymal stromal cell (MSC)-based therapy as a promising alternative for OA treatment. The objective of this review is to first, discuss how in vitro MSC chondrogenic differentiation mimics in vivo embryonic cartilage development, secondly, to describe various chondrogenic differentiation strategies followed by pre-clinical and clinical studies demonstrating their feasibility and efficacy. However, several challenges need to be tackled before this research can be translated to the clinics. In particular, better understanding of the post-transplanted cell behaviour and learning to enhance their potency in the disease microenvironment is essential. Final objective is to underscore the importance of isolation, storage, cell shipment, route of administration, optimum dosage and control batch to batch variations to realise the full potential of MSCs in OA clinical trials.

Human genome-wide expression analysis reorients the study of inflammatory mediators and biomechanics in osteoarthritis

A major objective of this article is to examine the research implications of recently available genome-wide expression profiles of cartilage from human osteoarthritis (OA) joints. We propose that, when viewed in the light of extensive earlier work, this novel data provides a unique opportunity to reorient the design of experimental systems toward clinical relevance. Specifically, in the area of cartilage explant biology, this will require a fresh evaluation of existing paradigms, so as to optimize the choices of tissue source, cytokine/growth factor/nutrient addition, and biomechanical environment for discovery. Within this context, we firstly discuss the literature on the nature and role of potential catabolic mediators in OA pathology, including data from human OA cartilage, animal models of OA, and ex vivo studies. Secondly, due to the number and breadth of studies on IL-1β in this area, a major focus of the article is a critical analysis of the design and interpretation of cartilage studies where IL-1β has been used as a model cytokine. Thirdly, the article provides a data-driven perspective (including genome-wide analysis of clinical samples, studies on mutant mice, and clinical trials), which concludes that IL-1β should be replaced by soluble mediators such as IL-17 or TGF-β1, which are much more likely to mimic the disease in OA model systems. We also discuss the evidence that changes in early OA can be attributed to the activity of such soluble mediators, whereas late-stage disease results more from a chronic biomechanical effect on the matrix and cells of the remaining cartilage and on other local mediator-secreting cells. Lastly, an updated protocol for in vitro studies with cartilage explants and chondrocytes (including the use of specific gene expression arrays) is provided to motivate more disease-relevant studies on the interplay of cytokines, growth factors, and biomechanics on cellular behavior.

Intravenous tocilizumab: a review of its use in adults with rheumatoid arthritis

Tocilizumab (Actemra®, RoActemra®) is a humanized monoclonal antibody that acts as an interleukin-6 receptor antagonist. Intravenous tocilizumab as monotherapy or in combination with disease-modifying anti-rheumatic drugs (DMARDs) is indicated for the treatment of adult patients with moderate to severe active rheumatoid arthritis (RA) who had an inadequate response to one or more DMARDs or tumor necrosis factor (TNF) α antagonists (the specific indication varies between countries); it may also be used as monotherapy in patients for whom continued methotrexate use is inappropriate. This article reviews the efficacy and tolerability of tocilizumab in these patients and briefly summarizes its pharmacology. Several large well-designed clinical trials and routine clinical practice studies showed that tocilizumab was an effective and generally well tolerated biologic for the treatment of adults with RA, including those with an inadequate response to DMARDs or TNFα antagonists. In these studies, tocilizumab as monotherapy or in combination with DMARDs (including methotrexate) had beneficial effects on the signs and symptoms of disease, health-related quality of life/physical function, and/or radiologic disease progression. In addition, tocilizumab monotherapy was more effective than adalimumab monotherapy in improving the signs and symptoms of disease in patients for whom continued methotrexate use was inappropriate. As with other biologic DMARDS, infections were the most common adverse event associated with tocilizumab therapy. Pooled and meta-analyses demonstrated that the efficacy and tolerability profile of tocilizumab was sustained during long-term (up to 9 years) therapy. Although additional comparative data are needed to position tocilizumab more definitively with respect to other biologic DMARDs, current evidence indicates that tocilizumab is effective as a first- or subsequent-line biologic in patients with moderate to severe RA.

Protective Effect of Ethanolic Extract of Seeds of Moringa oleifera Lam. Against Inflammation Associated with Development of Arthritis in Rats

The present investigation was carried out to study the anti-arthritic activity of ethanolic extract of seeds of Moringa oleifera Lam. (MOEE) in adjuvant-induced arthritis in adult female Wistar rats. During the experimental period, body weight, paw edema volume (primary lesion) and arthritic index (secondary lesion) was observed. On the 21st day, serum from each animal was used for estimation of Rheumatoid Factor (RF) value and levels of selected cytokines (TNFalpha, IL-1, and IL-6). Whole blood was used for measurement of erythrocyte sedimentation rate (ESR). Liver homogenate was utilized for assessment of oxidative stress and histopathology was performed to measure degree of inflammation in synovial joint. Our results suggest that, percentage reduction in body weight was less, paw edema volume and arthritic index score was decreased significantly as compared to diseased control animals. Serum levels of RF, TNF-alpha, IL-1, and IL-6 also showed decreased levels as compared to those in the diseased control group. Treatment with MOEE also altered oxidative stress in relation to its anti-inflammatory activity. Histopathological observations showed mild or less infiltration of lymphocytes, angiogenesis and synovial lining thickening. From all above results and observations, it can be concluded that Moringa oleifera possesses promising antiarthritic property.

Emerging drugs for osteoarthritis

INTRODUCTION

Osteoarthritis (OA), the most prevalent form of joint disease, affects as much as 13% of the world's population. In the USA, it is the leading cause of disability in people over age 65 and is characterized by progressive cartilage loss, bone remodeling, osteophyte formation and synovial inflammation with resultant joint pain and disability. There are no treatments marketed for structural disease modification; current treatments mainly target symptoms, with > 75% of patients reporting need for additional symptomatic treatment.

AREAS COVERED

Drugs in later development (Phase II - III) for OA pain and joint structural degeneration are reviewed. Topics that are not covered in this article are procedural-based (e.g., arthrocentesis, physical therapy), behavioral-based (e.g., weight loss, pain coping techniques) or device-based (e.g., knee braces, surgical implants) treatments.

EXPERT OPINION

More in-depth understanding of the pathophysiology of the disease, as well as elucidation of the link between clinical symptomatology and structural changes in the joint will likely lead to the development of novel target classes with promising efficacy in the future. Efficacy notwithstanding, there remain significant hurdles to overcome in clinical development of these therapeutics, inherent in the progression pattern of the disease as well as challenges with readouts for both pain and structure modification trials.

The tumor necrosis factor-{alpha}-blocking agent infliximab inhibits interleukin 1beta (IL-1beta) and IL-6 gene expression in human osteoblastic cells

OBJECTIVE

Tumor necrosis factor-alpha (TNF-alpha) is a proinflammatory cytokine involved in the pathogenesis of several rheumatic diseases, including rheumatoid arthritis (RA), associated with systemic bone loss and subchondral bone erosions. TNF-alpha-blocking agents such as infliximab have been successful in treatment of disease-modifying antirheumatic drug-resistant rheumatic diseases. Infliximab therapy in RA also had beneficial effects on local bone destruction and bone mineral density. We assessed effects of infliximab treatment on the bone tissue compartment and cytokine profile expression in vitro.

METHODS

Osteoblast-like cells were exposed for 24 h to sera of RA patients collected at baseline and after 1 month (T1) and 3 years (T2) of infliximab treatment. Total RNA was extracted, and expression of interleukin 1beta (IL-1beta), IL-6, and osteoprotegerin (OPG) was measured by RT-PCR.

RESULTS

IL-1beta gene expression was significantly reduced by the T1 serum, and the same decrease was elicited by the T2 serum. IL-6 downregulation was evident with the T2 serum. OPG was unaffected.

CONCLUSION

The finding of downregulation of inflammatory cytokines was interesting, particularly IL-6, which plays a crucial role in arthritis-related bone loss due to its involvement in osteoclast recruitment and activation. These results may represent a biological explanation and a link for the clinical observation of the beneficial effects of anti-TNF-alpha agents on the progression of rheumatic diseases at the bone level.

Joint injury and osteoarthritis: soluble mediators in the course and treatment of cartilage pathology

Osteoarthritis is a disabling disease of the aging generation, which results in loss of quality of life and increased healthcare costs. Cytokines appear to play an important role in the cartilaginous degeneration characterizing the pathological process. Increasing experience is being gained with cytokine-modulating therapies aimed at interfering with effects of chondrodegradative cytokines in the synovial fluid. Although in vitro and in vivo effectiveness of several of these therapies has been demonstrated, clinical effectiveness remains disputable, which may be related to the low levels of inflammatory cytokines found in osteoarthritic joints. By contrast, directly after joint trauma, which has been shown to predipose to early osteoarthritis, synovial fluid cytokine levels are strongly increased. Cytokine-modulating therapies, however, have hardly been considered for this indication. Increased knowledge of intra-articular soluble mediators correlating with cartilage pathology will lead to further development of cytokine-modulating products and, eventually, to effective inhibition of cartilage degeneration, in both the osteoarthritic as well as injured joints.

Breaking old paradigms: Th17 cells in autoimmune arthritis

Aberrant helper T cell activation has been implicated in the pathogenesis of an array of autoimmune diseases. In this review, we summarize evidence that suggests the involvement of a novel T cell subset, the Th17 lineage, in rheumatoid arthritis. In particular, we focus on the role of Th17 cells in inducing and perpetuating the chronic inflammation, cartilage damage, and bone erosion that are hallmark phases of joint destruction and consider current and emerging therapies that seek to disrupt the inflammatory Th17 network and shift the immune system back towards homeostasis.

Oral and Maxillofacial Pathology: Interleukin-1 β, interleukin-6, and tissue inhibitor of metalloproteinase-1 in the synovial fluid of the temporomandibular joint with respect to cartilage destruction

OBJECTIVE

The distribution and biological roles of interleukin (IL)-1 beta, IL-6, and tissue inhibitor of metalloproteinase-1 (TIMP-1) in the synovial fluid of patients with non-inflammatory chronic temporomandibular joint (TMJ) disorders were evaluated in relation to pain upon joint movements and X-ray and magnetic resonance imaging (MRI) findings.

MATERIALS AND METHODS

TMJ aspirates were obtained from 48 patients (48 joints) with chronic TMJ disorders and from 18 controls (18 joints). The IL-1 beta and IL-6 levels in the aspirates were determined by using an enzyme-linked immunosorbent assay and the TIMP-1 level was measured by an enzyme immunoassay. Following examinations for pain upon joint movements and X-ray and MRI observations, the IL-1 beta, IL-6, and TIMP-1 levels and frequencies of their detection were compared.

RESULTS

The IL-1 beta level and frequency of detection showed no correlation with pain upon joint movements or with the X-ray and MRI findings. In the frequency of detection of IL-6, there were significant differences between control (no detection) and all chronic TMJ disorder groups that were classified by imaging diagnosis (P < 0.001). A correlation was also noted between the presence of IL-6 and pain upon joint movements. The IL-6 level was correlated with the TIMP-1 level and with pain upon joint movements. TIMP-1 level was correlated with pain upon joint movements. The TIMP-1 was present in higher level from patients with chronic TMJ disorders who exhibited osseous changes on the X-ray images.

CONCLUSION

The results indicated that the IL-6 and TIMP-1 levels in the TMJ aspirates of patients with chronic TMJ disorders have been raised. The former was not detected in the TMJ aspirates of the control. These findings suggest that IL-6 and TIMP-1 might play a role in the etiology of chronic TMJ disorders, but further studies are needed to validate this.

Crucial role of visfatin/pre-B cell colony-enhancing factor in matrix degradation and prostaglandin E2 synthesis in chondrocytes: possible influence on osteoarthritis

OBJECTIVE

Prostaglandin E2 (PGE2) is one of the main catabolic factors involved in osteoarthritis (OA), and metalloproteinases (MMPs) are crucial for cartilage degradation. PGE2 synthesis under inflammatory conditions is catalyzed by cyclooxygenase 2 and microsomal PGE synthase 1 (mPGES-1), whereas NAD+-dependent 15-hydroxy-PG dehydrogenase (15-PGDH) is the key enzyme implicated in PGE2 catabolism. The present study was undertaken to investigate the contribution of visfatin, an adipose tissue-derived hormone, to the pathophysiology of OA, by examining its role in PGE2 synthesis and matrix degradation.

METHODS

The synthesis of visfatin by human chondrocytes from OA patients, with and without stimulation with interleukin-1beta (IL-1beta) and the role of visfatin in PGE2 synthesis were analyzed by real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and immunoblotting. The effects of visfatin (1-10 microg/ml) on mPGES-1 and 15-PGDH synthesis, on the subsequent release of PGE2, and on MMP-3, MMP-13, ADAMTS-4, ADAMTS-5, and PG synthesis by primary immature mouse articular chondrocytes were examined by quantitative RT-PCR, immunoblotting, and enzyme-linked immunosorbent assay. Finally, small interfering RNA (siRNA) was used to assess the influence of visfatin on IL-1beta-induced release of PGE2 in immature mouse articular chondrocytes.

RESULTS

Human OA chondrocytes produced visfatin, and visfatin synthesis was increased by IL-1beta treatment. Visfatin, like IL-1beta, triggered excessive release of PGE2, due to increased mPGES-1 synthesis and decreased 15-PGDH synthesis. Visfatin knockout with siRNA reduced IL-1beta-induced PGE2 overrelease. Visfatin triggered ADAMTS-4 and ADAMTS-5 expression and MMP-3 and MMP-13 synthesis and release, and reduced synthesis of high molecular weight PG by immature mouse articular chondrocytes.

CONCLUSION

The findings of this study indicate that visfatin has a catabolic function in cartilage and may have an important role in the pathophysiology of OA.

Synovial proliferation differentially affects hypoxia in the joint cavities of rheumatoid arthritis and osteoarthritis patients

This study was performed to investigate whether synovial proliferation (SP) differentially affects hypoxia in the joint cavities of rheumatoid arthritis (RA) and osteoarthritis (OA) patients. Thirty RA and 42 OA patients who underwent synovitis assessment were classified into two groups based on the presence or absence of SP, as revealed by musculoskeletal ultrasonography. Synovial fluids (SFs) from the knee joints were analyzed for interleukin (IL)-8, pO(2), and white blood cell counts and blood samples were analyzed for erythrocyte sedimentation rate (ESR). No difference was found between the OA patients with and without SP in terms of SF oxygen tension (SF pO(2)) or IL-8 level, whereas the RA patients had significantly lower SF pO(2) levels in their knee joints than did the OA patients with SP, and the RA patients had higher levels of IL-8 in their joints than did the OA patients. The counts of infiltrated immune cells in the SF and tissues were much higher for patients with RA and SP than for those with OA and SP. The ESRs were not found to be correlated with SP in OA patients but were negatively correlated with SF pO(2) levels in RA patients. We conclude that ultrasonographically detected SP in OA patients does not generate a more hypoxic SF than that found in OA patients without SP. The SFs from RA patients with SP are hypoxic, which indicates that SP may have different impacts on hypoxia in the joint cavities of RA and OA patients.

New biochemical insights into the pathogenesis of osteoarthritis and the role of laboratory investigations in clinical assessment

Osteoarthritis (OA) is among the most frequent diseases in the population and a common cause of pain and disability in adults. The principal disease hallmarks for assessment of OA are still clinical observation and radiographic aspects. However, the efficacy of therapeutic interventions is complicated by the time required to observe radiographic signs, useful for both diagnosis and assessment. Thus, laboratory markers have received growing attention in recent years, in an attempt to improve diagnosis, assessment of disease activity and severity, and evaluation of therapeutic effects. Many biomarkers have been proposed, in particular those reflecting cartilage and bone turnover and synovitis. Among these, COMP, antigenic keratan sulphate, hyaluronan, YKL-40, type III collagen N-propeptide, and urinary glucosyl-galactosyl pyridinoline appear to be the most promising. However, serum or urinary determinations of these molecules are difficult to interpret adequately due to their complex metabolism. New ultrasensitive methods for C-reactive protein have improved the usefulness of this marker, especially in the assessment of disease activity. Routine examination of synovial fluid is still essential for diagnosis and includes leukocyte count and crystal detection; specialized testing includes the evaluation of the levels of markers of local inflammation such as metalloproteinases and cytokines, which appear to be crucial to the pathogenesis of OA.

Dipeptidyl peptidase IV activity and/or structure homologs: contributing factors in the pathogenesis of rheumatoid arthritis?

Several of the proinflammatory peptides involved in rheumatoid arthritis pathogenesis, including peptides induced downstream of tumor necrosis factor-α as well as the monocyte/T cell-attracting chemokines RANTES and stromal cell-derived factor (SDF)-1α and the neuropeptides vasoactive intestinal peptide (VIP) and substance P, have their biological half-lives controlled by dipeptidyl peptidase IV (DPPIV). Proteolysis by DPPIV regulates not only the half-life but also receptor preference and downstream signaling. In this article, we examine the role of DPPIV homologs, including CD26, the canonical DPPIV, and their substrates in the pathogenesis of rheumatoid arthritis. The differing specific activities of the DPPIV family members and their differential inhibitor response provide new insights into therapeutic design.

Anti-inflammatory effect of the ghrelin agonist growth hormone-releasing peptide-2 (GHRP-2) in arthritic rats

Chronic arthritis induces hypermetabolism and cachexia. Ghrelin is a gastrointestinal hormone that has been proposed as a treatment to prevent cachexia. The aim of this work was to examine the effect of administration of the ghrelin agonist growth hormone-releasing peptide-2 (GHRP-2) to arthritic rats. Male Wistar rats were injected with Freund's adjuvant, and 15 days later arthritic and control rats were daily injected with GHRP-2 (100 microg/kg) or with saline for 8 days. Arthritis induced an increase in serum ghrelin (P < 0.01) and a decrease in serum concentrations of leptin (P < 0.01), whereas GHRP-2 administration increased serum concentrations of leptin. GHRP-2 increased food intake in control rats but not in arthritic rats. However, in arthritic rats GHRP-2 administration ameliorated the external symptoms of arthritis, as it decreased the arthritis score (10.4 +/- 0.8 vs. 13.42 +/- 0.47, P < 0.01) and the paw volume. In addition, circulating IL-6 and nitrites/nitrates were increased by arthritis, and GHRP-2 treatment decreased the serum IL-6 levels (P < 0.01). To elucidate whether GHRP-2 is able to modulate IL-6 release directly on immune cells, peritoneal macrophage cultures were incubated with GHRP-2 or ghrelin, the endogenous ligand of the growth hormone (GH) secretagogue receptor. Both GHRP-2 (10(-7) M) and ghrelin (10(-7) M) prevented endotoxin-induced IL-6 and decreased nitrite/nitrate release from peritoneal macrophages in vitro. These data suggest that GHRP-2 administration has an anti-inflammatory effect in arthritic rats that seems to be mediated by ghrelin receptors directly on immune cells.

Different ELR (+) angiogenic CXC chemokine profiles in synovial fluid of patients with Behçet's disease, familial Mediterranean fever, rheumatoid arthritis, and osteoarthritis

The aim of the present study was to determine synovial levels of ELR (+) CXC chemokines, known to attract mainly neutrophils to inflamed tissues by binding the neutrophil chemokine receptors CXCR1 and CXCR2 and promoting neovascularization in patients with various inflammatory disorders. The study group consisted of 14 patients with Behçet's disease and nine with familial Mediterranean fever. Fourteen patients with rheumatoid arthritis and 16 with osteoarthritis served as controls. Synovial chemokine levels were measured by two-step sandwich enzyme-linked immunosorbent assay, and significant differences were found in the various chemokines studied. In addition to its angiogenic properties, increased synovial levels of interleukin-8 by attraction of more neutrophils to synovial fluids might also be responsible for the acute synovitis in patients with Behçet's disease. However, the absence of chronic changes with the eventual development of pannus and erosions might result from relatively lower expression of interleukin-8 and the transient, short-lived nature of the arthritis observed in these patients.

Up-regulation of microsomal prostaglandin E synthase 1 in osteoarthritic human cartilage: critical roles of the ERK-1/2 and p38 signaling pathways

OBJECTIVE

Microsomal prostaglandin E synthase 1 (mPGES-1) is the final enzyme of the cascade that produces prostaglandin E(2) (PGE(2)), a key actor in arthritis. To study mPGES-1 synthesis in human cartilage and its regulation by interleukin-1beta (IL-1beta), we used human cartilage and an immortalized human chondrocyte cell line. Furthermore, we investigated the signaling pathways involved in mPGES-1 expression.

METHODS

We used real-time quantitative reverse transcription-polymerase chain reaction, Northern blotting, and Western blotting to measure mPGES-1 messenger RNA (mRNA) and protein expression in human chondrocytes. PGE(2) production was measured by enzyme-linked immunosorbent assay.

RESULTS

Cartilage specimens from osteoarthritis (OA) patients contained far greater amounts of mPGES-1 and cyclooxygenase 2 (COX-2) mRNA than did normal cartilage. Incubation with IL-1beta markedly increased mPGES-1 mRNA and protein in a dose-dependent and time-dependent manner, in parallel with an increase in PGE(2) levels. Both PD98059, an ERK pathway inhibitor, and SB203580, a p38alpha/beta MAPK inhibitor, abolished the increases in mPGES-1 mRNA and protein in response to IL-1beta. The specific p38alpha MAPK inhibitor SC906 suppressed IL-1beta-induced COX-2 expression but not IL-1beta-induced mPGES-1 expression, suggesting preferential involvement of p38beta MAPK in IL-1beta-induced mPGES-1 expression.

CONCLUSION

This study is the first to show that mPGES-1 is stimulated in human chondrocytes by the proinflammatory cytokine IL-1beta via activation of both ERK-1/2 and p38 MAPK in an isoform-specific manner. We postulate that mPGES-1 may be a novel target for OA therapy.

Does hyaluronan affect inflammatory cytokines in knee osteoarthritis?

Our aim was to investigate the effects of hyaluronan on inflammatory cytokines in the synovial fluid of patients with knee osteoarthritis. The study was single blind, placebo-controlled, and randomized. We administered hyaluronan to 22 patients in the study group and placebo to 19 in the control group. Enzyme-linked immunosorbent assay was used to determine the levels of cytokines. Both HA and placebo caused a significant decrease in interleukin (IL)-6 levels (P=0.0001 and P=0.04, respectively). But it was more significant in the study group. However, IL-8 and tumor necrosis factor alpha (TNF-alpha) levels did not change in either group (P>0.05). The amount of effusion decreased significantly in the study group (P=0.001) but not in the control group (P=0.133). It can be concluded that hyaluronan considerably decreased IL-6 levels, which correlated with clinical improvement, but had no effect on IL-8 and TNF-alpha levels in synovial fluid. However, larger studies with longer follow-up periods are needed to explain the effect of hyaluronan on cytokines.

Laboratory investigations in osteoarthritis

Progress in the knowledge of pathogenic mechanisms and a better definition of the disease, together with the availability of new technologies, have recently improved the value of laboratory investigations in osteoarthritis (OA). The main objectives of these findings are early diagnosis, assessment of disease activity and severity, and evaluation of therapeutic effects. In this context, biochemical markers are potentially useful, as they are non-invasive and non-expansive. However, among the numerous substances increasingly proposed for these purposes, very few may be considered as true disease markers in OA; COMP, antigenic keratan sulphate, hyaluronic acid, YKL-40, type III collagen N-propeptide and urinary glucosyl-galactosyl pyridinoline seem to be the most promising. However, serum or urinary determinations of these molecules are difficult to interpret adequately, due to their complex metabolism. Careful analysis of synovial fluid, mainly directed to leukocyte count and crystal detection, is still essential for diagnosis, but also for the evaluation of the levels of important markers of local inflammation, such as metalloproteinases and cytokines, which seem to be crucial in the pathogenesis of OA.

Co-expression of interleukin-1beta and tumor necrosis factor alpha in synovial tissues and synovial fluids of temporomandibular joint with internal derangement: comparison with histological grading of synovial inflammation

BACKGROUND

It has been clarified that interleukin-1 (IL-1)beta and tumor necrosis factor (TNF)alpha play an important role in pathogenesis of various joint disease. The purpose of this study was to investigate the cellular source of IL-1beta and TNFalpha in temporomandibular joint (TMJ), and to analyze the relation between the expression of these cytokines and the intensity of TMJ synovial inflammation.

METHODS

We examined 33 synovial biopsy specimens from patients with internal derangement of the TMJ by an immunohistochemical technique using specific antibodies to IL-1beta and TNFalpha. We also studied 20 synovial fluids from the patients by enzyme-linked immunosorbent assay method. These data are compared with histological grading of synovial inflammation by Gynther's system.

RESULTS

Both IL-1beta and TNFalpha were predominantly localized in the synovial lining cell layer and the blood vessels of synovial biopsy specimens obtained from patients with TMJ internal derangement. A statistically significant correlation was found between the intensity of IL-1beta expression and that of TNFalpha. Additionally, the intensity of TNFalpha expression was statistically correlated with histological grading by Gynther's system.

CONCLUSION

These results supported that IL-1beta and TNFalpha may be involved in the occurrence of TMJ internal derangement and that they coordinately play an role in pathogenesis of TMJ internal derangement.

Immunomodulating drugs in the management of psoriatic arthritis

Psoriatic arthritis is a chronic inflammatory arthropathy which can be distinguished from rheumatoid arthritis on the basis of differing patient demographics, genetic predisposition, histopathologic change, radiographic appearance, and clinical course. The cause of psoriatic arthritis remains unknown but appears to be autoimmune in nature as its pathogenesis is characterized by persistent synovial inflammation resulting in damage to the articular cartilage and osteolysis. Compared with rheumatoid arthritis, distinct lymphocyte subpopulations and pro-inflammatory cytokine levels appear to be present within the joint but the importance and therapeutic implications of these differences is uncertain. The clinical presentation of psoriatic arthritis is variable and overlapping patterns of joint involvement affecting both the appendicular and axial skeleton are seen. For patients with mild synovial disease and a favorable prognosis, the use of a nonsteroidal anti-inflammatory drug for symptomatic relief is often sufficient. However, the destructive potential of psoriatic arthritis is increasingly recognized and patients with more synovial disease and radiographic change at presentation appear to be at risk for greater morbidity and increased mortality. Immunomodulating therapy has the potential to suppress joint inflammation and preserve functional capacity but true disease modification has yet to be shown. The toxicity associated with presently available immunomodulatory agents makes careful patient selection and conscientious monitoring essential. The efficacy of methotrexate and sulfasalazine in patients with psoriatic arthritis is well defined while more anecdotal reports of benefit exist for other agents including the antimalarials, azathioprine, colchicine, cyclosporine, and the retinoids. For all treatment regimens, the magnitude of clinical improvement demonstrated to date has been rather small and quite subjective in character with few controlled studies of adequate size and duration having been reported. Emerging biologic therapies, such as those which target tumor necrosis factor, will hopefully provide future treatment options with greater efficacy and improved safety for patients with psoriatic arthritis.

Clinical significance of cytokine determination in synovial fluid

Cytokines are a complex family of small regulatory proteins able to mediate intercellular communication and play a crucial role in immunologic and inflammatory reactions. Many reports have demonstrated that some cytokines, in particular tumor necrosis factor alpha (TNFalpha) and interleukin (IL)-1beta, IL-6, and IL-8, so-called proinflammatory, may have a major role in the pathogenesis of joint diseases. Thus, high levels of these substances have been found in inflammatory arthropathies, in particular in those characterized by a more aggressive and destructive outcome, such as rheumatoid arthritis, gout, and infectious arthritis. In keeping with their role, the determination of cytokines in synovial fluid may be proposed for clinical purposes, including diagnostic and prognostic assessments. Furthermore, as some of these cytokines may reflect disease activity, their determination may also be useful in the evaluation of therapy.

Potential biologic agents for treating rheumatoid arthritis

The encouraging clinical results observed in trials using anti-TNF therapy clearly warrant further studies to determine whether TNF inhibitors are capable of modifying the destructive component of this disease in long-term follow-up studies as well as to assess the safety of long-term use (see the article by Keystone in this issue). It is also reasonable to propose that interfering with the cytokine cascade earlier in the course of disease may be of even greater therapeutic benefit. As the pathogenetic mechanisms in RA are more clearly defined, especially in early disease and in those individuals destined to develop severe disease, the potential of other biologic agents to specifically inhibit these critical pathways may provide better treatments for our patients. Many potential targets in the immune-mediated process of RA are currently being rigorously evaluated in clinical trials. Use of combinations of biologic therapies, perhaps in human patients with RA, should be of considerable interest in future trials.

Predictors of rheumatoid arthritis in patients who have monoarthritis in a knee joint

Abstract To determine the predictive factors for rheumatoid arthritis (RA), 79 patients (11 men, 68 women; average age at onset of symptoms 37.1 years) with fixed joint effusion of one knee joint, of minimum 6 months' duration, were divided into three groups: group I, 11 patients (14%) who progressed to RA; group II, 8 patients (10%) with the correct diagnosis, except that RA became apparent during the subsequent follow-up; group III, 60 patients (76%) whose joint effusion resolved. In group I, the degree of joint effusion and the serological values of interleukin (IL)-1β, IgG-RF, and rheumatoid factor (RF) tended to be higher than those in the other groups at the time of our initial examination. The synovial fluid concentrations of IL-1β and IgG-RF in group I were significantly higher than those in the other groups. Magnetic resonance imaging (MRI)-determined stage and histological assessment of synovial inflammation also tended to be higher in group I than in the other groups. This study revealed that it might be possible to predict the outcome of cases of monoarthritis by examining IL-1β and IgG-RF levels in the synovial fluid, in addition to various elevated inflammation signs in the knee joint.

Interaction of monocytes from patients with psoriatic arthritis with cultured microvascular endothelial cells

The aim of this study was to investigate the interaction of monocytes of the peripheral blood of patients with psoriatic arthritis with cultured human dermal microvascular endothelial cells (HDMEC) compared to monocytes from control persons. The surface expression of adhesion molecules (ADM) and other cell surface molecules in psoriatic arthritis and control monocytes was investigated by quantitative flow cytometry. The receptor densities of these molecules were determined in terms of monoclonal antibody (mAb) binding sites. Cocultivation experiments including peripheral blood mononuclear cells and HDMEC were performed to determine the adhesion to and transmigration through activated or resting endothelial cell monolayers. In order to achieve optimal responses of cellular functions, activation for adhesion experiments was induced by lipopolysaccharide (LPS), while in transmigration experiments the endothelial cells were activated by TNF-alpha. For transendothelial migration studies HDMEC cultivated on collagen gels were used. In the supernatants of cocultivated cells the cytokines IL-6 and IL-8 were determined by ELISA. A significantly reduced expression of CD11b in nonactivated psoriatic arthritis peripheral blood monocytes compared to control monocytes was verified (mean number of adhesion molecules/cell: 33,756 +/- 10,138 vs 61,023 +/- 6925). In agreement with these findings, adhesion to, as well as transendothelial migration through, activated HDMEC was found to be significantly reduced in psoriatic arthritis monocytes. Transendothelial migration engendered an enrichment of monocytes in the migrated cell fraction for both control and psoriatic arthritis peripheral blood mononuclear cells. The activation of HDMEC by LPS induced a highly significantly enhanced cytokine release for IL-6 and IL-8, irrespective of the origin of monocytes (psoriatic arthritis vs. controls). However, IL-8 production in the supernatants of nonactivated monocytes/HDMEC cocultures was significantly reduced in the case of monocytes from psoriatic arthritis patients (6650 +/- 2489.32 pg/ml) vs 9280.00 +/- 3209.51 pg/ml in control patients. Impaired adhesion as well as transendothelial migration of monocytes derived from peripheral blood of psoriatic arthritis patients can be explained by the reduced expression of adhesion molecules MAC-1 (CD11b/CD18) at the surface of monocytes. The reduced IL-8 production also corresponds to a diminished cellular interaction under nonflow conditions. These results support the view that there are systemic immunological alterations in psoriatic arthritis patients.

Relationship between interleukin-6 levels in gingival crevicular fluid and periodontal status in patients with rheumatoid arthritis and adult periodontitis

BACKGROUND

The aim of this study was to determine and compare interleukin-6 (IL-6) levels in gingival crevicular fluid (GCF) and clinical periodontal findings in patients with rheumatoid arthritis (RA) and adult periodontitis (AP).

METHODS

A total of 45 patients divided into 3 groups (15 patients with RA and AP, 15 patients with AP, and 15 periodontally healthy subjects) were included in this study. Plaque index (PI), gingival index (GI), sulcus bleeding index (SBI), probing depth (PD), and attachment level (AL) values for each patient were recorded. Enzyme-linked immunosorbent assay for quantitative detection of IL-6 in each GCF sample was employed.

RESULTS

No significant difference could be detected between the RA and AP groups in the mean clinical parameter data except PI. Although the mean GCF IL-6 level in the RA group was the highest, no significant difference could be found among the groups. There was only a strong negative correlation between GCF IL-6 levels and GI scores in the RA group.

CONCLUSIONS

In the patients with RA, despite increased local tissue destruction potential due to autoimmunity and higher PI levels than in the AP patients, our findings suggest that medication including corticosteroid and non-steroidal anti-inflammatory drugs may decrease gingival inflammation, but the synthesis and degradation of IL-6 in gingival tissue of RA patients may be different. To our knowledge, this study is the first report determining GCF IL-6 levels in RA patients.

Effects of captopril on interleukin-6, leukotriene B(4), and oxidative stress markers in serum and inflammatory exudate of arthritic rats: evidence of antiinflammatory activity

We previously demonstrated that captopril (CP) exhibited a high ability to inhibit enzymatically generated leukotrienes, particularly LTB(4), from stimulated intact human neutrophils. This finding together with the immunosuppressive effect of CP have proposed a possible antiinflammatory activity for the drug. Thus, the present study was conducted to investigate the effect of CP on immunologically mediated chronic inflammation; two models were chosen, namely, Freund's adjuvant arthritis and mixed-type hypersensitivity in rat. The effect of CP was assessed on the basis of physical parameter (paw edema) and biochemical markers in blood and inflammatory exudate. CP was given daily during the course of inflammation development. It was administered ip at three doses, viz. 1, 10, and 100 mg/kg. The results claimed that CP succeeded in suppressing edema evolution in hind paws of Freund's arthritic animals, during all phases of the disease. During the chronic phase of inflammation, in either model, CP reduced the elevated serum and exudate (local) LTB(4) and IL-6 levels. The effect on LTB(4) was more pronounced in the exudate and tended to be dose-related. The antiarthritic effect of CP was also accompanied by augmentation of serum level of protein thiols, with reduction or normalization of elevated systemic and/or local levels of lipid peroxide, superoxide dismutase, and glutathione. It could be concluded that long-term treatment with CP confers a good antiinflammatory activity against arthritis in rat, leading to improvement of the oxidative stress induced by the arthritic insult. The reparative effect of the drug could be mediated via reduction of LTB(4) and IL-6.

Tryptophan catabolism in synovial fluid of various arthropathies and its relationship with inflammatory cytokines

Synovial fluids (SF) from patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA), gout, and osteoarthritis (OA) were investigated for the levels of interleukin (IL)-1 beta, IL-6 and IL-8, tryptophan (Trp) and indoleamine 2,3-dioxygenase (IDO) activity. Significant differences exist in the levels of IL-1 beta between inflammatory arthritides RA, PsA and gout and non inflammatory arthritis, such as OA. The highest concentration of IL-1 beta was found in RA, that showed high levels also of IL-6 and IL-8. In the same disease we also found the highest IDO activity and the lowest Trp concentration. In addition, IDO activity seems to be related with the decrease in Trp, as demonstrated by the inverse correlation found between these two substances in the SF of all patients.

Specific expression of interleukin-1 beta in temporomandibular joints with internal derangement: correlation with clinical findings

OBJECTIVE

Interleukin-1 beta appears to play an important role in the pathophysiology of joint diseases. The aim of this study was to analyze the expression of interleukin-1 beta in temporomandibular joint internal derangement.

STUDY DESIGN

Using an immunohistochemical technique with specific antibodies, we examined 20 human temporomandibular joint samples from patients with internal derangement of the temporomandibular joint: 5 extirpated disks and 15 biopsy specimens from the synovitic area of the temporomandibular joint upper compartment. We also examined 2 control specimens. The evaluation of interleukin-1 beta expression compared with clinical findings.

RESULTS

Interleukin-1 beta was predominantly localized in the synovial lining cells and endothelial cells of blood vessels. Statistically significant correlation was found between interleukin-1 beta expression and some clinical findings.

CONCLUSIONS

The results suggest that interleukin-1 beta may be involved in the pathogenesis of temporomandibular joint internal derangement and that the intensity of interleukin-1 beta expression may correlate with clinical findings, especially pain.

Establishment and characterization of nurse cell-like stromal cell lines from synovial tissues of patients with rheumatoid arthritis

OBJECTIVE

To investigate the features of synovial stromal cells established from patients with rheumatoid arthritis (RA), and to define these cells as nurse cells.

METHODS

Synovial nurse-like stromal cell lines (RA-SNCs) were established from patients with RA. These cell lines were examined for morphology, pseudoemperipolesis activity, cell surface markers, and cytokine production. The interaction between these RA-SNCs and a synovial tissue B cell clone was also examined.

RESULTS

RA-SNCs had nurse cell activity. They spontaneously produced interleukin-6 (IL-6), IL-8, granulocyte colony-stimulating factor, and granulocyte-macrophage colony-stimulating factor. Furthermore, they produced IL-1beta and tumor necrosis factor alpha and expressed higher levels of the other cytokines after coculture with the B cell clone. Proliferation and Ig production by the B cell clone were dependent on direct contact with RA-SNCs.

CONCLUSION

These results indicate that the RA-SNCs were nurse cells. The findings suggest that RA-SNCs may play an important role in the pathogenesis of RA by producing large amounts of cytokines and maintaining infiltrating lymphocytes.

Detection of interleukin-1 in the cartilage of patients with osteoarthritis: a possible autocrine/paracrine role in pathogenesis

The interleukin-1 (IL-1) cytokines stimulate the synthesis of degradative enzymes in joint tissues and may play a role in the pathological joint destruction in osteoarthritis (OA). In this study, we have used immunohistochemistry and Western blot analysis to identify IL-1 in human OA cartilage. IL-1 alpha and IL-1 beta were evident in chondrocytes at the articular surface, as well as distributed throughout the cartilage. In many specimens, IL-1 beta but not IL-1 alpha was detected as a diffuse staining of the extracellular matrix especially surrounding superficial zone chondrocytes. Although chondrocyte-associated IL-1 alpha and IL-1 beta were detected in most specimens, cartilages exhibiting early osteoarthritic changes had the highest intensity of staining and the highest frequency of positive cells. Western blot analysis revealed intense immunoreactive bands corresponding to the 35 kDa precursor form of IL-1 alpha in all four chondrocyte lysates tested. The processed 18 kDa IL-1 beta species was present in only one of four chondrocyte lysates, and there was no clear evidence of precursor form within these cells. The results of this study indicate increased IL-1 alpha in cartilage showing early degenerative changes, suggesting an autocrine/paracrine role for this cytokine in OA pathogenesis.

Therapy with cyclosporine in psoriatic arthritis

OBJECTIVE

To evaluate the efficacy and toxicity of cyclosporin A (CsA) in the treatment of patients with psoriatic arthritis (PsA).

METHODS

We reviewed the literature dealing with CsA treatment of PsA.

RESULTS

In the 1980s, some studies evaluating CsA in severe cases of psoriasis documented an improvement in the associated arthritis. Subsequently, open prospective studies included patients with active peripheral arthritis. Using initial CsA dose of 3 to 6 mg/kg/day, improvement in the clinical parameters was noted. A controlled trial showed that CsA and methotrexate (MTX) are equally effective treatment for PsA. CsA and MTX combination was effective in PsA patients resistant to previous second-line therapy. No studies have evaluated the efficacy of CsA on axial disease and on the progression of radiological damage. The most important side effect was nephrotoxicity. However, of 170 CsA-treated patients in 16 studies, only 10 (6%) discontinued the drug because of renal side effects.

CONCLUSIONS

CsA seems to be an effective and safe therapy for PsA. However, controlled studies on large number of patients are necessary.

Synovial fluid levels of proinflammatory interleukins and their inter-relationships in elderly vs younger onset rheumatoid arthritis

Elderly-onset rheumatoid arthritis (EORA) is thought to be different from younger-onset disease (YORA) for many reasons, including a more elevated acute phase response and a more abrupt onset; both events are mainly regulated by pro-inflammatory interleukins (ILs), in particular, IL-1, IL-6 and IL-8. To compare the synovial fluid (SF) levels of these ILs, and their relationship to local inflammation as well as the acute phase response, erythrocyte sedimentation rate (ESR) and serum C-reactive protein (CRP) in the two RA subsets, we determined white blood cell (WBC) number, total protein (TP), IL-1beta, IL-6 and IL-8 concentrations in the SF of 50 patients, 15 with EORA and 35 with YORA. Both ESR and CRP were higher in EORA than in YORA. IL-6 was higher in SF of EORA (2111.37 +/- 1425.03 pg/mL) than YORA (1077.53 +/- 757.62 pg/mL, p = 0.002), while no difference was observed for SF IL-1beta and IL-8. There was a weak correlation between SF IL-6 and IL-1beta in EORA, whereas SF ILs and CRP and/or ESR did not show any correlation in both groups. Our study indicates that in EORA, as in other diseases occurring in the elderly, there are elevated levels of IL-6. Higher SF levels of IL-6 may be, at least in part, responsible for the different behavior of EORA with respect to YORA.