Synovial interleukin-1 receptor antagonist and interleukin-1 balance in rheumatoid arthritis

Therapeutic potential of the topical recombinant human interleukin-1 receptor antagonist in guinea pigs with allergic rhinitis

BACKGROUND

Recombinant human Interleukin receptor antagonist (rhIL-Ra) can bind to the IL-1 receptor on the cell membrane and reversibly blocks the proinflammatory signaling pathway. However, its effect on allergic rhinitis (AR) and the underlying mechanism remains unknown. This study aims to investigate the efficacy of recombinant human interleukin-1 receptor antagonist (rhIL-1Ra) on AR guinea pigs.

METHODS

Guinea pigs were systemically sensitized by intraperitoneal injection and topical intranasal instillation with ovalbumin within 21 days. Animals administrated with saline served as the normal control. The AR animals were randomly divided into the model group and distinct concentrations of rhIL-1Ra and budesonide treatment groups. IL-1β and ovalbumin specific IgE levels were detected by ELISA kits. Nasal mucosa tissues were stained with hematoxylin & eosin (HE) for histological examination.

RESULTS

It was found that the numbers of sneezing and nose rubbing were remarkably reduced in rhIL-1Ra and budesonide-treated guinea pigs. Besides, rhIL-1Ra distinctly alleviated IgE levels in serum and IL-1β levels in nasal mucus, together with decreased exfoliation of epithelial cells, eosinophilic infiltration, tissue edema and vascular dilatation.

CONCLUSIONS

rhIL-1Ra is effective in AR guinea pigs and may provide a novel potential choice for AR treatments.

In Vitro Anti-Inflammatory and Regenerative Effects of Autologous Conditioned Serum from Dogs with Osteoarthritis

Osteoarthritis (OA) is mostly incurable and non-regenerative with long-term complications. Autologous conditioned serum (ACS), which is enriched in Interleukin 1 receptor antagonists (IL-1RA) and growth factors, could be an alternative treatment to accelerate the positive therapeutic effects. ACS is proposed to alleviate inflammation by blocking IL-1 receptors. However, to date, there is no report focusing on the cell-mediated anti-inflammation and regenerative effect caused by ACS, especially the ACS from patients. Therefore, this study aims to investigate the therapeutic potential of ACS generated from dogs with spontaneous OA, focusing on its promising anti-inflammatory and regenerative properties in vitro compared to the matched plasma. We found that ACS prepared from ten OA dogs contained significant concentrations of IL-1RA, vascular endothelial growth factor, and transforming growth factor beta, which are key cytokines in anti-inflammation and angiogenesis. Furthermore, we found that ACS suppressed T cell activity by reducing proliferation of effector T cells and simultaneously expanding numbers of immune suppressive FOXP3+ T cells. Lastly, we showed that ACS enhanced the proliferation of osteocytes and fibroblasts and promoted extracellular matrix gene expression in primary chondrocyte culture. Therefore, these studies indicate that ACS prepared from dogs with OA is active as an immunomodulatory and regenerative strategy for use in OA management.

Use of allogeneic freeze-dried conditioned serum for the prevention of degradation in cartilage exposed to IL-1ß

Background

Autologous conditioned serum (ACS) has been extensively used in the field of veterinary orthopaedics and sports medicine. Due to the autologous and blood-derived nature of this product, issues such as individual variability, need for storage at low temperatures and non-availability for immediate are frequently encountered for ACS use in the field. To address those issues, we proposed the evaluation of an off-the-shelf allogeneic freeze-dried version of conditioned serum in an in vitro model of osteoarthritis. In this study, we evaluated if origin (autologous and allogeneic) and preparation (frozen and freeze-dried) of conditioned serum could influence in its effect in an in vitro model.

Results

IL-1β stimulation in cartilage led to a significant increase in media GAG and decreased levels of GAG in cartilage explants at the termination of the experiment. No significant differences were noted in outcomes measured in the cartilage explants with respect to the main effects of treatment (frozen versus freeze-dried serum), autologous versus allogeneic preparations or based on serum concentration.

Conclusions

The study did not observe any substantial differences in the response of cartilage to allogeneic freeze-dried CS when compared to other independent parameters (autologous and frozen preparations). Further investigation using in vivo systems appears warranted.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-022-03227-2.

Biomarker Approach Towards Rheumatoid Arthritis Treatment

Rheumatoid arthritis is an auto-immune disorder, recognized by cartilage as well as bone destruction, which causes irreversible joint deformities, which further results in functional limitations in the patient. Genes like HLA-DRB1 and PTPN22 are likely implicated in the genetic predisposition of rheumatoid arthritis pathology. The first and foremost clinical manifestation in a person with rheumatoid arthritis is joint destruction followed by cartilage and bone destruction caused by cell-cell interactions. The cell-cell interactions are thought to be initialized through the contact of antigen-presenting cells (APC) with CD4+ cells, leading to the progression of the disease. APC includes a complex of class ІІ major histocompatibility complex molecules along with peptide antigens and binds to the receptors present on the surface of T-cells. Further, the activation of macrophages is followed by the release of various pro-inflammatory cytokines such as IL-1 and TNF-α, which lead to the secretion of enzymes that degrade proteoglycan and collagen, which in turn, increase tissue degradation. Biomarkers like IL-6, IL-12, IL-8 and IL-18, 14-3-3η, RANKL, IFN-γ, IFN-β and TGF-β have been designated as key biomarkers in disease development and progression. The study of these biomarkers is very important as they act as a molecular indicator of pathological processes that aggravate the disease.

PYRIN inflammasome activation abrogates IL1Ra expression providing a new mechanism underlying FMF pathogenesis

OBJECTIVE

Aberrant PYRIN inflammasome activity triggers FMF pathogenesis but the exact mechanism remains elusive and an obstacle to efficient treatment. Herein, we sought to identify PYRIN inflammasome specific mechanisms to improve FMF treatment and diagnostics in the future.

METHODS

PYRIN-specific protein secretion was assessed by proteome analysis in U937 derived macrophages, and specific findings were confirmed in PYRIN inflammasome activated monocytes from healthy blood donors (HD) and FMF patients, stratified by MEFV genotype categories corresponding to a suspected increasing FMF disease severity.

RESULTS

Proteome data revealed differential secretion pattern of IL1Rα from PYRIN and NLRP3 activated U937 derived macrophages, which was verified by ELISA and qPCR. Moreover, PYRIN activation significantly reduced IL1RN mRNA expression (p<0.001) and IL1Rα secretion (p<0.01) in healthy donor- and FMF monocytes, respectively. Independent of MEFV genotype, unstimulated FMF monocytes from colchicine treated patients secreted lower amounts of IL1Rα as compared to healthy donors (p<0.05) and displayed decreased ratios of IL1Rα/IL1β (p<0.05), suggesting a reduced anti-inflammatory capacity.

CONCLUSION

Our data show an inherent lack of IL-1 receptor antagonist expression specific to PYRIN inflammasome activation, providing a new mechanism underlying FMF pathogenesis. The reduced IL1Rα levels in FMF monocytes suggest a diminished anti-inflammatory capacity potentially leaving FMF patient monocytes more sensitive to pro-inflammatory stimuli, regardless of being in colchicine therapy. Thus, considering the potential clinical consequence of reduced monocyte IL1Rα secretion in FMF patients, we suggest further investigations into IL1Rα dynamics and its potential implications for FMF treatment in the future.

A Comparative Review of Autologous Conditioned Serum and Autologous Protein Solution for Treatment of Osteoarthritis in Horses

Many alternative treatments aimed at modulating osteoarthritis (OA) progression have been developed in the past decades, including the use of cytokine inhibitors. IL-1β is considered one of the most impactful cytokines in OA disease and therefore, its blockage offers a promising approach for the modulation of OA. Interleukin-1 receptor antagonist (IL-1Ra) is a naturally occurring anti-inflammatory protein belonging to the IL-1 family that competes with IL-1β for occupancy of its receptors, without triggering the same downstream inflammatory response. Because of its natural anti-inflammatory properties, different methods have been proposed to use IL-1Ra therapeutically in OA. Autologous conditioned serum (ACS) and autologous protein solution (APS) are blood-derived products produced with the use of specialized commercial kits. These processes result in hemoderivatives with high concentrations of IL-1Ra and other cytokines and growth factors with potential modulatory effects on OA progression. Several studies have demonstrated potential anti-inflammatory effect of these therapies with promising clinical results. However, as with any hemoderivatives, clinical outcomes may vary. For optimal therapeutic use, further research is warranted for a more comprehensive understanding of the product's composition and interaction of its components in joint inflammation. Additionally, differences between ACS and APS treatments may not be clear for many clients and clinicians. Thus, the objective of this narrative review is to guide the reader in important aspects of ACS and APS therapies, in vitro and in vivo applications and to compare the use of both treatments in OA.

Pharmacokinetics of Anakinra in Subjects of Heavier vs. Lighter Body Weights

This trial (20010168) studied how body weight (BW) and body mass index (BMI) influenced the pharmacokinetics (PK) of anakinra. Subjects (n = 32) were assigned to four groups (n = 8) according to BW and BMI. Randomization was according to a four‐treatment, four‐period, four‐sequence crossover design. The four anakinra injections were 100, 150, and 300 mg s.c. and 100 mg i.v. Plasma samples were measured by enzyme‐linked immunosorbent assay and noncompartmental PK parameters estimated. BW demonstrated the following effects: after i.v. administration, significant effects (P < 0.05) were observed for exposure (area under the concentration–time curve from zero to infinity (AUC_0–∞)), peak plasma concentration (C_max), volume of distribution at steady state, and clearance; whereas after s.c. administration, significant effects (P < 0.05) were observed for C_max, AUC_0–∞, terminal half‐life, and estimated apparent clearance. Mean AUC was reduced 24% and 33% for heavier (BW ≥ 100 kg) vs. lighter subjects (BW ≤ 90 kg) after i.v. and s.c. administration, respectively. BMI increased clearance for heavier subjects. For example, mean (SD) plasma clearance of i.v. anakinra increased from 1.17 ± 0.29 to 1.62 ± 0.24 mL/minute/kg (P < 0.05) for larger (> 100 kg) obese (BMI > 36) vs. larger (> 100 kg) less obese (BMI < 35) subjects, respectively. Similarly, results following s.c. supported those after i.v. administration. Derived half‐lives increased with higher BW and higher BMI ranging from 3.63 hour for less obese, lighter‐weight subjects to 7.62 hour for obese, heavier‐weight subjects. Absolute bioavailability ranged from 80–92% and was unrelated to BW or BMI. Anakinra exposure is statistically significantly related to BW and to a lesser extent BMI.

Anakinra for Recurrent Fevers in Systemic Lupus Erythematosus

Fever is a common manifestation in systemic lupus erythematosus (SLE) and may be associated with disease activity, but should be closely evaluated for infection, drug reaction, thromboembolism, malignancy, or other etiology. We present the case of a 44-year-old Peruvian female with SLE with periodic high fevers and elevated high-sensitivity C-reactive protein (hs-CRP) levels, treated with anakinra, an interleukin-1 (IL-1) inhibitor. Following the birth of her first child, she developed frequent episodic fevers followed by multiple hospitalizations, approximately two to three times per year. She was started on anakinra in September 2016 and had improvement of fevers and joint symptoms. On 26-month follow-up, she had one episode of fever with bandemia requiring hospitalization but otherwise remained afebrile with a significant drop in CRP. Anakinra is well-tolerable and safe due to a short half-life. We report that the inhibition of IL-1 may be a safe and effective treatment for recurrent fevers in SLE.

Pharmacokinetics and Safety of Recombinant Human Interleukin-1 Receptor Antagonist GR007 in Healthy Chinese Subjects

Background and Objectives

The recombinant human interleukin-1 receptor antagonist (rhIL-1Ra) GR007 is a candidate drug with the potential to prevent the toxicity induced by chemotherapy agents by blocking the IL-1 signaling pathway. The aim of this study was to assess the pharmacokinetics and safety of GR007 in healthy Chinese subjects.

Methods

Thirty subjects received a single intramuscular injection of 30 mg (n = 10), 90 mg (n = 10), or 150 mg (n = 10) GR007. After administration, the pharmacokinetic characteristics and safety were evaluated.

Results

No serious adverse events were reported in this study, and the adverse events reported showed no dose dependency. Pharmacokinetic analysis showed that the median time to maximum concentration (T_max) of GR007 in the three groups was between 2.75 and 4.00 h and the geometric mean elimination half-life (T_1/2) for each group was 2.38, 2.22, and 3.29 h, respectively. The area under the concentration vs time curve (AUC), but not the maximum concentration (C_max), increased in a dose-proportional manner.

Conclusions

The results showed that a single intramuscular injection of 30–150 mg GR007 had good safety and tolerability in healthy Chinese subjects. The results of the evaluation of the safety and pharmacokinetics of GR007 performed in this study support its use as a repeated daily injection in ongoing clinical trials focusing on patients with cancer.

Root resorptions associated with canine retraction treatment

INTRODUCTION

The hypothesis of this study was that multiple factors are dominant in causing external apical root resorption (EARR). The objective of this investigation was to better understand the clinical factors that may lead to EARR.

METHODS

Maxillary cone-beam computed tomography scans of 18 subjects who were treated with bilateral canine retractions during orthodontics were used to calculate EARR. The subjects were treated using well-calibrated segmental T-loops for delivering a 124-cN retraction force and the moment-to-force ratio suitable for moving the canine under either translation or controlled tipping. The subjects' age, sex, treatment duration, and genotype were collected.

RESULTS

Six subjects of the 18 showed definite EARR, meaning that load was not the only causing factor. All 5 subjects with the genotype identified had GG genotype of IL-1β rs11143634, indicating that people with this genotype may be at high risk. Longer treatment duration, female sex, and older age may also contribute to EARR, although the findings were not statistically significant.

CONCLUSIONS

EARR appears to be related to multiple factors. The orthodontic load and the genotype should be the focuses for future studies.

Therapeutic effect of ergotope peptides on CIA by down-regulation of inflammatory and Th1/Th17 responses and induction of regulatory T cells

Rheumatoid arthritis (RA) is a systemic autoimmune disease that results in a chronic and inflammatory disorder. Dynamic balance of helper T cells (Th)1, Th17 and regulatory T cells (Treg) is broken in RA. Since there is no cure for RA at present, it's necessary to find a truly effective and convenient treatment. Several studies intended to induce ergotopic regulation to treat autoimmune diseases. This study was undertaken to find the potential ergotope peptides and investigate its effect in treating the animal model of RA and their underlying regulatory mechanisms. Firstly, we selected the functional ergotope peptides from 25 overlapping peptides derived from interlukin(IL)-2 receptor (IL-2R) α chain, and then used these peptides to treat collagen-induced arthritis (CIA). The study showed ergotope peptides as immunomodulatory factors with great benefits at the clinical and pathologic levels. This effect was associated with the inhibition of type II collagen (CII)-specific proliferation and autoantibody production as well as the induction of anti-ergotypic immune response, the down-regulation of both Th1 and Th17 cells and their related components, and the emergence of Treg cells that had suppressive actions on autoreactive T cells. We also proved that cytotoxic T lymphocyte associated antigen-4 (CTLA-4) and IL-10 are two important mediators which are critical to Treg suppressive function. The inhibition of Th1 and Th17 in established CIA could be attributed to ergotope induced Treg cells. Our findings reveal that ergotope peptides induce regulatory immune responses and restore immune tolerance, suggesting ergotope peptides treatment appears to be a novel approach to the therapy of RA patients and has a good application prospect with cheap, effective, convenient, wide-spectrum features.

Interleukin-1 in Rheumatoid Arthritis: Its Inhibition by IL-1Ra and Anakinra

Objective:

To review the biology of interleukin-1 (IL-1) in the pathogenesis of rheumatoid arthritis (RA), as well as the biology of its natural inhibitor, IL receptor antagonist (IL-1Ra), and the clinical efficacy and safety of the recombinant form, anakinra.

Data Sources:

A MEDLINE search (1966–January 2007) of English-language articles was conducted using the key words anakinra, arthritis, clinical trial, interleukin-1 receptor antagonist, and Kineret.

Study Selection and Data Extraction:

Over 79 research articles and literature reviews were used to compile a discussion of the biology of IL-1 and IL-1Ra. Ten of these articles were selected to discuss the clinical safety and efficacy of anakinra.

Data Synthesis:

In RA, IL-1 primarily acts locally to mediate erosion of cartilage and bone. IL-1Ra serves to modulate its activity through competitive inhibition of cellular receptors. Administration of anakinra to animals with experimental arthritis reduced inflammation and joint damage. In clinical trials, anakinra was reasonably well tolerated; however, injection site reactions were frequent and there was a slight increased risk of serious infection. Alone or in combination with methotrexate, anakinra significantly reduced the symptoms and clinical signs of RA at the American College of Rheumatology 20% response level. However, no additive benefit was observed following coadministration with etanercept, a soluble tumor necrosis factor antagonist, and anakinra had no beneficial effect in patients that failed treatment with etanercept.

Conclusions:

Laboratory studies have indicated that IL-1 is primarily responsible for cartilage destruction and bone erosion in RA. The selective inhibition of IL-1 through administration of anakinra may offer symptomatic relief of RA in some patients.

Low magnitude of tensile stress represses the inflammatory response at intervertebral disc in rats

Objective

This study aims to determine if the involvement of tensile stress affects the expressions of inflammatory cytokines interleukin-17(IL-17), interleukin-1β (IL-1β), and inducible nitric oxide synthase (iNOS) at intervertebral discs in vivo.

Material and method

Sixty-four female Sprague–Dawley rats were randomly divided into four groups: sham, tail-suspended (TS), tail-suspended with needle puncture (TSNP), and single-needle puncture (SNP) groups. A tail-suspension device provides low magnitude of tensile stress (2.45 Newton (N)), and aseptic needle puncture on the tail disc induces inflammatory response. After 4 weeks, the treated discs were harvested for histologic analysis, quantitative real-time reverse transcription-polymerase chain reaction (RT-qPCR), and enzyme-linked immunosorbent assay (ELISA).

Result

Pathological examination demonstrated that compared to the sham group, the morphologies of nucleus pulposus (NP) and anulus fibrosus (AF) in TS, SNP, and TSNP groups displayed degenerative changes in varying degrees. Results from RT-qPCR showed that IL-17 and iNOS mRNA expression levels were significantly higher in both TSNP and SNP groups than those in the sham groups. Expression of IL-17 and iNOS are not significantly different between the sham and TS groups (P > 0.05). Compared with the SNP group, the mRNA expression of IL-17 and iNOS in the TSNP groups were markedly decreased (P < 0.05). The regulation of IL-1β and IL-17 detected by ELISA was coincident with the qRT-PCR results.

Conclusion

The results from this study suggested that relatively low magnitude tensile stress might play an essential role in the anti-inflammatory process and the relief of low-back pain (LBP).

Novel multimeric IL-1 receptor antagonist for the treatment of rheumatoid arthritis

Protein therapeutics targeting inflammatory mediators have shown great promise for the treatment of autoimmunities such as rheumatoid arthritis (RA). However, a significant challenge in this area has been their low in vivo stability and consequently their severely compromised therapeutic efficacy. One such therapeutic molecule IL-1 receptor antagonist (IL-1ra), used in the treatment of rheumatoid arthritis, has displayed only modest efficacy in human clinical trials owing to its short biological half-life. Herein, we report a novel approach to conglomerate individual protein entities into a drug depot by incorporation of an amyloidogenic motif Lys-Phe-Phe-Glu (KFFE) thereby dramatically improving their systemic persistence and in turn their therapeutic efficacy in a mice model of autoimmune arthritis.

The levels of leukemia inhibitory factor in synovial tissues of patients with rheumatoid arthritis: inflammation and other proinflammatory cytokines

Abstract To clarify the effect of leukemia inhibitory factor (LIF) on the destruction of rheumatoid arthritis (RA) joints, we investigated the production of LIF and the expression of LIF mRNA in synovial tissues from patients with RA and osteoarthritis (OA). Synovial fluids from RA were used to measure the LIF concentrations using enzyme-linked immunosorbent assay (ELISA). Immunohistochemistory and RT-PCR were used to examine the expression of LIF by synovial cells. LIF mRNA was detected in all cases in RA synovial cells. Although LIF protein was detected only in 20 cases (19%) in RA synovial fluids, LIF concentration in the synovial fluids significantly correlated with the peripheral leukocyte count (P < 0.001) and C-reactive protein (CRP) (P < 0.01). Moreover, levels of IL-1β, IL-6, and IL-8, but not TNF-α, were significantly correlated with LIF in the RA synovial fluids. LIF production was promoted by IL-1β and TNF-α stimulation; in contrast, IL-1 ra and IL-4 were found to markedly decrease LIF production by cultured synovial cells. LIF appeared to be a cytokine produced by RA synovium leading to a proinflammatory secretion profile. Moreover, IL-4 and IL-1 ra may represent attenuated activity for reducing the effect of the destruction of joints by LIF.

Lipopolysaccharide of Aggregatibacter actinomycetemcomitans up-regulates inflammatory cytokines, prostaglandin E2 synthesis and osteoclast formation in interleukin-1 receptor antagonist-deficient mice

BACKGROUND AND OBJECTIVE

The interleukin (IL)-1 receptor antagonist (Ra) binds to IL-1 receptors and inhibits IL-1 activity. However, it is unclear whether the IL-1Ra plays a protective role in periodontal disease. The purpose of this study was to compare IL-1Ra knockout (KO) and wild-type (WT) mice in regard to proinflammatory cytokine production, osteoclast formation and bone resorption in response to periodontal bacterial lipopolysaccharide (LPS).

MATERIAL AND METHODS

Peritoneal macrophages (Mφs) were obtained from 13-wk-old IL-1Ra KO and WT mice. Peritoneal Mφs were cultured with or without 10 μg/mL of Aggregatibacter actinomycetemcomitans LPS for 24 h. The levels of IL-1alpha (IL-1α), IL-1beta (IL-1β), tumor necrosis factor-α (TNF-α) and IL-6 were measured in periotoneal Mφs supernatant fluid (PM-SF) using an ELISA. Bone marrow cells were obtained from the mice and stimulated with PM-SF for 9 d, then stained with TRAP. The frequency of TRAP-positive multinucleated giant cell formation was calculated based on a fusion index. PM-SF-stimulated calvarial bone resorption was analyzed using micro-computed tomography, and calvarial histological analysis was performed using hematoxylin and eosin and TRAP staining. The expression of cyclooxygenase-2 (Cox2), prostanoid receptor EP4 (Ep4) and Rank mRNAs in bone marrow cells were measured using real-time quantitative PCR, while prostaglandin E2 (PGE2 ) production was determined by ELISA.

RESULTS

The levels of IL-1α, IL-1β, TNF-α and IL-6 in IL-1Ra KO mice PM-SF stimulated with A. actinomycetemcomitans LPS were significantly increased by approximately 4- (p < 0.05), 5- (p < 0.05), 1.3- (p < 0.05) and 6- (p < 0.05) fold, respectively, compared with the levels in WT mice. Moreover, osteoclast formation, expression of Rank, Ep4 and Cox2 mRNAs and production of PGE2 were significantly increased by approximately 2- (p < 0.05), 1.6- (p < 0.05), 2.5- (p < 0.05), 1.6- (p < 0.05) and 1.9- (p < 0.05) fold, respectively, in IL-1Ra KO mice stimulated with A. actinomycetemcomitans LPS compared with WT mice.

CONCLUSION

IL-1Ra regulates IL-1 activity and appears to reduce the levels of other inflammatory cytokines, including TNF-α and IL-6, while it also reduces expression of the EP4 receptor related to prostanoid sensitivity and osteoclast formation. These results suggest that IL-1Ra is an important molecule for inhibition of inflammatory periodontal bone resorption.

Increased synovial expression of nuclear receptors correlates with protection in pristane-induced arthritis: a possible novel genetically regulated homeostatic mechanism

OBJECTIVE

To use microarray analyses of gene expression to characterize the synovial molecular pathways regulated by the arthritis regulatory locus Cia25 and to determine how it operates to control disease severity and joint damage.

METHODS

Synovial tissues from DA rats and DA.ACI(Cia25) rats obtained 21 days after induction of pristane-induced arthritis were used for RNA extraction and hybridization to Illumina RatRef-12 Expression BeadChips (22,228 genes). Genes with a P value≤0.01 and a fold difference in expression≥1.5 between DA rats and DA.ACI(Cia25) rats were considered significant.

RESULTS

Interleukin-1β (IL-1β) (7.4-fold), IL-6 (67-fold), Ccl2, Cxcl10, Mmp3, Mmp14, and innate immunity genes were expressed at increased levels in DA rats and at significantly lower levels in DA.ACI(Cia25) congenic rats. DA.ACI(Cia25) rats had increased expression of 10 nuclear receptor (NR) genes, including those known to interfere with NF-κB activity and cytokine expression, such as Lxra, Pparg, and Rxrg. DA.ACI(Cia25) rats also had increased expression of NR targets, suggesting increased NR activity. While Vdr was not differentially expressed, a Vdr expression signature was detected in congenic rats, along with up-regulation of mediators of vitamin D synthesis.

CONCLUSION

This is the first description of the association between increased synovial levels of NRs and arthritis protection. The expression of NRs was inversely correlated with the expression of key mediators of arthritis, suggesting reciprocally opposing effects either via NF-κB or at the genomic level in the synovial tissue. We consider that the NR signature may have an important role in maintaining synovial homeostasis and an inflammation-free tissue. These processes are regulated by the Cia25 gene and suggest a new function for this gene.

IL-1 family cytokines trigger sterile inflammatory disease

Inflammation plays vital roles in protective responses against pathogens and tissue repair, however, improper resolution of inflammatory networks is centrally involved in the pathogenesis of many acute and chronic diseases. Extensive advances have been made in recent years to define the inflammatory processes that are required for pathogen clearance, however, in comparison, less is known about the regulation of inflammation in sterile settings. Over the past decade non-communicable chronic diseases that are potentiated by sterile inflammation have replaced infectious diseases as the major threat to global human health. Thus, improved understanding of the sterile inflammatory process has emerged as one of the most important areas of biomedical investigation during our time. In this review we highlight the central role that interleukin-1 family cytokines play in sterile inflammatory diseases.

Profile of circulating levels of IL-1Ra, CXCL10/IP-10, CCL4/MIP-1β and CCL2/MCP-1 in dengue fever and parvovirosis

Dengue virus (DENV) and parvovirus B19 (B19V) infections are acute exanthematic febrile illnesses that are not easily differentiated on clinical grounds and affect the paediatric population. Patients with these acute exanthematic diseases were studied. Fever was more frequent in DENV than in B19V-infected patients. Arthritis/arthralgias with DENV infection were shown to be significantly more frequent in adults than in children. The circulating levels of interleukin (IL)-1 receptor antagonist (Ra), CXCL10/inducible protein-10 (IP-10), CCL4/macrophage inflammatory protein-1 beta and CCL2/monocyte chemotactic protein-1 (MCP-1) were determined by multiplex immunoassay in serum samples obtained from B19V (37) and DENV-infected (36) patients and from healthy individuals (7). Forward stepwise logistic regression analysis revealed that circulating CXCL10/IP-10 tends to be associated with DENV infection and that IL-1Ra was significantly associated with DENV infection. Similar analysis showed that circulating CCL2/MCP-1 tends to be associated with B19V infection. In dengue fever, increased circulating IL-1Ra may exert antipyretic actions in an effort to counteract the already increased concentrations of IL-1β, while CXCL10/IP-10 was confirmed as a strong pro-inflammatory marker. Recruitment of monocytes/macrophages and upregulation of the humoral immune response by CCL2/MCP-1 by B19V may be involved in the persistence of the infection. Children with B19V or DENV infections had levels of these cytokines similar to those of adult patients.

Fibroblast-like synoviocytes: key effector cells in rheumatoid arthritis

Rheumatoid arthritis (RA) remains a significant unmet medical need despite significant therapeutic advances. The pathogenesis of RA is complex and includes many cell types, including T cells, B cells, and macrophages. Fibroblast-like synoviocytes (FLS) in the synovial intimal lining also play a key role by producing cytokines that perpetuate inflammation and proteases that contribute to cartilage destruction. Rheumatoid FLS develop a unique aggressive phenotype that increases invasiveness into the extracellular matrix and further exacerbates joint damage. Recent advances in understanding the biology of FLS, including their regulation regulate innate immune responses and activation of intracellular signaling mechanisms that control their behavior, provide novel insights into disease mechanisms. New agents that target FLS could potentially complement the current therapies without major deleterious effect on adaptive immune responses.

[Pathophysiological relevance of peroxisome proliferators activated receptors (PPAR) to joint diseases - the pro and con of agonists]

Peroxisome proliferators activated receptors (PPAR) are ligand-inducible nuclear transacting factors comprising three subtypes, PPARalpha, PPARbeta/delta and PPARgamma, which play a key role in lipids and glucose homeostasis. All PPAR subtypes have been identified in joint or inflammatory cells and their activation resulted in a transcriptional repression of pro-inflammatory cytokines (IL-1, TNFalpha), early inflammatory genes (NOS(2), COX-2, mPGES-1) or matrix metalloproteases (MMP-1, MMP-13), at least for the gamma subtype. PPAR full agonists were also shown to stimulate IL-1 receptor antagonist (IL-1Ra) production by cytokine-stimulated articular cells in a subtype-dependent manner. These anti-inflammatory and anti-catabolic properties were confirmed in animal models of joint diseases where PPAR agonists reduced synovial inflammation while preventing cartilage destruction or inflammatory bone loss, although many effects required much higher doses than needed to restore insulin sensitivity or to lower circulating lipid levels. However, these promising effects of PPAR full agonists were hampered by their ability to reduce the growth factor-dependent synthesis of extracellular matrix components or to induce chondrocyte apoptosis, by the possible contribution of immunosuppressive properties to their anti-arthritic effects, by the increased adipocyte differentiation secondary to prolonged stimulation of PPARgamma, and by a variable contribution of PPAR subtypes depending on the system. Clinical data are scarce in rheumatoid arthritis (RA) patients whereas thousands of patients worldwilde, treated with PPAR agonists for type 2 diabetes or dyslipidemia, are paradoxically prone to suffer from osteoarthritis (OA). Whereas high dosage of full agonists may expose RA patients to cardiovascular adverse effects, the proof of concept that PPAR agonists have therapeutical relevance to OA may benefit from an epidemiological follow-up of joint lesions in diabetic or hyperlipidemic patients treated for long periods of time with glitazones or fibrates. Additionally, cellular and animal studies are required to assess whether partial agonists of PPAR (SPPARMs) may preserve therapeutical properties with potentially less safety concern.

Translating basic research into clinical rheumatology

Findings from basic research in combination with precise clinical observations of the disease course in rheumatoid arthritis (RA) have led to the development of a multistage model to explain the pathophysiology of RA. Different cellular and soluble mediators, which play principal roles at different phases of the disease, have been identified. New therapeutic agents, which specifically target these factors, now allow us to intervene at several levels of the pathogenesis. This has already resulted in significant improvements for patients suffering from RA, and the development of new promising agents continues at a high pace. However, many questions concerning the optimal use of the new therapies remain unanswered. Combined efforts of basic research and clinical trials investigating the optimal timing and combination of the new treatments will be necessary to allow them to achieve their full potential and to result in the maximum benefit for patients.

Co-expression of IL-18 binding protein and IL-4 regulates Th1/Th2 cytokine response in murine collagen-induced arthritis

We constructed a recombinant adenoviral vector containing a murine interleukin (IL)-18 binding protein (mIL-18BP) and murine IL-4 (mIL-4) fusion gene (AdmIL-18BP/mIL-4) and used a gene therapy approach to investigate the role of IL-18BP and IL-4 in modulating the T-helper1 and T-helper2 (Th1/Th2) balance in mice with collagen-induced arthritis (CIA). Mice with CIA were intra-articularly injected with 107 pfu/6 microl of either AdmIL-18BP/mIL-4, or a control adenovirus, or with the control vehicle (phosphate-buffered saline). After intra-articular gene therapy with AdmIL-18BP/mIL-4, the serum levels of tumor necrosis factor-alpha (TNF-alpha), gamma-interferon (IFN-gamma), IL-4, IL-10, and IL-18 in mice with CIA were assessed by ELISA. IFN-gamma-expressing and IL-4-expressing CD4+ T cells from mice splenocytes were monitored by flow cytometry. Mice with CIA at weeks 1, 2, and 4 after intra-articular injection of AdmIL-18BP/mIL-4 showed significantly increased serum concentrations of IL-4 and IL-10 (P<0.01 at all time points) but greatly decreased serum concentrations of IFN-gamma, TNF-alpha, and IL-18 (P<0.01 at all time points) compared to both the control adenovirus and phosphate-buffered saline control groups. The percentage of IFN-gamma-producing CD4+ T cells was significantly decreased in response to local AdmIL-18BP/mIL-4 treatment. The percentage of IL-4-producing CD4+ T cells increased significantly at 1 week after local injection of AdmIL-18BP/mIL-4 then returned to normal by week 4. These data indicated the significant modifying effects on the Th1/Th2 imbalance in murine CIA produced by local overexpression of IL-18BP and IL-4. Combination treatment with IL-18BP and IL-4 is a promising potential therapy for rheumatoid arthritis.

IL-1 receptor antagonist in metabolic diseases: Dr Jekyll or Mr Hyde?

Interleukin-1 receptor antagonist (IL-1ra) has been shown to play a crucial role in the prevention of various inflammatory diseases. There is also convincing evidence that IL-1ra is able to counteract inflammatory effects of IL-1 members implicated in insulin resistance and diabetes. However, the use of knock-out animal models provides evidence to the contrary and the role of IL-1ra in obesity-linked anomalies remains controversial. This minireview gets an insight into recent findings on the implication of IL-1ra and its gene polymorphism in diabetes and obesity, discusses the potential dual effects of IL-1ra observed in different models, and comments on future directions.

Alpha-lipoic acid suppresses the development of collagen-induced arthritis and protects against bone destruction in mice

OBJECTIVE

To test the ability of alpha-lipoic acid (LA) to attenuate the development of collagen-induced arthritis (CIA) in mice.

METHODS

Mice were divided into three groups and treated with intraperitoneal administration of LA (10 or 100 mg/kg) or placebo. Clinical, histologic, and biochemical parameters were assessed. Human synovial fibroblasts and peripheral blood mononuclear cells were cocultured in various concentrations of LA to evaluate the effects on osteoclastogenesis.

RESULTS

LA was associated with a dose-dependent reduction of CIA, as well as preventing bone erosion and destructive changes. Intracellular reactive oxygen species in lymphocytes obtained from inguinal lymph nodes, which was significantly higher in CIA than control mice, was significantly reduced in CIA by LA. The concentrations of TNF-alpha, IL-1beta, and IL-6 in the paws, and synovial NF-kappaB binding, all of which were markedly higher in CIA than control mice, were reduced by treatment with LA. In addition, LA inhibited the formation of human osteoclasts in vitro.

CONCLUSION

Amelioration of joint disease by LA was associated with reduction in oxidative stress, as well as inhibition of inflammatory cytokine activation and NF-kappaB DNA binding activity. Moreover, LA inhibited bone destruction in vivo and osteoclastogenesis in vitro. Collectively, these results indicate that LA may be a new adjunctive therapy for rheumatoid arthritis.

Inflammatory cell and cytokine patterns in patients with chronic polyarthritis and temporomandibular joint involvement

OBJECTIVE

To investigate the occurrence of selected markers for inflammatory cells and cytokines in patients with chronic polyarthritis (CPA) and temporomandibular joint (TMJ) involvement.

MATERIAL AND METHODS

Eleven patients (11 joints) with CPA and TMJ disorder were included in the study. Synovial specimens were obtained during TMJ open surgery and these were subjected to immunohistochemistry on frozen sections post-fixed with paraformaldehyde and with the cell membranes permeabilized by saponin. In all patients, the cytokines IL-1alpha, IL-1beta, IL-1ra, TNFalpha, IFNgamma, IL2, and TGFbeta were investigated using specific antibodies. The occurrence of macrophages and T-lymphocytes was investigated using immunohistochemistry with monoclonal antibodies against antigens CD68 and CD45RO, respectively. In addition, PCNA was used as a marker for cell proliferation.

RESULTS

Staining of IL-1alpha, IL-1, and TGF was seen in all 11 specimens, IFN? in 1, TNFalpha in 4, and IL-2 in none. CD45RO-positive T cells were detected in 7 specimens, CD68-positive macrophages in 6, and cell proliferation seen with PCNA was noted in 8.

CONCLUSIONS

The predominant cytokines of TMJ CPA were IL-1alpha, IL-1beta, and TGFbeta, and there appeared to be no differences between the subgroups (rheumatoid arthritis, psoriatic arthritis, and ankylosing spondylitis) involved. Moreover, the cytokine pattern of TMJ CPA patients seemed to differ from patients with osteoarthritis, as shown in our previous study. The main difference was the absence of IFNgamma and TNFalpha in TMJ CPA patients and a stronger TGFbeta and IL-1alpha expression.

CXCL16-mediated cell recruitment to rheumatoid arthritis synovial tissue and murine lymph nodes is dependent upon the MAPK pathway

OBJECTIVE

Rheumatoid arthritis (RA) is characterized by profound mononuclear cell (MNC) recruitment into synovial tissue (ST), thought to be due in part to tumor necrosis factor alpha (TNFalpha), a therapeutic target for RA. Although chemokines may also be involved, the mechanisms remain unclear. We undertook this study to examine the participation of CXCL16, a novel chemokine, in recruitment of MNCs to RA ST in vivo and to determine the signal transduction pathways mediating this process.

METHODS

Using a human RA ST-SCID mouse chimera, immunohistochemistry, enzyme-linked immunosorbent assay, real-time reverse transcription-polymerase chain reaction, flow cytometry, and in vitro chemotaxis assays, we defined the expression and function of CXCL16 and its receptor, CXCR6, as well as the signal transduction pathways utilized by them for MNC homing in vitro and in vivo.

RESULTS

CXCL16 was markedly elevated in RA synovial fluid (SF) samples, being as high as 145 ng/ml. Intense macrophage and lining cell staining for CXCL16 in RA ST correlated with increased CXCL16 messenger RNA levels in RA ST compared with those in osteoarthritis and normal ST. By fluorescence-activated cell sorting analysis, one-half of RA SF monocytes and one-third of memory lymphocytes expressed CXCR6. In vivo recruitment of human MNCs to RA ST implanted in SCID mice occurred in response to intragraft injection of human CXCL16, a response similar to that induced by TNFalpha. Lipofection of MNCs with antisense oligodeoxynucleotides for ERK-1/2 resulted in a 50% decline in recruitment to engrafted RA ST and a 5-fold decline in recruitment to regional lymph nodes. Interestingly, RA ST fibroblasts did not produce CXCL16 in response to TNFalpha in vitro, suggesting that CXCL16 protein may function in large part independently of TNFalpha.

CONCLUSION

Taken together, these results point to a unique role for CXCL16 as a premier MNC recruiter in RA and suggest additional therapeutic possibilities, targeting CXCL16, its receptor, or its signaling pathways.

Gene therapy as a therapeutic approach for the treatment of rheumatoid arthritis: innovative vectors and therapeutic genes

In recent years, significant progress has been made in the treatment of rheumatoid arthritis (RA). In addition to conventional therapy, novel biologicals targeting tumour necrosis factor-alpha have successfully entered the clinic. However, the majority of the patients still has some actively inflamed joints and some patients suffer from side-effects associated with the high systemic dosages needed to achieve therapeutic levels in the joints. In addition, due to of the short half-life of these proteins there is a need for continuous, multiple injections of the recombinant protein. An alternative approach might be the use of gene transfer to deliver therapeutic genes locally at the site of inflammation. Several viral and non-viral vectors are being used in animal models of RA. The first gene therapy trials for RA have already entered the clinic. New vectors inducing long-term and regulated gene expression in specific tissue are under development, resulting in more efficient gene transfer, for example by using distinct serotypes of viral vectors such as adeno-associated virus. This review gives an overview of some promising vectors used in RA research. Furthermore, several therapeutic genes are discussed that could be used for gene therapy in RA patients.

Anakinra (interleukin-1 receptor antagonist) has positive effects on function and quality of life in patients with rheumatoid arthritis

Rheumatoid arthritis (RA) has severe and lasting effects on quality of life. This review (1) describes the disease progression, disability, and joint destruction that seriously alter a patient's quality of life, and (2) explains how the interleukin-1 receptor antagonist (IL-1Ra), anakinra, retards the progress of disease, thereby improving outcomes. Relevant articles were reviewed with a focus on RA, anakinra, and functional and quality-of-life outcomes. In randomized, controlled trials, the IL-1Ra anakinra provided meaningful benefits for patients with active RA, such as decreased signs and symptoms of disease, slower radiographic disease progression, reduced disability, and improved health-related quality of life. The biologic agent, anakinra, provides to patients with RA a valuable treatment option that has a positive impact on both function and quality of life.

Interleukin-1 receptor antagonist intervenes in signaling between different types of synoviocytes in rats with adjuvant arthritis

AIM

To investigate the mechanisms of interleukin-1 receptor antagonist (IL-1ra) in the treatment of adjuvant arthritis (AA).

METHODS

AA was induced in rats by treatment with Freunds complete adjuvant (FCA). Rats were given an intracutaneous injection of IL-1ra (2.5, 10, 40 mg/kg, 3 times per day) from d 14 to d 21 after immunization. Synoviocyte proliferation and the activity of IL-1 were determined by using MTT assay. Tumor necrosis factor alpha (TNF-alpha) and prostaglandin E(2) (PGE(2)) concentrations were measured by radioimmunoassay. The ultrastructure of synoviocytes was observed by using a transmission electron microscope. Phosphorylation of c-Jun N-terminal kinase (JNK), extracellular regulating kinase (ERK) and p38 kinase were detected by Western blot analysis.

RESULTS

IL-1ra (10 and 40 mg/kg, ic, d 14-21) modulated the secondary inflammatory reaction (P < 0.01), ultrastructure of synoviocytes and mitogen-activated protein kinase (MAPK) phosphorylation in AA rats. The administration of IL-1ra (10 and 40 mg/kg, ic, d 14-21) in AA rats significantly decreased the production of IL-1, PGE2 and TNF-alpha by macrophage-like synoviocytes (MLS) (P < 0.01). IL-1ra (2.5 mg/kg) also decreased the production of PGE2 (P < 0.01) and TNF-alpha (P < 0.05) by MLS in AA rats. The increased phosphorylation of MAPK and cell proliferation in fibroblast-like synoviocytes (FLS) stimulated by supernatants of MLS in AA rats was also inhibited by IL-1ra (10 and 40 mg/kg, ic, d 14-21).

CONCLUSION

IL-1ra has anti-inflammatory effects because it modulates the ultrastructure of synoviocytes, decreases the production of pro-inflammatory mediators by MLS, and inhibits the phosphorylation of MAPK in FLS.

Adverse cutaneous reactions to anakinra in patients with rheumatoid arthritis: clinicopathological study of five patients

BACKGROUND

Anakinra, a recombinant human form of interleukin-1 receptor antagonist, is used to treat patients with active rheumatoid arthritis (RA).

OBJECTIVES

To report five patients with cutaneous adverse drug reactions due to anakinra and to evaluate the histopathological and immunohistochemical findings with the aim of understanding the possible mechanisms involved.

METHODS

Five patients of a series of 10 patients with RA undergoing treatment with anakinra in a clinical trial presented inflammatory lesions at the anakinra injection sites. In each case, clinical features were recorded and skin biopsy specimens were obtained. In one patient sequential biopsy specimens were obtained from skin lesions at different stages of development. Tissue sections of the biopsy specimens were stained with haematoxylin and eosin and May-Grünwald-Giemsa, and were immunoreacted with antibodies to leucocyte common antigen, CD68, CD3, CD45RO, CD20 and CD45RA.

RESULTS

The onset of reaction was within the first month of treatment and appeared as well-defined erythema and oedema involving the injection sites. In two patients the treatment had to be discontinued because of the skin reaction, and in one patient it was associated with systemic involvement. All biopsy specimens exhibited marked dermal oedema and a lichenoid dermal infiltrate composed mainly of lymphomononuclear cells with prominent populations of eosinophils and large CD68+ dermal macrophages and an increase in the number of mast cells, which were spindle shaped in a significant proportion.

CONCLUSIONS

Cutaneous toxicity is a frequent, usually well-tolerated complication of treatment with anakinra in patients with RA, although in some cases it can be associated with systemic involvement. The most relevant histopathological findings include dermal oedema and a lichenoid, perivascular and periadnexal predominantly lymphomononuclear infiltrate, with many eosinophils and the presence of enlarged CD68+ macrophages. These findings resemble those seen in skin reactions in patients receiving chemotherapy and colony-stimulating factors. We also found an increase in mast cell numbers that could be a specific effect of anakinra.

New therapies for rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic, systemic inflammatory disease, which continues to cause significant morbidity in affected persons. In the past few years, a number of new exciting therapeutic options have become available. These reflect the application of knowledge obtained from advancements in understanding of disease pathogenesis and underlying molecular mechanisms. A number of these therapies are outlined in the following review, including the various biological modifiers, in particular, anti-tumour necrosis factor-alpha agents and interleukin-1 (IL-1) receptor antagonists, which have been developed in recognition of the role of pro-inflammatory cytokines in RA. Also notable, is the current interest centring on the development and trials with B cell depletion therapies, specifically rituximab, in patients with RA. This demonstrates acknowledgment for a more significant role for B cells in the aetiology of RA, in contrast to the long held view that RA was a predominantly T cell mediated disease. To evaluate this therapeutic option for RA, salient features from recent rituximab trials have been collated. Finally, a selection of other therapeutic alternatives, including anti-IL-6 receptor monoclonal antibody and tacrolimus, and newer anti-rheumatic therapies presently in development are summarized.

Rosiglitazone induces interleukin-1 receptor antagonist in interleukin-1beta-stimulated rat synovial fibroblasts via a peroxisome proliferator-activated receptor beta/delta-dependent mechanism

OBJECTIVE

To study the potency of 2 peroxisome proliferator-activated receptor gamma (PPARgamma) agonists, 15-deoxy-Delta(12,14)-prostaglandin J(2) (15-deoxy-PGJ(2)) and rosiglitazone, to modulate the expression of interleukin-1 receptor antagonist (IL-1Ra) in rat synovial fibroblasts.

METHODS

Levels of messenger RNA for IL-1Ra and PPAR isotypes (alpha, beta/delta, gamma) were assessed by real-time polymerase chain reaction in rat synovial fibroblasts exposed to 10 ng/ml of IL-1beta. PPAR levels were assessed by Western blotting and secreted IL-1Ra levels by immunoassay. The potency of PPARgamma agonists and the PPARbeta/delta agonist GW-501516 on IL-1Ra levels was tested in the range of 1-10 microM and at 100 pM, respectively. The contribution of PPARgamma to the effects of rosiglitazone on IL-1Ra secretion was examined either by its overexpression or by inhibition using wild-type or dominant-negative constructs and the antagonist GW-9662 (10 microM), respectively. The dominant-negative strategy was also performed to investigate the possible contribution of PPARbeta/delta and NF-kappaB activation.

RESULTS

IL-1beta-induced IL-1Ra production was increased by 10 microM rosiglitazone but was reduced dose-dependently by 15-deoxy-PGJ(2). Both agonists lowered IL-1beta secretion, but rosiglitazone alone reduced the imbalance of IL-1beta/IL-1Ra toward basal levels. Enhancement of IL-1beta-induced IL-1Ra production by rosiglitazone was not affected by PPARgamma overexpression or by its inhibition with dominant-negative PPARgamma or GW-9662. Inhibition of NF-kappaB was also ineffective against rosiglitazone but abolished the stimulating effect of IL-1beta on IL-1Ra. All PPAR isotypes were expressed constitutively in rat synoviocytes, but PPARgamma decreased dramatically upon IL-1beta exposure, whereas PPARbeta/delta remained stable. Dominant-negative PPARbeta/delta abolished the enhancement of IL-1Ra by rosiglitazone, whereas GW-501516 reproduced the effect of rosiglitazone on IL-1Ra secretion.

CONCLUSION

Rosiglitazone stimulates IL-1Ra production by a PPARbeta/delta mechanism in activated rat synovial fibroblasts, further contributing to its potential antiarthritic properties and opening new perspectives for the modulation of inflammatory genes by specific PPAR agonists in articular cells.

Human periprosthetic tissues implanted in severe combined immunodeficient mice respond to gene transfer of a cytokine inhibitor

BACKGROUND

Periprosthetic tissue formation and local inflammation that are associated with wear debris contribute to the pathogenesis of aseptic loosening of a prosthesis. This study evaluated a retrovirus-mediated gene therapy with use of a novel xenograft-based animal model.

METHODS

Human periprosthetic tissues obtained from patients during revision arthroplasty performed because of aseptic loosening of a prosthetic joint were transplanted into the left quadriceps and paravertebral muscles of severe combined immunodeficient (SCID) mice. The engrafted tissues were recovered seven, fifteen, or thirty days after implantation for histological and molecular analyses. The periprosthetic tissues were incubated with retroviruses encoding for human interleukin-1 receptor antagonist (hIL-1Ra) or bacteria beta-galactosidase (LacZ) at 37 degrees C for three hours prior to implantation to evaluate their responses to gene modification.

RESULTS

The human periprosthetic tissues were well accepted in SCID mice for up to thirty days, with angiogenesis occurring in the majority of the implanted tissue sections. The histological appearance was consistent between the recovered graft tissue and the original donor tissue. Strong expression of interleukin-1, tumor necrosis factor, and interleukin-6 was detected in the xenografts with use of immunohistochemical stains. Histological analysis revealed that interleukin-1 receptor antagonist gene modification significantly decreased the total number of inflammatory cells (p < 0.01) in engrafted human tissue containing implant wear debris. Real-time reverse transcription-polymerase chain reaction and immunohistochemical staining showed declining expression levels of interleukin-1 and tumor necrosis factor following interleukin-1 receptor antagonist gene transfer in comparison with LacZ-transduced or virus-free controls.

CONCLUSIONS

Human periprosthetic tissue can survive in the SCID mouse host for up to thirty days and responds to the interleukin-1 receptor antagonist gene transfer with the amelioration of inflammation.

Anakinra: review of recombinant human interleukin-I receptor antagonist in the treatment of rheumatoid arthritis

BACKGROUND

Interleukin-1 (IL-1) plays an important role in the pathophysiology and progression of rheumatoid arthritis (RA) by contributing to destruction of cartilage, bone, and periarticular tissues. Inhibiting IL-1 synthesis or activity with the use of recombinant human IL-1 receptor antagonist (anakinra) may prove to be an effective approach to the treatment of RA.

OBJECTIVE

The purpose of this article is to review the effects of anakinra in the treatment of RA.

METHODS

A MEDLINE search from 1982 to 2003 was used to identify animal studies and randomized clinical trials of anakinra and other therapies that target IL-1.

RESULTS

Clinical trials of anakinra have shown that it reduces the signs and symptoms of active disease and slows the rate of radiographic destruction in adults with RA. With anakinra 150 mg/d, 43% of patients achieved an American College of Rheumatology (ACR) 20% response, compared with 27% with placebo (P = 0.014). The ACR20 score indicates at least 20% improvement in the ACR composite score, which includes assessment of tender and swollen joint count, and other clinical end points such as pain and disability assessment. Patients treated with anakinra also experienced a 59% reduction in new bony erosion compared with controls (P < 0.001) and a 65% reduction in joint space narrowing as measured by the modified Sharp score (P = 0.020). Injection-site reactions were the most commonly reported adverse event, occurring in 50%, 73%, and 81% of patients receiving anakinra 30, 75, and 150 mg/d, respectively, compared with 25% of patients receiving placebo. Few serious adverse events were reported, and they typically occurred in patients receiving the highest daily dosage.

CONCLUSIONS

IL-1 is an important cytokine in promoting the damage associated with RA. Anakinra is mildly to moderately effective and well tolerated in patients with active RA when used as monotherapy or in combination with methotrexate.

Platelet-derived growth factor-AA increases IL-1beta and IL-8 expression and activates NF-kappaB in rheumatoid fibroblast-like synoviocytes

The effect of platelet-derived growth factor (PDGF)-AA on the inflammation in rheumatoid arthritis (RA) and osteoarthritis (OA) was investigated using cultured fibroblast-like synoviocytes (FLS) obtained from RA and OA patients as well as control nonarthritic (NA) individuals. PDGF-AA increased the mRNA and protein expressions of proinflammatory cytokines, interleukin (IL)-1beta and IL-8 in RA FLS. Biological activity of IL-1 in the culture supernatant of RA FLS was also increased by PDGF-AA stimulation. Interestingly, PDGF-AA synergized with tumour necrosis factor (TNF)-alpha to upregulate the protein expressions of IL-1beta and IL-8. PDGF-induced enhancement of the IL-1beta and IL-8 mRNA expressions was also observed in OA FLS. However, the expression of these proinflammatory cytokines in NA FLS did not change by PDGF treatment, suggesting that the inflammatory condition might have modified the biological effects of PDGF. In accordance with the enhanced expression of inflammatory cytokines, the activity of nuclear factor kappaB was also induced in response to PDGF-AA in RA FLS. These results suggest that PDGF-AA plays an important role in the progression of RA inflammation, and inhibiting PDGF activity may be useful for the effective RA treatment.

Pregnancy in patients with rheumatic disease: anti-inflammatory cytokines increase in pregnancy and decrease post partum

OBJECTIVE

To investigate changes in the levels of circulating cytokines with a focus on the Th1/Th2 balance during and after pregnancy in patients with rheumatoid arthritis (RA), juvenile idiopathic arthritis (JIA), and ankylosing spondylitis (AS).

METHODS

Plasma and serum samples of 34 pregnant patients, 19 with RA, 6 with JIA, and 9 with AS, and of 30 healthy pregnant women, 20 non-pregnant patients, and 10 non-pregnant healthy women were analysed for levels of interferon gamma (IFNgamma), interleukin (IL) 1beta, IL10, IL1 receptor antagonist (IL1Ra), soluble tumour necrosis factor receptor (sTNFR), and soluble CD30 (sCD30) by ELISA. Clinical assessment and blood sampling in pregnant women was done once in each trimester and 6, 12, and 24 weeks post partum. Disease activity in the patients was evaluated by validated clinical instruments and correlated with circulating levels of cytokines.

RESULTS

Low levels of IL10 were found sporadically, whereas IFNgamma and IL1beta were below detection level in the samples tested. Significantly higher concentrations of sTNFR and IL1Ra were measured in pregnant than in non-pregnant subjects. An increase of IL1Ra from the second to the third trimester correlated with improvement of disease activity in patients with RA and AS. Compared with non-pregnant patients and the other pregnant women, patients with RA showed markedly raised levels of sCD30 during pregnancy.

CONCLUSIONS

IFNgamma and IL10, markers of a Th1 and Th2 response, respectively, were either low or undetectable in the cohorts analysed. The increase of cytokine inhibitors IL1Ra and sTNFR was related to pregnancy and was independent of an underlying disease. These anti-inflammatory mediators seem to affect disease activity.

Interleukin-1 balance in the lungs of preterm infants who develop bronchopulmonary dysplasia

BACKGROUND

The local pulmonary balance between the agonist and antagonist of interleukin-1 (IL-1) may influence the development of inflammatory disease and resultant structural damage in a variety of human diseases including adult respiratory distress syndrome and asthma.

OBJECTIVES

We tested the hypothesis that IL-1 cytokines are early markers for bronchopulmonary dysplasia (BPD), when measured in tracheal aspirates (TAs) obtained from premature infants being ventilated for respiratory distress syndrome during the first week of life.

METHODS

Serial TAs were collected on days 1, 3, 5 and 7 from 35 preterm infants (16 BPD, 19 non-BPD) in the absence of chorioamnionitis, and were assayed for IL-1 cytokines and leukocytes.

RESULTS

In spite of comparable maternal demographic and clinical characteristics, premature infants who developed BPD had higher levels of IL-1 receptor antagonist (Ra) in their airways on the first day of life. This antagonist IL-1Ra was an early and persistent marker for BPD during the first week of life. The agonist IL-1beta also increased significantly for BPD patients early, both compared to non-BPD patients, and also within the BPD group. While the early (day 1) IL-1 antagonist/agonist molar balance offered protection, by days 5 and 7, a threshold for IL-1Ra in the presence of increasing IL-1beta expression-favored pro-inflammation in the BPD group.

CONCLUSIONS

We conclude that a strong and early expression of airway antagonist (IL-1Ra) proves ultimately to be sub-optimal and non-protective due to the robust expression of airway agonist (IL-1beta) seen by day 5 in premature infants who develop BPD.