An interleukin 1 inhibitor affects both cell-associated interleukin 1-induced T cell proliferation and PGE2/collagenase production by human dermal fibroblasts and synovial cells

Long-term Effect of Injection Treatment for Osteoarthritis in the Knee by Orthokin Autologous Conditioned Serum

Background Orthokin is an intra-articular autologous conditioned serum (ACS). Its use might have a beneficial biological effect on pain and function of osteoarthritis in the knee. However, earlier studies lack any consensus on its clinical application and disease modifying effect. Objective The aim of this study was to investigate the long-term effect of Orthokin injection treatment on prevention of surgical treatment for end-stage knee osteoarthritis. Study Design Prospective cohort study. Methods Patients of the previously published Orthokin cohort were contacted to determine whether any intra-articular surgical intervention or osteotomy of the study knee had taken place during the past decade. A log-rank test was performed to evaluate the differences in the survival distribution for the 2 types of intervention: Orthokin versus placebo. Results The survival distributions for the 2 interventions were not statistically significantly different, χ²(1) = 2.069, P = 0.150. After 7.5 ± 3.9 years, 46.3% of the placebo and 40.3% of the Orthokin group had been treated surgically. Conclusion The use of Orthokin in knee osteoarthritis patients did not result in a delay regarding surgical treatment. Clinical Relevance The intra-articular use of Orthokin does not seem to prevent or delay surgical intervention at 10 years after treatment for end-stage knee osteoarthritis.

Autologous interleukin-1 receptor antagonist improves function and symptoms in osteoarthritis when compared to placebo in a prospective randomized controlled trial

INTRODUCTION

Incubation of blood with CrSO(4)-coated glass beads stimulates the synthesis of anti-inflammatory cytokines, such as interleukin-1 receptor antagonist (IL-1ra), IL-4, IL-10, and IL-13. As IL-1beta is thought to play a key role in the development of osteoarthritis (OA), this product, also known as Orthokin, might be a viable treatment for symptomatic knee OA. The aim of the current study was to evaluate the efficacy of Orthokin for treatment of symptomatic knee OA in a randomized, multicentre, double-blind, placebo-controlled trial.

PATIENTS AND METHODS

One hundred and sixty-seven patients received six intra-articular injections either with Orthokin or physiological saline. The primary efficacy objective consisted of 30% superiority on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at 3, 6, 9, and 12 months post-treatment. Additionally, the patients completed the visual analogue scale for pain, the Knee injury and Osteoarthritis Outcome Score (KOOS) and Knee Society Clinical Rating System.

RESULTS

Orthokin and placebo treatment resulted in similar improvements on the WOMAC (16.8% vs 16.5%, respectively; n.s.). Orthokin resulted in significantly more improvement for KOOS symptom (P = 0.002) and KOOS sport (P = 0.042) parameters as compared to placebo treatment. For most other outcome parameters, Orthokin-treated patients consistently showed higher improvement compared to placebo-treated patients, although none of these differences were statistically significant. Two serious adverse events were observed in the Orthokin group: one patient with repeated severe inflammatory reactions of the knee joint within hours after the injection and one patient with septic arthritis which was attributed to the injection procedure rather than the product.

CONCLUSION

The statistically significant improvement of KOOS symptom and sport parameters together with the consistently higher, though non-statistically significant, improvement of most other parameters demonstrates that Orthokin clearly induces a biological response different from placebo treatment and warrant future investigations into the possible chondroprotective effect of Orthokin. However, in the current study the primary efficacy objective was not met and, therefore, the use of Orthokin currently cannot yet be recommended for the treatment of OA.

The anesthetic management of children with neonatal-onset multi-system inflammatory disease

BACKGROUND

Neonatal-onset multi-system inflammatory disease (NOMID), a rare autosomal dominantly inherited disease, belongs to a growing spectrum of autoinflammatory diseases, is characterized by urticarial rash, arthropathy, and chronic aseptic meningitis, and is associated with mutations in the cold-induced autoinflammatory gene, CIAS1, the gene that encodes the protein, cryopyrin. As little is known about the anesthetic considerations of the disease, we sought to identify the main features and respective anesthetic and perioperative implications of NOMID.

METHODS

We examined perianesthetic records of children with NOMID who were anesthetized for invasive diagnostic and therapeutic interventions between 2003 and 2006. In addition, we conducted an extensive literature review of the genetic, clinical, and biochemical abnormalities of the disease.

RESULTS

Seventeen children with NOMID (median age 8 yr, range 9 mo to 11 yr) were anesthetized for diagnostic and therapeutic procedures. All patients had neurological involvement, including increased intracranial pressure, chronic aseptic meningitis, and developmental delay; 7 had bony overgrowth, 15 ocular, and 14 otological manifestations of NOMID. Despite the complexity of the disease, the perioperative course was uncomplicated, and no serious adverse events were observed.

CONCLUSIONS

This study is the first to investigate the anesthetic implications of NOMID, an autoinflammatory disease associated with arthropathy, recurrent fevers, urticarial rash, and chronic aseptic meningitis. While for the pediatric anesthesiologist, the presence of fever and aseptic meningitis might make the conduct of anesthetics for elective procedures less desirable, our findings suggest that without evidence of active infection, even in the presence of fever and chronic aseptic meningitis, general and regional anesthesia may be conducted in patients with NOMID without untoward complications.

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.

Membrane-associated IL-1 contributes to chronic synovitis and cartilage destruction in human IL-1 alpha transgenic mice

IL-1 molecules are encoded by two distinct genes, IL-1alpha and IL-1beta. Both isoforms possess essentially identical activities and potencies, whereas IL-1alpha, in contrast to IL-1beta, is known to act as a membrane-associated IL-1 (MA-IL-1) and plays an important role in a variety of inflammatory situations. The transgenic (Tg) mouse line (Tg1706), which was generated in our laboratory, overexpresses human IL-1alpha (hIL-1alpha) and exhibits a severe arthritic phenotype characterized by autonomous synovial proliferation with subsequent cartilage destruction. Because the transgene encoded Lys(64) to Ala(271) of the hIL-1alpha amino acid sequence, Tg mice may overproduce MA-IL-1 as well as soluble IL-1alpha. The present study investigated whether MA-IL-1 contributes to synovial proliferation and cartilage destruction in the development of arthritis. Flow cytometric analysis revealed that both macrophage-like and fibroblast-like synoviocytes constitutively produce MA-IL-1. D10 cell proliferation assay revealed MA-IL-1 bioactivity of paraformaldehyde-fixed synoviocytes and the further induction of endogenous mouse MA-IL-1 via autocrine mechanisms. MA-IL-1 expressed on synoviocytes triggered synoviocyte self-proliferation through cell-to-cell (i.e., juxtacrine) interactions and also promoted proteoglycan release from the cartilage matrix in chondrocyte monolayer culture. Interestingly, the severity of arthritis was significantly correlated with MA-IL-1 activity rather than with soluble IL-1alpha activity or concentration of serum hIL-1alpha. Moreover, when the Tg1706 line was compared with the Tg101 line, which selectively overexpresses the 17-kDa mature hIL-1alpha, the severity of arthritis was significantly higher in the Tg1706 line than in the Tg101 line. These results suggest that MA-IL-1 contributes to synoviocyte self-proliferation and subsequent cartilage destruction in inflammatory joint disease such as rheumatoid arthritis.

A comparative study of the inhibitory effects of interleukin-1 receptor antagonist following administration as a recombinant protein or by gene transfer

Anakinra, the recombinant form of IL-1 receptor antagonist (IL-1Ra), has been approved for clinical use in the treatment of rheumatoid arthritis as the drug Kineret trade mark, but it must be administered daily by subcutaneous injection. Gene transfer may offer a more effective means of delivery. In this study, using prostaglandin E2 production as a measure of stimulation, we quantitatively compared the ability of anakinra, as well as that of IL-1Ra delivered by gene transfer, to inhibit the biologic actions of IL-1beta. Human synovial fibroblast cultures were incubated with a range of doses of anakinra or HIG-82 cells genetically modified to constitutively express IL-1Ra. The cultures were then challenged with recombinant human IL-1beta either simultaneously with addition of the source of IL-1Ra or 24 hours later. In a similar manner, the potencies of the two sources of IL-1Ra were compared when human synovial fibroblasts were challenged with IL-1beta produced constitutively by genetically modified cells. No significant difference in inhibitory activity was observed between recombinant protein and IL-1Ra provided by the genetically modified cells, under static culture conditions, even following incubation for 4 days. However, under culture conditions that provided progressive dilution of the culture media, striking differences between these methods of protein delivery became readily apparent. Constitutive synthesis of IL-1Ra by the genetically modified cells provided sustained or increased protection from IL-1 stimulation over time, whereas the recombinant protein became progressively less effective. This was particularly evident under conditions of continuous IL-1beta synthesis.

The balance between IL-1 and IL-1Ra in disease

IL-1 is an important mediator of inflammation and tissue damage in multiple organs, both in experimental animal models of disease and in human diseases. The IL-1 family consists of two agonists, IL-1alpha and IL-1beta, two receptors, biologically active IL-1RI and inert IL-1RII, and a specific receptor antagonist, IL-1Ra. The balance between IL-1 and IL-1Ra in local tissues plays an important role in the susceptibility to and severity of many diseases. An allelic polymorphism in the IL-1Ra gene has been associated with a variety of human diseases primarily of epithelial and endothelial cell origin. This association may be secondary to an imbalance in the IL-1 system with enhanced production of IL-1beta and reduced production of the major intracellular isoform of IL-1Ra. Treatment of RA with daily subcutaneous injections of recombinant IL-1Ra protein has been shown to be efficacious. Gene therapy approaches with IL-1Ra are being evaluated for the treatment of RA and other human diseases.

IL-1 inhibitors: novel agents in the treatment of rheumatoid arthritis

IL-1 is a pleiotropic cytokine shown to play a major role in synovitis and in the mechanisms that lead to the progressive joint destruction of rheumatoid arthritis (RA). IL-1 receptor antagonist (IL-1Ra), a member of the IL-1 family, binds IL-1 receptors but does not induce a cellular response. IL-1Ra competitively inhibits the binding of IL-1 to its cell surface receptors and thus acts as an endogenous anti-inflammatory mediator. In different experimental animal models of arthritis systemic administration of IL-1Ra, or local delivery into the joints by gene therapy attenuated the severity of the inflammatory response and reduced articular destruction. In addition, treatment of RA patients with IL-1Ra led to an improvement in different clinical and biological parameters and to a reduction in the radiological signs of joint erosions. Recently, interesting results were obtained using IL-1Ra in combination with methotrexate, a well-known antirheumatic drug, or in combination with other strategies designed to block the effects of tumour necrosis factor (TNF)-alpha. Encouraging results also have been reported in both in vitro and in vivo experimental models of arthritis by using other strategies designed to block the effects of IL-1.

Treatment of rheumatoid arthritis with IL-1 inhibitors

Extensive evidence from both in vivo and in vitro experiments indicate that IL-1, a prototypic proinflammatory cytokine, is involved in the mechanisms that lead to progressive joint destruction in RA. IL-1Ra, a member of the IL-1 family, binds IL-1 receptors but does not induce any cellular responses. IL-1Ra competitively inhibits the binding of IL-1 to its cell surface receptors and thus, acts as an endogenous antiinflammatory mediator. However, the results of several studies suggest that a relatively deficient production in IL-1Ra as compared to that of IL-1 in RA synovium may predispose to the perpetuation of chronic inflammation. Systemic administration of IL-1Ra, or local delivery into the joint by gene therapy, in different experimental animal models of arthritis attenuated the severity of the inflammatory response and reduced articular destruction. In addition, treatment of rheumatoid patients with IL-1Ra led to an improvement in different clinical and biological parameters and to a reduction in the radiological signs of joint erosions. Encouraging results also have been reported in both in vitro and in vivo experimental animal models of arthritis through using other strategies designed to block the effects of IL-1 at the level of production, prevent the binding of IL-1 to its cell surface receptors, or interfere with the effects of IL-1 at the post-receptor level.

Imbalance between interstitial collagenase and tissue inhibitor of metalloproteinases 1 in synoviocytes and fibroblasts upon direct contact with stimulated T lymphocytes: involvement of membrane-associated cytokines

OBJECTIVE

To determine whether direct cell-cell contact with stimulated T lymphocytes (a) differentially modulates the production of interstitial collagenase (matrix metalloproteinase 1 [MMP-1]) and tissue inhibitor of metalloproteinases 1 (TIMP-1) on human synoviocytes and dermal fibroblasts, and (b) induces the production of prostaglandin E2 (PGE2); and to identify the membrane-associated factors on T cell surfaces involved in these mechanisms.

METHODS

Dermal fibroblasts and fibroblast-like synovial cells (synoviocytes) were cultured with fixed T cells, isolated plasma membranes from T cells, interleukin-1beta (IL-1beta; 250 pg/ml), or transforming growth factor beta (TGFbeta; 5 ng/ml). Culture supernatants were assayed for the production of MMP-1, TIMP-1, and PGE2. The expression of MMP-1 and TIMP-1 messenger RNA was analyzed by Northern blot of total fibroblast RNA.

RESULTS

Membranes of stimulated T cells, i.e., human peripheral blood T lymphocytes (PBTL) and the human T cell line HUT-78, induced the production of PGE2 and MMP-1 on both synoviocytes and dermal fibroblasts. TIMP-1 production was enhanced upon contact with PBTL stimulated for short periods of time (2-4 hours) but not for longer periods. Similar results were obtained with CD4+ and CD8+ synovial tissue T cell clones (TCCs), which induced the production of TIMP-1 by fibroblasts when stimulated for short (2-4 hours), but not long, periods of time. This time dependency was not observed with HUT-78 cells. The production of MMP-1 by fibroblasts and synoviocytes upon cellular contact with stimulated T cells was higher than that induced by an optimum concentration of IL-1beta, whereas the production of PGE2 was equivalent or slightly lower. Cell membrane-associated IL-1alpha and tumor necrosis factor a, but not CD69, CD40 ligand, or CD11b, were involved in the induction of MMP-1 and PGE2 production, as shown by blockade experiments using monoclonal antibodies and cytokine antagonists.

CONCLUSION

Synovial tissue TCCs and PBTL stimulated for long periods of time trigger the production of PGE2 and MMP-1, but not TIMP-1, in synoviocytes and dermal fibroblasts, thus inducing an imbalance between the metalloenzyme and its inhibitor. These results demonstrate that T cells may affect fibroblast and synoviocyte functions directly (i.e., by contact activation) and indirectly (i.e., by activation of cytokine production in monocyte/macrophages, which in turn, trigger stromal cell functions). Since the production of MMPs in monocyte/macrophages is also induced upon contact with stimulated T cells, our results strongly suggest that contact of synovial cells with chronically stimulated T lymphocytes favors matrix catabolism. By analogy, this mechanism may trigger tissue destruction in vivo and, thus, may potentiate tissue destruction in chronic inflammatory diseases such as RA.

The inhibitory activity of human interleukin-1 receptor antagonist is enhanced by type II interleukin-1 soluble receptor and hindered by type I interleukin-1 soluble receptor

Interleukin-1 (IL-1) is a major proinflammatory cytokine produced by monocytes/macrophages. At the inflammatory site, IL-1 is a potent inducer of the production of prostaglandin E2 (PGE2) and metalloproteinases on fibroblast-like cells, thus triggering tissue damage. The biological activity of IL-1 is counterbalanced by two types of inhibitors: the IL-1 receptor antagonist (IL-1Ra) which competitively binds IL-1 receptor without inducing signal transduction; and IL-1 soluble receptors (IL-1sR) which bind IL-1 and diminish the free concentration of soluble cytokine, thus hampering its binding to the cell surface receptor. Since IL-1sR can also bind IL-1Ra, we studied the simultaneous effects of both inhibitors on the production of interstitial collagenase (C'ase) and PGE2 by human dermal fibroblasts and synovial cells stimulated by either IL-1 alpha or IL-1 beta. IL-1Ra inhibited fibroblast and synovial cell stimulation by approximately 90%, with the exception of C'ase production by synovial cells which was inhibited by approximately 55%. Type I IL-1sR (IL-1sRI) preferentially inhibited IL-1 alpha, whereas type II IL-1sR (IL-1sRII) mainly inhibited IL-1 beta. When IL-1Ra was used simultaneously with IL-1sRI, the final inhibition was lower than that of either of the inhibitors. The simultaneous presence of IL-1Ra and IL-1sRII abolished the IL-1-induced production of PGE2 and C'ase on both dermal fibroblasts and synovial cells, demonstrating that concurrently these two inhibitors are able to abolish most of the inflammatory response. To our knowledge, this is the first example of two types of inhibitors that abolish each other's effects, one of which acts at the receptor level and the other at the ligand level, thus leaving ligand activity unimpaired.

Inhibition of the production and effects of interleukin-1 and tumor necrosis factor alpha in rheumatoid arthritis

This review has summarized information published over the last 5 years on the presence and pathophysiologic role of IL-1 and TNF alpha in RA. The evidence to date shows that 5 of 6 criteria for identifying mediators of tissue damage in human autoimmune diseases are satisfied (Table 1). The last criterion, prevention of clinical progression in patients with RA, is currently being evaluated. Many new therapeutic approaches are currently being developed, including the use of soluble receptors to IL-1 or TNF, monoclonal antibodies to TNF alpha, a specific IL-1 receptor antagonist, and gene therapy with the latter molecule. It should be emphasized that both IL-1 and TNF alpha play important roles in normal host defense; the possible complications of blocking their production or effects need to be carefully evaluated in long-term studies. A recent review has emphasized that although IL-1 and TNF alpha have many overlapping biologic properties, each may exhibit distinct effects in joint disease (99). Anti-TNF treatment may be primarily antiinflammatory but blocking IL-1 may be more effective in preventing cartilage destruction (100). The possibility exists that simultaneous inhibition of TNF alpha and IL-1 may be more therapeutically efficacious than blockade of either agent alone, as was recently demonstrated with IL-1ra and soluble TNF receptors in bacterial cell wall-induced arthritis in rats (101). The next level of clinical studies in rheumatoid arthritis should include the use of two biologic response modifiers together, or one agent combined with a more traditional form of therapy.

Adhesion molecules and cytokine production

The exchange of cross-talks between cells relies on soluble factors or direct cell-cell contact. Soluble factors increase the expression of cell surface molecules that activate adjacent cells by direct contact to produce cytokines. In the lung, dendritic cells are potent inducers of T-cell proliferation, and the interaction between the two leads to the production of high amounts of TNF alpha and TNF beta. Of the molecules involved in these biologic functions, LFA-3, CD11c, and the combination of beta 1 and beta 2 integrins are the most efficient. However, blocking TNF alpha or TNF beta production does not affect the alloreaction. The interaction between activated T cells and monocytes resulted in a large production of IL-1 beta. In this reaction, CD69, CD2, and the beta 2 integrins (CD11a, b, c, and CD18) and also other molecules such as a 25- to 35-kD glycoprotein play an important part. Finally, interaction between monocytes and fibroblasts leads to the production of large amounts of collagenase and PGE2 by fibroblasts. Cell-associated IL-1, particularly IL-1 alpha and membrane-bound TNF alpha, can also play a crucial role in the process of cell-cell interaction. This interaction may be controlled by inhibitors to IL-1 and TNF.

Interleukin-1 receptor antagonist

IL-1ra is the first described naturally occurring receptor antagonist of any cytokine or hormone-like molecule. IL-1ra is a member of the IL-1 family by three criteria: amino acid sequence homology of 26 to 30% to IL-1 beta and 19% to IL-1 alpha; similarities in gene structure; and common gene localization to human chromosome 2q14. Two structural variants of IL-1ra exist: sIL-1ra, a secretory molecule produced by monocytes, macrophages, neutrophils, fibroblasts, and other cells; and icIL-1ra, an intracellular molecule produced by keratinocytes and other epithelial cells, macrophages, and fibroblasts. IL-1ra production by monocytes, macrophages, and neutrophils may be regulated in a differential fashion with IL-1 beta. Human IL-1ra binds to both human IL-1RIs and IL-1RIIs on cell surfaces, although with 100-fold greater avidity to IL-1RIs. IL-1ra may bind preferentially to soluble IL-1RIs and not at all to soluble IL-1RIIs. IL-1ra competitively inhibits binding of both IL-1 alpha and IL-1 beta to cell surface receptors without inducing any discernible intracellular responses. All three forms of IL-1 may bind to IL-1 receptors in a similar fashion but IL-1ra may lack the secondary interactions necessary to trigger cell responses. A 100-fold or greater excess of IL-1ra over IL-1 may be necessary to inhibit biological responses to IL-1 both in vitro and in vivo. The roles of sIL-1ra and icIL-1ra in normal physiology or in host defense mechanisms remain unclear. The administration of IL-1ra blocks the effects of IL-1 in some animal models of septic shock, inflammatory arthritis, graft-versus-host disease, and inflammatory bowel disease. The preliminary results of clinical trials in humans indicate possible efficacy of IL-1ra in sepsis syndrome, rheumatoid arthritis, and GVHD.