Fibroblast growth factor-2 determines severity of joint disease in adjuvant-induced arthritis in rats.

Rheumatoid arthritis (RA), a systemic inflammatory disease of unknown etiology, mainly affects synovial joints. Although angiogenic growth factors, including fibroblast growth factor-2 (FGF-2) and vascular endothelial growth factor (VEGF), may play a critical role in the development and progression of RA joint disease, little information is now available regarding their exact role in initiation and/or progression of RA. In this study, we show that both polypeptides were up-regulated in the rat joint synovial tissue of an adjuvant-induced model of arthritis (AIA), as well as human subjects with RA. FGF-2 overexpression via Sendai virus-mediated gene transfer significantly worsened clinical symptoms and signs of rat AIA, including hind paw swelling and radiological bone destruction, as well as histological findings based on inflammatory reaction, synovial angiogenesis, pannus formation, and osteocartilaginous destruction, associated with up-regulation of endogenous VEGF. FGF-2 gene transfer to non-AIA joints was without effect. These findings suggested that FGF-2 modulated disease progression, but did not affect initiation. Reverse experiments using anti-FGF-2-neutralizing rabbit IgG attenuated clinical symptoms and histopathological abnormalities of AIA joints. To our knowledge, this is the first report indicating direct in vivo evidence of disease-modulatory effects of FGF-2 in AIA, as probably associated with endogenous VEGF function. FGF-2 may prove to be a possible therapeutic target to treat subjects with RA.     

Blockade of vascular endothelial growth factor receptor I (VEGF-RI), but not VEGF-RII, suppresses joint destruction in the K/BxN model of rheumatoid arthritis

It was recently shown that vascular endothelial growth factor (VEGF), a growth factor for endothelial cells, plays a pivotal role in rheumatoid arthritis. VEGF binds to specific receptors, known as VEGF-RI and VEGF-RII. We assessed the physical and histological effects of selective blockade of VEGF and its receptors in transgenic K/BxN mice, a model of rheumatoid arthritis very close to the human disease. Mice were treated with anti-mouse VEGF Ab, anti-mouse VEGF-RI and -RII Abs, and an inhibitor of VEGF-RI tyrosine kinase. Disease activity was monitored using clinical indexes and by histological examination. We found that synovial cells from arthritic joints express VEGF, VEGF-RI, and VEGF-RII. Treatment with anti-VEGF-RI strongly attenuated the disease throughout the study period, while anti-VEGF only transiently delayed disease onset. Treatment with anti-VEGF-RII had no effect. Anti-VEGF-RI reduced the intensity of clinical manifestations and, based on qualitative and semiquantitative histological analyses, prevented joint damage. Treatment with a VEGF-RI tyrosine kinase inhibitor almost abolished the disease. These results show that VEGF is a key factor in pannus development, acting through the VEGF-RI pathway. The observation that in vivo administration of specific inhibitors targeting the VEGF-RI pathway suppressed arthritis and prevented bone destruction opens up new possibilities for the treatment of rheumatoid arthritis.     

CD97 neutralisation increases resistance to collagen-induced arthritis in mice

Synovial tissue of rheumatoid arthritis (RA) patients is characterised by an influx and retention of CD97-positive inflammatory cells. The ligands of CD97, CD55, chondroitin sulfate B, and α5β1 (very late antigen [VLA]-5) are expressed abundantly in the synovial tissue predominantly on fibroblast-like synoviocytes, endothelium, and extracellular matrix. Based upon this expression pattern, we hypothesise CD97 expression to result in accumulation of inflammatory cells in the synovial tissue of RA patients. To determine the therapeutic effect of blocking CD97 in an animal model of RA, collagen-induced arthritis was induced in a total of 124 DBA/J1 mice. Treatment was started on day 21 (early disease) or on day 35 (longstanding disease) with the blocking hamster anti-mouse CD97 monoclonal antibody (mAb) 1B2, control hamster immunoglobulin, or NaCl, applied intraperitoneally three times a week. The paws were evaluated for clinical signs of arthritis and, in addition, examined by radiological and histological analysis. Mice receiving 0.5 mg CD97 mAb starting from day 21 had significantly less arthritis activity and hind paw swelling. Furthermore, joint damage and inflammation were reduced and granulocyte infiltration was decreased. When treatment was started on day 35, CD97 mAb treatment had similar effects, albeit less pronounced. The results support the notion that CD97 contributes to synovial inflammation and joint destruction in arthritis.     

Treatment with recombinant interferon-beta reduces inflammation and slows cartilage destruction in the collagen-induced arthritis model of rheumatoid arthritis

We investigated the therapeutic potential and mechanism of action of IFN-beta protein for the treatment of rheumatoid arthritis (RA). Collagen-induced arthritis was induced in DBA/1 mice. At the first clinical sign of disease, mice were given daily injections of recombinant mouse IFN-beta or saline for 7 days. Disease progression was monitored by visual clinical scoring and measurement of paw swelling. Inflammation and joint destruction were assessed histologically 8 days after the onset of arthritis. Proteoglycan depletion was determined by safranin O staining. Expression of cytokines, receptor activator of NF-kappaB ligand, and c-Fos was evaluated immunohistochemically. The IL-1-induced expression of IL-6, IL-8, and granulocyte/macrophage-colony-stimulating factor (GM-CSF) was studied by ELISA in supernatant of RA and osteoarthritis fibroblast-like synoviocytes incubated with IFN-beta. We also examined the effect of IFN-beta on NF-kappaB activity. IFN-beta, at 0.25 microg/injection and higher, significantly reduced disease severity in two experiments, each using 8-10 mice per treatment group. IFN-beta-treated animals displayed significantly less cartilage and bone destruction than controls, paralleled by a decreased number of positive cells of two gene products required for osteoclastogenesis, receptor activator of NF-kappaB ligand and c-Fos. Tumor necrosis factor alpha and IL-6 expression were significantly reduced, while IL-10 production was increased after IFN-beta treatment. IFN-beta reduced expression of IL-6, IL-8, and GM-CSF in RA and osteoarthritis fibroblast-like synoviocytes, correlating with reduced NF-kappaB activity. The data support the view that IFN-beta is a potential therapy for RA that might help to diminish both joint inflammation and destruction by cytokine modulation.     

Investigation of the role of endosomal Toll-like receptors in murine collagen-induced arthritis reveals a potential role for TLR7 in disease maintenance

Introduction

Endosomal toll-like receptors (TLRs) have recently emerged as potential contributors to the inflammation observed in human and rodent models of rheumatoid arthritis (RA). This study aims to evaluate the role of endosomal TLRs and in particular TLR7 in the murine collagen induced arthritis (CIA) model.

Methods

CIA was induced by injection of collagen in complete Freund''s adjuvant. To investigate the effect of endosomal TLRs in the CIA model, mianserin was administered daily from the day of disease onset. The specific role of TLR7 was examined by inducing CIA in TLR7-deficient mice. Disease progression was assessed by measuring clinical score, paw swelling, serum anti-collagen antibodies histological parameters, cytokine production and the percentage of T regulatory (T_reg) cells.

Results

Therapeutic administration of mianserin to arthritic animals demonstrated a highly protective effect on paw swelling and joint destruction. TLR7^-/- mice developed a mild arthritis, where the clinical score and paw swelling were significantly compromised in comparison to the control group. The amelioration of arthritis by mianserin and TLR7 deficiency both corresponded with a reduction in IL-17 responses, histological and clinical scores, and paw swelling.

Conclusions

These data highlight the potential role for endosomal TLRs in the maintenance of inflammation in RA and support the concept of a role for TLR7 in experimental arthritis models. This study also illustrates the potential benefit that may be afforded by therapeutically inhibiting the endosomal TLRs in RA.     

IL-23 Dependent and Independent Stages of Experimental Arthritis: No Clinical Effect of Therapeutic IL-23p19 Inhibition in Collagen-induced Arthritis

IL-23p19 deficient mice have revealed a critical role of IL-23 in the development of experimental autoimmune diseases, such as collagen-induced arthritis (CIA). Neutralizing IL-23 after onset of CIA in rats has been shown to reduce paw volume, but the effect on synovial inflammation and the immunological autoimmune response is not clear. In this study, we examined the role of IL-23 at different stages of CIA and during T cell memory mediated flare-up arthritis with focus on changes in B cell activity and Th1/Th17 modulation. Anti-IL-23p19 antibody (anti-IL23p19) treatment, starting 15 days after the type II collagen (CII)-immunization but before clinical signs of disease onset, significantly suppressed the severity of CIA. This was accompanied with significantly lower CII-specific IgG1 levels and lower IgG2a levels in the anti-IL-23p19 treated mice compared to the control group. Importantly, neutralizing IL-23 after the first signs of CIA did not ameliorate the disease. This was in contrast to arthritic mice that underwent an arthritis flare-up since a significantly lower disease score was observed in the IL-23p19 treated mice compared to the control group, accompanied by lower synovial IL-17A and IL-22 expression in the knee joints of these mice. These data show IL-23-dependent and IL-23-independent stages during autoimmune CIA. Furthermore, the memory T cell mediated flare-up arthritis is IL-23-mediated. These data suggest that specific neutralization of IL-23p19 after onset of autoimmune arthritis may not be beneficial as a therapeutic therapy for patients with rheumatoid arthritis (RA). However, T cell mediated arthritis relapses in patients with RA might be controlled by anti-IL-23p19 treatment.     

TWEAK is a novel arthritogenic mediator

TNF-like weak inducer of apoptosis (TWEAK) is a TNF family member with pleiotropic effects on a variety of cell types, one of which is the induction of proinflammatory cytokines by synovial fibroblasts derived from rheumatoid arthritis (RA) patients. In this study, we report that the serum TWEAK level was dramatically elevated during mouse collagen-induced arthritis (CIA) and blocking TWEAK by a neutralizing mAb significantly reduced the clinical severity of CIA. Histological analyses also revealed that TWEAK inhibition diminished joint inflammation, synovial angiogenesis, as well as cartilage and bone erosion. Anti-TWEAK treatment proved efficacious when administered just before the disease onset but not during the priming phase of CIA. Consistent with this, TWEAK inhibition did not affect either cellular or humoral responses to collagen. In contrast, TWEAK inhibition significantly reduced serum levels of a panel of arthritogenic mediators, including chemokines such as MIP-1beta (CCL-4), lymphotactin (XCL-1), IFN-gamma-inducible protein 10 (IP-10) (CXCL-10), MCP-1 (CCL-2), and RANTES (CCL-5), as well as the matrix metalloprotease-9. Exploring the possible role of the TWEAK/Fn14 pathway in human RA pathogenesis, we showed that TWEAK can target human primary chondrocytes and osteoblast-like cells, in addition to synovial fibroblasts. We further demonstrated that TWEAK induced the production of matrix metalloproteases in human chondrocytes and potently inhibited chondrogenesis and osteogenesis using in vitro models. These results provide evidence for a novel cytokine pathway that contributes to joint tissue inflammation, angiogenesis, and damage, as well as may inhibit endogenous repair, suggesting that TWEAK may be a new therapeutic target for human RA.     

Differential effects of Th1 versus Th2 cytokines in combination with hypoxia on HIFs and angiogenesis in RA

Introduction

Dysregulated angiogenesis is implicated in the pathogenesis of rheumatoid arthritis (RA). To provide a more profound understanding of arthritis-associated angiogenesis, we evaluated the expression of angiogenesis-modulating genes at onset, peak and declining phases of collagen-induced arthritis (CIA), a well-established mouse model for RA.

Methods

CIA was induced in DBA/1 mice with type II collagen. Functional capillary density in synovial tissue of knee joints was determined by intravital fluorescence microscopy. To assess the ability of arthritic joint homogenates to induce angiogenesis, an endothelial chemotaxis assay and an in vivo matrigel plug assay were employed. The temporal expression profile of angiogenesis-related genes in arthritic paws was analysed by quantitative real-time RT-PCR using an angiogenesis focused array as well as gene specific PCR. Finally, we investigated the therapeutic effect of a monoclonal antibody specifically blocking the binding of VEGF to neuropilin (NRP)-1.

Results

Although arthritic paw homogenates displayed angiogenic activity in vitro and in vivo, and synovia of arthritic paws appeared highly vascularised on histological examination, the functional capillary density in arthritic knee synovia was significantly decreased, whereas capillary diameter was increased. Of the 84 genes analysed, 41 displayed a differential expression in arthritic paws as compared to control paws. Most significant alterations were seen at the peak of clinical arthritis. Increased mRNA expression could be observed for VEGF receptors (Flt-1, Flk-1, Nrp-1, Nrp-2), as well as for midkine, hepatocyte growth factor, insulin-like growth factor-1 and angiopoietin-1. Signalling through NRP-1 accounted in part for the chemotactic activity for endothelial cells observed in arthritic paw homogenates. Importantly, therapeutic administration of anti-NRP1^B antibody significantly reduced disease severity and progression in CIA mice.

Conclusions

Our findings confirm that the arthritic synovium in murine CIA is a site of active angiogenesis, but an altered balance in the expression of angiogenic factors seems to favour the formation of non-functional and dilated capillaries. Furthermore, our results validate NRP-1 as a key player in the pathogenesis of CIA, and support the VEGF/VEGF receptor pathway as a potential therapeutic target in RA.     

The role of an epithelial neutrophil-activating peptide-78-like protein in rat adjuvant-induced arthritis.

The chemokine, epithelial neutrophil-activating peptide-78 (ENA-78), is a potent neutrophil chemotaxin whose expression is increased in inflamed synovial tissue and fluid in human rheumatoid arthritis compared with osteoarthritis. Since ENA-78 has been implicated in the pathogenesis of RA, we examined the expression of an ENA-78-like protein during the development of rat adjuvant-induced arthritis (AIA). Using an ELISA assay, we found increased levels of antigenic ENA-78-like protein in the sera of AIA animals compared with control normal animals by day 7 postadjuvant injection. ENA-78-like protein levels continued to increase as AIA developed. ENA-78-like protein levels in joint homogenates were increased in AIA animals later in the development of the disease, by day 18 during maximal arthritis, compared with control animals. Expression of ENA-78-like protein in both the AIA serum and joint correlated with the progression of inflammation of the joints. Anti-human ENA-78 administered before disease onset modified the severity of AIA, while administration of anti-ENA-78 after clinical onset of AIA did not modify the disease. These data support a role for an ENA-78-like protein as an important chemokine in the progression and maintenance of AIA.     

Relationship between angiogenesis and inflammation in experimental arthritis

Background. Angiogenesis is involved in rheumatoid arthritis (RA) leading to leucocyte recruitment and inflammation in the synovium. Furthermore, synovial inflammation itself further potentiates endothelial proliferation and angiogenesis. In this study, we aimed at evaluating the reciprocical relationship between synovial inflammation and angiogenesis in a RA model, namely collagen-induced arthritis (CIA). Methods. CIA was induced by immunization of DBA/1 mice with collagen type II in adjuvant. Endothelial cells were detected using a GSL-1 lectin-specific immunohistochemical staining on knee joint sections. Angiogenesis, clinical scores and histological signs of arthritis were evaluated from the induction of CIA until the end of the experiment. Angiogenesis was quantified by counting both the isolated endothelial cells and vessels stained on each section. To evaluate the effect of increased angiogenesis on CIA, VEGF gene transfer was performed using an adeno-associated virus encoding VEGF (AAV-VEGF), by intra-muscular or intra-articular injection in mice with CIA. Results. We showed an increase in synovial angiogenesis from day 6 to day 55 after CIA induction, and, moreover, joint vascularization and clinical scores of arthritis were correlated (p < 0.0001, r = 0.61). Vascularization and histological scores were also correlated (p = 0.0006, r = 0.51). Systemic VEGF overexpression in mice with CIA was followed by an aggravation of arthritis as compared to AAV-lacZ control group (p < 0.0001). In contrast, there was no difference in clinical scores between control mice and mice injected within the knee with AAV-VEGF, even if joint vascularization was higher in this group than in all other groups (p = 0,05 versus non-injected group). Intra-articular AAV-VEGF injections induced more severe signs of histological inflammation and bone destruction than AAV-Lac Z or no injection. Conclusion. Angiogenesis and joint inflammation evolve in parallel during collagen-induced arthritis. Furthermore, this work shows that exogenous VEGF can aggravate CIA. It is direct evidence that the increase in joint vascularization leads to an exacerbation of arthritis. Taken together, these results emphasize the role of angiogenesis in inflammatory arthritis. It also suggests an early involvement of angiogenesis in joint inflammation.     

Gene expression profiling and functional analysis of angiogenic markers in murine collagen-induced arthritis

Introduction

Dysregulated angiogenesis is implicated in the pathogenesis of rheumatoid arthritis (RA). To provide a more profound understanding of arthritis-associated angiogenesis, we evaluated the expression of angiogenesis-modulating genes at onset, peak and declining phases of collagen-induced arthritis (CIA), a well-established mouse model for RA.

Methods

CIA was induced in DBA/1 mice with type II collagen. Functional capillary density in synovial tissue of knee joints was determined by intravital fluorescence microscopy. To assess the ability of arthritic joint homogenates to induce angiogenesis, an endothelial chemotaxis assay and an in vivo matrigel plug assay were employed. The temporal expression profile of angiogenesis-related genes in arthritic paws was analysed by quantitative real-time RT-PCR using an angiogenesis focused array as well as gene specific PCR. Finally, we investigated the therapeutic effect of a monoclonal antibody specifically blocking the binding of VEGF to neuropilin (NRP)-1.

Results

Although arthritic paw homogenates displayed angiogenic activity in vitro and in vivo, and synovia of arthritic paws appeared highly vascularised on histological examination, the functional capillary density in arthritic knee synovia was significantly decreased, whereas capillary diameter was increased. Of the 84 genes analysed, 41 displayed a differential expression in arthritic paws as compared to control paws. Most significant alterations were seen at the peak of clinical arthritis. Increased mRNA expression could be observed for VEGF receptors (Flt-1, Flk-1, Nrp-1, Nrp-2), as well as for midkine, hepatocyte growth factor, insulin-like growth factor-1 and angiopoietin-1. Signalling through NRP-1 accounted in part for the chemotactic activity for endothelial cells observed in arthritic paw homogenates. Importantly, therapeutic administration of anti-NRP1^B antibody significantly reduced disease severity and progression in CIA mice.

Conclusions

Our findings confirm that the arthritic synovium in murine CIA is a site of active angiogenesis, but an altered balance in the expression of angiogenic factors seems to favour the formation of non-functional and dilated capillaries. Furthermore, our results validate NRP-1 as a key player in the pathogenesis of CIA, and support the VEGF/VEGF receptor pathway as a potential therapeutic target in RA.     

Delayed administration of VEGF rescues spinal motor neurons from death with a short effective time frame in excitotoxic experimental models in vivo

VEGF (vascular endothelial growth factor) prevents neuronal death in different models of ALS (amyotrophic lateral sclerosis), but few studies have addressed the efficacy of VEGF to protect motor neurons after the onset of symptoms, a critical point when considering VEGF as a potential therapeutic target for ALS. We studied the capability of VEGF to protect motor neurons after an excitotoxic challenge in two models of spinal neurodegeneration in rats induced by AMPA (α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid) administered either chronically with osmotic minipumps or acutely by microdialysis. VEGF was administered through osmotic minipumps in the chronic model or injected intracerebroventricularly in the acute model, and its effects were assessed by immunohistochemical and histological analyses and motor performance tests. In the chronic model, VEGF stopped the progression of the paralysis and protected motor neurons when administered after AMPA before the onset of the motor symptoms, whereas no protection was observed when administered after the onset. VEGF was also protective in the acute model, but with a short time window, since the protection was effective when administered 1 h but not 2 h after AMPA. Our results indicate that while VEGF has an indubitable neuroprotective effect, its therapeutic potential for halting or delaying the progression of motor neuron loss in ALS would likely have a short effective time frame.     

A monoclonal antibody against kininogen reduces inflammation in the HLA-B27 transgenic rat

The human leukocyte antigen B27 (HLA-B27) transgenic rat is a model of human inflammatory bowel disease, rheumatoid arthritis and psoriasis. Studies of chronic inflammation in other rat models have demonstrated activation of the kallikrein–kinin system as well as modulation by a plasma kallikrein inhibitor initiated before the onset of clinicopathologic changes or a deficiency in high-molecular-mass kininogen. Here we study the effects of monoclonal antibody C11C1, an antibody against high-molecular-mass kininogen that inhibits the binding of high-molecular-mass kininogen to leukocytes and endothelial cells in the HLA-B27 rat, which was administered after the onset of the inflammatory changes. Thrice-weekly intraperitoneal injections of monoclonal antibody C11C1 or isotype IgG₁ were given to male 23-week-old rats for 16 days. Stool character as a measure of intestinal inflammation, and the rear limbs for clinical signs of arthritis (tarsal joint swelling and erythema) were scored daily. The animals were killed and the histology sections were assigned a numerical score for colonic inflammation, synovitis, and cartilage damage. Administration of monoclonal C11C1 rapidly decreased the clinical scores of pre-existing inflammatory bowel disease (P < 0.005) and arthritis (P < 0.001). Histological analyses confirmed significant reductions in colonic lesions (P = 0.004) and synovitis (P = 0.009). Decreased concentrations of plasma prekallikrein and high-molecular-mass kininogen were found, providing evidence of activation of the kallikrein–kinin system. The levels of these biomarkers were reversed by monoclonal antibody C11C1, which may have therapeutic potential in human inflammatory bowel disease and arthritis.     

Suppression of collagen arthritis with antibodies to an arthritogenic, oligoclonal T cell line.

Rats immunized with type II collagen (CII) develop an immunologically mediated polyarthritis. T cells have been implicated in the pathogenesis of this model since they can adoptively transfer the disease. A CII-specific T cell line (VA), consisting of three distinct clones by Southern blot analysis, has been shown to be arthritogenic. Antibodies specific for this line were generated by immunizing rabbits. In an attempt to prevent collagen-induced arthritis (CIA), Louvain rats were injected with 1 ml of anti-VA ip on Days -1, +1, +3 and 0.5 ml on Day +5 (early treatment). To evaluate its effect on existing disease, rats received anti-VA on the day of arthritis onset and subsequently on 4 successive alternate days using the same dosage protocol (late treatment). Control rats received no therapeutic injections or were administered normal rabbit serum. All rats were immunized with CII on Day 0 to induce CIA. Rats administered antibodies using the early anti-VA treatment protocol had a significantly diminished incidence of arthritis compared to controls. Established arthritis was significantly diminished compared to controls in rats given the late anti-VA treatment. In both protocols, radiographic evidence of joint destruction was significantly reduced compared to controls. T cell phenotyping using flow cytometry analysis demonstrated that the anti-VA antibody therapy selectively eliminated a small subset of T cells since there was little difference in total T cell counts in the experimental versus control groups. Delayed type hypersensitivity and IgG antibody titers to CII were minimally decreased in the experimental versus control group. These results suggest that antibodies raised to an oligoclonal arthritogenic T cell line can suppress collagen arthritis. This may have implications with respect to 1) the size of the T cell receptor repertoire involved in the pathogenesis of collagen arthritis and 2) immunospecific protocols for CIA and other autoimmune diseases.     

Methionine aminopeptidase-2 blockade reduces chronic collagen-induced arthritis: potential role for angiogenesis inhibition

The enzyme methionine aminopeptidase-2 (MetAP-2) is thought to play an important function in human endothelial cell proliferation, and as such provides a valuable target in both inflammation and cancer. Rheumatoid arthritis (RA) is a chronic inflammatory disease associated with increased synovial vascularity, and hence is a potential therapeutic target for angiogenesis inhibitors. We examined the use of PPI-2458, a selective non-reversible inhibitor of MetAP-2, in disease models of RA, namely acute and chronic collagen-induced arthritis (CIA) in mice. Whilst acute CIA is a monophasic disease, CIA induced with murine collagen type II manifests as a chronic relapsing arthritis and mimics more closely the disease course of RA. Our study showed PPI-2458 was able to reduce clinical signs of arthritis in both acute and chronic CIA models. This reduction in arthritis was paralleled by decreased joint inflammation and destruction. Detailed mechanism of action studies demonstrated that PPI-2458 inhibited human endothelial cell proliferation and angiogenesis in vitro, without affecting production of inflammatory cytokines. Furthermore, we also investigated release of inflammatory cytokines and chemokines from human RA synovial cell cultures, and observed no effect of PPI-2458 on spontaneous expression of cytokines and chemokines, or indeed on the angiogenic molecule vascular endothelial growth factor (VEGF). These results highlight MetAP-2 as a good candidate for therapeutic intervention in RA.     

A novel human anti-interleukin-1β neutralizing monoclonal antibody showing in vivo efficacy

The pro-inflammatory cytokine interleukin (IL)-1β is a clinical target in many conditions involving dysregulation of the immune system; therapeutics that block IL-1β have been approved to treat diseases such as rheumatoid arthritis (RA), neonatal onset multisystem inflammatory diseases, cryopyrin-associated periodic syndromes, active systemic juvenile idiopathic arthritis. Here, we report the generation and engineering of a new fully human antibody that binds tightly to IL-1β with a neutralization potency more than 10 times higher than that of the marketed antibody canakinumab. After affinity maturation, the derived antibody shows a >30-fold increased affinity to human IL-1β compared with its parent antibody. This anti-human IL-1β IgG also cross-reacts with mouse and monkey IL-1β, hence facilitating preclinical development. In a number of mouse models, this antibody efficiently reduced or abolished signs of disease associated with IL-1β pathology. Due to its high affinity for the cytokine and its potency both in vitro and in vivo, we propose that this novel fully human anti-IL-1β monoclonal antibody is a promising therapeutic candidate and a potential alternative to the current therapeutic arsenal.     

Elevated levels of vascular endothelial growth factor in the sera of patients with rheumatoid arthritis correlation with disease activity.

To evaluate vascular endothelial growth factor (VEGF) levels in relation to disease activity in rheumatoid arthritis (RA), VEGF in the serum of 155 patients with RA and 75 healthy control subjects was quantified by our highly sensitive enzyme-linked immunosorbent assay. VEGF levels were found to correlate with the articular index (AI) and Lansbury's activity index (LI). Patients with RA had a mean serum VEGF concentration of 153.5+/-111.8 pg/ml, which was significantly higher than control subjects (104.8+/-65.7 pg/ml; P<0.01). VEGF concentration was elevated significantly according to disease progression as expressed by stages I to IV and correlated with AI (r=0.530, P<0.0001) and LI (r=0.688, P<0.0001) in stages I and II as well as with the conventional erythrocyte sedimentation rate or serum C-reactive protein concentration. Serum VEGF levels may therefore be valuable as a marker of disease activity in patients with early RA, and this cytokine may play a significant role in the pathophysiology of RA.     

Bone loss: Quantitative imaging techniques for assessing bone mass in rheumatoid arthritis

Osteoporosis is associated with low bone mass and microarchitectural deterioration of bone tissue with clinical manifestation of low trauma fractures. Rheumatoid arthritis (RA) is a risk factor due to generalized and articular bone loss. This minireview presents past and current bone mass measurement techniques in RA. These techniques include: plain radiographs, absorptiometry, quantitative computed tomography (QCT) and ultrasound. The most widely used technique is dual x-ray absorptiometry (DXA). RA patients have lower bone mass as compared with normals and substantial bone loss may occur early after the onset of disease. Measurement of bone mineral density (BMD) at the hand using either DXA or ultrasound maybe a useful tool in the management of RA patients.