Anti-interleukin-6 receptor antibody therapy reduces vascular endothelial growth factor production in rheumatoid arthritis

OBJECTIVE: To investigate whether interleukin-6 (IL-6) is a regulator of vascular endothelial growth factor (VEGF) in rheumatoid arthritis (RA). METHODS: Serum VEGF levels in RA patients were assayed before and after 8 weeks or 24 weeks of maintenance therapy with humanized anti-IL-6 receptor monoclonal antibody (anti-IL-6R mAb). VEGF secreted by RA synovial fibroblasts cultured in the presence of IL-6, IL-1beta, and/or tumor necrosis factor alpha (TNFalpha) was measured. The inhibitory effect of anti-IL-6R mAb, recombinant IL-1 receptor antagonist (IL-1Ra), and anti-TNFalpha mAb on VEGF production was also examined. RESULTS: Serum VEGF levels in RA patients before anti-IL-6R mAb therapy were significantly higher than those in healthy controls (P < 0.0005). Treatment of RA patients with anti-IL-6R mAb normalized serum VEGF levels. In the in vitro study, IL-6 and IL-1beta each induced a slight amount of VEGF production in synovial cells, but TNFalpha did not. Although VEGF-inducing activity of these cytokines was not remarkable when they were added alone, IL-6 acted synergistically with IL-1beta or TNFalpha to induce VEGF production. There was no synergistic effect between IL-1beta and TNFalpha. In the presence of all of these cytokines, anti-IL-6R mAb eliminated the synergistic effect of IL-6, IL-1beta, and TNFalpha, while IL-1Ra or anti-TNFalpha mAb did not. CONCLUSION: Anti-IL-6R mAb therapy reduced VEGF production in RA. IL-6 is the pivotal cytokine that induces VEGF production in synergy with IL-1beta or TNFalpha, and this may be the mechanism by which IL-6 blockade effectively suppresses VEGF production in synovial fibroblasts.     

Anti–interleukin‐6 receptor antibody therapy favors adrenal androgen secretion in patients with rheumatoid arthritis: A randomized,double‐blind,placebo‐controlled study

Objective

Proinflammatory cytokines such as tumor necrosis factor (TNF) were demonstrated to inhibit adrenal steroidogenesis in patients with rheumatoid arthritis (RA), and this was particularly evident in the increase in adrenal androgen levels during anti‐TNF therapy. This study investigated the influence on steroidogenesis of an interleukin‐6 (IL‐6)–neutralizing strategy using IL‐6 receptor monoclonal antibodies (referred to as MRA).

Methods

In a placebo‐controlled, double‐blind, randomized study over 12 weeks in 29 patients with RA being treated with prednisolone, 13 of whom received placebo and 16 of whom received 8 mg MRA/kg body weight, the effects of MRA on serum levels of adrenocorticotropic hormone (ACTH), cortisol, 17‐hydroxyprogesterone (17OHP), dehydroepiandrosterone (DHEA), DHEA sulfate (DHEAS), androstenedione (ASD), estrone, and 17β‐estradiol, as well as their respective molar ratios, were determined.

Results

MRA therapy markedly improved clinical signs of inflammation (the erythrocyte sedimentation rate, swollen joint score, and Disease Activity Score in 28 joints). Serum levels of ACTH and cortisol and the molar ratio of cortisol to ACTH did not change. Although serum levels of DHEA and DHEAS remained stable during therapy, the DHEAS:DHEA molar ratio significantly decreased in treated patients (P = 0.048). Serum levels of ASD as well as the ASD:cortisol and ASD:17OHP molar ratios increased in MRA‐treated patients (minimum P < 0.004). Serum levels of estrone and 17β‐estradiol did not change. but the estrone:ASD molar ratio (an indicator of aromatization) decreased during 12 weeks of MRA treatment (P = 0.001).

Conclusion

Neutralization of IL‐6 increases secretion of biologically active adrenal androgens in relation to that of precursor hormones and estrogens. This is another important indication that proinflammatory cytokines interfere with adrenal androgen steroidogenesis in patients with RA.

     

Anti–tumor necrosis factor therapy increases synovial osteoprotegerin expression in rheumatoid arthritis

Objective

Treatment of rheumatoid arthritis (RA) with tumor necrosis factor (TNF)–blocking agents, including etanercept and infliximab, has resulted in reductions in the radiographic progression of RA. However, the exact mechanism by which this protection occurs has not been determined. In order to add to such knowledge, we investigated the effect of anti‐TNF therapy on the expression of osteoprotegerin (OPG) and receptor activator of NF‐κB ligand (RANKL) in synovial tissue.

Methods

The expression of OPG and RANKL in synovial biopsy specimens was evaluated by immunohistochemistry. Serial synovial biopsy specimens were obtained from 18 patients with RA, before and after treatment with etanercept (9 patients) or infliximab (9 patients). Biopsy specimens were evaluated by double‐blind semiquantitative analysis and image analysis. The in vitro effect of TNF antagonists on the RANKL/OPG expression in osteoblasts and endothelial cells was evaluated by Western blotting. Statistical analysis was performed using Wilcoxon's signed rank test, followed by the Bonferroni correction for multiple comparisons of paired samples. The results of in vitro experiments were evaluated by one‐way analysis of variance, with Tukey's post hoc test.

Results

Treatment with both infliximab and etanercept increased the expression of OPG in synovial tissue. After 8 weeks of treatment, neither infliximab nor etanercept influenced RANKL expression. In both groups of patients, the RANKL:OPG ratio decreased following therapy. In vitro, both of the TNF antagonists mimicked the in vivo effect, inducing a decrease in the RANKL:OPG ratio in TNF‐primed osteoblasts and endothelial cells.

Conclusion

Therapy with TNF antagonists in RA modulates the OPG/RANKL system, a potential mechanism that could explain the retardation of radiographic damage observed following anti‐TNF therapy.

     

Serum vascular endothelial growth factor in late rheumatoid arthritis.

OBJECTIVES: To investigate the serum levels of VEGF in patients with rheumatoid arthritis of long duration. METHODS: Serum VEGF levels were measured in 118 patients with long-standing rheumatoid arthritis according to the ACR criteria (mean duration 12 years). The disease activity score was evaluated by the method of van der Heijde et al. RESULTS: Serum levels of VEGF in patients with RA were significantly higher than in healthy controls. VEGF levels showed no correlation with CRP, SAA amyloid protein, or the disease activity score. CONCLUSIONS: Our findings suggest that, contrary to the results reported in patients with early onset RA, where VEGF appears to play an active part in joint inflammation, in long-standing RA elevated VEGF serum levels may be an independent marker although its significance remain to be established.     

Imbalance in production between vascular endothelial growth factor and endostatin in patients with rheumatoid arthritis

OBJECTIVE: To clarify whether synovial cell proliferation indicates an imbalance in production between angiogenic growth factors and angiogenesis inhibitors in rheumatoid arthritis (RA), we investigated the production of basic fibroblast growth factor (b-FGF) and vascular endothelial growth factor (VEGF) as representative angiogenic growth factors and endostatin as a representative angiogenesis inhibitor. METHODS: The b-FGF, VEGF, and endostatin levels in 90 samples of peripheral blood (PB) and 15 samples of joint fluid obtained from patients with RA and 30 samples of PB and 10 samples of joint fluid from patients without RA, including 20 patients with inflammatory arthritis without purulent arthritis, and 10 patients with osteoarthritis were measured by ELISA. VEGF and endostatin levels in blood samples from 22 patients with RA were measured at 2 points: before and 4 or 5 months after the commencement of medication. RESULTS: The b-FGF and VEGF levels in the PB and joint fluid samples from patients with RA were markedly elevated compared to samples from patients without RA. In contrast, endostatin levels in PB and joint fluid samples from patients with RA were almost the same as in the samples from patients without RA. VEGF levels in blood samples obtained 4 or 5 months after the commencement of medication (combination of prednisolone 5 mg/day and disease modifying antirheumatic drugs: either bucillamine 100 mg/day or salazosulfapyridine 1,000 mg/day) were significantly decreased from 27.1 +/- 8.5 pg/ml in samples obtained before commencement of medication to 18.1 +/- 16.2 pg/ml. Endostatin levels in the corresponding samples were significantly increased, from 31.5 +/- 7.0 to 57.1 +/- 22.8 ng/ml [correction]. CONCLUSION: Our results reveal significant differences in b-FGF and VEGF levels in PB and joint fluid samples, but no difference in endostatin levels, between patients with RA and those without RA, suggesting that angiogenesis in RA occurs as a result of an imbalance in production between angiogenic growth factors and angiogenesis inhibitors.     

Treatment of rheumatoid arthritis with humanized anti–interleukin‐6 receptor antibody: A multicenter,double‐blind,placebo‐controlled trial

Objective

Interleukin‐6 (IL‐6) is a pleiotropic cytokine that regulates the immune response, inflammation, and hematopoiesis. Overproduction of IL‐6 plays pathologic roles in rheumatoid arthritis (RA), and the blockade of IL‐6 may be therapeutically effective for the disease. This study was undertaken to evaluate the safety and efficacy of a humanized anti–IL‐6 receptor antibody, MRA, in patients with RA.

Methods

In a multicenter, double‐blind, placebo‐controlled trial, 164 patients with refractory RA were randomized to receive either MRA (4 mg/kg body weight or 8 mg/kg body weight) or placebo. MRA was administered intravenously every 4 weeks for a total of 3 months. The clinical responses were measured using the American College of Rheumatology (ACR) criteria.

Results

Treatment with MRA reduced disease activity in a dose‐dependent manner. At 3 months, 78% of patients in the 8‐mg group, 57% in the 4‐mg group, and 11% in the placebo group achieved at least a 20% improvement in disease activity according to the ACR criteria (an ACR20 response) (P < 0.001 for 8‐mg group versus placebo). Forty percent of patients in the 8‐mg group and 1.9% in the placebo group achieved an ACR50 response (P < 0.001). The overall incidences of adverse events were 56%, 59%, and 51% in the placebo, 4‐mg, and 8‐mg groups, respectively, and the adverse events were not dose dependent. A blood cholesterol increase was observed in 44.0% of the patients. Liver function disorders and decreases in white blood cell counts were also observed, but these were mild and transient. There was no increase in antinuclear antibodies or anti‐DNA antibodies. Anti‐MRA antibodies were detected in 2 patients.

Conclusion

Treatment with MRA was generally well tolerated and significantly reduced the disease activity of RA.

     

Histone deacetylases are dysregulated in rheumatoid arthritis and a novel histone deacetylase 3–selective inhibitor reduces interleukin‐6 production by peripheral blood mononuclear cells from rheumatoid arthritis patients

Objective

To characterize the role of histone deacetylase (HDAC) activity in rheumatoid arthritis (RA) and to evaluate the effects of MI192, a novel HDAC‐3–selective inhibitor, compared with the established nonselective HDAC inhibitor trichostatin A (TSA), on proinflammatory cytokine production.

Methods

Activity of HDAC and histone acetyltransferase was measured in peripheral blood mononuclear cells (PBMCs) from RA patients by spectrophotometric assay, prior to and after 12 weeks of etanercept therapy. The effects of HDAC inhibitor treatment on cytokine production in both RA and healthy PBMCs were assessed by enzyme‐linked immunosorbent assay.

Results

RA PBMCs exhibited significantly increased HDAC activity (P = 0.007) compared to PBMCs from healthy individuals, and the increase was unaltered after 12 weeks of etanercept therapy. TSA was a potent inhibitor of tumor necrosis factor (TNF) and interleukin‐6 (IL‐6) production in both RA and healthy PBMCs and of interferon‐γ (IFNγ) production in healthy PBMCs; IFNγ was not produced by RA PBMCs. MI192 inhibited TNF production at high concentrations and dose‐dependently inhibited IL‐6 in RA PBMCs but not healthy PBMCs, across a dose range of 10 μM–5 nM.

Conclusion

HDAC activity is dysregulated in RA PBMCs and is a potential target for therapeutic intervention, as it is not affected by conventional anti‐TNF treatment with etanercept. Both the selective and the nonselective HDAC inhibitors (MI192 and TSA, respectively) were found to regulate cytokine production from PBMCs, but their effects were cell type and compound specific. HDAC inhibitors have potential in the treatment of RA, and HDAC‐selective inhibition may improve the therapeutic margin of safety; however, further clinical characterization and evaluation for adverse effects is needed.

     

Therapeutic benefit of blocking interleukin‐6 activity with an anti–interleukin‐6 receptor monoclonal antibody in rheumatoid arthritis: A randomized,double‐blind,placebo‐controlled,dose‐escalation trial

Objective

To investigate the safety and efficacy of MRA, a recombinant human anti–interleukin‐6 (anti–IL‐6) receptor monoclonal antibody of the IgG1 subclass that inhibits the function of IL‐6, in patients with established rheumatoid arthritis (RA).

Methods

A randomized, double‐blind, placebo‐controlled, dose‐escalation trial was conducted in 45 patients with active RA, as defined by the American College of Rheumatology (ACR) revised criteria. Patients were sequentially allocated to receive a single intravenous dose of either 0.1, 1, 5, or 10 mg/kg of MRA or placebo. The primary efficacy end point was meeting the ACR 20% response criteria at week 2 after treatment.

Results

Demographic features were similar between treatment groups. At week 2, a significant treatment difference was observed between the 5 mg/kg of MRA and placebo, with 5 patients (55.6%) in the MRA cohort and none in the placebo cohort achieving ACR 20% improvement. There was no statistically significant difference in the ACR 20% response between the other 3 MRA cohorts and placebo at week 2. The mean disease activity score at week 2 in those who received 5 mg/kg and 10 mg/kg of MRA was 4.8 and 4.7 (P < 0.001 and P < 0.001 by analysis of variance), respectively. These mean scores were statistically significantly lower than those in the 0.1‐ and 1‐mg/kg MRA and the placebo cohorts (6.4, 6.2, and 7.0, respectively). The erythrocyte sedimentation rate and C‐reactive protein values fell significantly in the 5‐ and 10‐mg/kg MRA cohorts and normalized 2 weeks after treatment. Seventeen patients (5, 4, 6, 2, and 0 patients in the placebo, 0.1‐, 1‐, 5‐, and 10‐mg/kg MRA cohorts, respectively) required corticosteroid or disease‐modifying antirheumatic drug treatment because of active disease before study end. They were regarded as nonresponders from the time they received these treatments. Diarrhea was the most common adverse event, occurring in 8% of patients. Seven patients (15.6%) reported a severe adverse event (3, 1, 2, and 2 patients in the placebo, 0.1‐, 1‐, and 10‐mg/kg MRA cohorts). There were no serious adverse events that were thought to be related to the study drug.

Conclusion

This is the first randomized controlled trial showing that inhibition of IL‐6 significantly improved the signs and symptoms of RA and normalized the acute‐phase reactants. Further research with multiple dosing is necessary to define the most appropriate therapeutic regimen of MRA in RA.

     

Elevated expression of interleukin‐7 receptor in inflamed joints mediates interleukin‐7–induced immune activation in rheumatoid arthritis

Objective

To evaluate the expression and functional ability of the high‐affinity interleukin‐7 receptor (IL‐7Rα) in patients with rheumatoid arthritis (RA).

Methods

Expression of IL‐7Rα and IL‐7 was determined in synovial tissue from RA patients and was compared with that in synovial tissue from patients with undifferentiated arthritis (UA) and osteoarthritis (OA). IL‐7Rα expression on CD4 T cells, CD19 B cells, and CD14 monocyte/macrophages from RA synovial tissue, synovial fluid, and peripheral blood was also assessed. The proliferative capacity of IL‐7Rα^bright and IL‐7Rα^dim/− T cells was measured. In addition, we examined IL‐7R blockade with soluble human IL‐7Rα (hIL‐7Rα) in the prevention of immune activation of peripheral blood mononuclear cells.

Results

We found significantly higher IL‐7Rα expression in RA and UA synovial tissue than in OA synovial tissue, and the level of IL‐7Rα expression correlated significantly with the levels of CD3 and IL‐7 expression. CD4 T cells from RA synovial fluid and synovial tissue strongly expressed IL‐7Rα. A substantial percentage of B cells and macrophages from RA synovial fluid and synovial tissue also expressed IL‐7Rα, although less prominently than T cells. We found that peripheral blood IL‐7Rα^bright T cells that did not express FoxP3 were highly proliferative as compared with IL‐7Rα^dim/− T cells that did express high levels of FoxP3. Soluble hIL‐7Rα inhibited IL‐7–induced proliferation and interferon‐γ production by mononuclear cells from RA patients.

Conclusion

Our data suggest that enhanced expression of IL‐7Rα and IL‐7 in RA patients contributes significantly to the joint inflammation by activating T cells, B cells, and macrophages. The inhibition of IL‐7R–mediated immune activation by soluble hIL‐7Rα further indicates an important role of IL‐7Rα in inflammatory responses in RA, suggesting IL‐7Rα as a therapeutic target for immunotherapy in RA.

     

Therapeutic efficacy of humanized recombinant anti–interleukin‐6 receptor antibody in children with systemic‐onset juvenile idiopathic arthritis

Objective

To investigate the safety and efficacy of a recombinant human anti–interleukin‐6 (anti–IL‐6) receptor monoclonal antibody (MRA) that indirectly inhibits the effects of IL‐6 in children with systemic‐onset juvenile idiopathic arthritis (JIA) refractory to high‐dose, long‐term corticosteroids.

Methods

An individual escalating‐dose trial was conducted in 11 children with active systemic‐onset JIA who met the inclusion criteria. All were first administered an intravenous dose of 2 mg/kg MRA. Each child without active inflammation was given a second identical dose 2 weeks later and a third identical dose 2 weeks after the second dose. Children with disease flares according to laboratory marker values received a 4‐mg/kg dose. Those without disease flares at this dose received a second 4‐mg/kg dose 2 weeks later and a third 4‐mg/kg dose 2 weeks after the second dose, while those with active inflammation received an additional 3 doses of 8 mg/kg MRA. Efficacy was evaluated every 2 weeks according to responses on the JIA core set of improvement criteria and the results of laboratory tests.

Results

MRA abruptly reduced disease activity in 10 of the 11 children, as assessed by the occurrence of febrile episodes, active arthritis, scores on the Childhood Health Assessment Questionnaire, and levels of acute‐phase reactants. However, levels of inflammatory reactants fluctuated until the proper MRA dose for each child was reached. Two weeks after the third fixed dose of MRA, 90.9% of all patients had a 30% improvement response, 90.9% had a 50% improvement response, and 63.6% had a 70% improvement response.

Conclusion

MRA treatment of children with active systemic disease results in clinical improvement and in normalized levels of acute‐phase reactants. MRA was safe and well tolerated and provided greater clinical benefit than conventional corticosteroids, considering the ill effects of IL‐6 and adverse events.

     

类风湿关节炎血管内皮生长因子趋化因子RANTES的研究

目的探讨血管内皮生长因子(VEGF)、调节活化和正常T细胞表达及分泌的趋化因子(RANTES)在类风湿关节炎(RA)发病中的作用,在疾病活动性判断、鉴别诊断中的价值,以及二者是否在RA发病中具有协同作用。方法用酶联免疫吸附试验(ELISA)法测定36例RA患者、20例骨关节炎(OA)患者及20名健康体检人员血清中VEGF和RANTES水平。结果①活动期RA患者血清中VEGF、RANTES水平显著高于缓解期RA组、OA组(P<0.05)及健康对照组(P<0.01),缓解期RA患者血清中VEGF亦显著高于健康对照组(P<0.05),而与OA组相比差异无显著性(P>0.05)。缓解期RA患者血清RANTES水平与OA组及健康对照组之间差异均无显著性(P>0.05)。②RA患者血清VEGF与RANTES之间具有相关性(P<0.05)。结论①活动期RA患者血清VEGF、RANTES水平高于RA缓解期,提示VEGF、RANTES可作为RA活动期判断指标之一。②活动期RA患者血清中VEGF、RANTES水平升高,高于OA组,有助于二者之间的鉴别诊断。③活动期RA患者血清中VEGF、RANTES呈正相关关系,提示VEGF、RANTES在RA的发生、发展中具有相辅相承、互相促进作用。     

Role of interleukin‐6 in a patient with tumor necrosis factor receptor–associated periodic syndrome: Assessment of outcomes following treatment with the anti–interleukin‐6 receptor monoclonal antibody tocilizumab

In this report, we describe treatment outcomes in the first case of a patient with tumor necrosis factor receptor–associated periodic syndrome (TRAPS) treated with the anti–interleukin‐6 (anti–IL‐6) receptor monoclonal antibody tocilizumab. Since IL‐6 levels are elevated in TRAPS, we hypothesized that tocilizumab might be effective. The patient, a 52‐year‐old man with lifelong TRAPS in whom treatment with etanercept and anakinra had failed, was administered tocilizumab for 6 months, and the therapeutic response was assessed by measurement of monocyte CD16 expression and cytokine levels. Following treatment, the evolving acute attack was aborted and further attacks of TRAPS were prevented. The patient did not require corticosteroids and showed significant clinical improvement in scores for pain, stiffness, and well‐being. Moreover, the acute‐phase response diminished significantly with treatment. Monocyte CD16 expression was reduced and the numbers of circulating CD14+CD16+ and CD14++CD16− monocytes were transiently decreased. However, cytokine levels were not reduced. This case supports the notion of a prominent role for IL‐6 in mediating the inflammatory attacks in TRAPS, but blockade of IL‐6 did not affect the underlying pathogenesis. These preliminary findings require confirmation.     

血管内皮生长因子及水通道蛋白1与类风湿关节炎滑膜血管生成的相关性分析

目的 探讨血管内皮生长因子(VEGF)和水通道蛋白1(AQP1)在类风湿关节炎(RA)滑膜组织中的表达及其与滑膜血管生成的关系.方法 采用免疫组织化学技术检测7例RA,12例骨关节炎患者关节滑膜组织中VEGF和AQP1的表达,对VEGF,AQP1阳性细胞数及血管数的表达进行评分,并比较它们之间的相关性.统计学方法采用秩和检验及Spearman相关分析.结果 RA滑膜VEGF阳性细胞数与血管数呈正相关(rs=0.971,P＜0.01),骨关节炎滑膜VEGF阳性细胞数与血管数无相关性(rs=0.235,P=0.462),VEGF阳性细胞数在RA与骨关节炎间差异无统计学意义(Z=-0.390,P=0.711);RA滑膜AQP1阳性细胞数与血管数呈正相关(rs=0.828,P=0.022),骨关节炎滑膜AQP1阳性细胞数与血管数无相关性(rs=0.396,P=0.203),AQP1阳性细胞数在RA与骨关节炎间差异无统计学意义(Z=-0.302,P=0.773);RA 中,VEGF阳性细胞数与AQP1阳性细胞数呈正相关(rs=0.891,P=0.007),骨关节炎中,VEGF阳性细胞数与AQP1阳性细胞数无相关性(rs=0.338.P=0.283).结论 VEGF,AQP1与RA滑膜血管的生成密切相关,二者在RA病情的发生和发展过程中有重要作用.另外在RA中,VEGF和AQP1还可能有协同作用.