Nobuyuki Miyasaka

Study of active controlled monotherapy used for rheumatoid arthritis, an IL‐6 inhibitor (SAMURAI): evidence of clinical and radiographic benefit from an x ray reader‐blinded randomised controlled trial of tocilizumab

Objective: To evaluate the ability of tocilizumab (a humanised anti-IL-6 receptor antibody) monotherapy to inhibit progression of structural joint damage in patients with RA. Methods: In a multi-centre, x ray reader-blinded, randomised, controlled trial, 306 patients with active RA of <5 years’ duration were allocated to receive either tocilizumab monotherapy at 8 mg/kg intravenously every 4 weeks or conventional disease-modifying antirheumatic drugs (DMARDs) for 52 weeks. Radiographs of hands and forefeet were scored by the van der Heijde modified Sharp method. Results: Patients had a mean disease duration of 2.3 years and a disease activity score in 28 joints of 6.5 at baseline. Mean total modified Sharp score (TSS) was 29.4, which was very high despite the relatively short disease duration. At week 52, the tocilizumab group showed statistically significantly less radiographic change in TSS (mean 2.3; 95% CI 1.5 to 3.2) than the DMARD group (mean 6.1; 95% CI 4.2 to 8.0; p<0.01). Tocilizumab monotherapy also improved signs and symptoms. The overall incidences of AEs were 89% and 82% (serious AEs: 18% and 13%; serious infections: 7.6% and 4.1%) in the tocilizumab and DMARD groups, respectively. Conclusion: Tocilizumab monotherapy was generally well tolerated and provided radiographic benefit in patients with RA.

Nitric oxide production and inducible nitric oxide synthase expression in inflammatory arthritides.

In this study, we have identified the source of nitric oxide (NO) produced in the human inflammatory joints by analyzing expression of inducible NO synthase. In ex vivo organ cultures, both inflammatory synovium and cartilage from patients with rheumatoid arthritis produced NO. The NO production was suppressed by NG-monomethyl-L-arginine, an inhibitor of NO synthase. The amount of NO produced by the synovium correlated with the proportion of CD14+ cells in the corresponding tissue (r = 0.8, P < 0.05). Immunohistochemical analysis as well as in situ hybridization showed that inducible NO synthase was predominantly expressed in synovial lining cells, endothelial cells, chondrocytes, and to a lesser extent, in infiltrating mononuclear cells and synovial fibroblasts. The synovial lining cells and the infiltrating cells expressing inducible NO synthase were identified where CD14+ cells were located. Together with morphological features, this suggests that they are type A synoviocytes. NO production from freshly isolated synoviocytes and chondrocytes was up-regulated by in vitro stimulation with a combination of IL-TNF-beta, TNF-alpha, and LPS. In summary, the present results suggest that NO is produced primarily by CD14+ synoviocytes, chondrocytes, and endothelial cells in inflammatory joints of arthritides. NO production can be upregulated by cytokines present in inflamed joints. The increased NO production may thus contribute to the pathological features in inflammatory arthritides.

Long-term safety and efficacy of tocilizumab, an anti-IL-6 receptor monoclonal antibody, in monotherapy, in patients with rheumatoid arthritis (the STREAM study): evidence of safety and efficacy in a 5-year extension study

Objectives: To evaluate the safety and efficacy of 5-year, long-term tocilizumab monotherapy for patients with rheumatoid arthritis. Methods: In an open-label, long-term extension trial following an initial 3-month randomised phase II trial, 143 of the 163 patients who participated in the initial blinded study received tocilizumab monotherapy (8 mg/kg) every 4 weeks. Concomitant therapy with non-steroidal anti-inflammatory drugs and/or oral prednisolone (10 mg daily maximum) was permitted. All patients were evaluated with American College of Rheumatology (ACR) improvement criteria, disease activity score (DAS) in 28 joints, and the European League Against Rheumatism response, as well as for safety issues. Results: 143 patients were enrolled in the open-label, long-term extension trial and 94 (66%) patients had completed 5 years as of March 2007. 32 patients (22%) withdrew from the study due to adverse events and one patient (0.7%) due to unsatisfactory response. 14 patients withdrew because of the patient’s request or other reasons. The serious adverse event rate was 27.5 events per 100 patient-years, with 5.7 serious infections per 100 patient-years, based on a total tocilizumab exposure of 612 patient-years. Of the 88 patients receiving corticosteroids at baseline, 78 (88.6%) were able to decrease their corticosteroid dose and 28 (31.8%) discontinued corticosteroids. At 5 years, 79/94 (84.0%), 65/94 (69.1%) and 41/94 (43.6%) of the patients achieved ACR20, ACR50, and ACR70 improvement criteria, respectively. Remission defined as DAS28 less than 2.6 was achieved in 52/94 (55.3%) of the patients. Conclusion: In this 5-year extension study, tocilizumab demonstrated sustained long-term efficacy and a generally good safety profile.

Discontinuation of infliximab after attaining low disease activity in patients with rheumatoid arthritis: RRR (remission induction by Remicade in RA) study

Background Tumour necrosis factor (TNF) inhibitors enable tight control of disease activity in patients with rheumatoid arthritis (RA). Discontinuation of TNF inhibitors after acquisition of low disease activity (LDA) is important for safety and economic reasons. Objective To determine whether infliximab might be discontinued after achievement of LDA in patients with RA and to evaluate progression of articular destruction during the discontinuation. Methods 114 patients with RA who had received infliximab treatment, and whose Disease Activity Score, including a 28-joint count (DAS28) was <3.2 (LDA) for 24 weeks, were studied. Results The mean disease duration of the 114 patients was 5.9 years, mean DAS28 5.5 and mean modified total Sharp score (mTSS) 63.3. After maintaining LDA for >24 weeks by infliximab treatment, the drug was discontinued and DAS28 in 102 patients was evaluated at year 1. Fifty-six patients (55%) continued to have DAS28<3.2 and 43% reached DAS<2.6 at 1 year after discontinuing infliximab. For 46 patients remission induction by Remicade in RA (RRR) failed: disease in 29 patients flared within 1 year and DAS28 was >3.2 at year 1 in 17 patients. Yearly progression of mTSS (ΔTSS) remained <0.5 in 67% and 44% of the RRR-achieved and RRR-failed groups, respectively. The estimated ΔmTSS was 0.3 and 1.6 and Health Assessment Questionnaire-Disability Index was 0.174 and 0.614 in the RRR-achieved and RRR-failed groups, respectively, 1 year after the discontinuation. Conclusion After attaining LDA by infliximab, 56 (55%) of the 102 patients with RA were able to discontinue infliximab for >1 year without progression of radiological articular destruction.

Chemokines regulate IL-6 and IL-8 production by fibroblast-like synoviocytes from patients with rheumatoid arthritis.

Rheumatoid arthritis (RA) is characterized by proliferation of synoviocytes that produce inflammatory cytokines and chemokines. The expressed chemokines are thought to be involved in the migration of inflammatory cells into the synovium. In this study we show that CCL2/monocyte chemotactic protein-1, CCL5/RANTES, and CXCL12/stromal cell-derived factor-1 enhanced IL-6 and IL-8 production by fibroblast-like synoviocytes (FLS) from patients with RA, and their corresponding receptors, CCR2, CCR5, and CXCR4, respectively, were expressed by RA FLS. The chemokines stimulated RA FLS more effectively than skin fibroblasts. Culture with CCL2 enhanced phosphorylation of extracellular signal-related kinase 1 (ERK1) and ERK2, but not phosphorylation of p38 or Src. Moreover, activation of ERK1/2 was inhibited by pertussis toxin, a Gi-coupled protein inhibitor, and RS-504393, CCR2 antagonist, suggesting that ERK1/2 was activated by CCL2 via CCR2 and Gi-coupled protein. On the other hand, CCL2, CCL5, and CXCL12 were expressed on RA FLS, and their production was regulated by TNF-α, IL-1β, and TGF-β1. Our results indicate that the chemokines not only play a role in inflammatory cell migration, but are also involved in the activation of FLS in RA synovium, possibly in an autocrine or paracrine manner.

Induction of the p16INK4a senescence gene as a new therapeutic strategy for the treatment of rheumatoid arthritis.

Synovial tissue affected by rheumatoid arthritis is characterized by proliferation, which leads to irreversible cartilage and bone destruction. Current and experimental treatments have been aimed mainly at correcting the underlying immune abnormalities, but these treatments often prove ineffective in preventing the invasive destruction. We studied the expression of cyclin-dependent kinase inhibitors in rheumatoid synovial cells as a means of suppressing synovial cell proliferation. Synovial cells derived from hypertrophic synovial tissue readily expressed p16INK4a when they were growth-inhibited. This was not seen in other fibroblasts, including those derived from normal and osteoarthritis-affected synovial tissues. In vivo adenoviral gene therapy with the p16INK4a gene efficiently inhibited the pathology in an animal model of rheumatoid arthritis. Thus, the induction of p16INK4a may provide a new approach to the effective treatment of rheumatoid arthritis.

Amelioration of Collagen-Induced Arthritis by Blockade of Inducible Costimulator-B7 Homologous Protein Costimulation

B7 homologous protein (B7h)/B7-related protein 1 (B7RP-1) is a new member of the B7 family of costimulatory molecules that specifically interacts with inducible costimulator (ICOS) expressed on activated T cells. Collagen type II (CII)-induced arthritis (CIA) is an experimental model of arthritis that has been used to dissect the pathogenesis of human rheumatoid arthritis. In this study, we have investigated the effect of neutralizing anti-B7h mAb on the development and disease progression of CIA. Administration of anti-B7h mAb significantly ameliorated the disease as assessed by clinical arthritis score and histology in the joints, and a beneficial effect was also obtained by a delayed treatment after the onset of disease. Expression of ICOS and B7h was observed in the inflamed synovial tissue as well as in the draining lymph nodes (LNs) and expansion of ICOS+ T cells in the LN was reduced by the anti-B7h mAb treatment. Expression of mRNA for proinflammatory cytokines such as TNF-α, IL-1β, and IL-6 in the joints was inhibited by the treatment. Proliferative responses and production of IFN-γ and IL-10 upon restimulation with CII in vitro were significantly inhibited in LN cells from the anti-B7h mAb-treated mice. Serum anti-CII IgG1, IgG2a, and IgG2b levels were also reduced. Our present results showed a beneficial effect of the B7h blockade on CIA through anti-inflammatory actions and inhibition of both Th1- and Th2-mediated immune responses, suggesting that the ICOS-B7h interaction plays an important role in the pathogenesis of CIA and thus the blockade of this pathway may be beneficial for the treatment of human rheumatoid arthritis.

Upregulated expression of chemokines in herniated nucleus pulposus resorption.

Study Design Immunohistologic examination was performed on surgically removed samples of herniated nucleus pulposus. Objectives To determine what cell types predominate in the granulation tissues of herniated nucleus pulposus, and to elucidate whether chemokines are involved in the resorption process of herniated nucleus pulposus. Summary of Background Data The study population consisted of 30 patients suffering from herniated nucleus pulposus. Five macroscopically normal discs were obtained from spinal cord tumor and spinal cord injury managed with anterior discectomy (age range, 27‐63 years) as a healthy control group. Methods Immunohistochemical analysis was used to analyze the expression of chemokines. Results A marked infiltration of macrophage and vascular proliferation was identified with a T lymphocyte infiltration of mild degree in the granulation tissues. This tendency was more prominent in the exposed group compared with the nonexposed group. Infiltrating macrophages, fibroblasts, and endothelial cells in the granulation tissues strongly expressed monocyte chemotactic protein‐1 and macrophage inflammatory protein‐1α. Statistical analysis demonstrated that the exposed group was more abundant in Factor VIII, monocyte chemotactic protein‐1, and macrophage inflammatory protein‐1α positive cells than the unexposed group. Conclusions Inflammatory cells and their positivity for chemokines, such as monocyte chemotactic protein‐1 and macrophage inflammatory protein‐1α, are associated with blood vessels. Chemokines, such as monocyte chemotactic protein‐1 and macrophage inflammatory protein‐1α, were overexpressed in macrophages, fibroblasts, and endothelial cells, suggesting that these chemokines contribute to activation and recruitment of macrophages in a paracrine or autocrine fashion.

Ceramide induces apoptosis via CPP32 activation

Although both ceramide and interleukin‐1β converting enzyme (ICE) family proteases are key molecules during apoptosis, their relationship remains to be elucidated. We report here that cell‐permeable ceramide induced cleavage and activation of CPP32, a Ced‐3/ICE‐like protease, but not ICE. Ceramide‐induced apoptosis of Jurkat cells was blocked by the CPP32‐specific tetrapeptide inhibitor DEVD‐CHO, but not by the ICE inhibitor YVAD‐CHO. Furthermore, variant Jurkat cells with defective CPP32 activation were resistant to both antiFas‐ and ceramide‐induced apoptosis. These results indicate that CPP32 activation is required for ceramide‐induced apoptosis, and suggest sphingomyelin‐ceramide pathway functions upstream of CPP32.

Excessive Production of IFN-γ in Patients with Systemic Lupus Erythematosus and Its Contribution to Induction of B Lymphocyte Stimulator/B Cell-Activating Factor/TNF Ligand Superfamily-13B

Expression and immunological significance of IFN-γ, a pivotal cytokine in murine lupus, have not been clearly demonstrated in human systemic lupus erythematosus (SLE). In the present study we investigated the expression of IFN-γ in peripheral blood T cells from patients with SLE and its role in the production of the soluble B lymphocyte stimulator (sBLyS). Peripheral blood T cells from patients with SLE expressed significantly larger amounts of IFN-γ in response to stimulation with anti-CD3 mAb plus anti-CD28 mAb than those from normal controls as shown by three analytical methods, including ELISA, flow cytometry, and quantitative RT-PCR. The ratio of IFN-γ-producing T cells to effector memory T cells in CD3+CD4+ and CD3+CD8+ populations in patients with SLE was significantly higher than that of normal controls. The T-box expressed in T cells (T-bet) mRNA/GATA-binding protein-3 (GATA-3) mRNA ratio was significantly higher in patients with SLE than in normal controls. T cell culture supernatants from patients with SLE contained significantly higher sBLyS-inducing activity than normal controls; this was almost completely inhibited by the addition of anti-human IFN-γ mAb. Percentages of BLyS-expressing peripheral blood monocytes in patients with SLE were significantly higher than those of normal controls. Monocytes from patients with SLE produced significantly larger amounts of sBLyS in response to IFN-γ than those from normal controls. Taken together, these data strongly indicate that the overexpression of IFN-γ in peripheral blood T cells contributes to the immunopathogenesis of SLE via the induction of sBLyS by monocytes/macrophages, which would promote B cell activation and maturation.