Shunsuke Fukuyo

Discontinuation of adalimumab after achieving remission in patients with established rheumatoid arthritis: 1-year outcome of the HONOR study

Objectives To investigate the possibility of discontinuing adalimumab (ADA) for 1 year without flaring (DAS28-erythrocyte sedimentation rate (ESR) ≥3.2), and to identify factors enabling established patients with rheumatoid arthritis (RA) to remain ADA-free. Methods Of 197 RA patients treated with ADA+methotrexate (MTX), 75 patients who met the ADA-free criteria (steroid-free and sustained DAS28-ESR remission for 6 months with stable MTX doses) were studied for 1 year. Results The mean disease duration and DAS28-ESR score in 75 patients was 7.5 years and 5.1 at baseline, respectively. The proportion of patients who sustained DAS28-ESR <2.6 (48%) and DAS28-ESR <3.2 (62%) for 1 year were significantly lower in the ADA discontinuation group than in the ADA continuation group; however, in patients with deep remission (DAS28-ESR ≤1.98) identified by receiver operating characteristics analysis following logistic analysis, these rates increased to 68% and 79%, respectively, with no significant difference between both groups. Remarkably, ADA readministration to patients with flare was effective in returning DAS28-ESR to <3.2 within 6 months in 90% and 9 months in 100% patients; among the patients who sustained DAS28-ESR <3.2 during ADA discontinuation, 100% remained in structural remission and 94% in functional remission. Conclusions The possibility of remaining ADA-free for 1 year was demonstrated in established patients with RA with outcomes that ADA can be discontinued without flaring in 79% patients with deep remission, with similar rates in the ADA continuation group, and showed no functional or structural damage in patients with DAS28-ESR <3.2. ADA readministration to patients with flare during ADA discontinuation was effective.

Interleukin-1β induces differentiation of human mesenchymal stem cells into osteoblasts via the Wnt-5a/receptor tyrosine kinase-like orphan receptor 2 pathway.

OBJECTIVE Mesenchymal stem cells (MSCs) are considered to be a novel tool for the treatment of rheumatoid arthritis (RA) because of their multipotency to differentiate into osteoblasts and chondrocytes, their immunosuppressive effects, and availability. The aim of this study was to assess the mechanisms of human MSC differentiation into osteoblasts under inflammatory conditions. METHODS Human MSCs were cultured in commercialized osteogenic induction medium with inflammatory cytokines for up to 10 days. Osteoblast differentiation was detected by alkaline phosphatase staining and messenger RNA (mRNA) expression of multiple osteoblast markers. Mineralization was assessed by alizarin red S staining. RESULTS Among the various cytokines tested, interleukin-1β (IL-1β) induced differentiation of human MSCs into osteoblasts, which was confirmed by alkaline phosphatase activity, expression of RUNX2 mRNA, and strong alizarin red S staining. Among various molecules of the Wnt family, Wnt-5a and receptor tyrosine kinase-like orphan receptor 2 (Ror2), a major receptor of Wnt-5a, were significantly induced in human MSCs by IL-1β. Silencing of either WNT5A or ROR2 by small interfering RNA with 2 different sequences reduced alkaline phosphatase activity, RUNX2 expression, and alizarin red S staining of human MSCs induced by IL-1β. CONCLUSION IL-1β effectively and rapidly induced human MSC differentiation into osteoblasts and mineralization, mainly through the noncanonical Wnt-5a/Ror2 pathway. These results suggest potential benefits of IL-1β-treated human MSCs in the treatment of damaged bone as well as in the induction of self-renewal and self-repair of damaged tissue, including osseous tissue.

Clinical, radiographic and functional effectiveness of tocilizumab for rheumatoid arthritis patients—REACTION 52-week study

Objectives. To evaluate the effectiveness and safety of tocilizumab in RA patients in clinical practice. Methods. We observed 232 consecutive RA patients who began tocilizumab in three rheumatology centres in Japan for 52 weeks. Clinical, radiographic and functional status and safety were evaluated. Results. Mean age of the 232 patients was 59.1 years, mean duration of disease was 12.4 years and average DAS using the 28-joint count (DAS-28) was 5.6. Although 62.8% of the patients had been treated previously with anti-TNF biologics, clinical remission at Week 52 was achieved in 43.7%, radiographic non-progression in 62.8% and functional remission in 26.4%. Retention rate at Week 52 was 71.1%, and the same for those with or without previous anti-TNF treatment. Adverse drug reactions leading to tocilizumab discontinuation were observed in 15.5% of patients, the most frequent adverse drug reaction being pneumonia in eight cases. On multivariate logistic regression analysis, DAS-28, HAQ-disability index (HAQ-DI), concomitant MTX and concomitant glucocorticoids (GCs) were predictive variables for clinical remission at Week 52 of tocilizumab treatment. In particular, HAQ-DI was found to be a predictive variable for remission of all three types—clinical, radiographic and functional—at Week 52 of tocilizumab treatment. Conclusions. In daily clinical practice, tocilizumab exhibited excellent effectiveness in established RA patients, some of whom had failed to respond to previous anti-TNF treatment. Although further detailed safety findings are required, this study provides valuable real-world findings on the management of RA with tocilizumab.

Phenotypic changes of lymphocytes in patients with systemic lupus erythematosus who are in longterm remission after B cell depletion therapy with rituximab

Objective. Rituximab has recently emerged as a novel treatment strategy for systemic lupus erythematosus (SLE). We investigated longitudinally the differentiation and phenotypic changes of peripheral B cells and T cells in patients with SLE after rituximab treatment. Methods. Phenotypic changes on B cells and T cells in 10 patients with SLE treated with rituximab were analyzed before, 28 days after, and 2 years after rituximab treatment, and at relapse. Results. Rituximab rapidly depleted naive and memory B cells from the peripheral blood. In the patients with prolonged remission, the memory B cells remained depleted while naive B cells recovered within 3–9 months, and the expression levels of CD40 and CD80 remained downregulated for 2 years. There was also a decrease of memory T cells relative to naive T cells, and the expression of CD40L and inducible costimulator (ICOS) on CD4-positive T cells rapidly decreased and remained downregulated for 2 years. In 1 patient, an increase in the number of memory B cells with upregulation of CD40 and CD80 expression was noted just before relapse. In another patient with relapse, however, recovery of CD4-positive memory T cells with upregulation of ICOS expression was noted, with no change in the number of memory B cells. Conclusion. Our results suggest that the phenotypic changes of peripheral B cells result in inhibition of T cell differentiation and activation mediated by B cells and thereby bring about longterm remission of SLE. Activated memory B cells or ICOS-positive CD4-positive memory T cells reappeared in association with relapse, probably reflecting the heterogeneity of SLE.

Human Mesenchymal Stem Cells Inhibit Osteoclastogenesis Through Osteoprotegerin Production

OBJECTIVE Mesenchymal stem cells (MSCs) have been proposed to be a useful tool for treatment of rheumatoid arthritis (RA), not only because of their multipotency but also because of their immunosuppressive effect on lymphocytes, dendritic cells, and other proinflammatory cells. Since bone destruction caused by activated osteoclasts occurs in RA, we undertook the present study to investigate the effect of MSCs on osteoclast function and differentiation in order to evaluate their potential use in RA therapy. METHODS Human MSCs and peripheral blood mononuclear cells were cultured under cell-cell contact-free conditions with osteoclast induction medium. Differentiation into osteoclast-like cells was determined by tartrate-resistant acid phosphatase staining and expression of osteoclast differentiation markers. RESULTS The number of osteoclast-like cells was decreased and expression of cathepsin K and nuclear factor of activated T cells c1 (NF-ATc1) was down-regulated by the addition of either MSCs or a conditioned medium obtained from MSCs. Osteoprotegerin (OPG) was constitutively produced by MSCs and inhibited osteoclastogenesis. However, osteoclast differentiation was not fully recovered upon treatment with either anti-OPG antibody or OPG small interfering RNA, suggesting that OPG had only a partial role in the inhibitory effect of MSCs. Moreover, bone-resorbing activity of osteoclast-like cells was partially recovered by addition of anti-OPG antibody into the conditioned medium. CONCLUSION The present results indicate that human MSCs constitutively produce OPG, resulting in inhibition of osteoclastogenesis and expression of NF-ATc1 and cathepsin K in the absence of cell-cell contact. Therefore, we conclude that human MSCs exert a suppressive effect on osteoclastogenesis, which may be beneficial in inhibition of joint damage in RA.

Activation of Syk in peripheral blood B cells in patients with rheumatoid arthritis: a potential target for abatacept therapy.

B cells play a pivotal role in the pathogenesis of autoimmune diseases. Although Syk functions as a key molecule in B cell receptor signaling, the pathologic role of Syk in B cells in rheumatoid arthritis (RA) remains unclear. The purpose of this study was to assess the relevance of activation of Syk in B cells to the pathologic development of RA and to the responsiveness of RA patients to treatment with biologics.

IL-17 Inhibits Chondrogenic Differentiation of Human Mesenchymal Stem Cells

Objective Mesenchymal stem cells (MSCs) can differentiate into cells of mesenchymal lineages, such as osteoblasts and chondrocytes. Here we investigated the effects of IL-17, a key cytokine in chronic inflammation, on chondrogenic differentiation of human MSCs. Methods Human bone marrow MSCs were pellet cultured in chondrogenic induction medium containing TGF-β3. Chondrogenic differentiation was detected by cartilage matrix accumulation and chondrogenic marker gene expression. Results Over-expression of cartilage matrix and chondrogenic marker genes was noted in chondrogenic cultures, but was inhibited by IL-17 in a dose-dependent manner. Expression and phosphorylation of SOX9, the master transcription factor for chondrogenesis, were induced within 2 days and phosphorylated SOX9 was stably maintained until day 21. IL-17 did not alter total SOX9 expression, but significantly suppressed SOX9 phosphorylation in a dose-dependent manner. At day 7, IL-17 also suppressed the activity of cAMP-dependent protein kinase A (PKA), which is known to phosphorylate SOX9. H89, a selective PKA inhibitor, also suppressed SOX9 phosphorylation, expression of chondrogenic markers and cartilage matrix, and also decreased chondrogenesis. Conclusions IL-17 inhibited chondrogenesis of human MSCs through the suppression of PKA activity and SOX9 phosphorylation. These results suggest that chondrogenic differentiation of MSCs can be inhibited by a mechanism triggered by IL-17 under chronic inflammation.

Discontinuation of adalimumab after attaining disease activity score 28-erythrocyte sedimentation rate remission in patients with rheumatoid arthritis (HONOR study): an observational study

IntroductionEvidences of biologics-free disease control after discontinuing adalimumab (ADA) in rheumatoid arthritis (RA) patients in clinical practice have not been sufficiently investigated. Purpose of this study is to investigate whether disease activity score 28 (DAS28)- erythrocyte sedimentation rate (ESR) remission was preserved after discontinuation of ADA in patients with RA.MethodsThis is an observational but not a randomized controlled study. Among 197 RA patients who initiated with combination of ADA with concomitant MTX, 69 (35%) acquired DAS28 (ESR) < 2.6 for at least 24 weeks. Of those 69 patients, 51 went on ADA discontinuation with their consent, and finally 50 of those with follow-up of > 24 weeks were evaluated. The effect of discontinuing ADA on clinical disease activity, functional disability and radiographic progression were evaluated by DAS28 (ESR), the clinical disease activity index (CDAI) and the simplified disease activity index (SDAI), by a health assessment questionnaire-disability index (HAQ-DI) and by the modified total Sharp score (mTSS), respectively.ResultsThe mean age of the participants was 59.5 years with the mean disease duration of 7.1 years. Out of the 50 patients, 29 (58%) were maintained in DAS28 (ESR) < 2.6 at 24 weeks after discontinuing ADA. A logistic regression analysis showed that DAS28 (ESR) at baseline significantly predicted a DAS28 (ESR) < 2.6 maintained after discontinuation of ADA, and a receiver-operating characteristic (ROC) analysis showed that the cut-off value of DAS28 (ESR) at discontinuation was 2.16. The mean HAQ-DI at six months after discontinuing ADA was 0.1 in patients who kept in DAS28 (ESR) < 2.6, and 94.9% (37/39) showed no evidence of radiographic progression (> 0.5 per year of a change in mTSS) at 1 year.ConclusionsIt was possible to maintain DAS28 (ESR) < 2.6 after discontinuation of ADA without functional and radiographic progression and very low DAS28 (ESR) at the discontinuation was associated with successful ADA-free DAS28 (ESR) < 2.6 in patients with RA.Trial registrationUniversity Hospital Medical Information Network Identifier: UMIN000006669.

Effects of tofacitinib on lymphocytes in rheumatoid arthritis: relation to efficacy and infectious adverse events

OBJECTIVES To assess the effects of tofacitinib on T lymphocytes in RA patients with a special focus on efficacy and infectious adverse events (iAEs). METHODS Forty-four RA patients participated in 12-month phase II/III randomized clinical trials and an open-label extension trial. Peripheral lymphocyte subsets and in vitro CD4(+) T lymphocyte proliferation were measured in 23 patients of 44 at baseline and at the end of the 12-month trial. RESULTS Forty-four patients [35 females, age 54.3 years, disease duration 84.3 months, simplified disease activity index (SDAI) 36.5, CRP 24.9 mg/l, ESR 53 mm/h, MMP-3 284 pg/ml, RF 172.6 IU/ml, neutrophil count 4842 per μl, lymphocyte count 1410 per μl] were treated with tofacitinib. At the end of the study, the SDAI improved to 6.2, but the peripheral lymphocyte count and absolute numbers of CD4(+) and CD8(+) subpopulations did not change during this period. However, CD4(+) T lymphocyte proliferation was suppressed, which correlated with the improvement in SDAI, but not with iAEs (n = 19) during the 12-month treatment. Receiver operating characteristic analysis identified a CD8(+) T lymphocyte count ≤ 211 per μl at baseline as a significant predictor of clinically significant iAEs. CONCLUSION The efficacy of tofacitinib is mediated through the suppression of CD4(+) T lymphocyte proliferation without affecting the absolute number of these cells in the periphery. A low CD8(+) T cell count at baseline correlated with the development of iAEs during the treatment of RA patients.

Effect of interleukin-6 receptor inhibitor, tocilizumab, in preventing joint destruction in patients with rheumatoid arthritis showing inadequate response to TNF inhibitors

Abstract Objectives. To examine the effectiveness of tocilizumab (TCZ) in preventing joint destruction in patients with inadequate response to tumor necrosis factor inhibitors (TNF-IR) by assessing X-rays. Methods. RA patients were extracted from the Retrospective actemra investigation for optimal needs of RA patients (REACTION) study. Parameters and components of disease activity were evaluated during anti-TNF treatment and during TCZ treatment. X-ray images of hands and feet at the beginning of this study during anti-TNF treatment (Pre), at the start point of TCZ treatment (Baseline) and after TCZ treatment (Post) were collected for assessing joint destruction. Results. Forty-five patients from the REACTION study fulfilled the criteria of clinical TNF-IR. During anti-TNF treatment, mean DAS28-ESR rose from 5.35 to 5.87 (mean observation duration, 16 months) but improved significantly to 2.94 (P < 0.0001) at 52 weeks after switching to TCZ. Mean change in van der Heijde-modified Sharp score (TSS) during anti-TNF treatment was 3.17 in this TNF-IR population. After switching to TCZ, mean change in TSS was 1.20 (P < 0.05). Rate of radiographic non-progression improved to 66.7% during TCZ treatment from 40.0% during anti-TNF treatment. The predictive factor for no radiographic progression after switching to TCZ was a HAQ disability index (HAQ-DI) score of ≤ 1.88 at switching to TCZ. Conclusion. TCZ was a good treatment option for improving signs and symptoms and inhibiting progression of joint damage in patients with clinical and structural TNF-IR.