Identification of definitive serum biomarkers associated with disease activity in primary Sjögren's syndrome

Background

In this study, we sought to identify definitive biomarkers associated with disease activity in primary Sjögren’s syndrome (pSS).

Methods

Serum protein concentrations in pSS patients and healthy controls (HCs) were comprehensively screened using high-throughput proteomic analysis, and differentially expressed proteins were extracted. Correlation between differentially expressed proteins and European League Against Rheumatism Sjögren’s Syndrome Disease Activity Index (ESSDAI) scores was analyzed and disease activity-associated biomarkers were identified. These biomarkers were validated by enzyme-linked immunosorbent assay (ELISA) in a separate pSS cohort.

Results

The serum concentrations of 1100 proteins were compared between 30 pSS patients and 30 HCs, with 82 differentially expressed proteins identified as pSS-associated proteins. Of these 82 proteins, 9 were identified as disease activity-associated biomarkers. These nine biomarkers underwent validation by ELISA in a separate pSS validation cohort (n = 58), with five proteins (CXCL13, TNF-R2, CD48, B-cell activating factor (BAFF), and PD-L2) subsequently being confirmed as candidate biomarkers. Of these five candidate biomarkers, CXCL13 exhibited the most significant correlation with the lymphadenopathy, glandular, and pulmonary domains of the ESSDAI. CXCL13, TNF-R2 and CD48 exhibited a positive correlation with the biological domain of the ESSDAI. TNF-R2 exhibited the most negative correlation with uptake in the submandibular gland on technetium 99m-pertechnetate salivary gland scintigraphy.

Conclusions

Our approach successfully identified serum biomarkers associated with disease activity in pSS patients. These markers might be potential therapeutic targets in pSS patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-016-1006-1) contains supplementary material, which is available to authorized users.

[Potential of bone regenerative therapy with mesenchymal stem cells in rheumatoid arthritis]

Mesenchymal stem cell(MSC)exists throughout the body. The discovery of the immunosuppressive effect with low immunogenicity has led MSC as a new tool for cell therapy in various diseases. Within the arthritis animal model, periarticular implantation of bone marrow derived MSC with a scaffold has demonstrated treatment effect with low cell number whereas systemic administration had limited effect. Bone marrow derived MSC suppressed in vitro osteoclastogenesis and osteoblastogenesis of MSC was enhanced in the presence of IL-1β.On the other hand, experiments with adipose-derived MSC suggested the involvement in abnormal tissue calcification in the presence of IL-6. Therefore, MSC generated from the appropriate tissue and clarification of the major cytokines involved in pathogenesis is necessary when considering regenerative therapy for destructed joint in RA patients.

Spontaneous Differentiation of Human Mesenchymal Stem Cells on Poly-Lactic-Co-Glycolic Acid Nano-Fiber Scaffold

Introduction

Mesenchymal stem cells (MSCs) have immunosuppressive activity and can differentiate into bone and cartilage; and thus seem ideal for treatment of rheumatoid arthritis (RA). Here, we investigated the osteogenesis and chondrogenesis potentials of MSCs seeded onto nano-fiber scaffolds (NFs) in vitro and possible use for the repair of RA-affected joints.

Methods

MSCs derived from healthy donors and patients with RA or osteoarthritis (OA) were seeded on poly-lactic-glycolic acid (PLGA) electrospun NFs and cultured in vitro.

Results

Healthy donor-derived MSCs seeded onto NFs stained positive with von Kossa at Day 14 post-stimulation for osteoblast differentiation. Similarly, MSCs stained positive with Safranin O at Day 14 post-stimulation for chondrocyte differentiation. Surprisingly, even cultured without any stimulation, MSCs expressed RUNX2 and SOX9 (master regulators of bone and cartilage differentiation) at Day 7. Moreover, MSCs stained positive for osteocalcin, a bone marker, and simultaneously also with Safranin O at Day 14. On Day 28, the cell morphology changed from a spindle-like to an osteocyte-like appearance with processes, along with the expression of dentin matrix protein-1 (DMP-1) and matrix extracellular phosphoglycoprotein (MEPE), suggesting possible differentiation of MSCs into osteocytes. Calcification was observed on Day 56. Expression of osteoblast and chondrocyte differentiation markers was also noted in MSCs derived from RA or OA patients seeded on NFs. Lactic acid present in NFs potentially induced MSC differentiation into osteoblasts.

Conclusions

Our PLGA scaffold NFs induced MSC differentiation into bone and cartilage. NFs induction process resembled the procedure of endochondral ossification. This finding indicates that the combination of MSCs and NFs is a promising therapeutic technique for the repair of RA or OA joints affected by bone and cartilage destruction.

Janus kinase inhibitors for rheumatoid arthritis

Treatment of autoimmune diseases, such as rheumatoid arthritis (RA), has advanced substantially over the past decade with the development of biologics targeting inflammatory cytokines. Recent progress in treating RA has been achieved with janus kinase (JAK) inhibitors (Jakinibs), an orally available disease-modifying anti-rheumatic drug targeting the intracellular kinase JAK and with similar efficacy to biologics. The first Jakinib approved for RA was tofacitinib, which exerted superiority to methotrexate and non-inferiority to tumor necrosis factor (TNF) inhibitors. In recent years, the Jakinib baricitinib has demonstrated superiority to both methotrexate and a TNF inhibitor, adalimumab. Given these promising findings, Jakinibs are expected to represent the next generation compounds for treating RA, and a number of Jakinibs are currently in clinical trials. Jakinibs can differ substantially in their selectivity against JAKs; tofacitinib and baricitinib target multiple JAKs, whereas the most recently developed Jakinibs target only a single JAK. The influence of Jakinib selectivity on efficacy and side effects is of great interest, requiring further careful observation.

Association of plasmacytoid dendritic cells with B cell infiltration in minor salivary glands in patients with Sjögren's syndrome

OBJECTIVES

Sjogren's syndrome (SS) is an autoimmune disease with features of both over-production of specific autoantibodies and organ-specific disorders, mainly sialadenitis and dacryoadenitis. However, little is known about the factors that contribute to lymphocytic infiltration of SS.

METHODS

Minor salivary gland (MSG) tissue was obtained from 83 patients with primary SS (pSS) and 95 patients with secondary SS and examined pathologically, and correlation between infiltrated immune cells and histological features was evaluated.

RESULTS

Plasmacytoid dendritic cells (pDCs) were increased in MSG of SS compared to Sicca syndrome. The density of pDCs was characteristically correlated with the accumulation of CXCL13(+)CD68(+) macrophages and CXCR5(+)CD19(+) B in the MSG of pSS. In vitro analysis indicated that Type I interferon (IFN) enhanced CXCL13 production by macrophages. Type I IFN was mainly expressed in pDCs and its expression was correlated with the accumulation of CXCL13(+) macrophages in the MSG of pSS.

CONCLUSIONS

Our histological findings suggest the possible mechanism of type I IFN-CXCL13 axis during the pathological processes of acute/chronic salivary inflammation in SS; local production of type I IFN by pDCs, induction of CXCL13 production in macrophages by type I IFN, induction of accumulation of CXCR5(+)CD19(+) B cells by CXCL13 in the MSG.

Intriguing Findings of the Muscle on Magnetic Resonance Imaging in Polyarteritis Nodosa

Polyarteritis nodosa (PAN) confined to the muscle is rare and hard to diagnose. Recently, the utility of magnetic resonance imaging (MRI) for detecting muscle involvement of PAN has been introduced. We herein report the case of biopsy-proven, refractory PAN confined to the lower limb muscles with enhanced MRI demonstrating discretely granular hyperintensities, which was contrary to previous reports. Our results, with those of previous reports, suggest that the MRI findings of muscles in PAN reflect the vessel size involved and disease severity.

[Relation between disease modifying anti-rheumatic drugs and herpes zoster in rheumatoid arthritis]

Biologics have revolutionized the treatment of rheumatoid arthritis (RA). However certain amount of the patients cannot achieve goal of therapy. Recently, compounds targeting the intracellular kinase, Janus kinase (JAK) have demonstrated therapeutic effects resembling biologics. Tofacitinib is the only JAK inhibitor approved for RA and during the clinical trial, increased events of herpes zoster (HZ) was observed. Incidence rate was twice as much as patients treated with conventional anti-rheumatic drug and was especially increased in Japan that was four times as much. The risk factors were age and glucocorticoid that is identical to that of common RA patients and there was nothing specific for tofacitinib. Mechanism of increased incidence of HZ and the difference in ethnicity remains unknown. Analysis of clinical trials have identified that HZ do not correlate with further adverse events. Therefore, it is extremely important to accumulate clinical data with considerable amount of patients with long term follow up including the post marketing surveillance in Japan to reveal the significance of increased HZ in RA patients.

Early Prognostic Factors Associated with the Efficacy of Infliximab Treatment for Patients with Rheumatoid Arthritis with Inadequate Response to Methotrexate

INTRODUCTION

Early prognostic factors for the clinical response in patients with rheumatoid arthritis (RA) after 1 year of treatment with infliximab (IFX) as part of routine clinical practice were investigated.

METHODS

Thirty-five patients with RA with an inadequate response to methotrexate were enrolled and administered IFX (3-9 mg/kg, every 4-8 weeks). Serum trough levels of IFX and levels of 9 cytokines were measured at baseline and at 3, 6 months, and 1 year. Associations between these parameters and clinical indicators were statistically analyzed.

RESULTS

Serum trough levels of IFX and serum levels of interleukin (IL)-6 in the early phase of IFX treatment were investigated. Patients with low serum IL-6 achieved a higher clinical response as evaluated by the European League Against Rheumatism response criteria. Notably, the serum levels of IL-6 and IL-10 at baseline exhibited a significant positive correlation with disease activity at 1 year. Low serum levels of IL-6 and IL-10 at baseline were associated with low Disease Activity Score 28 erythrocyte sedimentation rate (DAS28-ESR). Cut-off values of IL-6 (5.45 pg/mL) and IL-10 and (1.68 pg/mL) enabled discrimination of DAS28-ESR remission from non-remission with high sensitivity and moderate specificity.

CONCLUSION

Following the initiation of IFX treatment, early disease activity and remission were associated with serum levels of IL-6. Serum levels of IL-6 and IL-10 at baseline predict the efficacy after 1 year of treatment with IFX. Patients with high serum levels of IL-6 and IL-10 at baseline before IFX treatment might require more intensive therapy to achieve higher rates of clinical remission at 1 year.

FUNDING

Eisai Co., Ltd.

Number of Circulating Follicular Helper 2 T Cells Correlates With IgG4 and Interleukin-4 Levels and Plasmablast Numbers in IgG4-Related Disease

OBJECTIVE

To elucidate the pathologic role of follicular helper T (Tfh) cells and their subsets in active, untreated IgG4-related disease.

METHODS

Fifteen patients with active, untreated, biopsy-proven IgG4-related disease, 24 patients with primary Sjögren's syndrome (SS), 12 patients with allergic rhinitis, and 23 healthy controls were evaluated. Tfh cells were defined as CD3+CD4+CXCR5+CD45RA- cells. Circulating Tfh cell subsets among CXCR5+CD45RA-CD4+ T cells were defined as Tfh17 cells (CXCR3-CCR6+), Tfh1 cells (CXCR3+CCR6-), or Tfh2 cells (CXCR3-CCR6-). CD19+CD20-CD27+CD38+ cells were defined as plasmablasts. Serum cytokine levels (interleukin-4 [IL-4], IL-10, IL-21, and IL-33) were measured by cytometric bead array or enzyme-linked immunosorbent assay.

RESULTS

Patients with IgG4-related disease had significantly increased levels of Tfh2 cells compared to healthy controls or patients with primary SS or allergic rhinitis. Increased Tfh2 levels were strongly associated with increased serum IgG4 levels and the IgG4:IgG ratio in IgG4-related disease. A positive correlation was observed between Tfh2 counts, plasmablast counts, and serum IL-4 levels. Interestingly, levels of plasmablasts and serum IL-4 and IgG4 decreased after treatment with glucocorticoids, whereas no obvious change was observed in Tfh2 cell counts.

CONCLUSION

The Tfh2 cell count was specifically increased in IgG4-related disease and was correlated with elevated serum levels of IgG4 and IL-4 and plasmablast counts. Tfh2 cells were the only component that was not affected by glucocorticoid treatment, suggesting that Tfh2 cells are the cell type implicated in IgG4-related disease.

Contribution of the Interleukin-6/STAT-3 Signaling Pathway to Chondrogenic Differentiation of Human Mesenchymal Stem Cells

OBJECTIVE

Mesenchymal stem cells (MSCs) are multipotent cells that can differentiate into chondrocytes. Articular cartilage contains MSC-like chondroprogenitor cells, which suggests their involvement in the maintenance of cartilage homeostasis by a self-repair mechanism. Interleukin-6 (IL-6) is a cytokine with a wide range of physiologic functions, which are produced by MSCs in a steady manner and in large quantities. The purpose of this study was to investigate the involvement of IL-6 signaling in MSC differentiation into chondrocytes.

METHODS

Human bone marrow-derived MSCs were cultured using a pellet culture system in medium containing transforming growth factor β3. Chondrogenic differentiation was detected by cartilage matrix accumulation and chondrogenic marker gene expression.

RESULTS

IL-6 was detected at a high concentration in culture supernatants during chondrogenic differentiation. The expression of the IL-6 receptor (IL-6R) was significantly increased, accompanied by markedly increased phosphorylation and expression of STAT-3. Addition of IL-6 and soluble IL-6R (sIL-6R) to the chondrogenic culture resulted in concentration-dependent increases in cartilage matrix accumulation and cartilage marker gene expression (type II collagen/aggrecan/type X collagen). Phosphorylation of the master transcription factor SOX9 was enhanced upon addition of IL-6 and sIL-6R. STAT-3 knockdown suppressed chondrogenic differentiation. IL-6 and the MSC markers CD166 and nestin were colocalized in macroscopically normal human cartilage taken from the lateral femoral compartment of knees with medial tibiofemoral osteoarthritis.

CONCLUSION

During differentiation of human MSCs into chondrocytes, the activation of IL-6/STAT-3 signaling positively regulated chondrogenic differentiation. The presence of IL-6 around MSC-like cells in the cartilage tissue was identified, suggesting that IL-6 contributes to homeostasis and cartilage self-repair by promoting chondrogenic differentiation.

CD14++CD16+ intermediate monocyte is induced by IL-10 and positively correlate with disease activity of rheumatoid arthritis. (CCR4P.206)

Introduction:Two different subsets of monocytes, classical(CD14+CD16-) and inflammatory(CD14+CD16+) monocytes have been identified. Recently, increased intermediate(CD14++CD16+) monocyte(Int-mo) and its decrease after treatment with anti-M-CSF antibody was reported in rheumatoid arthritis(RA), although the mechanism and involvement in RA remains unknown. The aim of this study is to elucidate the role of classical/inflammatory/intermediate monocytes in RA pathogenesis. Methods:Serum cytokines were measured by ELISA, CD14/CD16 expression was measured by flow cytometer and classical monocyte was sorted for in vitro culture. Results:Proportion of Int-mo, serum IL-6, IL-8, IL-10 but not M-CSF was increased in RA patients compared to healthy control subjects. Disease activity of RA positively correlated with serum IL-6, IL-10 and proportion of Int-mo but not with IL-8 and M-CSF. When sorted classical monocytes were stimulated with each cytokine, IL-10 and M-CSF but not other cytokines induced CD16 expression. Interestingly, CD16 expression was strongly induced by IL-10 at 14 hours whereas 72 hours was necessary for M-CSF. Discussion:Int-mo positively correlated with RA disease activity and was induced by IL-10 and M-CSF but not with other cytokines. Since, M-CSF is reported to induce IL-10 production and both cytokines are up-regulated in RA patients, our results suggest that IL-10 is the key cytokine that regulate Int-mo and presumably contribute to the anti-inflammatory process.

Circulating levels of vitamin D metabolites after renal transplantation

We investigated the change in the serum levels of vitamin D metabolites after renal transplantation in 5 uremic children. The serum 1,25-(OH)2D level showed a transient increase on the 1st or 2nd day after transplantation in all the patients. In 3 cases, it decreased after the initial peak and increased gradually to the normal level again within 2-4 weeks although, in the other 2 cases, it remained within the normal range after a slight decline. Serum 25-OHD and 24,25-(OH)2D level remained low for 4-8 weeks. Hypophosphatemia and/or hyperparathyroidism, which still remained after transplantation, may possibly stimulate 1 alpha-hydroxylase in the transplanted kidney.

Vitamin D metabolism in hypophosphatemic vitamin D-resistant rickets

Plasma levels of 1,25-(OH)2-D were low in children with hypophosphatemic vitamin D-resistant rickets (HVDRR), but increased after very large doses of 1 alpha-OH-D3. These results suggest that the metabolism of 1,25-(OH)2-D is accelerated in HVDRR. In addition, the lower level of plasma 1,25-(OH)2-D in untreated HVDRR was correlated with the lower level of serum phosphate and renal threshold phosphate concentration (TmP/GFR). The administration of 1 alpha-OH-D3 to the patients with HVDRR could enhance the renal threshold phosphate concentration.

Increased Syk phosphorylation leads to overexpression of TRAF6 in peripheral B cells of patients with systemic lupus erythematosus

OBJECTIVE

Activation of B cells is a hallmark of systemic lupus erythematosus (SLE). Syk and TRAF6 are key signaling molecules in B-cell activation through BCR and CD40/TLR, respectively. Nevertheless, whether expression of Syk and TRAF6 is altered in SLE B cells remains unknown.

METHODS

Phosphorylation and/or expression of Syk and TRAF6 were analyzed by flow cytometry in peripheral blood mononuclear cells isolated from SLE patients.

RESULTS

Pronounced phosphorylation and expression of Syk were noted in B cells from SLE patients compared with healthy donors. Levels of Syk phosphorylation correlated with the disease activity score. TRAF6 was significantly over-expressed in B cells of SLE patients as compared with healthy donors, and significant correlation of levels of TRAF6 expression and Syk phosphorylation was observed in SLE patients. Levels of TRAF6 expression were more pronounced in CD27+ memory B cells than in CD27-naïve B cells. In vitro treatment of SLE B cells with a Syk inhibitor (BAY61-3606) reduced Syk phosphorylation as well as TRAF6 expression.

CONCLUSION

Our results suggest that the activated Syk-mediated TRAF6 pathway leads to aberrant activation of B cells in SLE, and also highlight Syk as a potential target for B-cell-mediated processes in SLE.

Acquiring chondrocyte phenotype from human mesenchymal stem cells under inflammatory conditions

An inflammatory milieu breaks down the cartilage matrix and induces chondrocyte apoptosis, resulting in cartilage destruction in patients with cartilage degenerative diseases, such as rheumatoid arthritis or osteoarthritis. Because of the limited regenerative ability of chondrocytes, defects in cartilage are irreversible and difficult to repair. Mesenchymal stem cells (MSCs) are expected to be a new tool for cartilage repair because they are present in the cartilage and are able to differentiate into multiple lineages of cells, including chondrocytes. Although clinical trials using MSCs for patients with cartilage defects have already begun, its efficacy and repair mechanisms remain unknown. A PubMed search conducted in October 2014 using the following medical subject headings (MeSH) terms: mesenchymal stromal cells, chondrogenesis, and cytokines resulted in 204 articles. The titles and abstracts were screened and nine articles relevant to “inflammatory” cytokines and “human” MSCs were identified. Herein, we review the cell biology and mechanisms of chondrocyte phenotype acquisition from human MSCs in an inflammatory milieu and discuss the clinical potential of MSCs for cartilage repair.

A multi-biomarker disease activity score tracks clinical response consistently in patients with rheumatoid arthritis treated with different anti-tumor necrosis factor therapies: A retrospective observational study

OBJECTIVES

To assess the ability of a multi-biomarker disease activity (MBDA) score to track clinical response in patients with rheumatoid arthritis (RA) treated with different TNF inhibitors.

METHODS

The study included 147 patients who had received adalimumab, etanercept, or infliximab for a year or more, during routine clinical care at the University Hospital of Occupational and Environmental Health, Japan. MBDA scores and clinical measures of disease activity were evaluated at baseline and, after 24 weeks (N = 84) and 52 weeks of treatment. Relationships between the changes (∆) in MBDA score and changes in clinical measures or EULAR response categories were evaluated.

RESULTS

The median disease activity was 5.7 by DAS28-ESR and 64 by MBDA score at baseline, and decreased significantly with treatment. ∆MBDA scores over 1 year correlated with ∆DAS28-ESR (r = 0.48) and ∆DAS28-CRP (r = 0.46). Linear relationships between ∆MBDA scores and ∆DAS28-ESR or ∆DAS28-CRP were not significantly different between TNF inhibitors. The MBDA scores declined significantly more in good responders (median change: -29) than moderate (-21), and more in moderate than in non-responders (+ 2), by the EULAR criteria.

CONCLUSIONS

MBDA scores tracked disease activity and treatment response in patients with RA treated with three TNF inhibitors. The relationships between ∆MBDA scores and ∆DAS28-ESR or ∆DAS28-CRP were consistent across the three TNF inhibitor groups.

Low complements and high titre of anti-Sm antibody as predictors of histopathologically proven silent lupus nephritis without abnormal urinalysis in patients with systemic lupus erythematosus

OBJECTIVE

The aim of this study was to clarify the clinical characteristics and predictors of silent LN (SLN), a type of LN in SLE without abnormal urinalysis or renal impairment.

METHODS

Of 182 patients who underwent renal biopsy, 48 did not present with abnormal urinalysis or renal impairment at the time of biopsy. The patients with LN (SLN group, n = 36) and those without LN (non-LN group, n = 12) were compared with respect to their baseline characteristics. Bivariate analysis comprised Fisher's exact test and the Mann-Whitney test, whereas multivariate analysis employed binomial logistic regression analysis.

RESULTS

LN was histopathologically identified in 36 of 48 patients. According to the International Society of Nephrology/Renal Pathology Society classification, 72% of the SLN patients were classified as having class I/II, with a further 17% having class III/IV. Bivariate analyses indicated that platelet count, serum albumin, complement components (C3 and C4), complement haemolytic activity (CH50), anti-Sm antibody titre and anti-ribonucleoprotein antibody titre were significantly different between groups. Multivariate analysis indicated that CH50 and C3 titres were significantly lower in the SLN group, whereas anti-Sm antibody titre was significantly higher. The cut-off titre, calculated based on the receiver operating characteristic curve for CH50, was 33 U/ml, with a sensitivity and specificity of 89% and 83%, respectively. The cut-off titre for anti-Sm antibodies was 9 U/ml, with a sensitivity and specificity of 74% and 83%, respectively.

CONCLUSION

Low titres of CH50 and C3 and a high titre of anti-Sm antibody were identified as predictors of SLN.

Abatacept inhibits radiographic progression in patients with rheumatoid arthritis: a retrospective analysis of 6 months of abatacept treatment in routine clinical practice. The ALTAIR study

OBJECTIVES

Our objectives in this study were to determine the inhibitory effects of abatacept on joint damage and its clinical efficacy and safety in patients with rheumatoid arthritis (RA).

METHODS

Fifty Japanese patients with RA were treated with abatacept for 24 weeks in routine clinical practice.

RESULTS

At week 24, 20 % of patients achieved clinical remission [Simplified Disease Activity Index (SDAI) ≤3.3], whereas 50 % were in remission or had a low disease activity. Structural remission [progression of modified total Sharp score (ΔmTSS) ≤0.5] was achieved in 76 % of patients. The ΔmTSS decreased significantly from 7.1 ± 7.3 at baseline to 1.8 ± 5.7 at week 24. C-reactive protein (CRP) was the only independent prognostic factor for joint damage progression at week 24, whereas SDAI and matrix metalloproteinase-3 levels were not. A very high proportion of patients with CRP levels <1.5 mg/dl (88 %) achieved structural remission. In terms of safety, the retention rate for all patients was favorable (80 %), and stomatitis was the only adverse event observed. No patient withdrew from the study because of infections.

CONCLUSIONS

Abatacept has favorable clinical and structural effects, inhibits radiographic progression, and has a good safety profile in routine clinical practice.

IL-6-accelerated calcification by induction of ROR2 in human adipose tissue-derived mesenchymal stem cells is STAT3 dependent

OBJECTIVE

The mechanisms of ectopic calcification in inflammatory diseases are poorly understood. We investigated the effects of inflammatory cytokines on the mechanisms of calcification in human adipose tissue-derived mesenchymal stem cells (hADSCs).

METHODS

The effects of inflammatory cytokines were evaluated using hADSCs cultured in osteoblast induction medium. mRNA expression was measured by real-time PCR and protein levels were measured by western blotting. Cell mineralization was evaluated by Alizarin Red S staining.

RESULTS

In hADSCs, administration of IL-6/soluble IL-6 receptor (sIL-6R), TNF or IL-1β accelerated calcification through enhanced expression of an osteoblast differentiation marker, runt-related transcription factor 2 (RUNX2). IL-6/sIL-6R had the greatest effect. The transcription of mRNA for receptor tyrosine kinase-like orphan receptor 2 (ROR2), involved in the non-canonical wingless-type (WNT) MMTV integration site pathway, was increased, while β-catenin expression, an essential factor in the canonical WNT signalling pathway for osteoblast differentiation, did not change. Suppression of signal transducer and activator of transcription 3 (STAT3), but not STAT1, by small interfering RNA (siRNA) exerted a strong inhibitory effect on RUNX2 and ROR2 expression, and inhibited accelerated calcification.

CONCLUSION

IL-6/sIL-6R stimulation accelerated the ROR2/WNT5A pathway in hADSCs in a STAT3-dependent manner, resulting in augmented calcification. These results suggest that the mechanisms of ectopic calcification accelerated by IL-6 in hADSCs may be involved in chronic inflammatory tissues and that IL-6 inhibitors may be beneficial in the treatment of ectopic calcification in inflammatory diseases.

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.

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.

Study on the safety and efficacy of tocilizumab, an anti-IL-6 receptor antibody, in patients with rheumatoid arthritis complicated with AA amyloidosis

OBJECTIVES

Although treatment of rheumatoid arthritis (RA) has progressed by the use of biologics, amyloid A (AA) amyloidosis is still an intractable complication in patients with RA. In the present study, safety and efficacy of 1-year treatment with an anti-IL-6 receptor antibody tocilizumab (TCZ) on RA and AA amyloidosis were estimated.

METHODS

TCZ (8 mg/kg every 4 weeks) was administered to five RA patients complicated with AA amyloidosis. The primary end point was improvement in renal dysfunction and the secondary end point was CDAI at 1 year after the treatment.

RESULTS

An improvement in the renal dysfunction, including urinary protein secretion, was found, in four patients including two patients who were refractory to etanercept, with a remarkable decrease of SAA concentration, and the progression of organ dysfunction was prevented at 1 year in all patients treated with TCZ. The mean clinical disease activity index decreased from 33.9 to 4.7 (p = 0.012) in five patients treated with TCZ for 1 year. Three non-serious adverse events were observed in two patients.

CONCLUSIONS

TCZ ameliorates renal dysfunction in RA patients complicated with AA amyloidosis who are refractory to conventional therapies, thereby suggesting that TCZ has a potential to regulate AA amyloidosis.

Efficacy and safety of reducing duration of infliximab infusion

OBJECTIVE

To evaluate the safety and efficacy of reducing the duration of infliximab infusion for rheumatoid arthritis (RA) treatment.

METHODS

The first 6 infliximab infusions were each administered over a 2-h period. If no adverse reaction was observed, infusion times were shortened to 1 h starting with the seventh infusion with further shortening to 30 min starting with the thirteenth infusion. Subjects were divided into two groups: shortened infusion time group, in which infusion times were shortened as above; and constant infusion time group, in which infusion time was 2 h. Incidence of infusion reactions and improvement in disease activity score for 28 joints (DAS-28) erythrocyte sedimentation rate (ESR) for total infusions were compared for the seventh to twelfth and thirteenth to eighteenth infusions.

RESULTS

The incidences of infusion reactions after the seventh to twelfth and thirteenth to eighteenth infusions in the shortened infusion time group were 0.53% and 0.58%, respectively. In the constant infusion time group, these were 0.70% and 0.67%, respectively. Furthermore, shortening the infusion duration did not affect the DAS-28 (ESR) improvement rate.

CONCLUSIONS

We established that this stage-wise shortening of infusion duration, first to 1 h and then to 30 min, did not compromise the safety or efficacy of treatment.

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

Introduction

Evidences 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.

Methods

This 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.

Results

The 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.

Conclusions

It 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 registration

University Hospital Medical Information Network Identifier: UMIN000006669.