Published papers

Objective. The aim of this study was to determine whether biologic-free remission of RA is possible with discontinuation of abatacept. Methods. Japanese RA patients in 28-joint DAS with CRP (DAS28-CRP) remission (<2.3) after >2 years of abatacept treatment in a phase II study and its long-term extension entered this 52 week, multicentre, non-blinded, prospective, observational study. At enrolment, the patients were offered the option to continue abatacept or not. The primary endpoint was the proportion of patients who remained biologic-free at 52 weeks after discontinuation. Clinical, functional and structural outcomes were compared between those who continued and those who discontinued abatacept. Results. Of 51 patients enrolled, 34 discontinued and 17 continued abatacept treatment. After 52 weeks, 22 of the 34 patients (64.7%) remained biologic-free. Compared with the continuation group, the discontinuation group had a similar remission rate (41.2% vs 64.7%, P = 0.144) although they had a significantly higher mean DAS28-CRP score at week 52 (2.9 vs 2.0, P = 0.012). The two groups were also similar with regard to mean HAQ Disability Index (HAQ-DI) score (0.6 for both, P = 0.920), mean change in total Sharp score (ΔTSS; 0.80 vs 0.32, P = 0.374) and proportion of patients in radiographic remission (ΔTSS≤0.5) at the endpoint (64.3% vs 70.6%, P = 0.752). Those attaining DAS28-CRP<2.3 or<2.7 without abatacept at the endpoint had significantly lower HAQ-DI score and/or CRP at enrolment. Non-serious adverse events occurred in three patients who continued or resumed abatacept. Conclusion. Biologic-free remission of RA is possible in some patients after attaining clinical remission with abatacept. Lower baseline HAQ-DI or CRP may predict maintenance of remission or low disease activity after discontinuation of abatacept.

Objective. To investigate the performance of the new remission criteria for rheumatoid arthritis (RA) in daily clinical practice and the effect of possible misclassification of remission when 44 joints are assessed. Methods. Disease activity and remission rate were calculated according to the Disease Activity Score (DAS28), Simplified Disease Activity Index (SDAI), Clinical Disease Activity Index (CDAI), and a Boolean-based definition for 1402 patients with RA in Keio University Hospital. Characteristics of patients in remission were investigated, and the number of misclassified patients was determined - those classified as being in remission based on 28-joint count but as nonremission based on a 44-joint count for each definition criterion. Results. Of all patients analyzed, 46.6%, 45.9%, 41.0%, and 31.5% were classified as in remission in the DAS28, SDAI, CDAI, and Boolean definitions, respectively. Patients classified into remission based only on the DAS28 showed relatively low erythrocyte sedimentation rates but greater swollen joint counts than those classified into remission based on the other definitions. In patients classified into remission based only on the Boolean criteria, the mean physician global assessment was greater than the mean patient global assessment. Although 119 patients had ≤ 1 involved joint in the 28-joint count but > 1 in the 44-joint count, only 34 of these 119 (2.4% of all subjects) were found to have been misclassified into remission. Conclusion. In practice, about half of patients with RA can achieve clinical remission within the DAS28, SDAI, and CDAI; and one-third according to the Boolean-based definition. Patients classified in remission based on a 28-joint count may have pain and swelling in the feet, but misclassification of remission was relatively rare and was seen in only 2.4% of patients under a Boolean definition. The 28-joint count can be sufficient for assessing clinical remission based on the new remission criteria. Copyright © The Journal of Rheumatology 2013.

Objective. To clarify the characteristics, survival and predictors of mortality in Japanese patients with pulmonary arterial hypertension (PAH) associated with CTD.Methods. This single-centre cohort study enrolled 70 consecutive patients with PAH-CTD who visited a tertiary referral centre in Japan between 1970 and 1990 (n = 30, historical group) and between 2000 and 2009 (n = 40, recent group). Baseline clinical features, haemodynamic parameters and ANA profiles were recorded. The Cox proportional hazards regression model was used to determine independent factors associated with an increased risk of mortality.Results. MCTD and SLE were the major underlying CTDs, comprising 43% and 29% of PAH patients respectively, whereas SSc was less common (19%). Anti-U1RNP antibody was the most prevalent ANA (61%). The cumulative survival rate was significantly better in the recent group in comparison with the historical group (76% vs 26% at 3 years; P < 0.001). When both groups were combined, World Health Organization functional class III or IV at diagnosis was identified as an independent predictor of mortality, whereas modern PAH drug use was associated with a favourable outcome.Conclusion. The major PAH-CTD population in Japan suffers from MCTD or SLE with anti-U1RNP antibody, in contrast to PAH-CTD patients in the USA and Europe. Modern PAH treatment has improved survival rates, but long-term outcomes are still unsatisfactory. Independent predictors of mortality indicate that early diagnosis and the prompt use of PAH drugs should improve survival. © The Author 2012. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved.

The prototype autoimmune disease, systemic lupus erythematosus (SLE), has been known to be associated with deficiency of ξ chain, a component of the T-cell receptor-CD3 complex. Comprehensive analysis has shown that expression of the CD3 ξ chain is attenuated or absent in over half of SLE patients. Furthermore, aberrant transcripts of the CD3 ξ chain, including spliced variants lacking exon 7 or having a short 3′-untranslated region, have been detected in SLE T cells. Although attenuated expression of the CD3 ξ chain is also observed in cancer patients, infections and other autoimmune diseases, sustained attenuation of the CD3 ξ expression accompanied with aberrant transcripts are only observed in SLE. In this study, the authors review the unique features of CD3 ξ defects observed in SLE and discuss the molecular basis of the defects by recent findings in animal models, single-nucleotide polymorphisms and genome-wide association studies.

Objective: We undertook this phase III study to evaluate baricitinib, an orally administered JAK-1/JAK-2 inhibitor, as monotherapy or combined with methotrexate (MTX) compared to MTX monotherapy in patients with active rheumatoid arthritis (RA) who had received no or minimal conventional synthetic disease-modifying antirheumatic drugs (DMARDs) and who were naive to biologic DMARDs. Methods: A total of 588 patients were randomized 4:3:4 to receive MTX monotherapy (once weekly), baricitinib monotherapy (4 mg once daily), or the combination of baricitinib and MTX for 52 weeks. The primary end point assessment was a noninferiority comparison of baricitinib monotherapy to MTX monotherapy based on the proportion of patients meeting the American College of Rheumatology 20% improvement criteria (achieving an ACR20 response) at week 24. Results: The study met its primary objective. Moreover, baricitinib monotherapy was found to be superior to MTX monotherapy at week 24, with a higher ACR20 response rate (77% versus 62%; P ≤ 0.01). Similar results were observed for combination therapy. Compared to MTX monotherapy, significant improvements in disease activity and physical function were observed for both baricitinib groups as early as week 1. Radiographic progression was reduced in both baricitinib groups compared to MTX monotherapy; the difference was statistically significant for baricitinib plus MTX. The rates of serious adverse events (AEs) were similar across treatment groups, while rates of some treatment-emergent AEs, including infections, were increased with baricitinib plus MTX. Three deaths were reported, all occurring in the MTX monotherapy group. Malignancies, including nonmelanoma skin cancer, were reported in 1 patient receiving MTX monotherapy, 1 receiving baricitinib monotherapy, and 4 receiving baricitinib plus MTX. Conclusion: Baricitinib alone or in combination with MTX demonstrated superior efficacy with acceptable safety compared to MTX monotherapy as initial therapy for patients with active RA.

Background: Three different subsets of circulating human monocytes, CD14brightCD16- (classical), CD14brightCD16+ (intermediate), and CD14dimCD16+ (non-classical) have been recently identified. It has been reported that CD14brightCD16+ monocytes are increased in rheumatoid arthritis (RA). However, the role of each monocyte subset in the pathogenesis of RA is still unclear. The purpose of this study was to investigate the association of CD14brightCD16+ monocytes with RA. Methods: The study enrolled 35 patients with RA and 14 healthy volunteers. The three subsets of peripheral blood monocytes were analyzed by flow cytometry. Serum cytokines were measured at baseline in patients with RA and in healthy volunteers. CD14brightCD16- monocytes were isolated and cultured in vitro with different cytokines for 14 hours, and CD16 induction was assessed. Results: The proportion of CD14brightCD16+ monocytes, and serum interleukin (IL)-6, IL-8, and IL-10 were increased in patients with RA compared to healthy controls. The proportion of CD14brightCD16+ monocytes correlated with the disease activity of RA positively, whereas the proportion of CD14brightCD16- monocytes correlated negatively. When isolated CD14brightCD16- monocytes were stimulated with IL-6, IL-8, and IL-10, the only cytokine that significantly induced CD16 expression on the cells was IL-10. Conclusions: The proportion of CD16brightCD14+ monocytes was positively correlated with RA disease activity. The expression of CD16 in monocytes was induced by IL-10 but not IL-6, and IL-8 was enhanced in the sera of patients with RA. Our results suggest that CD16brightCD14+ monocytes are involved in the pathogenesis of RA and that IL-10 is a key cytokine that regulates CD16 expression in monocytes.

Objectives To investigate the clinical impact of 1-year certolizumab pegol (CZP) therapy added to the first year of 2-year methotrexate (MTX) therapy, compared with 2-year therapy with MTX alone. Methods MTX-naïve patients with early rheumatoid arthritis (RA) with poor prognostic factors were eligible to enter Certolizumab-Optimal Prevention of joint damage for Early RA (C-OPERA), a multicentre, randomised, controlled study, which consisted of a 52-week double-blind (DB) period and subsequent 52-week post treatment (PT) period. Patients were randomised to optimised MTX+CZP (n=159) or optimised MTX +placebo (PBO; n=157). Following the DB period, patients entered the PT period, receiving MTX alone (CZP+MTX→MTX; n=108, PBO+MTX→MTX; n=71). Patients who flared could receive rescue treatment with open-label CZP. Results 34 CZP+MTX→MTX patients and 14 PBO +MTX?MTX patients discontinued during the PT period. From week 52 through week 104, significant inhibition of total modified total Sharp score progression was observed for CZP+MTX versus PBO +MTX (week 104: 84.2% vs 67.5% (p<0.001)). Remission rates decreased after CZP discontinuation; however, higher rates were maintained through week 104 in CZP+MTX?MTX versus PBO+MTX?MTX (41.5% vs 29.3% (p=0.026), 34.6% vs 24.2% (p=0.049) and 41.5% vs 33.1% (p=0.132) at week 104 in SDAI, Boolean and DAS28(erythrocyte sedimentation rate) remission. CZP retreated patients due to flare (n=28) showed rapid clinical improvement. The incidence of overall adverse events was similar between groups. Conclusions In MTX-naïve patients with early RA with poor prognostic factors, an initial 1 year of add-on CZP to 2-year optimised MTX therapy brings radiographic and clinical benefit through 2 years, even after stopping CZP.

Objective: To assess the utility of erythrocyte methotrexate-polyglutamate (MTX-PG) concentrations in determining the safety and efficacy of MTX in patients with rheumatoid arthritis (RA). Methods: 79 MTX-naïve patients with RA were enrolled in this prospective 76-week cohort study. MTX was initiated, and a predefined dose-escalation protocol was followed. Erythrocyte MTX-PG concentrations were measured using liquid chromatography. The associations of MTX-PG concentrations with disease activity and adverse events were analysed. Results: Dose escalation of MTX resulted in increased MTX-PG concentrations and a decrease in the mean Disease Activity Score in 28 joints (DAS28). A significant association was observed between total MTX-PG concentrations and ΔDAS28 at week 12 (β=-0.013, p=0.003) and at week 24 (β=-0.014, p=0.003). The maximum MTX-PG levels were significantly higher in patients presenting with elevated transaminases (≥100 IU/L) than in those without (146 vs 106 nmol/L, p=0.009). Receiver operating characteristic curve analysis revealed that a total MTX-PG concentrations of 83 nmol/L at week 12 was the threshold for a DAS28 improvement of ≥1.2 at week 24, and 105 nmol/L was the threshold for transaminases of ≥50 IU/L and 131 nmol/L for transaminases of ≥100 IU/L. MTX-PG concentrations were strongly influenced by body mass index and a serum albumin level. Conclusions: MTX-PG concentrations are a useful biomarker in MTX therapy, in terms of efficacy and safety.

We investigated the effects of bendamustine on B cell functions and explored potential clinical applications of the drugs to autoimmune diseases. Proliferation of Ramos cells, a human B cell line, was significantly inhibited by 25–100 μM of bendamustine in a dose-dependent manner. Concordantly, IgM secretion from Ramos cells was significantly inhibited at these concentrations by up to 70%. Interestingly, however, the production and secretion of interleukin-10 (IL-10) were dramatically (at least > 10-fold) increased by bendamustine at growth inhibitory concentrations. Exploration of the molecular mechanism of IL-10 production revealed that bendamustine enhanced the phosphorylation of p38 MAP kinase. Further, Sp1 was identified as a downstream transcription factor, and the inhibition of p38 MAP kinase and Sp1 with their inhibitors led to the abrogation of bendamustine-induced IL-10 production and the DNA binding of Sp1. Importantly, when PBMC from healthy donors were cultured with bendamustine at the concentration of 30 μM, under the stimulation with an anti-IgM antibody, an anti-CD40 antibody, recombinant human IL-21 (rhIL-21) and recombinant human soluble BAFF (rhsBAFF), IL-10 production by B cells (CD20+CD4-CD8-CD14-) among peripheral blood mononuclear cell (PBMC) was significantly enhanced by adding bendamustine. These results collectively suggest that the p38 MAP kinase-Sp1 pathway plays a crucial role in bendamustine-induced IL-10 production by B cells. Our findings suggest a novel therapeutic possibility for autoimmune diseases through the upregulation of IL-10 which has an anti-inflammatory effects.

Background: Nearly all secreted proteins are glycosylated, and serum glycoproteins that exhibit disease-associated glycosylation changes have potential to be biomarkers. In rheumatoid arthritis (RA), C-reactive protein (CRP), and matrix metalloproteinase-3 (MMP-3) are widely used as serologic biomarkers, but they lack sufficient specificity or precision. We performed comparative glycosylation profiling of MMP-3 using a recently developed antibody-overlay lectin microarray technology that allows semicomprehensive and quantitative analysis of specific protein glycosylation to develop an RA-specific disease activity biomarker. Methods: Serum was taken from patients with RA (n = 24) whose disease activity was scored using composite measures, and MMP-3 was immunoprecipitated and subjected to lectin microarray analysis. A disease activity index (DAI) based on lectin signal was developed and validated using another cohort (n = 60). Synovial fluid MMP-3 in patients with RA and patients with osteoarthritis (OA) was also analyzed. Results: Intense signals were observed on a sialic acid-binding lectin (Agrocybe cylindracea galectin [ACG]) and O-glycan-binding lectins (Jacalin, Agaricus bisporus agglutinin [ABA], and Amaranthus caudatus agglutinin [ACA]) by applying subnanogram levels of serum MMP-3. ACG, ABA, and ACA revealed differences in MMP-3 quantity, and Jacalin revealed differences in MMP-3 quality. The resultant index, ACG/Jacalin, correlated well with disease activity. Further validation using another cohort confirmed that this index correlated well with several DAIs and their components, and reflected DAI changes following RA treatment, with correlations greater than those for MMP-3 and CRP. Furthermore, MMP-3, which generated a high ACG/Jacalin score, accumulated in synovial fluid of patients with RA but not in that of patients with OA. Sialidase digestion revealed that the difference in quality was derived from O-glycan α-2,6-sialylation. Conclusions: This is the first report of a glycoprotein biomarker using glycan change at a local lesion to assess disease activity in autoimmune diseases. Differences in the degree of serum MMP-3 α-2,6-sialylation may be a useful index for estimating disease activity.

The objective of the study was to identify risk factors for acute exacerbation of interstitial lung disease (ILD) during tocilizumab treatment in patients with rheumatoid arthritis (RA). This is a retrospective, case–control study. We reviewed 395 consecutive RA patients who received tocilizumab. First, we divided the patients according to the presence (RA-ILD) or absence of ILD (non-ILD) assessed by chest X-ray or high-resolution computed tomography, and compared them for characteristics relevant to RA-ILD. Subsequently, focusing on the patients with RA-ILD, we assessed their baseline characteristics and clinical courses comparing patients with acute exacerbation to those without. Comparing 78 with ILD and 317 without ILD, the following were identified as factors related to RA-ILD on multivariate analysis: age 60 years or older (OR 4.5, 95 % CI 2.2–9.4, P <0.0001), smoking habit (OR 2.9, 95 % CI 1.5–5.5, P = 0.002), and high rheumatoid factor levels (OR 2.8, 95 % CI 1.4–5.5, P = 0.002). Of 78 RA-ILD patients, six developed acute exacerbation during tocilizumab treatment. The median duration between the initiation of tocilizumab treatment and the acute exacerbation occurrence was 48 weeks. While baseline characteristics did not differ between acute exacerbation and non-acute exacerbation groups, patients experiencing acute exacerbation had significantly higher Clinical Disease Activity Index (CDAI) at 24 weeks (20.8 vs. 6.2, P = 0.019). Univariate analysis showed that CDAI > 10 at 24 weeks was a risk factor for acute exacerbation (OR 4.7, 95 % CI 2.1–10.4, P = 0.02). Uncontrolled arthritis activity during tocilizumab treatment may be associated with acute exacerbation of RA-ILD, suggesting post-treatment monitoring of disease activity is important not only with respect to RA itself but also for RA-ILD.

Objective: To explore the baseline predictors of clinical effectiveness after tocilizumab or infliximab treatment in biologic-naïve rheumatoid arthritis patients. Methods: Consecutive biologic-naïve patients with rheumatoid arthritis initiating infliximab (n = 57) or tocilizumab (n = 70) treatment were included in our prospective cohort study. Our cohort started in February 2010, and the patients observed for at least 1 year as of April 2013 were analysed. We assessed baseline variables including patients' characteristics (age, sex, disease duration, prednisolone dose, methotrexate dose, other disease-modifying antirheumatic drug use, Clinical Disease Activity Index [CDAI]) and serum biomarker levels (C-reactive protein, immunoglobulin M-rheumatoid factor, anti-cyclic citrullinated protein/pep-tide antibodies, interferon-y, interleukin (IL)-1β, IL-2, IL-6, IL-8, IL-10, IL-17, tumor necrosis factor-a, soluble intercellular adhesion molecule-1, bone alkaline phosphatase, osteonectin, osteopontin) to extract factors associated with clinical remission (CDAK2.8) at 1 year using univariate analyses, and the extracted factors were entered into a multivariate logistic regression model. Similar analyses were also performed for Simplified Disease Activity Index (SDAI) remission (

Objectives: To clarify the prevalence of anti-signal recognition particle (anti-SRP) antibody in connective tissue diseases (CTDs) and investigate the clinical characteristics of patients without inflammatory myopathy. Method: Sera from 6180 patients with CTD were examined by immunoprecipitation (IPP) assays, and the records of patients positive for anti-SRP antibody were reviewed retrospectively. The antibody against the 54-kDa protein of SRP (SRP54) was quantified by enzyme-linked immunosorbent assay (ELISA) in patients with anti-SRP antibody. Results: Of the 28 patients positive for anti-SRP antibody, nine (32.1%) did not have inflammatory myopathy. The clinical diagnoses and characteristics of those patients varied considerably. In patients with inflammatory myopathy, the index of anti-SRP54 was much higher than in those without myopathy (1.15 vs. 0.46; p = 0.036). Conclusions: The prevalence of anti-SRP antibody was 0.5% in a cohort of Japanese patients with CTD, and one-third of them did not have inflammatory myopathy. Sera from patients with inflammatory myopathy recognized SRP54 more strongly than in those without myopathy.

Objective To investigate whether leucine-rich α2-glycoprotein (LRG) could be a biomarker for disease activity during interleukin-6 (IL-6) blockade treatment of rheumatoid arthritis (RA). Methods In 59 RA patients who were treated with tocilizumab for 24 weeks, serum LRG levels were determined by enzyme-linked immunosorbent assay. RA disease activity was evaluated by the Clinical Disease Activity Index (CDAI). Receiver operating characteristic (ROC) curve analysis was used to examine the diagnostic performance of LRG and other biomarkers. In monkeys with experimental autoimmune arthritis, swollen joint counts, joint pathologic changes, and blood levels of C-reactive protein (CRP) and LRG were evaluated after treatment with anti-IL-6 receptor antibody. Results Among tocilizumab-treated RA patients, those with active disease (CDAI >2.8) had significantly higher serum LRG levels compared to those whose disease was in remission. ROC curve analysis suggested that the LRG level was more useful than the CRP or matrix metalloproteinase 3 level or the erythrocyte sedimentation rate in discriminating between remission and active disease during therapy with tocilizumab. In monkeys treated with IL-6 blockade, joint scores were more closely correlated with LRG levels than with CRP levels. Histologic analysis of joints revealed that LRG levels correlated significantly with granulomatous tissue formation, cartilage degeneration, and bone destruction in IL-6 blockade-treated monkeys with low levels of CRP. Conclusion Under conditions of IL-6 inhibition, LRG was more useful than other biomarkers in discriminating between active and inactive disease in human RA and in detecting joint inflammation in experimental arthritis. LRG may serve as a convenient biomarker for RA disease activity during IL-6 blockade treatment.

Introduction: Although susceptibility genes for anti-citrullinated peptide/protein antibodies (ACPA)-positive rheumatoid arthritis (RA) have been successfully discovered by genome-wide association studies (GWAS), little is known about the genetic background of ACPA-negative RA. We intended to elucidate genetic background of ACPA-negative RA. Method: We performed a meta-analysis of GWAS comprising 670 ACPA-negative RA and 16,891 controls for 1,948,138 markers, followed by a replication study of the top 35 single nucleotide polymorphisms (SNPs) using 916 cases and 3,764 controls. Inverse-variance method was applied to assess overall effects. To assess overlap of susceptibility loci between ACPA-positive and -negative RA, odds ratios (ORs) of the 21 susceptibility markers to RA in Japanese were compared between the two subsets. In addition, SNPs were stratified by the p-values in GWAS meta-analysis for either ACPA-positive RA or ACPA-negative RA to address the question whether weakly-associated genes were also shared. The correlations between ACPA-positive RA and the subpopulations of ACPA-negative RA (rheumatoid factor (RF)-positive and RF-negative subsets) were also addressed. Results: Rs6904716 in LEMD2 of the human leukocyte antigen (HLA) locus showed a borderline association with ACPA-negative RA (overall p = 5.7 × 10-8), followed by rs6986423 in CSMD1 (p = 2.4 × 10-6) and rs17727339 in FCRL3 (p = 1.4 × 10-5). ACPA-negative RA showed significant correlations of ORs with ACPA-positive RA for the 21 susceptibility SNPs and non-HLA SNPs with p-values far from significance. These significant correlations with ACPA-positive RA were true for ACPA-negative RF-positive and ACPA-negative RF-negative RA. On the contrary, positive correlations were not observed between the ACPA-negative two subpopulations. Conclusion: Many of the susceptibility loci were shared between ACPA-positive and -negative RA.