Junichi Hosokawa

Prediction of Relapse After Discontinuation of Biologic Agents by Ultrasonographic Assessment in Patients With Rheumatoid Arthritis in Clinical Remission: High Predictive Values of Total Gray‐Scale and Power Doppler Scores That Represent Residual Synovial Inflammation Before Discontinuation

This prospective study aimed to determine whether the comprehensive ultrasonographic assessment of synovial inflammation predicts relapse after discontinuation of treatment with a biologic agent in patients with rheumatoid arthritis (RA) in clinical remission.

Roles of mast cells in the pathogenesis of inflammatory myopathy

IntroductionIn addition to the pivotal roles of mast cells in allergic diseases, recent data suggest that mast cells play crucial roles in a variety of autoimmune responses. However, their roles in the pathogenesis of autoimmune skeletal muscle diseases have not been clarified despite their distribution in skeletal muscle. Therefore, the objective of this study is to determine the roles of mast cells in the development of autoimmune skeletal muscle diseases.MethodsThe number of mast cells in the affected muscle was examined in patients with dermatomyositis (DM) or polymyositis (PM). The susceptibility of mast cell-deficient WBB6F1-KitW/KitWv mice (W/Wv mice) to a murine model of polymyositis, C protein-induced myositis (CIM), was compared with that of wild-type (WT) mice. The effect of mast cell reconstitution with bone marrow-derived mast cells (BMMCs) on the susceptibility of W/Wv mice to CIM was also evaluated.ResultsThe number of mast cells in the affected muscle increased in patients with PM as compared with patients with DM. W/Wv mice exhibited significantly reduced disease incidence and histological scores of CIM as compared with WT mice. The number of CD8+ T cells and macrophages in the skeletal muscles of CIM decreased in W/Wv mice compared with WT mice. Engraftment of BMMCs restored the incidence and histological scores of CIM in W/Wv mice. Vascular permeability in the skeletal muscle was elevated in WT mice but not in W/Wv mice upon CIM induction.ConclusionMast cells are involved in the pathogenesis of inflammatory myopathy.

Efficacy of abatacept for arthritis in patients with an overlap syndrome between rheumatoid arthritis and systemic lupus erythematosus.

Introduction. This study aimed to investigate the efficacy of abatacept for arthritis in patients with rhupus, an overlap syndrome between rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). Methods. Patients who fulfilled both the 2010 ACR/EULAR criteria for RA classification and the 1997 ACR revised criteria for classification of SLE and received abatacept treatment for arthritis were retrospectively studied. Results. Six rhupus patients who fulfilled the inclusion criteria above were identified. All patients had active arthritis despite receiving antirheumatic drugs including methotrexate when abatacept was initiated. Clinical Disease Activity Index (CDAI) significantly decreased between baseline and 12 weeks (P = 0.028) and remained low through 24 weeks. All patients achieved either a good or moderate response according to the EULAR response criteria at 24 weeks. Health Assessment Questionnaire-Disability Index (HAQ-DI) also significantly decreased between baseline and 24 weeks (P = 0.043). In addition, the levels of immunoglobulin G and anti-DNA antibody significantly decreased between baseline and 24 weeks (P = 0.028 and P = 0.043, resp.). Conclusions. Treatment with abatacept is likely to be efficacious in patients with rhupus whose arthritis is refractory to methotrexate. In addition, abatacept may have a moderate effect on abnormal antibody production in rhupus patients.

Role of Bcl‐3 in the Development of Follicular Helper T Cells and in the Pathogenesis of Rheumatoid Arthritis

We have previously shown that expression of the Bcl‐3 gene, a member of the IκB family, is down‐regulated in CD4+ T cells from patients with rheumatoid arthritis (RA) following tocilizumab therapy. The objective of this study was to examine the role of Bcl‐3 in the pathogenesis of RA.

Matrix metalloproteinase 12 is produced by M2 macrophages and plays important roles in the development of contact hypersensitivity.

possible that toddlers who wheeze and cough a lot because of increased exposure to infectious agents (nursery care, crowding) have a better prognosis than do peers who have these symptoms in the absence of exposure. This might explain the trend toward a poorer prognosis in children who were not in nursery care and did not live in crowded households, which was seen in some of the models with reduced penalization. Our findings contrast with those reported by Balemans et al, who found that maternal smoking while children were toddlers predicted asthma in young adults in their cohort. Balemans et al included only a few symptoms as potential predictors and used stepwise logistic regression to derive the finalmodel, whichmight explain why maternal smoking was a better predictor in their model than in ours. In our cohort, maternal smoking was one of the first predictors joining the PARC tool score when we lowered the penalization, but it did not improve the predictive performance of the PARC tool. The strength of our study lies in its large sample size and clinically relevant population. We used an objective approach for variable selection that minimized overfitting the data. A limitation common to other tools is that symptoms and exposures are parentreported. This reflects the situation in clinical practice, in which many decisions are based on medical history taken from parents. Future research should evaluate whether such tools can be improved by including results from clinical tests, such as allergy tests, lung function, and exhaled nitric oxide. In summary, the asthma risk assessment tool PARC, which uses detailed clinical data, performs moderately well. Adding information on environmental and socioeconomic exposures did not improve the PARC tool’s predictive performance.

Role of Calcium Ionophore A23187-Induced Activation of IkappaB Kinase 2 in Mast Cells

Background: Mast cells are known to play a pivotal role in allergic diseases by releasing granules containing histamine and other preformed chemical mediators. Cross-linking of high-affinity receptors for IgE (FceRI) on mast cells results in rapid increases in intracellular free calcium concentration [Ca2+]i and consequent activation of many transcription factors, including NFAT, NF-κB, JNK and CREB. Ca2+ signaling is essential for many cellular activities such as proliferation, gene expression and degranulation in mast cells. In addition to Ca2+ signaling, previous reports have shown that IkappaB kinase 2 (IKK2 or IKKß), a central component of the IKK complex mediating NF-κB activation, also plays a crucial role in FceRI-mediated degranulation and cytokine production. Moreover, it has been demonstrated that activation of PKCß, a calcium-dependent PKC isoform, leads to IKK2 activation in many cell types. However, the roles of Ca2+ signaling and PKCß in the activation of IKK2 in mast cells remain largely unknown. Methods: We investigated the effect of PKC inhibitor Gö6976 on calcium ionophore A23187-induced activation of IKK2 in mast cells. We also examined the role of IKK2 in A23187-induced NF-κB-dependent gene induction, degranulation, proinflammatory cytokine production and extracellular signal-regulated kinases 1 and 2 (ERK1/2) activation by using IKK2-deficient (IKK2-/-) fetal liver-derived mast cells (FLMCs). Results: A23187 activated IKK2 and NF-κB even in the presence of Gö6976 in mast cells. A23187-induced degranulation, cytokine production and activation of ERK1/2 were diminished in IKK2-/- FLMCs compared to those in wild-type FLMCs. Conclusions: Ca2+-IKK2 signaling is involved in the degranulation and cytokine production in activated mast cells by a mechanism independent of PKCß.

Therapeutic Potential of B and T Lymphocyte Attenuator Expressed on CD8+ T Cells for Contact Hypersensitivity

In the past decade, mechanisms underlying allergic contact dermatitis have been intensively investigated by using contact hypersensitivity (CHS) models in mice. However, the regulatory mechanisms, which could be applicable for the treatment of allergic contact dermatitis, are still largely unknown. To determine the roles of B and T lymphocyte attenuator (BTLA), a CD28 family coinhibitory receptor, in hapten-induced CHS, BTLA-deficient (BTLA(-/-)) mice and littermate wild-type (WT) mice were subjected to DNFB-induced CHS, severe combined immunodeficient (SCID) mice were injected with CD4(+) T cells, and CD8(+) T cells from either WT mice or BTLA(-/-) mice were subjected to CHS. BTLA(-/-) mice showed enhanced DNFB-induced CHS and proliferation and IFN-γ production of CD8(+) T cells as compared with WT mice. SCID mice injected with WT CD4(+) T cells and BTLA(-/-) CD8(+) T cells exhibited more severe CHS as compared with those injected with WT CD4(+) T cells and WT CD8(+) T cells. On the other hand, SCID mice injected with BTLA(-/-) CD4(+) T cells and WT CD8(+) T cells exhibited similar CHS to those injected with WT CD4(+) T cells and WT CD8(+) T cells. Finally, to evaluate the therapeutic potential of an agonistic agent for BTLA on CHS, the effects of an agonistic anti-BTLA antibody (6A6) on CHS were examined. In vivo injection of 6A6 suppressed DNFB-induced CHS and IFN-γ production of CD8(+) T cells. Taken together, these results suggest that stimulation of BTLA with agonistic agents has therapeutic potential in CHS.

OP0120 Roles of B Cell Leukemia/Lymphoma 3 in The Development of T Follicular Helper Cells and the Pathogenesis of Rheumatoid Arthritis

Background Rheumatoid arthritis (RA) is a chronic inflammatory disease and proinflammatory cytokines such as TNFα and IL-6 play critical roles in the pathogenesis of RA. The blockade of IL-6 signaling by Tocilizumab (TCZ) has shown the clinical efficacy for patients with RA. To clarify the roles of IL-6 signaling in CD4+ T cells in the pathogenesis of RA, we previously compared gene expression profiles of CD4+ T cells by DNA microarray analysis before and after the treatment with TCZ in RA patients who exhibited good clinical responses to the treatment (1, 2), and identified that B cell leukemia/lymphoma 3 (Bcl3), an IκB family member, was down-regulated by TCZ therapy (1). However, the role of Bcl3 expressed in CD4+ T cells in the pathogenesis of RA remains unclear. Objectives The objective of this study is to examine the role of Bcl3 expressed in CD4+ T cells in the pathogenesis of RA. Methods We compared signal intensity of Bcl3 in CD4+ T cells between untreated RA patients and healthy controls by DNA microarray analysis. We examined the roles of IL-6-STAT3 signaling in Bcl3 induction. We also analyzed gene expression profiles of Bcl3-transduced CD4+ T cells by RNA-sequencing analysis. We examined the effect of enforced expression as well as gene silencing of Bcl3 on the development of T follicular helper (Tfh) cells. Finally, we examined a correlation between signal intensities of Bcl3 and Tfh cell-related genes in CD4+ T cells in untreated RA patients. Results Bcl3 levels were significantly higher in RA patients than those in healthy controls. IL-6 induced Bcl3 expression in CD4+ T cells in a STAT3-dependent manner. Transcriptome analysis revealed that the expression of Bcl6, a master regulator of Tfh cell differentiation, was significantly upregulated by the enforced Bcl3 expression (Figure1). The enforced Bcl3 expression increased but the Bcl3 silencing decreased IL-21-producing Tfh-like cells. Bcl3 levels were positively correlated with those of Tfh cell-related genes such as CXCR5, ICOS, and ASCL2 in CD4+ T cells in RA patients. Conclusions Bcl3 is involved in the development of Tfh cells and the pathogenesis of RA presumably by inducing IL-21 production. References Saito Y, Kagami SI, Sanayama Y, Ikeda K, Suto A, Kashiwakuma D, et al. AT-rich interactive domain-containing protein 5a functions as a negative regulator of RORγt-induced Th17 cell differentiation. Arthritis Rheum. 2014;66(5):1185-94. Sanayama Y, Ikeda K, Saito Y, Kagami S, Yamagata M, Furuta S, et al. Prediction of therapeutic responses to tocilizumab in patients with rheumatoid arthritis: biomarkers identified by analysis of gene expression in peripheral blood mononuclear cells using genome-wide DNA microarray. Arthritis Rheum. 2014;66(6):1241-31. Disclosure of Interest K. Meguro: None declared, K. Suzuki: None declared, J. Hosokawa: None declared, Y. Sanayama: None declared, S. Tanaka: None declared, S. Furuta: None declared, K. Ikeda: None declared, H. Takatori: None declared, A. Suto: None declared, O. Ohara: None declared, H. Nakajima Grant/research support from: Chugai Pharmaceutical Co., Ltd, Bristol-Myers Squibb, and Mitsubishi Tanabe Pharma Co.

SAT0021 Both Gray-Scale Synovial Hypertrophy and Synovial Power Doppler Signals on a Comprehensive Ultrasound Scan are the Predictive Factors of Relapse After Discontinuation of Biological Agents in Patients with Rheumatoid Arthritis

Background Clinical information does not accurately predict relapse after discontinuation of biological agents in patients with rheumatoid arthritis (RA). Although ultrasound is a sensitive tool to detect sub-clinical synovial inflammation in RA patients with low disease activity, the ultrasound findings on the unilateral hand did not discriminate between patients who relapsed and who did not after discontinuation of TNF antagonists in the previous report 1. Objectives This pilot, single-blinded, prospective study aimed to determine whether the comprehensive ultrasound scan on 40 joints is informative in the prediction of relapse after discontinuation of biological agents. Methods RA patients in remission states (DAS28 ≤ 2.6) receiving biological agents who agreed to discontinue the biological agent were recruited. Patients underwent a comprehensive ultrasound scan on 40 joints (DAS28 joints + ankles + MTP joints) and were prospectively followed up for 26 weeks. The physicians who evaluated the patients during the study period were blinded to the ultrasound findings at baseline. Results Thirty patients receiving either TNF antagonists (n = 24), or tocilizumab (n = 6) were enrolled. The disease activity was very low (median DAS28 1.64 [IQR 1.2-2.3]) before the biological agent was discontinued. Eleven patients had relapse which was defined as DAS28 > 3.2 and restarted receiving the same biological agent within 26 weeks. Total ultrasound scores provided with larger areas under the ROC curves for the prediction of relapse than DAS28 did. Using the optimal cut-off values determined by the ROC analysis, the PPV and NPV of total GS score ≥ 12 to predict flare were 88% and 82%, respectively. On the other hand, the PPV and NPV of total PD score ≥ 3 were 100% and 79%, respectively. Image/graph Conclusions In RA patients with very low disease activity receiving biological agents, a comprehensive ultrasound scan provides good diagnostic values to predict relapse after discontinuation of the biological agent. References Saleem B, Keen H, Goeb V, Parmar R, Nizam S, Hensor EM, et al. Patients with RA in remission on TNF blockers: when and in whom can TNF blocker therapy be stopped? Ann Rheum Dis 2010;69(9):1636-42. Disclosure of Interest T. Iwamoto: None Declared, K. Ikeda Grant/research support from: Mitsubishi-Tanabe Pharma Corporation, Abbott Japan Co., Ltd, Consultant for: Mitsubishi-Tanabe Pharma Corporation, Abbott Japan Co., Ltd, J. Hosokawa: None Declared, M. Yamagata: None Declared, S. Tanaka: None Declared, Y. Sanayama: None Declared, D. Nakagomi: None Declared, A. Okubo: None Declared, K. Takahashi: None Declared, K. Hirose: None Declared, M. Sueishi: None Declared, H. Nakajima Grant/research support from: Mitsubishi-Tanabe Pharma Corporation, Chugai Pharmaceutical Co., Ltd, Consultant for: Mitsubishi-Tanabe Pharma Corporation, Chugai Pharmaceutical Co., Ltd