中島 裕史

Toxoplasma is a common parasite worldwide that mainly affects the brain, lungs and eyes. Although toxoplasmic encephalitis is a lethal disease without treatment, past case reports show most patients with systemic lupus erythematosus who developed toxoplasmic encephalitis were misdiagnosed and treated as neuropsychiatric systemic lupus erythematosus, which led to unfavorable outcomes. We herein describe a case of disseminated toxoplasmosis affecting all the above organs with atypical symptoms, which developed with exacerbation of systemic lupus erythematosus. She had initially manifested with retinochoroiditis without vitritis, mild cognitive impairment and an isolated lung mass. These are completely different from the classic symptoms of toxoplasmosis that have been reported in patients with HIV infection and/or those after hematopoietic transplantation. Our case, together with previously reported cases, suggests the manifestation of toxoplasmosis that develops in systemic lupus erythematosus patients can be different from that seen in conventional cases and varies between individual patients. Our case highlights both the difficulty in and the importance of diagnosing toxoplasmosis in patients with systemic lupus erythematosus and provides helpful information to identify this rare, devastating, yet treatable disease.

OBJECTIVE: Pneumocystis pneumonia (PCP) is one of the most common opportunistic infections. In systemic autoimmune disease patients receiving immunosuppressive treatments, low lymphocyte count, old age and coexisting lung disease have been known as risk factors for the occurrence of PCP. However, factors relevant to prognosis of PCP have not been fully studied. METHODS: A total of 95 sequential patients who developed PCP during immunosuppressive treatment for systemic autoimmune diseases was identified from five Japanese centres. We retrospectively assessed baseline characteristics, immunosuppressive treatment prior to the onset of PCP, treatment for PCP and survival. Univariate and multivariate analyses were performed to identify prognostic factors. RESULTS: Forty-two deaths (44.2%) were observed in this study. Age at the diagnosis of PCP was higher in non-survivors than in survivors (74 years vs. 64 years, p = 0.008). Non-survivors more frequently had lung involvement than did survivors (47.6% vs. 13.2%, p<0.001). Median lymphocyte count at the diagnosis of PCP was lower in non-survivors than in survivors (499/μl vs. 874/μl, p = 0.002). Multivariate analysis identified lower lymphocyte count, older age and coexisting lung disease at the diagnosis of PCP as independent risk factors for death. Those risk factors for death were similar to the known risk factors for the occurrence of PCP. CONCLUSION: Although PCP can occur even in patients without these risk factors, our data demonstrate that the overall prognosis of PCP in such patients is good. Given that the standard prophylactic treatment against PCP has safety issues, the risk-stratified use of prophylactic treatment may be advisable.

Clinical manifestations of systemic lupus erythematosus (SLE) in female patients with polysomy X have been less characterized as compared to those in male patients. Here, we describe a 28-year-old woman with trisomy X (47,XXX) who developed SLE. She had polyarthritis, hemolytic anemia, and was positive for anti-nuclear and anti-dsDNA antibodies. We discuss the common SLE manifestations with female polysomy X and the possible link between the development of SLE and the presence of extra X-chromosomes.

Although innate immune responses are necessary for the initiation of acquired immune responses and the subsequent successful elimination of pathogens, excessive responses occasionally result in lethal endotoxic shock accompanied by a cytokine storm. B and T lymphocyte attenuator (BTLA), a coinhibitory receptor with similarities to cytotoxic T-lymphocyte antigen (CTLA)-4 and programmed death (PD)-1, is expressed in not only B and T cells but also dendritic cells (DCs) and macrophages (Mφs). Recently, several studies have reported that BTLA-deficient (BTLA-/-) mice show enhanced pathogen clearance compared withWTmice in early phase of infections. However, the roles of BTLA expressed on innate cells in overwhelming and uncontrolled immune responses remain unclear. Here, we found that BTLA-/- mice were highly susceptible to LPS-induced endotoxic shock. LPS-induced TNF-α and IL-12 production in DCs and Mφs was significantly enhanced in BTLA -/- mice. BTLA-/- DCs also produced high levels of TNF-α on stimulation with Pam3CSK4 but not poly(I:C) or CpG, suggesting that BTLA functions as an inhibitory molecule on Toll-like receptor signaling at cell surface but not endosome. Moreover, BTLA-/- DCs showed enhanced MyD88- and toll/IL-1R domain-containing adaptor inducing IFN (TRIF)-dependent signaling on LPS stimulation, which is associated with impaired accumulation of Src homology 2-containing protein tyrosine phosphatase in lipid rafts. Finally, we found that an agonistic anti-BTLA antibody rescued mice from LPS-induced endotoxic shock, even if the antibody was given to mice that had developed a sign of endotoxic shock. These results suggest that BTLA directly inhibits LPS responses in DCs and Mφs and that agonistic agents for BTLA might have therapeutic potential for LPS-induced endotoxic shock. © PNAS 2013.

INTRODUCTION: Antineutrophil cytoplasm antibody-associated vasculitis (AAV) is a form of systemic vasculitis. The current standard induction therapy with the combination of high-dose glucocorticoids and cyclophosphamide or rituximab has high remission rates of 80%-90%. However, it is also associated with various side effects, including death due to infection or cardiovascular disease. There is an unmet medical need of a new therapy to reduce side effects. METHODS AND ANALYSIS: This is a phase IV multicentre, open-label, randomised controlled trial that aims to evaluate the efficacy and safety of a new remission induction regimen with the combination of low-dose glucocorticoids and rituximab. Newly diagnosed patients with AAV will be assessed for eligibility at 34 tertiary rheumatology/nephrology centres in Japan. One hundred and forty patients will be randomised (1:1) to receive low-dose prednisolone (0.5 mg/kg daily) plus rituximab (375 mg/m2 weekly) or high-dose prednisolone (1 mg/kg daily) plus rituximab. The trial consists of remission induction and maintenance phases. The primary endpoint of the study is the remission rate at 6 months (induction phase). Relapse and long-term safety profile will also be assessed until 24 months (maintenance phase). ETHICS AND DISSEMINATION: The protocol was first approved by the Institutional Review Board of Chiba University Hospital (reference number: G25051), and then approved by each participating site. The trial was registered at the University hospital Medical Information Network (UMIN) clinical registry (UMIN000014222) and ClinicalTrials.gov registry (NCT02198248). The Low-dose Glucocorticoid Vasculitis Induction Study (LoVAS) trial is currently ongoing and is due to finish in September 2019. The findings of this trial will be disseminated to participants through peer-reviewed publications and presented at national and international conferences in accordance with the Consolidated Standards of Reporting Trials (CONSORT) Statement. TRIAL REGISTRATION NUMBER: UMIN000014222; NCT02198248.

Alternatively activated macrophages (M2 macrophages) play key roles in the suppression of Th1 cell responses and the orchestration of tissue repair. However, recent studies have shown that M2 macrophages have potentials to produce high levels of proinflammatory cytokines such as IL-1 beta, IL-6, and TNF-alpha, suggesting that M2 macrophages may exacerbate inflammation in some settings. In this regard, we have recently shown that large numbers of M2 macrophages accumulate in the sites of hapten-induced contact hypersensitivity (CHS), an animal model of allergic contact dermatitis, and that M2 macrophages exacerbate hapten-induced CHS by producing matrix metalloproteinase 12 (MMP12). We have also shown that suppressor of cytokine signaling-3 (SOCS3), a member of SOCS family proteins that are cytokine-inducible negative regulators of the JAK/STAT signaling pathways, is highly and preferentially expressed in M2 macrophages in hapten-induced CHS and that SOCS3 expressed in M2 macrophages is involved in the attenuation of CHS by suppressing MMP12 production. These findings underscore the importance of M2 macrophage-derived MMP12 in the development of CHS, and suggest that inhibition of M2 macrophages or MMP12 could be a potential therapeutic strategy for the treatment of allergic contact dermatitis. Copyright (C) 2017, Japanese Society of Allergology. Production and hosting by Elsevier B.V.

Allergic asthma is characterized by eosinophilic airway inflammation, mucus hyperproduction, and airway hyperreactivity, causing reversible airway obstruction. Accumulating evidence indicates that antigen-specific Th2 cells and their cytokines such as IL-4, IL-5, and IL-13 orchestrate these pathognomonic features of asthma. However, over the past decade, the understanding of asthma pathogenesis has made a significant shift from a Th2 cell-dependent, IgE-mediated disease to a more complicated heterogeneous disease. Recent studies clearly show that not only Th2 cytokines but also other T cell-related cytokines such as IL-17A and IL-22 as well as epithelial cell cytokines such as IL-25, IL-33, and thymic stromal lymphopoietin (TSLP) are involved in the pathogenesis of asthma. In this review, we focus on the roles of these players beyond Th2 pathways in the pathogenesis of asthma.

Background: Innate lymphoid cells (ILCs) are emerging subsets of immune cells that produce large amounts of cytokines upon cytokine and/or alarmin stimulation. Recent studies have shown that T-bet plays pivotal roles in the development of ILC3s and type 1 ILCs; however, the roles of T-bet in lung type 2 innate lymphoid cells (ILC2s) remain unknown. Objective: We sought to determine the role of T-bet in ILC2-mediated airway inflammation. Methods: The expression of T-bet in lung ILCs (defined as Thy1.2(+) Lin(-) cells) was examined. The roles of T-bet in the development of lung ILC2s and airway inflammation induced by IL-33 administration were examined by using T-bet-deficient (T-bet(-/-)) mice. Gene expression profiles of T-bet(-/-) lung ILCs were analyzed by RNA sequencing. Results: T-bet was expressed in lung ILC2s (defined as Thy1.2(+) Lin(-) cells expressing ST2 or CD25) and IFN-gamma enhanced its expression. Although the development of lung ILC2s at steady-state conditions was normal in T-bet(-/-) mice, IL-33-induced accumulation of lung ILC2s and eosinophilic airway inflammation were exacerbated in T-bet(-/-) mice. The exacerbated accumulation of ILC2s and eosinophilic airway inflammation by the absence of T-bet were evident even in a RAG2(-/-) background, suggesting that T-bet expressed in non-T/non-B population is involved in the suppression of IL-33-induced eosinophilic airway inflammation. Transcriptome analysis revealed that IL-9 expression in IL-33-stimulated lung ILCs was upregulated in T-bet(-/-) mice compared with that in wild-type mice. Importantly, neutralization of IL-9 markedly attenuated IL-33-induced accumulation of lung ILC2s and eosinophilic inflammation in T-bet(-/-) mice. Conclusions: T-bet suppresses IL-9 production from lung ILC2s and thereby inhibits IL-33-induced eosinophilic airway inflammation.

It is well known that sensitization against fungi is closely associated with severity of asthma. Dectin-1 (gene symbol Clec7a), a C-type lectin receptor, recognizes the fungal cell wall component beta-glucan, as well as some component(s) in house dust mite (HDM) extract. However, the roles of Dectin-1 in HDM-induced allergic airway inflammation remain unclear. In this study, we used Dectin-1-deficient (Clec7a(-/-)) mice to examine whether Dectin-1 is involved in HDM-induced allergic airway inflammation. We found that HDM-induced eosinophil and neutrophil recruitment into the airways was significantly attenuated in Clec7a(-/-) mice compared with that in wild-type mice. In addition, HDM-induced IL-5, IL-13, and IL-17 production from mediastinum lymph node cells was reduced in HDM-sensitized Clec7a(-/-) mice. Dectin-1 was expressed on CD11b(+) dendritic cells (DCs), an essential DC subset for the development of allergic inflammation, but not on CD103(+) DCs, plasmacytoid DCs, or lung epithelial cells. Transcriptome analysis revealed that the expression of chemokine/chemokine receptors, including CCR7, which is indispensable for DC migration to draining lymph nodes, was decreased in Clec7a(-/-) DCs. In accordance with these results, the number of HDM-labeled CD11b(+) DCs in mediastinum lymph nodes was significantly reduced in Clec7a(-/-) mice compared with wild-type mice. Taken together, these results suggest that Dectin-1 expressed on CD11b(+) DCs senses some molecule(s) in HDM extract and plays a critical role in the induction of HDM-induced allergic airway inflammation by inducing the expression of chemokine/chemokine receptors in DCs.

Asthma is a chronic allergic inflammatory disease of the airways. The symptoms can be controlled by inhaled corticosteroids together with long-acting β2 agonists in the majority of patients however, in some patients, their symptoms remain uncontrolled even under intensive treatment. Although underlying mechanisms of the heterogeneous responses to the treatment are largely unknown, a series of recent epidemiological studies have suggested a link between the severity of asthma and the sensitization to fungi. Dectin-1, a C-type lectin receptor expressed on myeloid cells and plays protective roles against fungi by recognizing a cell-wall component of fungi, has recently been suggested to be involved in the development of severe asthma. In this review, we summarize the roles of Dectin-1 in the pathogenesis of severe asthma and discuss the possibility of its therapeutic application.

Objective. To determine the prevalence of lung abnormalities on chest computed tomography (CT) in patients with microscopic polyangiitis (MPA), to assess the responsiveness of such abnormalities to initial treatment, and to assess associations between these abnormalities and patient and disease characteristics and mortality. Methods. We retrospectively identified 167 consecutive hospital-based patients with MPA in 3 hospitals in Japan. We longitudinally collected clinical information for 150 of these patients, for whom CT images obtained before treatment were available. We then determined the presence of 22 imaging components of lung abnormalities in these patients. Results. The vast majority of patients (97%) had at least 1 lung abnormality on chest CT images, including interstitial lung lesions (66%), airway lesions (66%), pleural lesions (53%), and emphysematous lesions (37%). In multivariate analyses, ground-glass opacity was associated with the Birmingham Vasculitis Activity Score, whereas 3 of 4 airway lesions were associated with myeloperoxidase-antineutrophil cytoplasmic antibodies. Latent class analysis identified a distinct group of patients with airway-predominant lung lesions. Airway lesions such as bronchiolitis and bronchovascular bundle thickening were among the components that showed improvement within 3 months of the initial treatment. An idiopathic pulmonary fibrosis pattern was the only chest CT variable that was independently associated with shorter survival. Conclusion. Abnormalities in a wide range of anatomic areas, including the whole airway, can be identified in the lungs of patients with MPA before treatment. The prevalence, clustering patterns, and responsiveness to treatment of individual lung abnormalities provide groundwork for informing future studies to understand the pathophysiology of MPA.

Numerous studies have clarified the immunological mechanisms of contact hypersensitivity (CHS). In addition, we have recently shown that M2 macrophages play key roles in the development of CHS by producing matrix metalloproteinase-12 (MMP-12). However, regulatory mechanisms of the elicitation phase in CHS remain largely unknown. To determine the roles of suppressor of cytokine signaling (SOCS) family members in M2 macrophages in the regulation of CHS, we investigated the expression of SOCS family members in M2 macrophages at the inflammatory sites of CHS. Transcriptome analysis revealed that among SOCS family members, SOCS3 was highly expressed in M2 macrophages at the site of CHS, and SOCS3 induction was reduced by IFN-g neutralization. 2,4-Dinitrofluorobenzeneeinduced CHS was significantly enhanced and prolonged in mice lacking SOCS3 expression in monocytes/macrophages (SOCS3D/D mice) compared with that in control mice. Importantly, expression of MMP-12 in M2 macrophages was significantly increased in SOCS3D/D mice at the site of CHS, and deletion of the MMP-12 gene reduced the exacerbated CHS in SOCS3D/D mice. Finally, IFN-g inhibited IL-4-induced MMP-12 expression in a SOCS3-dependent manner. Taken together, these results suggest that SOCS3 expressed in M2 macrophages is involved in the attenuation and/or resolution of CHS, presumably by suppressing MMP-12 production.

Objective. We have previously shown that expression of the Bcl-3 gene, a member of the IkB 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. Methods. DNA microarray analysis was used to compare the signal intensity of Bcl-3 in CD41+ T cells from untreated RA patients and healthy controls. We examined the roles of interleukin-6 (IL-6)/ STAT-3 signaling in the induction of Bcl-3. In addition, we analyzed the gene expression profiles of Bcl-3-transduced CD4+ T cells by RNA sequencing. The effects of enforced expression as well as gene silencing of Bcl-3 on the development of follicular helper T (Tfh) cells were evaluated. Finally, we examined correlations between the signal intensities of Bcl-3 and Tfh cell-related genes in CD4+ T cells from untreated RA patients. Results. Bcl-3 levels were significantly higher in RA patients than in healthy controls. IL-6 induced Bcl-3 expression in CD41 T cells in a STAT-3-dependent manner. Transcriptome analysis revealed that the expression of Bcl-6, a master regulator of Tfh cell differentiation, was significantly up-regulated by the enforced Bcl-3 expression. The enforced Bcl-3 expression increased, but Bcl-3 silencing decreased, the numbers of IL-21-producing Tfh-like cells. Bcl-3 levels in CD4+ T cells from RA patients correlated positively with the levels of Tfh cell-related genes CXCR5, inducible costimulator, and achaete-scute homolog 2. Conclusion. Bcl-3 is involved in the development of Tfh cells and the pathogenesis of RA, presumably by inducing IL-21 production.

Objective. Helios+FoxP3+CD4+ (Helios+) Treg cells are believed to be involved in the regulation of various autoimmune diseases; however, the regulatory mechanisms underlying the development of Helios+ Treg cells remain uncertain. This study was undertaken to elucidate the regulatory mechanisms of Helios expression in CD4+ T cells and its roles in transforming growth factor beta (TGF)-induced Treg cell function. Methods. We examined the expression of Helios in CD4+ T cells in patients with rheumatoid arthritis by DNA microarray analysis before and after treatment with biologic agents. We also examined the effect of interleukin-6 (IL-6) and TGF beta on Helios expression in CD4+ T cells in humans and mice. The effect of forced expression of Helios on murine induced Treg cell function was also examined. The role of FoxP3 in the induction and function of Helios was assessed by using CD4+ T cells from FoxP3-deficient scurfy mice. Results. Tocilizumab, but not tumor necrosis factor (TNF) inhibitors or abatacept, increased Helios expression in CD4+ T cells in patients with a good response. IL-6 inhibited the TGF beta-induced development of Helios+ induced Treg cells in both humans and mice. Both cell-intrinsic FoxP3 expression and TGF beta signaling were required for Helios induction in murine induced Treg cells. The forced expression of Helios enhanced the expression of various Treg cell-related molecules and the suppressive function in murine induced Treg cells. Helios-mediated enhancement of the suppressive function of induced Treg cells was obvious in FoxP3-sufficient CD4+ T cells but not in FoxP3-deficient CD4+ T cells. Conclusion. Our findings indicate that Helios enhances induced Treg cell function in cooperation with FoxP3.

Objective. In the treatment of polymyositis (PM) and dermatomyositis (DM), muscle inflammation and underlying autoimmunity need to be suppressed promptly; however, catabolic effects of corticosteroids such as myopathy can be detrimental in PM/DM. In this study, we aimed to assess the corticosteroid-sparing effect of tacrolimus in the initial treatment of PM/DM. Methods. We retrospectively identified 19 PM/DM patients who received initial treatment with prednisolone at an initial dose of 1 mg/kg/day (Conventional Monotherapy, our standard therapy before 2008) and 23 patients with tacrolimus plus prednisolone at an initial dose 0.8 mg/kg/day (Tacrolimus Combination, our standard therapy after 2008). Data until 36 months after commencing treatment were collected. Results. There were no statistically significant differences in baseline characteristics between two groups. Median daily dose of prednisolone in the Tacrolimus Combination Group was significantly lower than that in the Conventional Monotherapy Group during the study period, whereas the proportion of patients who required additional immunosuppressive medications for remission induction was comparable. Remission was achieved in all patients, except one who died of refractory interstitial lung disease after receiving Conventional Monotherapy. The time required for creatine kinase normalization and relapse rate was comparable between two groups. The period of hospitalization for initial treatment was significantly shorter and survival without serious infection or relapse tended to be longer in the Tacrolimus Combination than the Conventional Monotherapy. Conclusion. This study provides real-life data which demonstrate that tacrolimus has a corticosteroid-sparing effect and reduces the length of hospitalization period for the initial treatment of PM/DM.

Objective, 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. Methods. RA patients in clinical remission (Disease Activity Score in 28 joints [DAS28] &lt;2.6) receiving treatment with a biologic agent who agreed to discontinue the treatment were recruited. Patients underwent a comprehensive ultrasound scan on 134 synovial sites in 40 joints and were prospectively followed up for 6 months. Physicians who evaluated the patients during the study period were blinded to the baseline ultrasound findings. Results. Forty-two patients receiving either a tumor necrosis factor antagonist or tocilizumab were enrolled. Using the optimal cutoff values determined by receiver operating characteristic curve analysis, relapse rates were significantly higher in patients whose total ultrasound scores at discontinuation were high than in those whose total ultrasound scores were low (P &lt; 0.001 for both total gray-scale and power Doppler scores), whereas the difference between high and low DA528 was not statistically significant (P = 0.158 by log rank test). Positive and negative predictive values were 80.0% and 73.3% for the total gray-scale score and 88.9% and 74.2% for the total power Doppler score, respectively. Conclusion. In RA patients in clinical remission receiving treatment with a biologic agent, residual synovial inflammation determined by comprehensive ultrasound assessment predicted relapse within a short term after discontinuation of the treatment. Our data provide a rationale and groundwork to conduct a large-scale study for establishment of ultrasound-based strategies to optimize the period of treatment with a biologic agent.

Stat3 signaling is essential for the induction of ROR gamma t and subsequent Th17 cell differentiation. However, the downstream targets of Stat3 for ROR gamma t expression remain largely unknown. We show here that a novel isoform of Sox5, named Sox5t, is induced in Th17 cells in a Stat3-dependent manner. In vivo, T cell-specific Sox5-deficient mice exhibit impaired Th17 cell differentiation and are resistant to experimental autoimmune encephalomyelitis and delayed-type hypersensitivity. Retrovirus-mediated induction of Sox5 together with c-Maf induces Th17 cell differentiation even in Stat3-deficient CD4(+) T cells but not in ROR gamma t-deficient CD4(+) T cells, indicating that Sox5 and c-Maf induce Th17 cell differentiation as downstream effectors of Stat3 and as upstream inducers of ROR gamma t. Moreover, Sox5 physically associates with c-Maf via the HMG domain of Sox5 and DNA-binding domain of c-Maf, and Sox5 together with c-Maf directly activates the promoter of ROR gamma t in CD4(+) T cells. Collectively, our results suggest that Sox5 and c-Maf cooperatively induce Th17 cell differentiation via the induction of ROR gamma t as downstream targets of Stat3.