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Castleman disease (CD) includes a group of rare and heterogeneous disorders with characteristic lymph node histopathological abnormalities. CD can occur in a single lymph node station, which is referred to as unicentric CD (UCD). CD can also involve multicentric lymphadenopathy and inflammatory symptoms (multicentric CD [MCD]). MCD includes human herpesvirus-8 (HHV-8)–associated MCD, POEMS-associated MCD, and HHV-8−/idiopathic MCD (iMCD). The first-ever diagnostic and treatment guidelines were recently developed for iMCD by an international expert consortium convened by the Castleman Disease Collaborative Network (CDCN). The focus of this report is to establish similar guidelines for the management of UCD. To this purpose, an international working group of 42 experts from 10 countries was convened to establish consensus recommendations based on review of treatment in published cases of UCD, the CDCN ACCELERATE registry, and expert opinion. Complete surgical resection is often curative and is therefore the preferred first-line therapy, if possible. The management of unresectable UCD is more challenging. Existing evidence supports that asymptomatic unresectable UCD may be observed. The anti–interleukin-6 monoclonal antibody siltuximab should be considered for unresectable UCD patients with an inflammatory syndrome. Unresectable UCD that is symptomatic as a result of compression of vital neighboring structures may be rendered amenable to resection by medical therapy (eg, rituximab, steroids), radiotherapy, or embolization. Further research is needed in UCD patients with persisting constitutional symptoms despite complete excision and normal laboratory markers. We hope that these guidelines will improve outcomes in UCD and help treating physicians decide the best therapeutic approach for their patients.

A cytokine storm induces acute respiratory distress syndrome, the main cause of death in coronavirus disease 2019 (COVID-19) patients. However, the detailed mechanisms of cytokine induction due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remain unclear. To examine the cytokine production in COVID-19, we mimicked the disease in SARS-CoV-2-infected alveoli by adding the lysate of SARS-CoV-2-infected cells to cultured macrophages or induced pluripotent stem cell-derived myeloid cells. The cells secreted interleukin (IL)-6 after the addition of SARS-CoV-2-infected cell lysate. Screening of 25 SARS-CoV-2 protein-expressing plasmids revealed that the N protein-coding plasmid alone induced IL-6 production. The addition of anti-N antibody further enhanced IL-6 production, but the F(ab’)2 fragment did not. Sera from COVID-19 patients also enhanced IL-6 production, and sera from patients with severer disease induced higher levels of IL-6. These results suggest that anti-N antibody promotes IL-6 production in SARS-CoV-2-infected alveoli, leading to the cytokine storm of COVID-19. (150 words)

Background and Aim: Tocilizumab, a humanized anti-IL-6 receptor antibody, has been used to treat severely to critically ill patients with COVID-19. A living systematic review with meta-analysis of recent RCTs indicates that the combination therapy of corticosteroids and tocilizumab produce better outcomes, while previous observational studies suggest that tocilizumab monotherapy is beneficial for substantial numbers of patients. However, what patients could respond to tocilizumab monotherapy remained unknown.Methods: In this retrospective study we evaluated the effects of tocilizumab monotherapy on the clinical characteristics, serum biomediator levels, viral elimination, and specific IgG antibody induction in 13 severely to critically ill patients and compared with those of dexamethasone monotherapy and dexamethasone plus tocilizumab.Results: A single tocilizumab administration led to a rapid improvement in clinical characteristics, inflammatory findings, and oxygen supply in 7 of 11 patients with severe COVID-19, and could recover from mechanical ventilation management (MVM) in 2 patients with critically ill COVID-19. Four patients exhibited rapidly worsening even after tocilizumab administration and required MVM and additional methylprednisolone treatment. Tocilizumab did not delay viral elimination or inhibit IgG production specific for the virus, whereas dexamethasone inhibited IgG induction. A multiplex cytokine array system revealed a significant increase in the serum expression of 54 out of 80 biomediators in patients with COVID-19 compared with that in healthy controls. Compared with those who promptly recovered in response to tocilizumab, patients requiring MVM showed a significantly higher ratio of basal level of ferritin/CRP and a persistent increase in the levels of CRP and specific cytokines and chemokines including IL-6, IFN-γ, IP-10, and MCP-1. The basal high ratio of ferritin/CRP was also associated with clinical deterioration even in patients treated with dexamethasone and tocilizumab.Conclusion: Tocilizumab as monotherapy has substantial beneficial effects in some patients with severe COVID-19, who showed a relatively low level of the ratio of ferritin/CRP and prompt reduction in CRP, IL-6, IFN-γ, IP-10, and MCP-1. The high ratio of ferritin/CRP is associated with rapid worsening of pneumonia. Further evaluation is warranted to clarify whether tocilizumab monotherapy or its combination with corticosteroid is preferred for severely to critically ill patients with COVID-19.

Thrombocytopenia, anasarca, fever, reticulin fibrosis, renal insufficiency, and organomegaly (TAFRO) syndrome is a heterogeneous entity manifesting with a constellation of symptoms described above that can occur in the context of idiopathic multicentric Castleman disease (iMCD) as well as infectious diseases, malignancies, and rheumatologic disorders. So, iMCD-TAFRO is an aggressive subtype of iMCD with TAFRO syndrome and often hyper-vascularized lymph nodes. Since we proposed diagnostic criteria of iMCD-TAFRO in 2016, we have accumulated new insights on the disorder and additional cases have been reported worldwide. In this systematic review and cohort analysis, we established and validated a definition for iMCD-TAFRO. First, we searched PubMed and Japan Medical Abstracts Society databases using the keyword "TAFRO" to extract cases. Patients with possible systemic autoimmune diseases and hematologic malignancies were excluded. Our search identified 54 cases from 50 articles. We classified cases into three categories: (1) iMCD-TAFRO (TAFRO syndrome with lymph node histopathology consistent with iMCD), (2) possible iMCD-TAFRO (TAFRO syndrome with no lymph node biopsy performed and no other co-morbidities), and (3) TAFRO without iMCD or other co-morbidities (TAFRO syndrome with lymph node histopathology not consistent with iMCD or other comorbidities). Based on the findings, we propose an international definition requiring four clinical criteria (thrombocytopenia, anasarca, fever/hyperinflammatory status, organomegaly), renal dysfunction or characteristic bone marrow findings, and lymph node features consistent with iMCD. The definition was validated with an external cohort (the ACCELERATE Natural History Registry). The present international definition will facilitate a more precise and comprehensive approach to the diagnosis of iMCD-TAFRO.

Castleman's disease (CD), a heterogeneous group of lymphoproliferative disorders, is divided into unicentric CD (UCD) and multicentric CD (MCD) based on the number of regions of enlarged lymph nodes with characteristic histopathologic features. The clinical pictures and treatment differ greatly between these UCD and MCD. In MCD, cases of human herpesvirus 8-negative patients with unknown etiology are defined as idiopathic MCD (iMCD). Most cases of UCD are treatable by surgical excision. The prognosis of iMCD varies, and it may be challenging to achieve remission. Glucocorticoids are initiated as the first choice for therapy, but for glucocorticoid-resistant cases, interleukin (IL)-6 inhibition is initiated. However, an IL-6 inhibitor is not effective for all iMCD cases, and refractory cases occur despite these treatments. In this review, we briefly summarize the role of IL-6 in iMCD, and we discuss the efficacy that has been reported for tocilizumab (TCZ), the anti-IL-6 receptor antibody, for patients with iMCD in Japan. Factors predicting the therapeutic response to IL-6 remain to be identified, and the verification of the long-term safety of IL-6 inhibition is needed.

We administered tocilizumab into 13 severe-to-critically ill patients with coronavirus disease 2019 (COVID-19) for compassionate use in combination with potential anti-viral agents in those who required an oxygen supply and showed increased laboratory inflammatory markers such as C-reactive protein (CRP) and ferritin. One injection of tocilizumab led to rapid improvements in clinical features, inflammatory findings, and oxygen supply in seven patients with severe COVID-19 and substantial amelioration in two patients who were critically ill, whereas four patients, who exhibited rapidly worsened respiratory function, required artificial ventilatory support even after tocilizumab treatment. Three of these four patients ultimately recovered from deterioration after methylprednisolone treatment. Administration of tocilizumab did not affect viral elimination nor IgG production specific for the virus. Compared with well-responding patients, rapidly-worsened patients showed a significantly higher ratio of ferritin vs. CRP. These findings suggest that tocilizumab has beneficial effects in severe-to-critically ill patients with COVID-19; however, in some cases, addition of methylprednisolone is required for disease rescue.

Introduction: Castleman disease (CD) is a rare and heterogeneous cluster of disorders, characterized by lymphadenopathy and systemic symptoms. Although most cases of unicentric CD (UCD) are treatable by surgical excision, the prognosis of multicentric CD (MCD) is varied, and it may be challenging to achieve remission. Current treatments of MCD have advanced dramatically with the advent of the novel biologic therapies including interleukin-6 (IL-6) inhibition, but refractory cases occur despite these treatments.Areas covered: We review the etiology and pathogenesis of CD, summarize the current MCD treatments, and discuss the possibilities of a new therapeutic target in severe MCD.Expert opinion: The disease type, the presence of human immunodeficiency virus (HIV) and human herpesvirus 8 (HHV-8), and the progression of organ involvement determines the optimal therapeutic interventions for CD. IL-6 inhibition by tocilizumab or siltuximab has shown effectiveness for HIV/HHV­8-negative patients. Rituxi...

Human herpesvirus-8 (HHV-8)-negative, idiopathic multicentric Castleman disease (iMCD) is a rare and life-threatening disorder involving systemic inflammatory symptoms, polyclonal lymphoproliferation, cytopenias, and multiple organ system dysfunction caused by a cytokine storm often including interleukin-6. iMCD accounts for one third to one half of all cases of MCD and can occur in individuals of any age. Accurate diagnosis is challenging, because no standard diagnostic criteria or diagnostic biomarkers currently exist, and there is significant overlap with malignant, autoimmune, and infectious disorders. An international working group comprising 34 pediatric and adult pathology and clinical experts in iMCD and related disorders from 8 countries, including 2 physicians that are also iMCD patients, was convened to establish iMCD diagnostic criteria. The working group reviewed data from 244 cases, met twice, and refined criteria over 15 months (June 2015 to September 2016). The proposed consensus criteria require both Major Criteria (characteristic lymph node histopathology and multicentric lymphadenopathy), at least 2 of 11 Minor Criteria with at least 1 laboratory abnormality, and exclusion of infectious, malignant, and autoimmune disorders that can mimic iMCD. Characteristic histopathologic features may include a constellation of regressed or hyperplastic germinal centers, follicular dendritic cell prominence, hypervascularization, and polytypic plasmacytosis. Laboratory and clinical Minor Criteria include elevated C-reactive protein or erythrocyte sedimentation rate, anemia, thrombocytopenia or thrombocytosis, hypoalbuminemia, renal dysfunction or proteinuria, polyclonal hypergammaglobulinemia, constitutional symptoms, hepatosplenomegaly, effusions or edema, eruptive cherry hemangiomatosis or violaceous papules, and lymphocytic interstitial pneumonitis. iMCD consensus diagnostic criteria will facilitate consistent diagnosis, appropriate treatment, and collaborative research.

Background: Infliximab (IFX), is a most effective b-DMRD, and results in a 60% remission rate on average in rheumatoid arthritis (RA) patients. The remaining 40% of patients undergo other biologics treatments that follow a ‘treat-to-target method’ until they achieve remission. Predicting in advance that a patient cannot achieve clinical remission with IFX, would allow doctors to start such patients on treat-to-target treatments sooner. Unfortunately, no reliable method has yet been found to predict patient-response. Objectives: We tried to establish a prediction method using the serum of individual patient with RA related biomarkers present in varying amounts before they underwent IFX. Methods: This study uses an observational retrospective study with 85 patients. 22 clinical data were used as explanation variables, such as, disease duration, combination of c-DMRDs, DAS 28-ESR, and day 0 laboratory data. 84 biomarkers in patients’ pretreatment serum were measured using Multi-Plex Human Cytokine Chemokine beads array. DAS-28-ESR after 24 weeks was used as an objective variable. Patients administered IFX with regular method were divided into two groups: complete remission (DAS 28-ESR The receiver operating characteristic (ROC) analysis was used to evaluate the ability of the models to predict the 24-week outcome of patients. The area under the ROC curve is the product of the cross validation procedure. Results: We selected a combination from 104 markers. 3 to 5 combinations were most predictive of remission with 1.405 Cohen’s d and at 0.85 AUC, 0.826 PPV, 0.882 NPV, and 0.689 ACC. On the contrary, using 22 clinical parameters, AUC, PPV, NPV and ACC were 0.726, 0.713, 0.649 and 0.673, respectively. Conclusion: Using the pre-treatment serum, we were able to predict with high accuracy patients who would achieve remission. Our method is stable and economical; therefore, it may be applicable as a way of identifying individual patients who are resistant to IFX therapy, so as to avoid treating them with IFX in the first place. The next step is to confirm these results in larger scale retrospective and prospective studies. The first highly accurate method identified for predicting remission and non-remission in individual RA patients who are targeted for IFX treatment. Reference [1] Uno K, Yoshizaki K, et all. Pretreatment Prediction of Individual Rheumatoid Arthritis Patients’ Response to Anti-Cytokine Therapy Using Serum Cytokine/Chemokine/Soluble Receptor Biomarkers. PLoS One. 2015Jul15;10(7): e0132055. Acknowledgement: Russel Pandra for helping abstract translation Disclosure of Interests: Kazuyuki Yoshizaki: None declared, Kazuko Uno: None declared, Tsutomu Takeuchi Grant/research support from: Astellas Pharma Inc, Chugai Pharmaceutical Co, Ltd., Daiichi Sankyo Co., Ltd., Takeda Pharmaceutical Co., Ltd., AbbVie GK, Asahikasei Pharma Corp., Mitsubishi Tanabe Pharma Co., Pfizer Japan Inc., Eisai Co., Ltd., AYUMI Pharmaceutical Corporation, Nipponkayaku Co. Ltd., Novartis Pharma K.K., Grant/research support from: AbbVie, Asahi Kasei, Astellas, AstraZeneca, AYUMI, Bristol-Myers Squibb, Chugai, Daiichi Sankyo, Eisai, Eli Lilly Japan, Janssen, Mitsubishi Tanabe, Nippon Kayaku, Novartis, Pfizer Japan Inc, Taiho, Taisho Toyama, Takeda, Teijin, Grant/research support from: Astellas Pharma Inc., Bristol Myers Squibb, Chugai Pharmaceutical Co., Ltd., Mitsubishi Tanabe Pharma Co., Pfizer Japan Inc., Santen Pharmaceutical Co., Ltd., Takeda Pharmaceutical Co., Ltd., Teijin Pharma Ltd., AbbVie GK, Asahi Kasei Pharma Corp., Taisho Toyama Pharmaceutical Co., Ltd., SymBio Pharmaceuticals Ltd., Janssen Pharmaceutical K.K., Celltrion Inc., Nipponkayaku Co. Ltd., and UCB Japan, Consultant for: Astra Zeneca K.K., Eli Lilly Japan K.K., Novartis Pharma K.K., Mitsubishi Tanabe Pharma Co., Abbivie GK, Nipponkayaku Co.Ltd, Janssen Pharmaceutical K.K., Astellas Pharma Inc., Taiho Pharmaceutical Co. Ltd., Chugai Pharmaceutical Co. Ltd., Taisho Toyama Pharmaceutical Co. Ltd., GlaxoSmithKline K.K., UCB Japan Co. Ltd., Consultant for: AbbVie, Asahi Kasei, Astellas, AstraZeneca, AYUMI, Bristol-Myers Squibb, Chugai, Daiichi Sankyo, Eisai, Eli Lilly Japan, Janssen, Mitsubishi Tanabe, Nippon Kayaku, Novartis, Pfizer Japan Inc, Taiho, Taisho Toyama, Takeda, Teijin, Consultant for: Astra Zeneca K.K., Eli Lilly Japan K.K., Novartis Pharma K.K., Mitsubishi Tanabe Pharma Co., Asahi Kasei Medical K.K., AbbVie GK, Daiichi Sankyo Co., Ltd., Bristol Myers Squibb, and Nipponkayaku Co. Ltd., Speakers bureau: Astellas Pharma Inc., Bristol Myers Squibb, Chugai Pharmaceutical Co., Ltd., Mitsubishi Tanabe Pharma Co., Pfizer Japan Inc., Santen Pharmaceutical Co., Ltd., Takeda Pharmaceutical Co., Ltd., Teijin Pharma Ltd., AbbVie GK, Asahi Kasei Pharma Corp., Taisho Toyama Pharmaceutical Co., Ltd., SymBio Pharmaceuticals Ltd., Janssen Pharmaceutical K.K., Celltrion Inc., Nipponkayaku Co. Ltd., and UCB Japan, Speakers bureau: AbbVie, Asahi Kasei, Astellas, AstraZeneca, AYUMI, Bristol-Myers Squibb, Chugai, Daiichi Sankyo, Eisai, Eli Lilly Japan, Janssen, Mitsubishi Tanabe, Nippon Kayaku, Novartis, Pfizer Japan Inc, Taiho, Taisho Toyama, Takeda, Teijin, Speakers bureau: AbbVie GK., Bristol–Myers K.K., Chugai Pharmaceutical Co. Ltd., Mitsubishi Tanabe Pharma Co., Pfizer Japan Inc., Astellas Pharma Inc, Diaichi Sankyo Co. Ltd., Eisai Co. Ltd., Sanofi K.K., Teijin Pharma Ltd., Takeda Pharmaceutical Co. Ltd., Novartis Pharma K.K., Keisuke Izumi Grant/research support from: Asahi Kasei Pharma, Speakers bureau: Asahi Kasei Pharma Corp, Astellas Pharma Inc., Bristol Myers Squibb, Chugai Pharmaceutical Co., Ltd., Eli Lilly Japan K.K., Mitsubishi Tanabe Pharma Co., Mitsuhiro Iwahashi: None declared, Hitoshi Fujimiya: None declared

Tocilizumab (TCZ) is an interleukin-6 (IL-6) inhibitor used for the treatment of rheumatoid arthritis (RA). It was developed in 2008, and its effectiveness is supported by evidence from all over the world based on its first decade of use. Although the overall efficacy and safety profiles of TCZ are similar to those of tumor necrosis factor (TNF) inhibitors, TCZ displays certain differences. The most notable advantage of TCZ is its usefulness as a monotherapy. Additionally, TCZ is favorable in the improvement of systemic inflammatory symptoms such as anemia and fatigue. The low immunogenicity of TCZ contributes favorably to long-term drug retention. Due to frequent relapse after TCZ cessation, TCZ use should be tapered beyond remission. During TCZ therapy, C-reactive protein (CRP) is unable to recognize disease activity and the severity of infection. The most common adverse events (AEs) are infection and abnormalities in laboratory findings including dyslipidemia, neutropenia, thrombocytopenia, and abnormality of liver enzymes. TCZ obscures the symptoms of infection. Therefore, stealth infections without obvious CRP elevation can sometimes cause severe damage to patients. Lower intestinal perforation is an uncommon but serious AE in TCZ therapy. Further clinical investigations will continue to refine the IL-6 inhibitory strategy.

Castleman disease (CD) describes a group of heterogeneous hematologic disorders with characteristic histopathological features. CD can present with unicentric or multicentric (MCD) regions of lymph node enlargement. Some cases of MCD are caused by human herpesvirus-8 (HHV-8), whereas others are HHV-8–negative/idiopathic (iMCD). Treatment of iMCD is challenging, and outcomes can be poor because no uniform treatment guidelines exist, few systematic studies have been conducted, and no agreed upon response criteria have been described. The purpose of this paper is to establish consensus, evidence-based treatment guidelines based on the severity of iMCD to improve outcomes. An international Working Group of 42 experts from 10 countries was convened by the Castleman Disease Collaborative Network to establish consensus guidelines for the management of iMCD based on published literature, review of treatment effectiveness for 344 cases, and expert opinion. The anti–interleukin-6 monoclonal antibody siltuximab (or tocilizumab, if siltuximab is not available) with or without corticosteroids is the preferred first-line therapy for iMCD. In the most severe cases, adjuvant combination chemotherapy is recommended. Additional agents are recommended, tailored by disease severity, as second- and third-line therapies for treatment failures. Response criteria were formulated to facilitate the evaluation of treatment failure or success. These guidelines should help treating physicians to stratify patients based on disease severity in order to select the best available therapeutic option. An international registry for patients with CD (ACCELERATE, #NCT02817997) was established in October 2016 to collect patient outcomes to increase the evidence base for selection of therapies in the future.

We report a 65-years-old woman with rheumatoid meningitis presented with a generalized seizure. She has a 18-year history of rheumatoid arthritis, which has been successfully treated. She developed a generalized seizure. She was diagnosed as having subarachnoid hemorrhage, because the brain magnetic resonance imaging (MRI) showed increased fluid attenuated inversion recovery (FLAIR) signals in her left frontoparietal subarachnoid space. After one month of clinical stabilization, she developed numbness and weakness in her right lower extremity that spread to her right upper extremity and face. Brain MRI showed progression of subarachnoid lesion on FLAIR image and leptomeningeal enhancement on gadolinium-enhanced T1 weighted image. She was diagnosed as having rheumatoid meningitis, and methylprednisolone pulse therapy was started. Then, her symptoms and MRI findings were rapidly improved. Though rheumatoid meningitis is rare and presents a difficulty in the diagnosis, MRI features may support the diagnosis.

Since its discovery, improvements in treating Castleman disease and its variants have centered on interleukin-6 (IL-6). IL-6 was discovered from T-cell factors (BCDF or BSF-2), which induced B-cell maturation. Most symptoms of the plasma cell variant of Castleman disease are linked to the hyperfunction of IL-6, constitutively produced in the affected lymph nodes (1989), suggesting IL-6 is key in the pathogenesis of multicentric Castleman disease (MCD). The results of several studies have shown that most MCD symptoms and abnormal laboratory results are improved by anti-IL-6 MCD treatments, such as tocilizumab, a humanized anti-IL-6 receptor antibody, and siltuximab, an anti-IL-6 antibody.

Objectives: To determine the tentative diagnostic criteria and disease severity classification for Castleman disease (CD) and describe the clinical and pathologic features among human herpesvirus 8 (HHV-8) negative idiopathic multicentric CD (iMCD) in the Japanese population. Methods: We established the working groups for the research of CD in Japan and had meetings to discuss and define the tentative diagnostic criteria and disease severity classification for CD. We subsequently analyzed 142 patients classified into iMCD by using the nationwide Japanese patient registry. Results: We proposed the preliminary diagnostic criteria and disease severity classification for CD based on our discussion. In addition, we made a proposal for the disease activity score. We identified clinical and pathological features of patients with iMCD diagnosed by these diagnostic criteria. In the disease severity classification, 37, 33 and 30% patients were categorized into mild, moderate and severe diseases, respectively. Conclusion: This is the first proposal for diagnosis and classification of CD by the Japanese group. Further studies are required to validate whether they can distinguish CD from other inflammatory diseases and to determine their sensitivity and specificity.

Dysregulated overproduction of IL-6 has important roles in the pathogenesis of rheumatoid arthritis (RA). Tocilizumab (TCZ) is the only approved biologic agent inhibiting the IL-6 pathway for RA treatment, and is the focus of this review.This review summarizes the pharmacologic characteristics, clinical efficacy and safety profile of TCZ therapy in RA patients. The data reviewed were based mainly on Phase III randomized clinical trials and the literature until 2014 regarding TCZ in RA treatment.Being a first-line biologic agent for RA, TCZ is especially suitable for RA patients who have shown an inadequate response to TNF-α inhibitors or who cannot tolerate methotrexate. In view of its advantage in suppressing acute-phase reactions and as the only approved inhibitor of IL-6 signaling, TCZ might be particularly effective for RA patients with a high systemic inflammatory response, anemia, AA amyloidosis and other diseases mediated by IL-6. Being able to identify reliable predictors of response to TCZ, and finding more effective new biologic and treatment options, will reduce the number of patients who fail to respond to TCZ.

We previously demonstrated that though the human SAA1 gene shows no typical STAT3 response element (STAT3-RE) in its promoter region, STAT3 and the nuclear factor (NF-κB) p65 first form a complex following interleukin IL-1 and IL-6 (IL-1 + 6) stimulation, after which STAT3 interacts with a region downstream of the NF-κB RE in the SAA1 promoter. In this study, we employed a computational approach based on indirect read outs of protein–DNA contacts to identify a set of candidates for non-consensus STAT3 transcription factor binding sites (TFBSs). The binding of STAT3 to one of the predicted non-consensus TFBSs was experimentally confirmed through a dual luciferase assay and DNA affinity chromatography. The present study defines a novel STAT3 non-consensus TFBS at nt − 75/− 66 downstream of the NF-κB RE in the SAA1 promoter region that is required for NF-κB p65 and STAT3 to activate SAA1 transcription in human HepG2 liver cells. Our analysis builds upon the current understanding of STAT3 function, suggesting a wider array of mechanisms of STAT3 function in inflammatory response, and provides a useful framework for investigating novel TF-target associations with potential therapeutic implications.

Serum amyloid A (SAA) and C-reactive protein (CRP) are two major acute phase proteins whose serum concentrations increase in response to inflammation, though the exact mechanism underlying this induction remains unknown. Dysregulated production of interleukin (IL)-6 plays a pathogenic role in various inflammatory diseases such as rheumatoid arthritis, Castleman’s disease and systemic juvenile idiopathic arthritis. IL-6 blocking therapy with an anti-IL-6 receptor antibody (tocilizumab) can ameliorate clinical symptoms and abnormal laboratory findings, and completely normalize CRP and SAA levels in rheumatoid arthritis patients. Conversely, therapy for blocking tumor necrosis factor (TNF)-α, another key pathogenic factor in rheumatoid arthritis, barely lowers CRP and SAA to within their normal range, suggesting that IL-6 and TNF-α play different roles in the induction of acute phase protein expression. To clarify the different pathogenic roles and mechanisms of IL-6 and TNF-α or IL-1 in the induction of CRP and SAA in chronic inflammatory diseases, we investigated the transcriptional regulation mechanisms of SAA and CRP using hepatoma-derived cell lines in vitro, and related these mechanisms to the different effects of IL-6 and TNF-α blocking therapies on serum SAA and CRP in rheumatoid arthritis patients in vivo. We propose transcriptional regulation models for inflammatory cytokine-induced SAA and CRP expression that explain why IL-6 plays an essential role in the induction of SAA and CRP in the presence of inflammation.

A 47-year-old female patient with Behcet’s disease had been treated with colchicine, prednisolone, cyclosporine A, and infliximab. Because she relapsed, however, treatment with tocilizumab, a humanized anti-interleukin 6 receptor antibody, was started. This treatment suppressed the patient’s clinical manifestations, including ocular attacks, for 1 year and improved her visual acuity. This experience indicates that tocilizumab may constitute a therapeutic option for refractory Behcet’s disease.

Multicentric Castleman's disease (MCD) is a rare lymphoproliferative disorder characterized by overproduction of interleukin-6 (IL-6). Anemia is a common symptom of MCD but its mechanism has been poorly understood. Hepcidin is an IL-6-induced key regulator of iron metabolism and has a major role in anemia of inflammation (AI). Our study showed that treatment with tocilizumab (an anti-IL-6 receptor antibody) resulted in long-term reductions of serum hepcidin25 in MCD patients, which was accompanied by progressive normalization of iron-related parameters. In in vitro experiments, IL-6-induced hepcidin mRNA expression in hepatocytes was completely inhibited with tocilizumab and partially with erythropoietin (EPO), but enhanced by bone morphogenetic protein (BMP) and patient's serum. Our findings and evidence published elsewhere, leads us to suggest that, although multiple factors affect hepcidin levels, IL-6 plays an essential role in the induction of hepcidin which leads to anemia in MCD. Therefore, IL-6 blockage may constitute a promising molecular targeting therapy for AI.

Dysregulated overproduction of interleukin-6 (IL-6) from activated B cells in affected lymph nodes has been implicated in the pathogenesis of multicentric Castleman's disease (MCD), a rare lymphoproliferative disorder accompanied by systemic manifestations. We here report the case of a 32-year-old female presenting with MCD associated with a dermoid cyst in the pelvic cavity. The co-occurrence of MCD and dermoid cyst has not been reported before. Immunohistochemical analysis of the tissue sections showed IL-6 production in CD68-positive macrophage cells, which had infiltrated the dermoid cyst. Removal of the cyst resulted in partial improvement in systemic symptoms accompanied by a decrease in serum IL-6, while complete improvement was obtained by treatment with an anti-IL-6 receptor antibody following resection of the dermoid cyst. To the best of our knowledge, this is the first study to provide evidence of IL-6 production by CD68(+) cells in a dermoid cyst involved in MCD.

Dysregulated production of hepcidin is implicated in anemia of inflammation, whereas interleukin-6 (IL-6) is a major inducer of hepcidin production. Overproduction of IL-6 is responsible for pathogenesis of multicentric Castleman disease (MCD), a rare lymphoproliferative disorder accompanied by systemic inflammatory responses and anemia. In this study, we investigated the roles of hepcidin and IL-6 in anemia of inflammation and the long-term effects of anti–IL-6 receptor antibody (tocilizumab) treatment on serum hepcidin and iron-related parameters in MCD patients. We found that tocilizumab treatment resulted in a rapid reduction of serum hepcidin-25 in 5 of 6 MCD patients. Long-term reductions, accompanied by progressive normalization of iron-related parameters and symptom improvement, were observed in 9 of 9 cases 1.5, 3, 6, and 12 months after the start of tocilizumab treatment. In in vitro experiments, IL-6–induced up-regulation of hepcidin mRNA in hepatoma cell lines was completely inhibited by tocilizumab but increased in the presence of patients' sera. Our results suggest that, although multiple factors affect serum hepcidin levels, IL-6 plays an essential role in the induction of hepcidin in MCD. This accounts for the long-term ameliorative effect of IL-6 blockage with tocilizumab on anemia by inhibiting hepcidin production in MCD patients.

Remarkable clinical effects were observed by IL-6 blockage with a humanized anti IL-6 receptor antibody in patients with Castleman's disease, rheumatoid arthritis, and juvenile inflammatory arthritis. This evidence suggests that the hyper-function of IL-6 is an essential key cytokine in the pathogenesis of the above diseases, in which many cytokines, chemokines, and inflammatory molecules are activated. We found, for example, TNF-alpha blocking therapy showed a reduction of acute phase proteins, such as CRP and SAA, however, the IL-6 blockade induced not only reduction but also normalization of CRP and SAA serum levels. To elucidate this in vivo phenomenon, we analyzed the expression of cytokine inducing CRP and SAA mRNA with the intracellular signal transduction mechanism in vitro. The results, indicated that the IL-6 signal was essential though the activation of STAT3 for the induction and augmentation of CRP or SAA by the associated stimulation with TNF-alpha or IL-1. Recently, it is now known that IL-6 is a regulatory molecule in the induction of Th17 cells with TGF-beta. Therefore, IL-6 blockage may potentially improve autoimmune diseases, beginning with the pathogenic initiation phase. We believe that unknown pathogenic inflammatory phenomena can be clarified using this analytical strategy and cytokine blocking therapy. Furthermore, in the future we hope to induce complete remission of autoimmune diseases by using cytokine blockage freely.

C-reactive protein (CRP) is a sensitive marker and mediator of inflammation, whereas IL-6 blocking therapy can normalize serum levels of CRP in chronic inflammatory diseases. We investigated the precise synergistic induction mechanism of CRP gene expression by IL-1 and IL-6 in Hep3B cells. In the early induction phase, IL-1 inhibited IL-6-mediated CRP gene expression, and NF-κB p65 inhibited the luciferase activity of pGL3-CRP by IL-1 plus IL-6 even in the presence of overexpressed STAT3. In the late induction phase, we focused on JNK and p38 activated by IL-1. SP600125 reduced the expression of the CRP gene induced by IL-1 plus IL-6. Unexpectedly, overexpression of c-Fos dramatically enhanced the luciferase activity by IL-1 and IL-6 even though the CRP gene has no AP-1 response element (RE) in its promoter. The augmentative effect of c-Fos required the presence of STAT3 and 3′-hepatocyte NF-1 (HNF-1) RE, which were eliminated by dominant negative STAT3 and HNF-1α, respectively. SB203580 inhibited the phosphorylation of c-Fos enhanced by IL-1 plus IL-6, and diminished expression of the CRP gene. Immunoprecipitation, Western blot analysis, the Supershift assay using a CRP oligonucleotide containing STAT3 and 3′-HNF-1 RE, and the chromatin immunoprecipitation assay demonstrated that c-Fos/STAT3/HNF-1α forms a complex on the CRP gene promoter. Because human fetus liver cells failed to express c-Fos/STAT3/HNF-1α showed no CRP production, transcriptional complex formation of c-Fos/STAT3/HNF-1α is essential for the synergistic induction of CRP gene expression by IL-1 plus IL-6. Our findings fully explain the clinical results of IL-6 blocking therapy and are expected to contribute to the development of a therapeutic strategy for chronic inflammatory diseases.

The patient was a 33 year female. In 2001, she was diagnosed with systemic lupus erythematosus (SLE) and treated with prednisolone and ciclosporin. In May 2006, she noticed slight muscle weakness in the bilateral lower limbs. In July of the same year, she experienced gait difficulty and was admitted to our hospital because of fatigue, appetite loss, fever and disorientation. Soon afterwards, she had a fit of general convulsion and suffered from urinary retention and fecal incontinence. A brain magnetic resonance image revealed atrophy of the thoracic cord in T2 weighted images, and cerebrospinal fluid examination showed high total protein and interleukin-6 concentration, indicating complication of lupus myelitis as well as cerebral involvement. Steroid pulse and oral prednisolone treatment resulted in ameriolation of cerebral complications such as disorientation and convulsion, but muscle weakness and paresthesia in the lower limbs and urinary retention persisted. Cyclophosphamide pulse therapy was started and resulted in a marked recovery from muscle weakness, paresthesia and urinary retention, and she could discharge. We conclude that steroid and cyclophosphamide pulse therapy for a SLE patient with CNS lupus and lupus myelitisis is effective for ameriolation of symptoms such as disorientation, convulsion, urinary retension, fecal incontinence, muscle weakness and paresthesia in the lower limbs as well as elevated level of serum anti-ribosomal P antibody.

Behçet’s disease (BD), a chronic systemic inflammatory disorder, is characterized by recurrent oral and genital mucous ulcers, uveitis and skin lesions. We performed DNA microarray analysis of peripheral blood mononuclear cell (PBMC) mRNA from 41 Japanese BD patients and revealed elevated levels of interleukin (IL) 23 receptor (IL23R) mRNA in many BD patients. DNA sequencing around a SNV (Rs12119179) tightly linked to BD revealed an elevated frequency of the C genotype, consistent with a previous report that IL23R is a susceptibility locus for BD. Notably, four of these BD patients are members of familial BD; a whole-exome sequencing (WES) of these BD patients identified 19 novel single-nucleotide variations (SNVs) specific to these patients. They include heterozygous SNVs in the genes encoding IL-1 receptor-associated kinase 4 (IRAK4), nucleotide-binding oligomerization domain (NOD)-like receptor family pyrin domain-containing 14 (NRP14) and melanoma antigen-encoding gene E2 (MAGEE2); IRAK4 harbors a missense mutation, whereas NRP14 and MAGEE2 harbor nonsense mutations. These SNVs may serve as genetic markers that characterize BD.

Anti-cytokine therapies have been used for rheumatoid arthritis (RA) and their efficacy has been previously reported. Serum amyloid A (SAA) is an acute phase protein and known as a precursor of amyloid fibril in AA amyloidosis. IL-6 blocking therapy normalized the serum levels of SAA, in RA patients, while anti-TNFα or IL-1 therapy did not. From the clinical point of view, the exact identification of the induction mechanism of SAA is important. We found that IL-6 plays a critical role in the synergistic induction of the SAA gene by combining with proinflammatory cytokines. Moreover, we discovered that STAT3 plays an essential role in cytokine-driven SAA gene expression even though no typical STAT3 response element (RE) is located in its promoters. STAT3 and NF-κB p65 first form a complex following IL-1 and IL-6 stimulation, after which STAT3 interacts with non-consensus sequences at a 3'-site of NF-κB RE on the SAA gene promoter. STAT3 then recruits p300, which coordinates the interaction of NF-κB p65, STAT3 and C/EBPβ in the synergistic induction of the SAA gene. Our findings have a direct bearing on a better understanding of inflammatory status and are expected to contribute to the development of a therapeutic strategy for AA amyloidosis.

Serum amyloid A (SAA) is a sensitive marker of acute-phase responses and known as a precursor protein of amyloid fibril in amyloid A (AA) (secondary) amyloidosis. Since the serum SAA level is also closely related to activity of chronic inflammatory disease and coronary artery disease, it is important to clarify the exact induction mechanism of SAA from the clinical point of view. Here we provide evidence that STAT3 plays an essential role in cytokine-driven SAA expression, although the human SAA gene shows no typical STAT3 response element (RE) in its promoters. STAT3 and nuclear factor kappaB (NF-kappaB) p65 first form a complex following interleukin (IL)-1 and IL-6 (IL-1+6) stimulation, after which STAT3 interacts with nonconsensus sequences at a 3' site of the SAA gene promoter's NF-kappaB RE. Moreover, co-expression of p300 with STAT3 dramatically enhances the transcriptional activity of SAA. The formation of a complex with STAT3, NF-kappaB p65, and p300 is thus essential for the synergistic induction of the SAA gene by IL-1+6 stimulation. Our findings are expected to aid the understanding of the inflammatory status of AA amyloidosis to aid development of a therapeutic strategy for this disease by means of normalization of serum SAA levels.

Rheumatoid arthritis (RA) has been attributed to the abnormal production of cytokine interleukin-6 (IL-6), which has a variety of physiological activities. In vivo IL-6-receptor imaging provides useful suggestions regarding the mechanism of anti-IL-6-receptor antibody action and indicates a basic therapeutic strategy for treating RA. Therefore, this study was designed to establish a method for radiolabeling anti-IL-6-receptor antibodies and to investigate the feasibility of using radiolabeled anti-IL-6-receptor antibodies in the scintigraphic imaging of lesions in an animal RA model. Anti-IL-6-receptor antibodies were conjugated with a bifunctional chelating agent, hydrazinonicotinamide (HYNIC), and radiolabeled with technetium-99m (99mTc) using the ligand exchange reaction of 99mTc-tricine complex. The binding affinity was estimated using the U266 cell line. Whole body scintigraphy, biodistribution and autoradiography were undertaken in mice containing synovial cells that had been transplanted from an RA patient. Our findings showed that the antibodies accumulated in the implanted tissue. When radiolabeled anti-IL-6-receptor antibodies are used in scintigraphic imaging, the distribution of the IL-6-receptors is associated with the inflammatory cell infiltration that is seen in the early stage of RA. Accordingly, imaging with humanized anti-IL-6-receptor antibodies appears to be useful for detecting early pathophysiological conditions and assessing the efficacy of antibody treatment as well as the prognosis of patients with RA.

All-trans-retinoic acid (ATRA), a vitamin A derivative, was reported to suppress the interleukin-6 (IL-6) production and to downregulate the IL-6 receptor (IL-6R) and/or its signal transducer glycoprotein 130. We investigated the in vivo antinephritic effect of ATRA on IL-6 transgenic mice which had developed mesangial proliferative glomerulonephritis (PGN) as well as its in vitro inhibitory effect on the proliferation of rat mesangial cells. In vivo experiments on IL-6 transgenic mice showed that ATRA administration suppressed proteinuria and hematuria and reduced the IL-6 concentrations; furthermore, histological examination demonstrated that it improved PGN. In vitro experiments using rat mesangial cells demonstrated that ATRA inhibited cell growth in a dose-dependent manner within a range from 10–4 to 10–6M. This inhibition by ATRA was partially counteracted by the addition of IL-6. RT-PCR assay results showed that ATRA also reduced IL-6R, but not the glycoprotein 130 expression in mesangial cells. These findings indicate that, by blocking of the IL-6 function, ATRA may be therapeutically effective in PGN.

Interleukin-6 (IL-6) regulates immune response and inflammation. We carried out a pilot placebo-controlled study to investigate the efficacy, pharmacokinetics, and safety of MRA, a humanized monoclonal antibody to IL-6 receptor, in patients with active Crohn's disease.Thirty-six patients with active Crohn's disease (Crohn's Disease Activity Index [CDAI]or =150) were randomly assigned to receive biweekly intravenous infusion of either placebo, MRA, or MRA/placebo alternately for 12 weeks at a dose of 8 mg/kg. The study's primary end point was a clinical response rate that was defined as a reduction of CDAIor =70.At the final evaluation, 80% of the patients (8 of 10) given biweekly MRA had a clinical response as compared with 31% of the placebo-treated patients (4 of 13; P = 0.019). Twenty percent of the patients (2 of 10) on this regimen went into remission (CDAI150), as compared with 0% of the placebo-treated patients (0 of 13). The clinical response rate of the every-4-week regimen was 42% (5 of 12). The serum concentrations of MRA were detected at 2 weeks after every infusion, at which time acute phase responses were completely suppressed; however, they were not suppressed at 4 weeks. Endoscopic and histologic examination showed no difference between MRA and placebo groups. The incidence of adverse events was similar in all the groups.This is the first clinical trial of humanized anti-IL-6 receptor monoclonal antibody in Crohn's disease. A biweekly 8 mg/kg infusion of MRA was well tolerated, normalized the acute-phase responses, and suggests a clinical effect in active Crohn's disease.

Serum amyloid A (SAA) is known to be a precursor of amyloid A (AA) protein in AA (secondary) amyloidosis and SAA1 to be mainly involved in AA amyloidosis. We established an SAA isoform real-time quantitative RT-PCR assay and found that beta-2 microglobulin is more stable as an internal control than GAPDH and beta-actin for our system. Either IL-6 and IL-1beta or IL-6 and TNFalpha, but not IL-1beta and TNFalpha, induced the synergistic induction of SAA1 and SAA2 genes. Anti-IL-6 receptor monoclonal antibody completely inhibited the synergistic induction of SAA1 and SAA2 during triple stimulation with IL-6, IL-1beta, and TNFalpha, but, IL-1 receptor antagonist or anti-TNFalpha monoclonal antibody was only partially inhibited in HepG2, Hep3B, and PLC/PRF/5 cells. Although the SAA1 promoter has no STAT3 consensus sequence, the JAK2 inhibitor-AG490 reduced SAA1 gene expression to 30%, suggesting the involvement of STAT3. We were able to demonstrate that IL-6 plays a critical role in the synergistic induction of human SAA gene when stimulated with proinflammatory cytokines.

Objective Interleukin-6 (IL-6) is a pleiotropic cytokine that regulates the immune response, inflammation, and hematopoiesis. Overproduction of IL-6 plays pathologic roles in rheumatoid arthritis (RA), and the blockade of IL-6 may be therapeutically effective for the disease. This study was undertaken to evaluate the safety and efficacy of a humanized anti–IL-6 receptor antibody, MRA, in patients with RA. Methods In a multicenter, double-blind, placebo-controlled trial, 164 patients with refractory RA were randomized to receive either MRA (4 mg/kg body weight or 8 mg/kg body weight) or placebo. MRA was administered intravenously every 4 weeks for a total of 3 months. The clinical responses were measured using the American College of Rheumatology (ACR) criteria. Results Treatment with MRA reduced disease activity in a dose-dependent manner. At 3 months, 78% of patients in the 8-mg group, 57% in the 4-mg group, and 11% in the placebo group achieved at least a 20% improvement in disease activity according to the ACR criteria (an ACR20 response) (P < 0.001 for 8-mg group versus placebo). Forty percent of patients in the 8-mg group and 1.9% in the placebo group achieved an ACR50 response (P < 0.001). The overall incidences of adverse events were 56%, 59%, and 51% in the placebo, 4-mg, and 8-mg groups, respectively, and the adverse events were not dose dependent. A blood cholesterol increase was observed in 44.0% of the patients. Liver function disorders and decreases in white blood cell counts were also observed, but these were mild and transient. There was no increase in antinuclear antibodies or anti-DNA antibodies. Anti-MRA antibodies were detected in 2 patients. Conclusion Treatment with MRA was generally well tolerated and significantly reduced the disease activity of RA.

Human anti-IL-6 antibody may be useful for the immunotherapy of various inflammatory diseases, such as rheumatoid arthritis. Since IL-6 is a growth factor for B cell hybridoma, it is not easy to isolate murine B cell hybridomas producing the anti-IL-6 antibody with the IL-6-signaling inhibitory activity. In this study, the antibody library (Vgamma-Vkappa, Vgamma-Vlambda, Vmu-Vkappa or micro-Vlambda ligated into the pCANTAB 5E phagemid vector) was prepared from peripheral blood mononuclear cells of 20 healthy subjects. The phage display library was panned with an IL-6-coated plastic plate, and the binding specificity was confirmed by ELISA and BIAcore. From the antibody library (Vgamma-Vlambda), five IL-6-specific phage clones were isolated. The effects of the soluble scFvs purified from these phage clones were tested on the growth of the IL-6-dependent human cell line, KT-3. Two of these clones significantly inhibited the growth of KT-3, and three showed no inhibition.

The effect of the solvent quality on local concentration fluctuation was studied for concentrated solutions of polystyrene (PS) in toluene (Tol), ethylbenzene (EtBz), n-propylbenzene (PrBz), and n-butylbenzene (BuBz) by using dielectric spectroscopy. The exponents of the Mark−Houwink−Sakurada equation of those solutions indicate that the solvent quality deteriorates in the order of Tol, EtBz, PrBz, and BuBz. Three dielectric relaxations designated as α, β, and γ are observed in the temperature dependence curves of the dielectric loss in the order of decreasing temperature. According to our previous study on PS/Tol solution, the α, β, and γ relaxations have been assigned to local segmental motions of PS, rotation of the solvent molecules, and the secondary relaxation in the glassy state, respectively. The half-width of the dielectric loss curve Λα for the α relaxation of PS/Tol solutions is independent of temperature, but the values of Λα for solutions in EtBz, PrBz, and BuBz increase with decreasing tempe...

Hybridoma that produces rat anti-mouse interleukin 6 receptor (IL-6R) antibody, MR16-1, was established by the fusion of mouse P3U1 myeloma cells and spleen cells from mouse soluble IL-6R (sIL-6R)-immunized Wistar rat. In the present study, we examined the characteristics of MR16-1 in vitro and in vivo. MR16-1 bound to mouse sIL-6R dose-dependently. MR16-1 suppressed IL-6-induced proliferation of 7TD1 cells in a dose-dependent manner and this inhibitory effect was reversed by the addition of a higher concentration of IL-6. Cross-reactivity study using T cells from mouse, rat, and human revealed that MR16-1 did not cross-react with human and rat IL-6R. Binding region analysis using several human–mouse chimeric IL-6Rs showed that half of the fibronectin domain II of mouse IL-6R (amino acids 214–285) was required for MR16-1 binding. Furthermore, MR16-1 completely suppressed IL-6-induced antibody production in DNP–KLH immunized mice. These lines of evidence demonstrate that MR16-1 is useful to investigate the physiological and pathological roles of IL-6 and sIL-6R in mice.

Hepatoma-derived growth factor (HDGF) is the original member of the HDGF family of proteins, which contains a well-conserved N-terminal amino acid sequence (homologous to the amino terminus of HDGF; hath) and nuclear localization signals (NLSs) in gene-specific regions other than the hath region. In addition to a bipartite NLS in a gene-specific region, an NLS-like sequence is also found in the hath region. In cells expressing green fluorescence protein (GFP)-HDGF, green fluorescence was observed in the nucleus, whereas it was detected in the cytoplasm of cells expressing GFP-HDGF with both NLSs mutated or deleted. GFP-hath protein (GFP-HATH) was distributed mainly in the nucleus, although some was present in the cytoplasm, whereas GFP-HDGF with a deleted hath region (HDGFnonHATH) was found only in the nucleus. Exogenously supplied GFP-HDGF was internalized and translocated to the nucleus. GFP-HATH was internalized, whereas GFP-HDGFnonHATH was not. Overexpression of HDGF stimulated DNA synthesis and cellular proliferation, although HDGF with both NLSs deleted did not. Overexpression of HDGFnonHATH caused a significant stimulation of DNA synthesis, whereas that of hath protein did not. HDGF containing the NLS sequence of p53 instead of the bipartite NLS did not stimulate DNA synthesis, and truncated forms without the C- or N-terminal side of NLS2 did not. These findings suggest that the gene-specific region, at least the bipartite NLS sequence and the N- and C-terminal neighboring portions, is essential for the mitogenic activity of HDGF after nuclear translocation.

Expression of the human low-affinity Fc receptors for IgG (human Fc gamma RII) is differentially regulated. We report here the characterization of the promoter structure of the human Fc gamma RIIB gene and the isolation of the promoter region-binding proteins by a yeast one-hybrid assay. The minimal 154-bp region upstream from the transcription start site of the human Fc gamma RIIB gene was shown to possess promoter activity in a variety of cells. An electrophoretic mobility shift assay indicated that multiple nuclear factors in cell extracts bind to the two regions [F2-3 (-110 to -93) and F4-3 (-47 to -31)] of the human Fc gamma RIIB gene promoter. Mutation analysis indicated that GGGAGGAGC (-105 to -97) and AATTTGTTTGCC (-47 to -36) sequences are responsible for binding to nuclear factors respectively. By using GGGAGGAGC and AATTTGTTTGCC as bait sequences, we cloned two zinc-finger proteins (ZNF140 and ZNF91) that bind to the F2-3 and F4-3 regions within the promoter of the human Fc gamma RIIB gene respectively. When the ZNF140 and ZNF91 were transfected with reporter plasmid, both showed repressor activity with additive effects. Thus, these results indicate that these cloned ZNF140 and ZNF91 proteins function as repressors for the human Fc gamma RIIB transcription.

In the present study, we demonstrated the anti-arthritic effect of humanized anti-human IL-6 receptor (IL-6R) antibody, MRA, in cynomolgus monkey. MRA can react with monkey IL-6R and block signal transduction of IL-6. Collagen-induced arthritis (CIA) was induced by twice immunizing with bovine type II collagen (CII) emulsified with complete adjuvant. MRA was intravenously injected once a week, from the day of the first collagen immunization, for 13 weeks. The symptoms of arthritis were evaluated using a visual scoring system and radiography. Inflammatory parameters (C-reactive protein (CRP), fibrinogen, and erythrocyte sedimentation rate (ESR) and concentrations of anti-CII antibody, anti-MRA antibody, and MRA were monitored regularly. At the end of the study, histological evaluation was carried out. MRA, at a dose of 10 mg/kg, gave rise to statistically significant suppression. The elevation of serum CRP and fibrinogen levels and ESR were also inhibited. Furthermore, radiographic and histological examination showed that MRA treatment suppressed joint destruction. Our results demonstrate that IL-6 plays an important role in monkey CIA and that MRA may be an attractive agent for the treatment of rheumatoid arthritis.

The relation between HLA class II alleles and clinical findings were examined in Japanese patients with systemic lupus erythematosus (SLE). In 284 patients with multicenter SLE, HLA class II alleles were examined using the DNA typing method, and the results were compared with the clinical findings. The frequency of DRB1*0101 and DQB1*0501 significantly increased in male patients, and that of DRB1*0803 significantly increased in patients over 50 years of age. In relation to cutaneous manifestations, there were positive photosensitivity associations with DQA1*0101 and/or DQA1*0301, malar rash with DQA1*0101 and/or DRB1*0901, alopecia with DQA1*0101, skin ulcers with DRB1*0401, and oral ulcers with DQA1*0301. In addition, there were also positive associations of myalgia with DRB1*1406 and negative associations of aseptic bone necrosis with DQA1*0601, and hepatomegaly with DRB1*0405 and/or DQA1*0401. In relation to laboratory findings, there were positive associations of hemolytic anemia with DRB1*1402 and negative associations of leukopenia with DQA1*0601, lymphopenia with DQA1*0301, and proteinuria with DRB1*0901. Interestingly, DQA1*0101 and/or DQB1*0501 were significantly associated with WHO classification type II rather than type IV. In patients with SLE, some HLA types related to clinical or laboratory findings.

Interleukin 6 (IL6) is a pleiotropic cytokine with a wide range of biological activities. IL6 transgene into mice gives rise to the abnormalities such as hyper-γ-globulinaemia, thrombocytosis, infiltration of inflammatory cells into the tissues, mesangial cell proliferation of the kidney as well as splenomegaly and lymphadenopathy, which are predictable by the biological functions of IL6 shown in vitro. Continuous overproduction of IL6 is observed in patients with some immune-inflammatory diseases such as Castleman's disease and rheumatoid arthritis that are frequently associated with similar abnormalities to those of IL6 transgenic mice, strongly suggesting the involvement of IL6 in the human diseases. Successful treatment of the model animals for immune-inflammatory diseases with anti-IL6 receptor (IL6R) antibody thus indicates the possible application of IL6 blocking agents to treat the IL6 related immune-inflammatory diseases of humans. In this review, the new therapeutic strategy for Castleman's disease and RA using humanised antibody to human IL6 receptor, MRA, is discussed.