Gp130-HIF1α axis-induced vascular damage is prevented by the short-term inhibition of IL-6 receptor signaling.

Protection against endothelial damage is recognized as a frontline approach to preventing the progression of cytokine release syndrome (CRS). Accumulating evidence has demonstrated that interleukin-6 (IL-6) promotes vascular endothelial damage during CRS, although the molecular mechanisms remain to be fully elucidated. Targeting IL-6 receptor signaling delays CRS progression; however, current options are limited by persistent inhibition of the immune system. Here, we show that endothelial IL-6 trans-signaling promoted vascular damage and inflammatory responses via hypoxia-inducible factor-1α (HIF1α)-induced glycolysis. Using pharmacological inhibitors targeting HIF1α activity or mice with the genetic ablation of gp130 in the endothelium, we found that inhibition of IL-6R (IL-6 receptor)-HIF1α signaling in endothelial cells protected against vascular injury caused by septic damage and provided survival benefit in a mouse model of sepsis. In addition, we developed a short half-life anti-IL-6R antibody (silent anti-IL-6R antibody) and found that it was highly effective at augmenting survival for sepsis and severe burn by strengthening the endothelial glycocalyx and reducing cytokine storm, and vascular leakage. Together, our data advance the role of endothelial IL-6 trans-signaling in the progression of CRS and indicate a potential therapeutic approach for burns and sepsis.

Efficacy and Safety of Levilimab in Combination with Methotrexate in Patients with Active Rheumatoid Arthritis: 56-Week Results of Phase III Randomized Double-Blind Placebo-Controlled Trial SOLAR.

. Previously, 24-week results of phase III double-blind, placebo-controlled randomized clinical study (SOLAR) of levilimab in subjects with active rheumatoid arthritis (RA) proved a superiority of levilimab over placebo. Here, we present 1-year efficacy and safety data of the SOLAR study. OBJECTIVES: . To evaluate the efficacy and safety of levilimab in combination with methotrexate (MTX) in subjects with MTX resistant active RA. MATERIALS AND METHODS: : The study was conducted at 21 clinical sites in Russia and Belarus. All randomized subjects have completed the study between November 2019 and October 2021. Adult subjects (154) aged ≥18 years with confirmed diagnosis of RA1 were randomly assigned (2 : 1) to receive either levilimab (162 mg, SC, QW) + MTX (n = 102) or placebo + MTX (n = 52). After W24 of the study all subjects continued to  receive open label levilimab. Subjects who have achieved DAS28-CRP ≤ 2.6 at W24 were switched to maintenance (Q2W) regimen of levilimab at W28 (LVL QW/Q2W and PBO/LVL Q2W arms). Those with DAS28-CRP > 2.6 at W28 continued with QW regimen (LVL QW and PBO/LVL QW arm). The PBO/LVL Q2W arm contained only one subject, thus not included in the analysis. The efficacy analysis was performed in a population of all randomized subjects. Those with missing data due to study discontinuation or rescue therapy prescription were considered non-responders. Otherwise, the analysis was performed on complete cases. Safety was assessed through monitoring of adverse events (AEs) in a population of those, who received at least on dose of LVL (n = 152). RESULTS: : Better response to treatment was observed in LVL QW/Q2W as it composed of those who reach DAS28-CRP ≤ 2.6 at W24. At this time point 15/27 (55.6%) of them achieved ACR70; 23/27 (85.2%) achieved DAS28-CRP remission (<2.6) and 7/27 (25.9%) achieved ACR/EULAR2011 remission of RA. After switching to LVL Q2W, rates of ACR70 and DAS28-CRP<2.6 did not significantly changed until W52: 17/27 (63.0%) and 21/27 (77.8%), respectively, yet the proportion of subject with ACR/EULAR 2011 remission further increased and reached 12/27 (44.4%). LVL QW arm was diminished by subjects who achieved high response to treatment at W24 and composed LVL QW/Q2W arm. Thus, ACR70, and remissions rate in this arm was close to zero at W24. However, continuation of LVL QW in those who not achieved DAS28-CRP ≤ 2.6 at W24 induced ACR70 response in 37/75 (36.0%), DAS28-CRP remission in 35/75 (46.7%) and ACR/EULAR 2011 remission in 8/75 (10.7%) at W52. The most common adverse events (reported in ≥5% of subjects) were blood cholesterol increase (30.3%), ALT increase (23.0%), lymphocyte count decrease (17.1%), ANC decrease (16.4%), blood triglycerides increase (13.8%), bilirubin increase (11.2%), AST increase (9.9%), WBC decrease (9.9%), IGRA with Mycobacterium tuberculosis antigen positive (7.2%), and injection site reactions (5.9%). No deaths occurred. CONCLUSIONS: : Open label period confirmed the lasting efficacy and safety of levilimab in combination with MTX in subjects with MTX resistant active RA and suggested the possibility of switching to levilimab maintenance regimen (once every 2 weeks) (Q2W) in those who achieved remission of RA at week 24.

The effect of anti-IL-6 receptor antibody for the treatment of McH-lpr/lpr-RA1 mice that spontaneously developed destructive arthritis and enthesitis.

BACKGROUND: McH-lpr/lpr-RA1 mice are a new strain of mice which spontaneously develop destructive arthritis and enthesitis in the ankle. There is no published data that drug treatment has been trialed on these mice. This study examined the effect of the mouse anti-IL-6 receptor antibody, MR16-1, for the treatment of arthritis and enthesitis in McH-lpr/lpr-RA1 mice. METHODS: Male McH-lpr/lpr-RA1 mice were randomly divided into control and treatment groups. MR16-1 was administered from 10 weeks of age for the treatment group. Saline was applied for the control group. The drug was administered once a week, at an initial dose of 2 mg, then maintained at 0.5 mg once per week thereafter. The effects were evaluated by the histopathological synovitis score, in vivo imaging using indocyanine green liposomes, and analysis of the gene expression of inflammatory cytokines. RESULTS: Tissue analyses were carried out at 14, 17 and 20 weeks of age. The synovitis scores of treated groups were significantly lower compared with those of the control group at 14 and 17 weeks of age. The kappa coefficient was 0.77. However, progression of entheseal ossification persisted in the MR16-1 treated group. In vivo imaging using indocyanine green liposomes showed significant decreases in signal intensities of treated groups at week 14, but no significant differences were observed at week 18. Blood serum amyloid A levels in treated groups were significantly lower at 17 weeks of age. The gene expression levels of Tnf and Il17 were also significantly lower in MR16-1 treated groups. CONCLUSIONS: Administration of the anti-IL-6 receptor antibody is effective for the treatment of synovitis and bone destruction of McH-lpr/lpr-RA1 mice. McH-lpr/lpr-RA1 mice may be a suitable experimental model for the development of new treatments for destructive arthritis and enthesitis. IL-6 signal blockade could contribute to the treatment of destructive arthritis, and further studies should be carried out to confirm its potential in the prevention of enthesopathy developed to ossification.

Therapeutic response of metastatic angiomatoid fibrous histiocytoma carrying EWSR1-CREB1 fusion to the interleukin-6 receptor antibody tocilizumab.

Angiomatoid fibrous histiocytoma (AFH) is a rare soft tissue tumor that has been associated with EWSR1-CREB1 gene fusion. Outcome in patients with unresectable distant metastases is generally fatal. Interleukin-6 (IL-6) secretion has been described in tumors with EWSR1-CREB1 fusion, and may promote tumor growth due to autocrine stimulation. Tocilizumab is an IL-6 receptor antibody that has potential benefit as a targeted therapy in refractory neoplasms with IL-6 secretion. We describe a child with metastatic AFH with EWSR1-CREB1 fusion and elevated IL-6 whose disease progressed during treatment with traditional chemotherapeutic agents, but improved after targeted therapy with tocilizumab.

Successful management of recurrent bleeding with tocilizumab in an acquired hemophilia A patient with rheumatoid arthritis.

A 61-year-old woman with rheumatoid arthritis was diagnosed as having acquired hemophilia A with extensive subcutaneous bleeding. The patient was treated with a corticosteroid, and her symptoms improved temporarily. However, these recurred during the tapering of her corticosteroid dose, and neither the re-increase in the dose nor the addition of cyclophosphamide could control her bleeding tendency. After the administration of an anti-IL-6 receptor antibody (tocilizumab), the doses of corticosteroid and cyclophosphamide could be tapered. Tocilizumab combined with another immunosuppression therapy might be effective in the treatment of acquired hemophilia A.

Safety and Effectiveness of Satralizumab in Japanese Patients with Neuromyelitis Optica Spectrum Disorder: A 6-month Interim Analysis of Post-marketing Surveillance.

INTRODUCTION: Satralizumab, an anti-interleukin-6 receptor antibody, is approved in Japan for relapse prevention in neuromyelitis optica spectrum disorder (NMOSD) and is undergoing post-marketing surveillance (PMS) of clinical use. We aimed to describe the real-world safety and effectiveness of satralizumab in Japanese patients with NMOSD. METHODS: This is an ongoing PMS (planned completion: February 2027). This 6-month interim analysis assessed the safety and effectiveness of satralizumab in Japanese patients with NMOSD using data collected from August 2020 to July 2021. RESULTS: Among 570 patients who participated, 523 (91.75%) were female and the mean ± standard deviation (SD) age was 52.4 ± 14.1 years. At baseline, NMOSD expanded disability status scale mean ± SD was 4.19 ± 2.19; 490 (85.96%) patients used glucocorticoids and 277 (48.59%) patients used immunosuppressants concomitantly. Of 570 satralizumab-treated patients, 85 (14.91%) had discontinued satralizumab treatment at 6 months. For the overall adverse drug reactions (ADRs), 76.22 (66.07-87.48) events/100 person-years occurred in 118 (20.70%) patients, and infections occurred in 28 (4.91%) patients. Serious infections occurred in 18 (3.15%) patients, with an event rate of 9.05 (5.80-13.47) events/100 person-years. Of the 24 events of serious infections, respiratory tract infections (29.17%; 7) and urinary tract infections (25.00%; 6) were the most common serious infection events. One fatal ADR (septic shock) suspected to be related to satralizumab was reported. The mean ± SD glucocorticoid dose reduced from 12.28 ± 10.17 mg/day at the index date to 8.11 ± 7.30 mg/day at 6 months. The Kaplan-Meier cumulative relapse-free rate (95% confidence interval) was 94.59% (92.25-96.23) at 6 months. CONCLUSION: In this study, satralizumab was found to be safe, well tolerated, and effective in patients with NMOSD in routine clinical practice. The results are consistent with those of previous clinical trials. The safety and effectiveness of satralizumab in Japanese patients with NMOSD will be analyzed over the 6-year surveillance period. TRIAL REGISTRATION: UMIN Clinical Trials Registry, UMIN000041047.

Insulin Requirements During Severe COVID-19 Were Relatively Low in Japanese Patients With Type 2 Diabetes: Two Case Reports.

The global coronavirus disease 2019 (COVID-19) pandemic has caused myriad adverse effects on the pathology of other diseases. Numerous studies on COVID-19 have reported that, in patients with type 2 diabetes mellitus (T2DM) who have contracted severe COVID-19, glucose metabolism is exacerbated by multiple factors, such as severe inflammation, beta-cell dysfunction caused by the SARS-CoV-2 infection itself, corticosteroid therapy, vasopressor administration, and enteral or parenteral nutrition. Very high doses of insulin are often required in the acute phase of such patients; however, the factors that affect insulin requirements and to what extent remain unclear. A 50-year-old Japanese woman and a 67-year-old Japanese man, both with T2DM and obesity, were admitted to our hospital with severe COVID-19. Both patients required mechanical ventilation and were treated with dexamethasone and tocilizumab, an interleukin-6 (IL-6) receptor monoclonal antibody. Subcutaneous insulin injections failed to control the patients' hyperglycemia, requiring up to 1.83 and 1.81 units/kg/day of intravenous insulin, respectively. Insulin requirements were rapidly decreased with improvement of the respiratory condition, termination of dexamethasone, and discontinuation of tube feeding. Both patients were discharged with oral antidiabetic agents alone. We experienced two Japanese patients who achieved satisfactory glycemic control with a lower intravenous insulin dose than previous reports. Comparing the clinical factors with the previous literature, ethnic differences in insulin sensitivity and the administration of IL-6 receptor antibodies may have been related to the relatively low insulin requirements.

Reduced epilepsy development in synapsin 2 knockout mice with autistic behavior following early systemic treatment with interleukin-6 receptor antibody.

BACKGROUND: Individuals with autism spectrum disorder (ASD) have an increased risk of developing epilepsy. Both ASD and epilepsy have been associated with increased levels of immune factors in the blood, including the proinflammatory cytokine interleukin 6 (IL-6). Mice lacking the synapsin 2 gene (Syn2 KO) exhibit ASD-like behavior and develop epileptic seizures. Their brains display neuroinflammatory changes including elevated IL-6 levels. We aimed to investigate the effect of systemic IL-6 receptor antibody (IL-6R ab) treatment on seizure development and frequency in Syn2 KO mice. MATERIAL AND METHODS: Weekly systemic (i.p.) injections of IL-6R ab or saline were given to Syn2 KO mice starting either early in life at 1 month of age, before seizure debut or at 3 months of age, directly after seizure debut and continued for 4 or 2 months, respectively. Seizures were provoked by handling the mice three times per week. The neuroinflammatory response and synaptic protein levels in the brain were determined by ELISA, immunohistochemistry and western blots. In an additional group of Syn2 KO mice, with IL-6R ab treatment early in life, ASD-related behavioral tests including social interaction and repetitive self-grooming, as well as cognitive memory and depressive-/anxiety-like tests, and actigraphy measurements of circadian sleep-awake rhythm were analyzed. RESULTS: The IL-6R ab treatment reduced seizure development and frequency in Syn2 KO mice when initiated before, but not after, seizure debut. However, early treatment did not reverse the neuroinflammatory response or the imbalance in synaptic protein levels in the brain previously reported in Syn2 KO mice. The treatment did not affect social interaction, performance in memory, depressive-/anxiety-like tests or the sleep-awake rhythm of Syn2 KO mice. CONCLUSION: These findings suggest the involvement of IL-6 receptor signaling during epilepsy development in Syn2 KO mice, without significant alterations of the immune reaction in the brain, and independently of cognitive performance, mood and circadian sleep-awake rhythm.

Intradermal AQP4 peptide immunization induces clinical features of neuromyelitis optica spectrum disorder in mice.

We challenged to create a mouse model of neuromyelitis optica spectrum disorder (NMOSD) induced by AQP4 peptide immunization. Intradermal immunization with AQP4 p201-220 peptide induced paralysis in C57BL/6J mice, but not in AQP4 KO mice. AQP4 peptide-immunized mice showed pathological features similar to NMOSD. Administration of anti-IL-6 receptor antibody (MR16-1) inhibited the induction of clinical signs and prevented the loss of GFAP/AQP4 and deposition of complement factors in AQP4 peptide-immunized mice. This novel experimental model may contribute to further understanding the pathogenesis of NMOSD, elucidating the mechanism of action of therapeutic agents, and developing new therapeutic approaches.

Linear IgA bullous dermatosis and elevated bullous interleukin-6 levels: Responsive to treatment with Anti-IL-6 receptor monoclonals.

Linear IgA bullous dermatosis (LABD) is  a rare autoimmune/inflammatory skin condition. Here, we report on a patient who developed treatment resistant LABD. At diagnosis, elevations of IL-6 and C-reactive protein in the blood and extreme elevations of IL-6 in LABD bullous fluid were seen. The patient responded well to tocilizumab (anti-IL-6 receptor) treatment.

RIPK3 Suppresses the Progression of Spontaneous Intestinal Tumorigenesis.

Receptor-interacting protein 3 (RIPK3), a member of the family of serine/threonine protein kinases, emerged as a critical regulator of necroptosis. Downregulated expression of RIPK3 is correlated with poor prognosis in multiple tumor types. Here, we show that RIPK3 is involved in the progression of spontaneous intestinal tumorigenesis. As a clinical correlate, reduced expression of RIPK3 is positively associated with histological grade, lymphatic metastasis and poor prognosis in CRC patients. RIPK3-deficient (Ripk3-/- ) mice exhibit increased tumor formation in Apcmin/+ spontaneous intestinal tumorigenesis. Apcmin/+Ripk3-/- tumors promote hyperactivation of IL-6/STAT3 signaling, which exacerbates proliferation and inhibits apoptosis. Blocking IL-6 signaling suppressed tumor formation and reduced STAT3 activation in Apcmin/+Ripk3-/- mice. Thus, our results reveal that RIPK3 is a tumor suppressor in spontaneous intestinal tumorigenesis, and implicate targeting the IL-6/STAT3 signaling axis as a potential therapeutic strategy for intestinal tumor patients with reduced RIPK3.

Takayasu's Arteritis Diagnosed in an Adolescent Patient with Crohn's Disease: Management of Biologicals.

We report a 14-year-old man with Crohn's disease (CD) who developed right upper arm pain while being treated with the anti-tumor necrosis factor (TNF)-alpha monoclonal antibody, infliximab. There were no symptoms suggestive of active CD, but the inflammatory response was high, and a contrast-enhanced CT showed the occlusion of the right brachial artery. We diagnosed the patient as having Takayasu's arteritis (TA) and started treatment with corticosteroids, then tapered off the steroids as the symptoms of TA resolved. Later, TA flared up, and his treatment was changed from infliximab to an anti-IL-6 receptor antibody, tocilizumab. The change to TCZ stabilized TA, but exacerbated CD. It is difficult to control both diseases at the same time, and the choice of biologics for treatment must be carefully considered.

Interleukin-6: evolving role in the management of neuropathic pain in neuroimmunological disorders.

BACKGROUND: Neuropathic pain in neuroimmunological disorders refers to pain caused by a lesion or disease of the somatosensory system such as multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD). MS and NMOSD are autoimmune disorders of the central nervous system, and ≥ 50% of patients with these disorders experience chronic neuropathic pain. The currently available medications for the management of neuropathic pain have limited effectiveness in patients with MS and NMOSD, and there is an unmet medical need to identify novel therapies for the management of chronic neuropathic pain in these patients. In this review article, we summarize the role of interleukin-6 (IL-6) in the pathogenesis of MS and NMOSD and the ameliorative effects of anti-IL-6 therapies in mouse models of experimental autoimmune encephalomyelitis (EAE). MAIN BODY: Intraperitoneal injection of MR16-1, an anti-IL-6 receptor (IL-6R) antibody, reduced mechanical allodynia and spontaneous pain in EAE mice, which was attributed to a reduction in microglial activation and inhibition of the descending pain inhibitory system. The effect of anti-IL-6 therapies in ameliorating neuropathic pain in the clinical setting is controversial; a reduction in pain intensity has been reported with an anti-IL-6 antibody in four studies, namely a case report, a pilot study, a retrospective observational study, and a case series. Pain intensity was evaluated using a numerical rating scale (NRS), with a lower score indicating lesser pain. A reduction in the NRS score was reported in all four studies. However, in two randomized controlled trials of another anti-IL-6R antibody, the change in the visual analog scale pain score was not statistically significantly different when compared with placebo. This was attributed to the low mean pain score at baseline in both the trials and the concomitant use of medications for pain in one of the trials, which may have masked the effects of the anti-IL-6R antibody on neuropathic pain. CONCLUSION: Thus, anti-IL-6 therapies might have a potential to reduce neuropathic pain, but further investigations are warranted to clarify the effect of inhibition of IL-6 signaling on neuropathic pain associated with MS and NMOSD.

Interleukin-6 released by oral lichen planus myofibroblasts promotes angiogenesis.

Oral lichen planus (OLP), defined as a potential for malignant transformation, is a chronic inflammatory disease in which abnormal angiogenesis serves a role in the malignant changes of the disease. OLP-associated fibroblasts (OLP-MFs), derived from the stroma of OLP tissues, are characterized by the presence of myofibroblasts and contribute to the secretion of pro-inflammatory cytokines, which may be involved in the molecular pathogenesis of OLP. However, the associated mechanisms of angiogenesis in OLP remain unknown. The present study aimed to verify the expression of intercellular adhesion molecular 1, vascular cell adhesion molecule 1, VEGF and CD34 in OLP, and to investigate whether IL-6 secreted by OLP-MFs promoted OLP angiogenesis and the effect of its corresponding antibody inhibition. The results of the experiments demonstrated that inflammation was present and OLP upregulated the secretion of IL-6 by OLP stromal fibroblasts, thereby enhancing OLP angiogenesis. Anti-IL-6 receptor antibody inhibited OLP-stroma IL-6 signaling and suppressed OLP angiogenesis. The antibody inhibited the inflammatory response by inhibiting the secretion of inflammatory factors, including IL-6, to suppress angiogenesis and reduce disease progression, thus indicating that this could be a potential target to develop a treatment for OLP.

Progressive Multifocal Leukoencephalopathy during Tocilizumab Treatment for Rheumatoid Arthritis.

A 61-year-old woman was diagnosed with rheumatoid arthritis 12 years ago and received multiple treatment regimens before achieving symptomatic stability with methotrexate plus tocilizumab, a humanized monoclonal antibody against the IL-6 receptor, about 2 years prior to the current presentation. Sixteen months after tocilizumab initiation, she exhibited dysarthria and disorientation; five months later, she was hospitalized with movement difficulties. Her neurological symptoms deteriorated thereafter, accompanied by enlarged cerebral white matter lesions on magnetic resonance imaging. A biopsy of the right frontal lesion confirmed progressive multifocal leukoencephalopathy (PML). While several therapeutic monoclonal antibodies have been linked to PML, this is the first case associated with tocilizumab.

Anti-IL-6 Receptor Antibody Inhibits Spontaneous Pain at the Pre-onset of Experimental Autoimmune Encephalomyelitis in Mice.

Chronic pain is a significant symptom in patients with autoimmune encephalomyelitis, such as multiple sclerosis and neuromyelitis optica. The most commonly used animal model of these diseases is experimental autoimmune encephalomyelitis (EAE). We previously reported that evoked pain, such as mechanical allodynia, was improved by an anti-IL-6 receptor antibody in EAE mice. However, few reports have evaluated spontaneous pain in EAE mice. Here, we assessed spontaneous pain in EAE mice by utilizing the Mouse Grimace Scale (MGS, a standardized murine facial expression-based coding system) and evaluated the influence of an anti-IL-6 receptor antibody (MR16-1). EAE was induced in female C57BL/6J mice by subcutaneous immunization with myelin oligodendrocyte glycoprotein 35-55 emulsified in adjuvant and administration of pertussis toxin. Mice were placed individually in cubicles and filmed for about 10 min. Ten clear head shots per mouse from the video recording were given a score of 0, 1, or 2 for each of three facial action units: orbital tightening, nose bulge, and ear position. Clinical symptoms of EAE were also scored. Measurement of 5-HT in the spinal cord and functional imaging of the periaqueductal gray (PAG) were also performed. Compared with control mice, MGS score was significantly higher in EAE mice. MR16-1 prevented this increase, especially in pre-onset EAE mice. Promotion of spinal 5-HT turnover and reduction of PAG activity were observed in pre-onset EAE mice. These results suggest that MR16-1 prevented spontaneous pain developed before EAE onset.

Anti-IL-6 receptor antibody improves pain symptoms in mice with experimental autoimmune encephalomyelitis.

BACKGROUND AND AIMS: Chronic pain is a prevalent symptom in patients with autoimmune encephalomyelitis such as multiple sclerosis and neuromyelitis optica. Although IL-6 is involved in various inflammatory and immune diseases, the roles of IL-6 in autoimmune-related pain have not been clarified. Therefore, we examined the effect of anti-IL-6 receptor antibody (MR16-1) on the pain sensitivity of experimental autoimmune encephalomyelitis (EAE) mice. MATERIALS AND METHODS: EAE was induced in female C57BL/6J mice by subcutaneous immunization with myelin oligodendrocyte glycoprotein 35-55 emulsified in adjuvant (Day 0). Pertussis toxin was intravenously administered at Days 0 and 2. Mice were sequentially scored for clinical symptoms of EAE. [Exp. 1] MR16-1 was intraperitoneally administered on Days 0 or 3. Sensitivity to pain was measured by the von Frey test (Days 7, 14, 20). The spinal cord was isolated and assessed by immunohistochemistry. [Exp. 2] MR16-1 was intraperitoneally administered on Day 12 when significant pain had already occurred. Pain assessment was conducted before the immunization, on Day 12 and after EAE onset. And then, spinal cord was isolated and flow cytometry was performed. RESULTS: [Exp. 1] MR16-1 prevented the increase in clinical score and sensitivity to pain in EAE mice. Immunohistochemical analysis showed that Iba1+ microglia were increased in the spinal cord of EAE mice, and were reduced by MR16-1. [Exp. 2] Administration of MR16-1 on Day 12 also reduced sensitivity to pain under EAE onset. Flow cytometry showed that CD45lowCD11b+ microglia were increased in the spinal cord of EAE mice, and that this increase was inhibited by MR16-1. CONCLUSION: These findings suggest that MR16-1 can decrease mechanical allodynia in EAE mice through inhibition of microglial activation and proliferation in the spinal cord.

The Role of Interleukin-6 in Castleman Disease.

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.

Adult-onset Still's disease: Advances in the treatment.

Adult-onset Still's disease (AOSD) is a rare systemic inflammatory disorder mainly characterized by persistent high spiking fevers, evanescent rash, and joint involvement. The pathogenesis of AOSD is only partially known, but pro-inflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-1, IL-6, IL-18, and IFN-γ seem to play a major role in this disorder. AOSD is at the crossroad of auto-inflammatory syndromes and autoimmune diseases. It is diagnosed by exclusion to determine the presence of high serum ferritin levels, which is usually >1000 µg/L. AOSD is generally treated with non-steroidal anti-inflammatory drugs, corticosteroids, and disease-modifying anti-rheumatic drugs (DMARDs). Although information on biologic therapy in the management of AOSD is scarce, these drugs represent a major breakthrough in the management of patients with AOSD refractory to corticosteroids or conventional DMARDs or in patients presenting life-threatening manifestations. In this regard, TNF-α, IL-1, and IL-6 antagonists had been proved effective in patients with AOSD.

Novel approaches for preventing acute graft-versus-host disease after allogeneic hematopoietic stem cell transplantation.

INTRODUCTION: Allogeneic hematopoietic stem cell transplantation (alloHSCT) offers potential curative treatment for a wide range of malignant and nonmalignant hematological disorders. However, its success may be limited by post-transplant acute graft-versus-host disease (aGVHD), a systemic syndrome in which donor's immune cells attack healthy tissues in the immunocompromised host. aGVHD is one of the main causes of morbidity and mortality after alloHSCT. Despite standard GVHD prophylaxis regimens, aGVHD still develops in approximately 40-60% of alloHSCT recipients. AREAS COVERED: In this review, after a brief summary of current knowledge on the pathogenesis of aGVHD, the authors review the current combination of a calcineurin inhibitor with an antimetabolite with or without added anti-thymocyte globulin (ATG) and emerging strategies for GVHD prevention. EXPERT OPINION: A new understanding of the involvement of cytokines, intracellular signaling pathways, epigenetics and immunoregulatory cells in GVHD pathogenesis will lead to new standards for aGVHD prophylaxis allowing better prevention of severe aGVHD without affecting graft-versus-tumor effects.