IL-6 inhibitor for the treatment of rheumatoid arthritis: A comprehensive review

Acid Sphingomyelinase and Acid β-Glucosidase 1 Exert Opposite Effects on Interleukin-1β-Induced Interleukin 6 Production in Rheumatoid Arthritis Fibroblast-Like Synoviocytes

Acid sphingomyelinase (ASM) and acid β-glucosidase 1 (GBA1) catalyze ceramide formation through different routes, and both are involved in rheumatoid arthritis (RA) pathogenesis as well as IL-6 production. However, whether ASM and GBA1 regulate IL-6 production in RA remains unknown. Serum ASM, GBA1, and ceramide levels were measured in RA patients and healthy controls by enzyme-linked immunosorbent assay, and their correlations with clinical indicators of patients were evaluated. Pharmacologic inhibitors or small hairpin RNAs of ASM and GBA1 were employed to explore the roles of ASM and GBA1 in IL-6 production, cell behavior, and MAPK signaling in fibroblast-like synoviocytes from RA patients (RAFLS). ASM, GBA1, and ceramide serum levels were significantly elevated in patients with RA. GBA1 and ceramide serum levels were negatively and positively correlated with IL-6 serum level in RA patients, respectively. ASM inhibitor or knockdown of ASM abolished IL-1β-induced IL-6 expression and secretion. Functionally, ASM inhibitor suppressed IL-1β-induced cell proliferation, migration, and invasion in RAFLS. Mechanistically, ASM inhibitor or knockdown of ASM effectively countered IL-1β-induced activation of p38 MAPK signaling. The pharmacologic inhibitor or knockdown of GBA1 exhibited the opposite effects. Importantly, p38 inhibitor blocked IL-1β-induced IL-6 production in RAFLS. ASM plays a pathogenic role in RA, whereas GBA1 plays a protective role in RA possibly by regulating IL-6 production in RAFLS at least partially via p38 signaling, serving as potential therapeutic targets in RA treatment.

Clinical features of large vessel vasculitis (LVV): Elderly-onset versus young-onset

OBJECTIVES

We compared large vessel vasculitis (LVV) clinical features between age groups.

METHODS

We retrospectively examined clinical features and therapies in 41 LVV patients at our hospital from January 2010 to March 2020. We compared two patient groups, elderly (≥50 years) and young (<50 years).

RESULTS

Of all patients, 29 were elderly and 12 were young. In the younger group, upper extremity symptoms (p <.05), bruits (p <.01), and cardiovascular complications (p <.01) were more common. Of the elderly group, 7 (24%) met classification criteria for giant cell arteritis while none of the younger group met these criteria; however, 10 (83%) of the younger group and 3 (10%) of the elderly group met the ACR classification criteria for Takayasu arteritis (p <.01). In the elderly group, 16 patients (66%) met no criteria (p <.01). There were no significant differences in laboratory findings but imaging showed a significantly higher incidence of head and neck artery lesions in the younger group (p <.05). The younger group was more likely to receive additional tocilizumab (p <.01) and cardiovascular complications were more likely to occur in younger patients (p < .01).

CONCLUSION

LVV clinical features differed between elderly- and young-age-onset groups.

Strategies to Target ADAM17 in Disease: From its Discovery to the iRhom Revolution

For decades, disintegrin and metalloproteinase 17 (ADAM17) has been the object of deep investigation. Since its discovery as the tumor necrosis factor convertase, it has been considered a major drug target, especially in the context of inflammatory diseases and cancer. Nevertheless, the development of drugs targeting ADAM17 has been harder than expected. This has generally been due to its multifunctionality, with over 80 different transmembrane proteins other than tumor necrosis factor α (TNF) being released by ADAM17, and its structural similarity to other metalloproteinases. This review provides an overview of the different roles of ADAM17 in disease and the effects of its ablation in a number of in vivo models of pathological conditions. Furthermore, here, we comprehensively encompass the approaches that have been developed to accomplish ADAM17 selective inhibition, from the newest non-zinc-binding ADAM17 synthetic inhibitors to the exploitation of iRhom2 to specifically target ADAM17 in immune cells.

Renohepatic crosstalk: a review of the effects of acute kidney injury on the liver

Several theories regarding acute kidney injury (AKI)-related mortality have been entertained, although mounting evidence supports the paradigm that impaired kidney function directly and adversely affects the function of several remote organs. The kidneys and liver are fundamental to human metabolism and detoxification, and it is therefore hardly surprising that critical illness complicated by hepatorenal dysfunction portends a poor prognosis. Several diseases can simultaneously impact the proper functioning of the liver and kidneys, although this review will address the impact of AKI on liver function. While evidence for this relationship in humans remains sparse, we present supportive studies and then discuss the most likely mechanisms by which AKI can cause liver dysfunction. These include 'traditional' complications of AKI (uremia, volume overload and acute metabolic acidosis, among others) as well as systemic inflammation, hepatic leukocyte infiltration, cytokine-mediated liver injury and hepatic oxidative stress. We conclude by addressing the therapeutic implications of these findings to clinical medicine.

Repurposed Tocilizumab in Patients with Severe COVID-19

The coronavirus disease 2019 (COVID-19) has caused a global pandemic, resulting in considerable morbidity and mortality. Tocilizumab, an inhibitor of IL-6, has been widely repurposed as a treatment of severely ill patients without robust evidence supporting its use. In this study, we aimed to systematically describe the effectiveness of treatment and prevention of the cytokine storms in COVID-19 patients with tocilizumab. In this multicentered retrospective and observational cohort study, 65 patients with COVID-19 receiving tocilizumab and 130 not receiving tocilizumab were propensity score matched at a ratio of 2:1 based on age, sex, and comorbidities from January 20, 2020 to March 18, 2020 in Wuhan, China. After adjusting for confounding, the detected risk for in-hospital death was lower in the tocilizumab group versus nontocilizumab group (hazard ratio = 0.47; 95% confidence interval = 0.25-0.90; p = 0.023). Moreover, use of tocilizumab was associated with a lower risk of acute respiratory distress syndrome (odds ratio = 0.23; 95% confidence interval = 0.11-0.45; p < 0.0001). Furthermore, patients had heightened inflammation and more dysregulated immune cells before treatment, which might aggravate disease progression. After tocilizumab administration, abnormally elevated IL-6, C-reactive protein, fibrinogen, and activated partial thromboplastin time decreased. Tocilizumab may be of value in prolonging survival in patients with severe COVID-19, which provided a novel strategy for COVID-19-induced cytokine release syndrome. Our findings could inform bedside decisions until data from randomized, controlled clinical trials become available.

Inflammation-Driven Breast Tumor Cell Plasticity: Stemness/EMT, Therapy Resistance and Dormancy

Cellular heterogeneity poses an immense therapeutic challenge in cancer due to a constant change in tumor cell characteristics, endowing cancer cells with the ability to dynamically shift between states. Intra-tumor heterogeneity is largely driven by cancer cell plasticity, demonstrated by the ability of malignant cells to acquire stemness and epithelial-to-mesenchymal transition (EMT) properties, to develop therapy resistance and to escape dormancy. These different aspects of cancer cell remodeling are driven by intrinsic as well as by extrinsic signals, the latter being dominated by factors of the tumor microenvironment. As part of the tumor milieu, chronic inflammation is generally regarded as a most influential player that supports tumor development and progression. In this review article, we put together recent findings on the roles of inflammatory elements in driving forward key processes of tumor cell plasticity. Using breast cancer as a representative research system, we demonstrate the critical roles played by inflammation-associated myeloid cells (mainly macrophages), pro-inflammatory cytokines [such as tumor necrosis factor α (TNFα) and interleukin 6 (IL-6)] and inflammatory chemokines [primarily CXCL8 (interleukin 8, IL-8) and CXCL1 (GROα)] in promoting tumor cell remodeling. These inflammatory components form a common thread that is involved in regulation of the three plasticity levels: stemness/EMT, therapy resistance, and dormancy. In view of the fact that inflammatory elements are a common denominator shared by different aspects of tumor cell plasticity, it is possible that their targeting may have a critical clinical benefit for cancer patients.

Major reduction of ultrasound-detected synovitis during subcutaneous tocilizumab treatment: results from a multicentre 24 week study of patients with rheumatoid arthritis

Objective: Few studies have investigated the efficacy of subcutaneous tocilizumab (TCZ-SC) on ultrasound-detected inflammation. This study aimed to explore the clinical efficacy of TCZ-SC treatment in rheumatoid arthritis (RA) patients and to evaluate the response by ultrasound compared to Composite Disease Activity Scores (CDAS).Method: This open-label, single-arm study enrolled RA patients with inadequate response to conventional synthetic disease-modifying anti-rheumatic drugs initiating TCZ-SC 162 mg once weekly for 24 weeks, with clinical assessments at baseline, 2, 4, 8, 12, 16, 20, and 24 weeks. Ultrasound examinations [semi-quantitative score (0-3) of 36 joints and four tendons] were performed at baseline, 4, 12, and 24 weeks. CDAS and American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) response, and sum scores of ultrasound grey scale/Doppler were calculated. Changes during follow-up were explored by the Mann-Whitney test and correlations by Spearman's rho.Results: In total, 133 patients (mean ± sd age 55.9 ± 12.0 years) were assessed clinically and 110 patients were also examined with ultrasound. All clinical and ultrasound scores decreased significantly after 4 weeks (p < 0.001). At 24 weeks there was EULAR good response in 87.7% and ACR 70% response in 47.4%. Ultrasound scores had no or low correlations with patient-reported outcomes. At 24 weeks, CDAS remission was achieved in 27.4-83.5% and a sum score Doppler of 0 was found in 53.3%.Conclusions: Clinical and ultrasound scores decreased rapidly. Ultrasound scores were not associated with patient-reported variables. Half of the patients reached ultrasound remission, while there were large discrepancies in the percentage of patients reaching remission based on different CDAS.Trial registration: Study ML28691, registered 28 January 2014, ClinicalTrials.gov identifier: NCT02046616.

The potential anti-inflammatory and anti-nociceptive effects of rat hemopressin (PVNFKFLSH) in experimental arthritis

Inflammatory arthritis, such as rheumatoid arthritis (RA), stands out as one of the main sources of pain and impairment to the quality of life. The use of hemopressin (PVNFKFLSH; Hp), an inverse agonist of type 1 cannabinoid receptor, has proven to be effective in producing analgesia in pain models, but its effect on neuro-inflammatory aspects of RA is limited. In this study, antigen-induced arthritis (AIA) was evoked by the intraarticular (i.art.) injection of methylated bovine serum albumin (mBSA) in male Sprague Dawley rats. Phosphate buffered saline (PBS)-injected ipsilateral knee joints or AIA contralateral were used as control. Nociceptive and inflammatory parameters such as knee joint oedema and leukocyte influx and histopathological changes were carried out in addition to the local measurement of interleukins (IL) IL-6, IL-1β, tumor necrosis factor-α and the immunoreactivity of the neuropeptides substance P (SP) and calcitonin gene related peptide (CGRP) in the spinal cord (lumbar L3-5 segments) of AIA rats. For 4 days, AIA rats were treated daily with a single administration of saline, Hp injected (10 or 20 μg/day, i.art.), Hp given orally (20 μg/Kg, p.o.) or indomethacin (Indo; 5 mg/Kg, i.p.). In comparison to the PBS control group, the induction of AIA produced a significant and progressive mono-arthritis condition. The degree of AIA severity progressively compromised the normal walking pattern and impaired mobility over the next four days in relation to PBS-injected rats or contralateral knee joints. In AIA rats, the reduction of the distance between footprints and disturbances of gait evidenced signs of nociception. This response worsened at day 4, and a loss of footprint from the ipsilateral hind paw was evident. Daily treatment of the animals with Hp either i.art. (10 and 20 μg/knee) or p.o. (20 μg/Kg) as well as Indo (5 mg/Kg, i.p.) ameliorated the impaired mobility in a time-dependent manner (P < 0.05). In parallel, the AIA-injected ipsilateral knee joints reach a peak of swelling 24 h after AIA induction, which persisted over the next four days in relation to PBS-injected rats or contralateral knee joints. There was a significant but not dose-dependent inhibitory effect produced by all dosages and routes of Hp treatments on AIA-induced knee joint swelling (P < 0.05). In addition, the increased synovial levels of MPO activity, total leukocytes number and IL-6, but not IL-1β, were significantly reduced by the lower i.art. dose of Hp. In conclusion, these results successfully demonstrate that Hp may represent a novel therapeutic strategy to treat RA, an effect which is unrelated to the proinflammatory actions of the neuropeptides CGRP and SP.

Biological characteristics of IL-6 and related intestinal diseases

The intestine serves as an important digestive and the largest immune organ in the body. Interleukin-6(IL-6), an important mediator of various pathways, participates in the interactions between different kinds of cells and closely correlates with intestinal physiological and pathological condition. In this review we summarize the signaling pathways of IL-6 and its functions in maintaining intestinal homeostasis. We also explored its relation with nervous system and highlight its potential role in Parkinson's disease. Based on its specialty of the double-side influences on intestinal tumors and inflammation, we summarize how they are done through distinctive process.

Construction of CII-Specific CAR-T to Explore the Cytokine Cascades Between Cartilage-Reactive T Cells and Chondrocytes

Cytokine cascades exist in many autoimmune disorders which amplify and sustain the autoimmune process and lead to chronic inflammatory injury to the host tissues. Increasing evidence indicates that chondrocytes can interact with T cells, which may be a crucial event in inflammatory arthritis. To address the reciprocal influences of cartilage-reactive T cells and chondrocytes, we constructed cartilage-reactive T cells by developing a type II collagen-specific chimeric antigen receptor (CII-CAR). An in vitro co-culture model of CII-CAR-T cells and fresh cartilage was developed, in which CII-CAR-T displayed specific proliferative capacity and cytokine release against fresh cartilage samples, and chondrocytes could respond to CII-CAR-T cells by secreting IL-6. The proposed model will help us to explore the possible cytokine cascades between cartilage-reactive T cells and cartilage.

Cyr61 synthesis is induced by interleukin-6 and promotes migration and invasion of fibroblast-like synoviocytes in rheumatoid arthritis

Background

Interleukin-6 (IL-6) is involved in fibroblast-like synoviocyte (FLS) activation and promotes pannus formation and bone and cartilage destruction in rheumatoid arthritis (RA). Cysteine-rich 61 (Cyr61) protein regulates cell proliferation, migration, and differentiation. The aim of this study was to investigate the role of Cyr61 in RA-FLS migration and invasion after IL-6 stimulation.

Methods

Western blotting, immunohistochemistry, reverse transcription-polymerase chain reaction, and real time-polymerase chain reaction were used to examine protein and mRNA levels of Cyr61, matrix metalloproteinases (MMPs), and other signalling proteins. Knockdown of gene expression was performed with siRNA, and RNA sequencing was performed for differential gene analysis. Migration and invasion were assessed by wound healing and Boyden chamber assays.

Results

Cyr61 levels were elevated in FLSs from RA patients compared to those in osteoarthritis patients. Control and IL-6-treated FLSs showed differential gene expression. IL-6 stimulated protein synthesis of Cyr61, which was attenuated by the extracellular signal-related kinase 1/2 (ERK 1/2) inhibitor, PD98059, and knockdown of early growth response 3 (EGR3), but not of JUN. IL-6-induced Cyr61 protein synthesis increased expression of MMP2. Cyr61 promoted FLS migration and invasion in an autocrine manner. Knockdown of CYR61 and a neutralising antibody attenuated Cyr61 synthesis and IL-6-induced FLS migration.

Conclusions

By modulating the ERK/EGR3 pathway, IL-6 stimulated Cyr61 production and in turn increased invasiveness of FLS. Our data suggest that Cyr61 might be a potential target to prevent the progression of joint damage in RA.

Hematological Manifestations among Patients with Rheumatic Diseases

BACKGROUND

Rheumatic diseases have many hematological manifestations. Blood dyscrasias and other hematological abnormalities are sometimes the first sign of rheumatic disease. In addition, novel antirheumatic biological agents may cause cytopenias.

SUMMARY

The aim of this review was to discuss cytopenias caused by systemic lupus erythematosus and antirheumatic drugs, Felty's syndrome in rheumatoid arthritis, and autoimmune hemolytic anemia, thrombosis, and thrombotic microangiopathies related to rheumatological conditions such as catastrophic antiphospholipid syndrome and scleroderma renal crisis. Key Message: The differential diagnosis of various hematological disorders should include rheumatic autoimmune diseases among other causes of blood cell and hemostasis abnormalities. It is crucial that hematologists be aware of these presentations so that they are diagnosed and treated in a timely manner.

Tocilizumab-induced Leukoencephalopathy with a Reversible Clinical Course

Tocilizumab (TCZ; Actemra/RoActemra) is an anti-interleukin (IL)-6 receptor antibody for the treatment of rheumatoid arthritis (RA) and other autoimmune diseases and cytokine storms. The present case is a 63-year-old female well-controlled RA patient, who presented with a progressive cognitive impairment after 34 months of TCZ administration. Brain magnetic resonance imaging (MRI) showed leukencephalopathy with a lactic acid peak in magnetic resonance spectroscopy (MRS), a decreased blood flow in single photon emission computed tomography (SPECT), and a decreased accumulation in fluorodeoxyglucose positron emission tomography (FDG-PET). The discontinuation of TCZ improved her cognitive function and brain MRI findings at 3 months after drug cessation. The present case suggests that TCZ may sometimes cause leukoencephalopathy after long-term administration, and thus the early discontinuation of TCZ is recommended to achieve a good prognosis.

Role of signaling pathway in biological cause of Rheumatoid arthritis

Rheumatoid Arthritis is a chronic progressive inflammatory auto-immune disease in which the immune system of the body attacks its cartilage and joints lining. It not only affects synovial joints but also many other sites including heart, blood vessels, and skins. It is more common in females than in males. The exact cause of rheumatoid arthritis is not well established but the hypothesis reported in the literature is that in the development stage of the disease, both genetics and environmental factors can play an inciting role. Along with these factors alteration in the normal physiology of enzymatic action, acts as a trigger to develop this condition. Numerous signaling pathways involved in the pathogenesis of Rheumatoid Arthritis involves activation of mitogen-activated protein kinase, kinases Janus family, P-38 Mitogen-Activated Protein Kinase, Nuclear Factor-kappa B. Interleukin-1 to play a proinflammatory cytokine that plays an important role in inflammation in RA. These are also associated with an increase in neutrophil, macrophage and lymphocytic chemotaxis, mast cell degranulation, activation, maturation and survival of T-cells and B-cells activated. These signaling pathways also show that p38α downregulation in myeloid cells exacerbates the severity of symptoms of arthritis. Thus, present review carters about the detail of different signaling pathways and their role in rheumatoid arthritis.

Transforming clinical trials in rheumatology: towards patient-centric precision medicine

Despite the success of targeted therapies in the treatment of inflammatory arthritides, the lack of predictive biomarkers drives a 'trial and error' approach to treatment allocation, leading to variable and/or unsatisfactory responses. In-depth characterization of the synovial tissue in rheumatoid arthritis, as well as psoriatic arthritis and spondyloarthritis, is bringing new insights into the diverse cellular and molecular features of these diseases and their potential links with different clinical and treatment-response phenotypes. Such progress raises the tantalizing prospect of improving response rates by matching the use of specific agents to the cognate target pathways that might drive particular disease subtypes in specific patient groups. Innovative patient-centric, molecular pathology-driven clinical trial approaches are needed to achieve this goal. Whilst progress is clearly being made, it is important to emphasize that this field is still in its infancy and there are a number of potential barriers to realizing the premise of patient-centric clinical trials.

Immunopathology and immunotherapeutic strategies in severe acute respiratory syndrome coronavirus 2 infection

The outbreak of coronavirus disease 2019 (COVID-19) and pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a major concern globally. As of 14 April 2020, more than 1.9 million COVID-19 cases have been reported in 185 countries. Some patients with COVID-19 develop severe clinical manifestations, while others show mild symptoms, suggesting that dysregulation of the host immune response contributes to disease progression and severity. In this review, we have summarized and discussed recent immunological studies focusing on the response of the host immune system and the immunopathology of SARS-CoV-2 infection as well as immunotherapeutic strategies for COVID-19. Immune evasion by SARS-CoV-2, functional exhaustion of lymphocytes, and cytokine storm have been discussed as part of immunopathology mechanisms in SARS-CoV-2 infection. Some potential immunotherapeutic strategies to control the progression of COVID-19, such as passive antibody therapy and use of interferon αβ and IL-6 receptor (IL-6R) inhibitor, have also been discussed. This may help us to understand the immune status of patients with COVID-19, particularly those with severe clinical presentation, and form a basis for further immunotherapeutic investigations.

The role of IL-6 and other mediators in the cytokine storm associated with SARS-CoV-2 infection

The coronavirus disease 2019 pandemic caused by severe acute respiratory syndrome coronavirus 2 presents with a spectrum of clinical manifestations from asymptomatic or mild, self-limited constitutional symptoms to a hyperinflammatory state ("cytokine storm") followed by acute respiratory distress syndrome and death. The objective of this study was to provide an evidence-based review of the associated pathways and potential treatment of the hyperinflammatory state associated with severe acute respiratory syndrome coronavirus 2 infection. Dysregulated immune responses have been reported to occur in a smaller subset of those infected with severe acute respiratory syndrome coronavirus 2, leading to clinical deterioration 7 to 10 days after initial presentation. A hyperinflammatory state referred to as cytokine storm in its severest form has been marked by elevation of IL-6, IL-10, TNF-α, and other cytokines and severe CD4+ and CD8+ T-cell lymphopenia and coagulopathy. Recognition of at-risk patients could permit early institution of aggressive intensive care and antiviral and immune treatment to reduce the complications related to this proinflammatory state. Several reports and ongoing clinical trials provide hope that available immunomodulatory therapies could have therapeutic potential in these severe cases. This review highlights our current state of knowledge of immune mechanisms and targeted immunomodulatory treatment options for the current coronavirus disease 2019 pandemic.

DAS28-CRP Cutoffs for High Disease Activity and Remission Are Lower Than DAS28-ESR in Rheumatoid Arthritis

Objective

Guidelines do not specify how cutoffs for high disease activity differ between the Disease Activity Score 28‐joint count indices DAS28–erythrocyte sedimentation rate (ESR) and DAS28–C‐reactive protein (CRP). Studies that compare DAS28‐CRP and DAS28‐ESR depend on data from clinical trials, registries, or practices with multiple providers. Existing studies use data from patients who received immunosuppressive therapy. This study compared the DAS28‐ESR and DAS28‐CRP values from immunosuppressive treatment–naïve patients in a single physician practice.

Methods

A retrospective electronic medical chart review was conducted for new diagnoses of rheumatoid arthritis (RA; International Classification of Diseases [ICD]‐9 714), based on the American College of Rheumatology/European League against Rheumatology 2010 RA classification criteria. The number of patients with high disease activity (>5.1) was compared using ESR and CRP data to calculate the proportion of discordance. A receiver operator curve and Youden index was used to calculate the DAS28‐CRP high disease activity cutoff estimation that corresponds with DAS28‐ESR of more than 5.1.

Results

There were 171 patients included in this study. The baseline mean DAS28‐ESR was higher than the baseline mean DAS‐28 CRP: 5.1 ± 1.2 versus 4.1 ± 1.0 (P < 0.001); 48.5% of patients met criteria for high disease activity (score >5.1) compared with only 14.6% when measured by DAS28‐CRP. Discordance was 33.9%. κ coefficient was only .307. Receiver operator curve and Youden index analysis suggested that the cutoff point for high disease activity of DAS28‐CRP greater than 4.1, which corresponds to DAS28‐ESR greater than 5.1. Similarly, DAS28‐ESR posttreatment scores were significantly higher than DAS28‐CRP. When measured by DAS28‐ESR, patients in remission had higher scores as measured by DAS28‐ESR (1.81) than DAS28‐CRP (1.45).

Conclusion

There is a difference between DAS28‐ESR and DAS28‐CRP, even when calculated for immunosuppressive treatment–naïve patients. DAS28‐CRP is significantly lower than DAS28‐ESR.

Secreted Osteoclastogenic Factor of Activated T Cells (SOFAT) Is Associated With Rheumatoid Arthritis and Joint Pain: Initial Evidences of a New Pathway

Rheumatoid arthritis (RA) has an inflammatory milieu in the synovial compartment, which is regulated by a complex cytokine and chemokine network that induces continuously degenerative and inflammatory reactions. The secreted osteoclastogenic factor of activated T cells (SOFAT) is a unique cytokine and represents an alternative pathway for osteoclast activation. In this study, we examined whether SOFAT is able to induce joint pain and investigated the presence of SOFAT in a Collagen-induced Arthritis (CIA) model and in human subjects. Here, we found that an intra-articular stimulation with SOFAT (1, 10, 100, or 1,000 ng/10 μl) in the knee joint significantly decreases the mechanical threshold in the hind paw of mice (p < 0.05). Moreover, after a second injection of SOFAT, the mechanical threshold decrease was sustained for up to 8 days (p < 0.05). In the CIA model, the immunohistochemical assay of knee joint showed positivity stained for SOFAT, and the mRNA and protein expression of SOFAT were significantly higher in the affected-group (p < 0.05). Besides, the mRNA of RANKL, IL-1β, IL-6, and IL-15 were significantly higher in the affected-group (p < 0.05). Finally, SOFAT was detected in the synovial fluid of RA patients, but not in OA patients (p < 0.05). In conclusion, SOFAT is up regulated in inflammatory milieu such as RA but not in non-inflammatory OA. SOFAT may be a novel molecule in the complex inflammatory phenotype of RA.

Potential Role of Anti-interleukin (IL)-6 Drugs in the Treatment of COVID-19: Rationale, Clinical Evidence and Risks

The epidemic due to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection has been spreading globally, raising increasing concerns. This public health emergency has triggered a race to find medications to improve the prognosis of this disease. There is currently great interest in drug repositioning to manage SARS-CoV-2 infection, that is, the evaluation of the potential benefits of a drug that has already been proven safe and effective in humans for other approved indications. As interleukin-6 (IL-6) acts as a key driver of the inflammation associated with coronavirus disease 2019 (COVID-19), IL-6 and IL-6 receptor (IL-6R) inhibition appear to be promising targets for the treatment of COVID-19 patients. It is important to critically analyze the available evidence concerning the use of the available anti-IL-6 (siltuximab) and anti-IL-6R (tocilizumab and sarilumab) agents in COVID-19 patients, in terms of both benefit and risk. In this review, the pathogenesis of the cytokine storm induced by COVID-19, the role of IL-6 in this cytokine storm, the rationale for the use of anti-IL-6 agents, and key information on potential benefits and safety monitoring of these biologicals in COVID-19 patients is discussed.

Early use of low dose tocilizumab in patients with COVID-19: A retrospective cohort study with a complete follow-up

BACKGROUND

Pneumonia with severe respiratory failure represents the principal cause of death in COVID-19, where hyper-inflammation plays an important role in lung damage. An effective treatment aiming at reducing the inflammation without preventing virus clearance is thus urgently needed. Tocilizumab, an anti-soluble IL-6 receptor monoclonal antibody, has been proposed for treatment of patients with COVID-19.

METHODS

A retrospective cohort study at the Montichiari Hospital, Brescia, Italy, was conducted. We included consecutive patients with COVID-19 related pneumonia at the early stage of respiratory failure, all treated with a standard protocol (hydroxychloroquine 400 mg daily, lopinavir 800 mg plus ritonavir 200 mg per day). We compared survival rate and clinical status in a cohort of patients who received additional treatment with tocilizumab once (either 400 mg intravenous or 324 mg subcutaneous) with a retrospective cohort of patients who did not receive tocilizumab (referred to as the standard treatment group). All outcomes were assessed at the end of the follow-up, that correspond to death or complete recovery and discharge from the hospital.

FINDINGS

158 patients were included, 90 of which received tocilizumab. 34 out of 68 (50%) patients in the standard treatment group and 7 out of 90 (7.7%) in the tocilizumab group died. Tocilizumab significantly improved survival compared to standard care (multivariate HR: 0.057; 95% C.I = 0.017- 0.187, p < 0.001). No differences between the two administration routes of tocilizumab were observed. No tocilizumab-related infections and/or side effects were observed.

INTERPRETATION

Early treatment with tocilizumab could be helpful to prevent excessive hyper-inflammation and death in COVID-19 related pneumonia. Low dose administration of tocilizumab is not associated with adverse events.

FUNDING

none.

Novel Analgesics with Peripheral Targets

A limited number of peripheral targets generate pain. Inflammatory mediators can sensitize these. The review addresses targets acting exclusively or predominantly on sensory neurons, mediators involved in inflammation targeting sensory neurons, and mediators involved in a more general inflammatory process, of which an analgesic effect secondary to an anti-inflammatory effect can be expected. Different approaches to address these systems are discussed, including scavenging proinflammatory mediators, applying anti-inflammatory mediators, and inhibiting proinflammatory or facilitating anti-inflammatory receptors. New approaches are contrasted to established ones; the current stage of progress is mentioned, in particular considering whether there is data from a molecular and cellular level, from animals, or from human trials, including an early stage after a market release. An overview of publication activity is presented, considering a IuPhar/BPS-curated list of targets with restriction to pain-related publications, which was also used to identify topics.

Notch-Inflammation Networks in Regulation of Breast Cancer Progression

Members of the Notch family and chronic inflammation were each separately demonstrated to have prominent malignancy-supporting roles in breast cancer. Recent investigations indicate that bi-directional interactions that exist between these two pathways promote the malignancy phenotype of breast tumor cells and of their tumor microenvironment. In this review article, we demonstrate the importance of Notch-inflammation interplays in malignancy by describing three key networks that act in breast cancer and their impacts on functions that contribute to disease progression: (1) Cross-talks of the Notch pathway with myeloid cells that are important players in cancer-related inflammation, focusing mainly on macrophages; (2) Cross-talks of the Notch pathway with pro-inflammatory factors, exemplified mainly by Notch interactions with interleukin 6 and its downstream pathways (STAT3); (3) Cross-talks of the Notch pathway with typical inflammatory transcription factors, primarily NF-κB. These three networks enhance tumor-promoting functions in different breast tumor subtypes and act in reciprocal manners, whereby Notch family members activate inflammatory elements and vice versa. These characteristics illustrate the fundamental roles played by Notch-inflammation interactions in elevating breast cancer progression and propose that joint targeting of both pathways together may provide more effective and less toxic treatment approaches in this disease.

Impact of low dose tocilizumab on mortality rate in patients with COVID-19 related pneumonia

BACKGROUND

Pneumonia with respiratory failure represents the main cause of death in COVID-19, where hyper inflammation plays an important role in lung damage. This study aims to evaluate if tocilizumab, an anti-soluble IL-6 receptor monoclonal antibody, reduces patients' mortality.

METHODS

85 consecutive patients admitted to the Montichiari Hospital (Italy) with COVID-19 related pneumonia and respiratory failure, not needing mechanical ventilation, were included if satisfying at least one among: respiratory rate ≥ 30 breaths/min, peripheral capillary oxygen saturation ≤ 93% or PaO2/FiO2<=300 mmHg. Patients admitted before March 13th (n=23) were prescribed the standard therapy (hydroxychloroquine, lopinavir and ritonavir) and were considered controls. On March 13th tocilizumab was available and patients admitted thereafter (n=62) received tocilizumab once within 4 days from admission, plus the standard care.

RESULTS

Patients receiving tocilizumab showed significantly greater survival rate as compared to control patients (hazard ratio for death, 0.035; 95% confidence interval [CI], 0.004 to 0.347; p = 0.004), adjusting for baseline clinical characteristics. Two out of 62 patients of the tocilizumab group and 11 out of 23 in the control group died. 92% and 42.1% of the discharged patients in the tocilizumab and control group respectively, recovered. The respiratory function resulted improved in 64.8% of the observations in tocilizumab patients who were still hospitalized, whereas 100% of controls worsened and needed mechanical ventilation. No infections were reported.

CONCLUSIONS

Tocilizumab results to have a positive impact if used early during Covid-19 pneumonia with severe respiratory syndrome in terms of increased survival and favorable clinical course.

Metformin, an AMPK Activator, Inhibits Activation of FLSs but Promotes HAPLN1 Secretion

AMP-activated protein kinase (AMPK) is essential for maintaining energy balance and has a crucial role in various inflammatory pathways. In this study, AMPK levels positively correlated with many inflammatory indexes in rheumatoid arthritis (RA) patients, especially in the affected synovium. In RA sera, a positive correlation between phosphorylated (p-)AMPK-α1 levels and DAS28 (disease activity score 28) activity (r = 0.270, p < 0.0001) was found. Similarly, a positive correlation was observed between AMPK-α1 and tumor necrosis factor α (TNF-α) levels (r = 0.460, p = 0.0002). Differentially expressed genes between osteoarthritis (OA) and RA synovium from NCBI GEO profiles and our RNA sequencing data suggested activation of metabolic pathways specific to RA-fibroblast-like synoviocytes (FLSs). AMPK-α1 was highly expressed in the synovium of RA but not OA patients. An AMPK activator, metformin, inhibited FLS proliferation at higher but not lower concentrations, whereas the inhibitor dorsomorphin promoted the proliferation of RA-FLSs. Interestingly, both metformin and dorsomorphin inhibited the migration of RA-FLSs. After metformin treatment, expression of interleukin 6 (IL-6), TNF-α, and IL-1β were significantly downregulated in RA-FLSs; however, increased expression of p-AMPK-α1, protein kinase A (PKA)-α1, and HAPLN1 (hyaluronan and proteoglycan link protein 1) was observed. Increased levels of HAPLN1 in RA-FLSs by an AMPK activator could potentially be beneficial in protecting the joints. Hence, our results demonstrate the potential of an AMPK activator as a therapeutic for RA.

Therapeutic Potential of Dental Pulp Stem Cells and Leukocyte- and Platelet-Rich Fibrin for Osteoarthritis

Osteoarthritis (OA) is a degenerative and inflammatory joint disorder with cartilage loss. Dental pulp stem cells (DPSCs) can undergo chondrogenic differentiation and secrete growth factors associated with tissue repair and immunomodulation. Leukocyte- and platelet-rich fibrin (L-PRF) emerges in regenerative medicine because of its growth factor content and fibrin matrix. This study evaluates the therapeutic application of DPSCs and L-PRF in OA via immunomodulation and cartilage regeneration. Chondrogenic differentiation of DPSCs, with or without L-PRF exudate (ex) and conditioned medium (CM), and of bone marrow-mesenchymal stem cells was compared. These cells showed differential chondrogenesis. L-PRF was unable to increase cartilage-associated components. Immature murine articular chondrocytes (iMACs) were cultured with L-PRF ex, L-PRF CM, or DPSC CM. L-PRF CM had pro-survival and proliferative effects on unstimulated and cytokine-stimulated iMACs. L-PRF CM stimulated the release of IL-6 and PGE2, and increased MMP-13, TIMP-1 and IL-6 mRNA levels in cytokine-stimulated iMACs. DPSC CM increased the survival and proliferation of unstimulated iMACs. In cytokine-stimulated iMACs, DPSC CM increased TIMP-1 gene expression, whereas it inhibited nitrite release in 3D culture. We showed promising effects of DPSCs in an in vitro OA model, as they undergo chondrogenesis in vitro, stimulate the survival of chondrocytes and have immunomodulatory effects.

Update on the Pathomechanism, Diagnosis, and Treatment Options for Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune disease that involves multiple joints bilaterally. It is characterized by an inflammation of the tendon (tenosynovitis) resulting in both cartilage destruction and bone erosion. While until the 1990s RA frequently resulted in disability, inability to work, and increased mortality, newer treatment options have made RA a manageable disease. Here, great progress has been made in the development of disease-modifying anti-rheumatic drugs (DMARDs) which target inflammation and thereby prevent further joint damage. The available DMARDs are subdivided into (1) conventional synthetic DMARDs (methotrexate, hydrochloroquine, and sulfadiazine), (2) targeted synthetic DMARDs (pan-JAK- and JAK1/2-inhibitors), and (3) biologic DMARDs (tumor necrosis factor (TNF)-α inhibitors, TNF-receptor (R) inhibitors, IL-6 inhibitors, IL-6R inhibitors, B cell depleting antibodies, and inhibitors of co-stimulatory molecules). While DMARDs have repeatedly demonstrated the potential to greatly improve disease symptoms and prevent disease progression in RA patients, they are associated with considerable side-effects and high financial costs. This review summarizes our current understanding of the underlying pathomechanism, diagnosis of RA, as well as the mode of action, clinical benefits, and side-effects of the currently available DMARDs.

[Biologicals and small molecules for rheumatoid arthritis]

In recent years tremendous progress has been made in the therapeutic management of rheumatoid arthritis. Rheumatologists now have a large armamentarium of highly efficient drugs with different mechanisms of action at their disposal. These new drugs consist of biologicals (biological disease-modifying antirheumatic drugs, bDMARDs) as well as targeted synthetic DMARDs (tsDMARD). A common feature of these new drugs for treatment of rheumatoid arthritis is that the molecular target of the drug is known, which is not the case for conventional DMARDs. With the help of the new drugs, the therapeutic goal of inducing remission in patients with rheumatoid arthritis has become reality for many patients. Nevertheless, there is still a significant proportion of patients who do not adequately respond to all available drugs, leaving room for still further improvement. This review gives a short overview on the currently available and effective substances for the treatment of rheumatoid arthritis.

Therapeutic Effect of Exogenous Regulatory T Cells on Collagen-induced Arthritis and Rheumatoid Arthritis

Regulatory T (Treg) cells have anti-inflammatory functions and heighten immune tolerance. The proportion and functions of Treg cells are perturbed in rheumatoid arthritis (RA), contributing to the excessive immune activation associated with this disease. We therefore hypothesized that supplementation with foreign Treg cells could be used to treat RA. To investigate the therapeutic effects of exogenous Treg cells on RA and its mechanism, we used human Treg cells to treat collagen-induced arthritis (CIA) in a rat model to observe whether exogenous Treg cells can treat the disease across species. Successful treatment would indicate that Treg cell transplantation in humans is more likely to affect RA. In the present study, human Treg cells were collected from healthy human peripheral blood and culture-expanded in vitro. Induced human Treg cells were injected into CIA rats via the tail vein. The rats' lymphocyte subtypes, cytokines, and Th1/Th2 ratios were measured using flow cytometry. In the rats, following injection of the human Treg cells, the severity of CIA was significantly reduced (P < 0.01), the proportion of endogenous Treg cells increased in the peripheral blood and spleen (P = 0.007 and P < 0.01, respectively), and the proportion of B cells decreased (P = 0.031). The IL-5 level, IL-6 level, and Th1/Th2 ratio in the peripheral blood were decreased (P = 0.013, 0.009, and 0.012, respectively). The culture-expanded human Treg cells were also cultured with synovial fibroblast cells from RA patients (RASFs). After coculture with Treg cells, RASFs showed reduced proliferation (P < 0.01) and increased apoptosis (P = 0.037). These results suggest that exogenous and induced Treg cells can produce a therapeutic effect in RA and CIA by increasing endogenous Treg cells and RASF apoptosis and reducing B cells, the Th1/Th2 ratio, and secretion levels of IL-5 and IL-6. Treg cell transplantation could serve as a therapy for RA that does not cause immune rejection.

Safety and efficacy of tocilizumab as monotherapy or in combination with methotrexate in Tunisian patients with active rheumatoid arthritis and inadequate response to disease-modifying anti-rheumatic drugs in conditions close to clinical practice

OBJECTIVES

We aimed to assess the safety and efficacy of tocilizumab as monotherapy or in combination with methotrexate in a routine clinical practice setting in Tunisian patients with RA who did not respond to conventional treatment with disease-modifying anti-rheumatic drugs (DMARDs-IR).

METHOD

A total of 51 DMARDs-IR adult patients with moderate to severe RA participated in a phase IIIb, open-label clinical trial. Patients received 8 mg/kg of tocilizumab every 4 weeks in combination with a DMARD or as monotherapy during 24 weeks. The study was extended to 24 other weeks for those who had at least a moderate response at the end of the initial phase. Safety and efficacy of tocilizumab were analysed.

RESULTS

Four patients discontinued treatment prematurely due to an adverse event. The most common AEs were hypercholesterolemia (18 cases), increased triglycerides (17 cases), increased transaminases (15 cases), rash (14 cases), neutropenia (7 cases), digestive disorders (3 cases) and respiratory disorders (3 cases). After 52 weeks, 90.5% of patients responded to treatment. At the end of the study, 61.9% of the patients had a mild RA and almost 50% of patients were in remission. Overall, 29.2, 6.3 and 4.3% of patients achieved ACR20, ACR50 and ACR70 responses, respectively. Additionally, the study showed a significant improvement in all individual parameters of ACR core data.

CONCLUSIONS

Treatment with tocilizumab was well tolerated and showed a fast and sustained efficacy in Tunisian patients with moderate to severe active RA who had an inadequate response to DMARDs.Key Points• Up to 40% of RA patients remain inadequate responders to a prior csDMARD or a tumour necrosis factor α inhibitor (TNFi) biological agent. A non-TNF biological agent like tocilizumab with or without methotrexate is recommended in those patients.• In this study, tocilizumab treatment improved the number of responders, the number of patients in remission, and the evolution of disease activity. The meaningful clinical improvement seen denotes a rapid and sustained response to treatment.• Tocilizumab presented a favourable safety profile with few withdrawals due to AEs, consistently with what was observed in other trials.• This study provides new information about the safety and efficacy of tocilizumab in a patient population resembling that expected in clinical practice among the Tunisian population.

Chemokines in rheumatic diseases: pathogenic role and therapeutic implications

Chemokines, a family of small secreted chemotactic cytokines, and their G protein-coupled seven transmembrane spanning receptors control the migratory patterns, positioning and cellular interactions of immune cells. The levels of chemokines and their receptors are increased in the blood and within inflamed tissue of patients with rheumatic diseases, such as rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis, vasculitis or idiopathic inflammatory myopathies. Chemokine ligand-receptor interactions control the recruitment of leukocytes into tissue, which are central to the pathogenesis of these rheumatic diseases. Although the blockade of various chemokines and chemokine receptors has yielded promising results in preclinical animal models of rheumatic diseases, human clinical trials have, in general, been disappointing. However, there have been glimmers of hope from several early-phase clinical trials that suggest that sufficiently blocking the relevant chemokine pathway might in fact have clinical benefits in rheumatic diseases. Hence, the chemokine system remains a promising therapeutic target for rheumatic diseases and requires further study.

General principles and escalation options of immunotherapy in autoantibody-associated disorders of the CNS

Autoimmune diseases associated with antineuronal and antiglial autoantibodies (Abs) is one of the most rapidly expanding research fields in clinical neuroimmunology, with more than 30 autoantibodies described so far. Being associated with a wide range of clinical presentations these syndromes can be diagnostically challenging. Surface or intracellular antigen localizations are crucial for the treatment response and outcome. In the latter Abs are mostly of paraneoplastic cause and tumor management should be performed as soon as possible in order to stop peripheral antigen stimulation. Immunotherapy should be started early in both groups, before irreversible neuronal loss occurs. Despite serious prognosis, aggressive therapeutic approaches can be effective in many cases. In this article we review main pathogenic mechanisms leading to Abs-related syndromes and describe standard as well as emerging strategies of immunotherapy, including tocilizumab and bortezomib. Several special therapeutic approaches will be illustrated by clinical cases recently treated in our department.