IL-1 Blockade Research Articles

Neuroinflammation and status epilepticus: a narrative review unraveling a complex interplay

Status epilepticus (SE) is a medical emergency resulting from the failure of the mechanisms involved in seizure termination or from the initiation of pathways involved in abnormally prolonged seizures, potentially leading to long-term consequences, including neuronal death and impaired neuronal networks. It can eventually evolve to refractory status epilepticus (RSE), in which the administration of a benzodiazepine and another anti-seizure medications (ASMs) had been ineffective, and super-refractory status epilepticus (SRSE), which persists for more than 24 h after the administration of general anesthesia. Objective of the present review is to highlight the link between inflammation and SE. Several preclinical and clinical studies have shown that neuroinflammation can contribute to seizure onset and recurrence by increasing neuronal excitability. Notably, microglia and astrocytes can promote neuroinflammation and seizure susceptibility. In fact, inflammatory mediators released by glial cells might enhance neuronal excitation and cause drug resistance and seizure recurrence. Understanding the molecular mechanisms of neuroinflammation could be crucial for improving SE treatment, wich is currently mainly addressed with benzodiazepines and eventually phenytoin, valproic acid, or levetiracetam. IL-1β signal blockade with Anakinra has shown promising results in avoiding seizure recurrence and generalization in inflammatory refractory epilepsy. Inhibiting the IL-1β converting enzyme (ICE)/caspase-1 is also being investigated as a possible target for managing drug-resistant epilepsies. Targeting the ATP-P2X7R signal, which activates the NLRP3 inflammasome and triggers inflammatory molecule release, is another avenue of research. Interestingly, astaxanthin has shown promise in attenuating neuroinflammation in SE by inhibiting the ATP-P2X7R signal. Furthermore, IL-6 blockade using tocilizumab has been effective in RSE and in reducing seizures in patients with febrile infection-related epilepsy syndrome (FIRES). Other potential approaches include the ketogenic diet, which may modulate pro-inflammatory cytokine production, and the use of cannabidiol (CBD), which has demonstrated antiepileptic, neuroprotective, and anti-inflammatory properties, and targeting HMGB1-TLR4 axis. Clinical experience with anti-cytokine agents such as Anakinra and Tocilizumab in SE is currently limited, although promising. Nonetheless, Etanercept and Rituximab have shown efficacy only in specific etiologies of SE, such as autoimmune encephalitis. Overall, targeting inflammatory pathways and cytokines shows potential as an innovative therapeutic option for drug-resistant epilepsies and SE, providing the chance of directly addressing its underlying mechanisms, rather than solely focusing on symptom control.

Interleukin-6 plasma levels are elevated in patients with acute myocardial infarction and predict death or recurrent infarction within 1 year - a case-control study

Abstract Background Acute myocardial infarction (AMI) harbours marked inflammatory components. While cytokines of the same family have been causally related to patient outcome, the role of interleukin (IL)-6 in AMI remains incompletely understood. Recent trials suggest benefits of inhibiting IL-6 in patients with ST-segment elevation myocardial infarction (STEMI). In patients at high atherosclerotic risk, IL-6 blockade reduces markers of inflammation and thrombosis. Purpose This study aimed to assess the levels of IL-6 in AMI patients and their predictive value. Methods 160 cases (recurrent AMI or death within 1 year) and 160 matched controls were selected from the prospective, multicentric SPUM-ACS Cohort. All patients had an AMI (STEMI or NSTEMI) as initial event and underwent percutaneous coronary intervention (PCI) within 24h of symptom onset. Blood samples were drawn before PCI and biomarker plasma levels were assessed (mesoscale). Comparisons were made with age- and sex-matched healthy blood donors (HD). IL-6 levels are presented as medians and interquartile ranges. Cases, controls and HD were compared using the Kruskal-Wallis test. Correlations of baseline variables to IL-6 levels within cases and controls were assessed by linear regression analyses. Patients were divided into those with higher or lower IL-6 levels according to the median IL-6 level. Kaplan-Meier (KM) analyses for the combined endpoint of death or recurrent AMI were performed. Results The overall median IL-6 level was 21.3pg/ml. Patients with higher IL-6 had more previous AMI (n=22, 14%) than patients with lower IL-6 (n=12, 7%, p=0.045). Patients with increased IL-6 had more previous PCI (n=30, 20%) than patients with lower IL6 (n=19, 11%, p=0.045). Both cases and controls showed higher levels of IL-6 than HD (cases: 25.7pg/ml [14.8–81.6], controls: 20.0pg/ml [11.3–40.1], HD: 5.9pg/ml [3.6–9.9]; cases/controls vs. HD: p<0.0001). Among AMI patients, cases showed higher IL-6 levels than controls (p=0.030) (Figure 1). Within cases and controls, IL-6 was related to IL-1beta (r=0.628, p<0.001), IL-1alpha (r=0.174, p=0.002) and IL-1 receptor antagonist (r=0.422, p<0.001). IL-6 was related to neutrophil/lymphocyte ratio (r=0.147, p=0.016), but not to high-sensitivity C-reactive protein (r=0.087, p=0.142) or N-terminal pro B-type natriuretic peptide (r=0.091, p=0.118). IL-6 was related to Killip Class upon presentation (r=0.190, p<0.001). KM analyses showed significantly higher rates of death or recurrent AMI within 1 year for patients with higher IL-6 (log-rank p=0.006, Figure 2), with early divergence of the curves. Conclusions IL-6 is markedly higher in patients with AMI compared to healthy controls and predicts death or recurrent AMI within 1 year. IL-6 might be a valuable target for early anti-inflammatory therapy to patients with AMI. A deeper understanding of factors influencing IL-6 levels may help select those patients that will benefit most from such treatment.Figure 1:Cases vs. Controls vs. HDFigure 1:Kaplan-Meier Analysis

TRANSLATIONAL RESEARCH-02 THE KEYSTONE CYTOKINE, INTERLEUKIN-6, A KEY TARGET AND “ORGANIZING PRINCIPLE” FOR GLIOBLASTOMA THERAPY: A DECADE OF TRANSLATIONAL PROGRESS FROM GENOMICS TO THE LABORATORY AND TO A MULTICENTER CLINICAL TRIAL

Abstract Interleukin-6 (IL-6), the ‘keystone cytokine’, affects homeostatic processes, including innate and adaptive immunity, and is regarded as a prominent target for clinical intervention (Hunter, 2015). IL-6 is also a senescence-associated-gene (SAG), linked to cellular aging, the aging brain, and cancer pathogenesis. We hypothesized that SAGs, including IL-6, are overexpressed in older patients, in higher grades of glioma, portending a poor prognosis (Coppola, 2014). Indeed, in an analysis of 47 gliomas at the Moffitt Cancer Center, we found that the ‘senescence score’ composed of genes central to the pathogenesis of glioma, defined a novel signature, provided prognostic biomarkers as well as targets for drug discovery and immunotherapy (Coppola, 2014). We suggested that IL-6 could be linked to neoplastic transformation and could be predictive of glioma progression (US Patent #8741575). At the University of Pennsylvania, we found an inhibitor of IL-6 to be well-tolerated in patients with glioblastoma undergoing CAR T cell therapy (O’Rourke, 2017). Yi Fan’s team discovered (Wang, 2018) that targeting IL-6 led to a remarkable change in the tumor microenvironment (TME), with a “switch” from the M2 (immunosuppressive, pro-tumorigenic) macrophage phenotype to an immunostimulatory (M1) phenotype, resulting in a significant increase in survival. Adding CD40 agonist enhanced the activity of infiltrated T cells, and an almost complete cure in GBM models. The use of immune checkpoint inhibitors in these experiments and by others (Lamano, 2019) produced a significant increase in survival. These findings led to a multicenter trial (PI, Stephen Bagley; NCT 047299959), by NRG Oncology (BN010), combining IL-6 inhibition (tocilizumab), PD-L1 blockade (atezolizumab) and stereotactic radiotherapy to treat recurrent glioblastoma. More recently, a MDACC team discovered that IL-6 blockade not only promotes tumor immunity but also abrogates the toxicity of checkpoint blockade, decoupling the autoimmune toxicity while promoting tumor immunity through the IL-12 pathway (Hailemichael, 2022).

GLIOMA-05 A NOVEL CONCEPT FOR TREATMENT OF GLIOBLASTOMA: VAGUS NERVE ELECTRICAL STIMULATION FOR SUPPRESSION OF CYTOKINE (IL-6) SIGNALING

Abstract Glioblastoma is an aggressive, incurable cancer. Innovative approaches are urgently needed. There is resurgent interest in harnessing the power of the immune system (O’Rourke DM, 2017; Liau LM, 2023). Glioblastoma is a key target for cytokine reprogramming of the tumor microenvironment involving macrophages, monocytes, lymphocytes, and myeloid-derived cells. Furthermore, as with other cancers, the incidence and poor prognosis is linked to the age of the patient, and chronic, low-grade inflammation, or “inflammaging” (Franceschi, 2014). There is strong clinical, genomic (Coppola, 2014), preclinical data linking the progression of glioblastoma to the cytokine, IL-6. Yi Fan and colleagues (Wang, 2018; Yang, 2021) showed that blockade of IL-6 increases survival in mouse models of glioblastoma, an effect enhanced with the use of immune checkpoint blockade (ICB). These results were validated and extended by others (Tsukamoto, 2018; Lamano,2019). Taken together, we translated the findings to a prospective, multicenter clinical trial (NRG BRAIN-010, NCT04729959; PI, Stephen Bagley) for recurrent glioblastoma, combining stereotactic radiosurgery, IL-6R blockade (tocilizumab) and ICB (atezolizumab). To date, the regimen is well-tolerated with an acceptable safety profile. Vagus nerve stimulation is FDA-approved for control of medically refractory epilepsy. It is currently being evaluated in a multicenter, pivotal trial to treat advanced rheumatoid arthritis (RESET-RA, NCT04539964). Electrical stimulation of the vagus nerve activates the inflammatory reflex (Kelly, 2022), with a reduction of inflammatory cytokines, including IL-6 (Koopman, 2016). Electrical stimulation of the vagus nerve uses the ‘inflammatory reflex’ and exploits the cholinergic effect on T-cells (Levine, 2020). Taken together, we now propose a clinical trial to assess the safety and efficacy of vagal nerve stimulation for patients with glioblastoma and are in discussion with industry (SetPoint Medical) to design a prospective, clinical trial for treatment of glioblastoma.

Cutting Edge: TLR2 Signaling in B Cells Promotes Autoreactivity to DNA via IL-6 Secretion.

Autoantibodies to chromatin and dsDNA are a hallmark of systemic lupus erythematosus (SLE). In a mouse model of monogenic human SLE caused by DNASE1L3 deficiency, the anti-DNA response is dependent on endosomal nucleic acid-sensing TLRs TLR7 and TLR9. In this study, we report that this response also required TLR2, a surface receptor for microbial products that is primarily expressed on myeloid cells. Cell transfers into lymphopenic DNASE1L3-deficient mice showed that TLR2 was required for anti-DNA Ab production by lymphocytes. TLR2 was detectably expressed on B cells and facilitated the production of IL-6 by B cells activated in the presence of microbial products. Accordingly, treatment with broad-spectrum antibiotics or Ab-mediated blockade of IL-6 delayed the anti-DNA response in DNASE1L3-deficient mice. These studies reveal an unexpected B cell-intrinsic role of TLR2 in systemic autoreactivity to DNA, and they suggest that microbial products may synergize with self-DNA in the activation of autoreactive B cells in SLE.

Anakinra authorized to treat severe coronavirus disease 2019; Sepsis breakthrough or time to reflect?

The European Medicines Agency (EMA) and the United States Food and Drug Administration (FDA) announced conditions for using recombinant human interleukin-1 receptor antagonist (rhIL-1ra) to treat hospitalized patients with Coronavirus disease 2019 (COVID-19) and risk for progression. These decisions followed publication of the suPAR-guided Anakinra treatment for Validation of the risk and early Management OF seveRE respiratory failure by COVID-19 (SAVE- MORE) phase 3 clinical trial that yielded positive results. We conducted a literature review and theoretical analysis of IL-1 blockade as a therapy to treat COVID-19. Using a stepwise analysis, we assessed clinical applicability of the SAVE-MORE results and evaluated conceptual support for interleukin-1 suppression as a suitable approach to COVID-19 treatment. This therapeutic approach was then examined as an example of inflammation-suppressing measures used to treat sepsis. Anakinra use as a COVID-19 therapy seems to rely on a view of pathogenesis that incorrectly reflects human disease. Since COVID-19 is an example of sepsis, COVID-19 benefit due to anti-inflammatory therapy contradicts an extensive history of unsuccessful clinical study. Repurposing rhIL-1ra to treat COVID-19 appears to exemplify a cycle followed by inflammation-suppressing sepsis treatments. A landscape of treatment failures is interrupted by a successful clinical trial. However, subsequent confirmatory study fails to replicate the positive data. We suggest further experimentation is not a promising pathway to discover game-changing sepsis therapies. A different kind of approach may be necessary.

Pathogenic pathways and therapeutic targets of inflammation in heart diseases: A focus on Interleukin-1.

An exuberant and dysregulated inflammatory response contributes to the development and progression of cardiovascular diseases (CVDs). This narrative review includes original articles and reviews published over the past 20 years and found through PubMed. The following search terms (or combination of terms) were considered: "acute pericarditis," "recurrent pericarditis," "myocarditis," "cardiac sarcoidosis," "atherosclerosis," "acute myocardial infarction," "inflammation," "NLRP3 inflammasome," "Interleukin-1" and "treatment." Recent evidence supports the role of inflammation across a wide spectrum of CVDs including myocarditis, pericarditis, inflammatory cardiomyopathies (i.e. cardiac sarcoidosis) as well as atherosclerotic CVD and heart failure. Interleukins (ILs) are the signalling mediators of the inflammatory response. The NACHT, leucine-rich repeat and pyrin-domain containing protein 3 (NLRP3) inflammasome play a key role in producing IL-1β, the prototypical pro-inflammatory cytokine involved in CVDs. Other pro-inflammatory cytokines (e.g. tumour necrosis factor) have been implicated in cardiac sarcoidosis. As a proof of this, IL-1 blockade has been proven efficacious in pericarditis and chronic coronary syndrome. Tailored strategies aiming at quenching the inflammatory response have emerged as promising to treat CVDs. In this review article, we summarize recent evidence regarding the role of inflammation across a broad spectrum of CVDs. We also review novel evidence regarding targeted therapeutic strategies.

Sex-Specific Dysconnective Brain Injuries and Neuropsychiatric Conditions such as Autism Spectrum Disorder Caused by Group B Streptococcus-Induced Chorioamnionitis.

Global health efforts have increased against infectious diseases, but issues persist with pathogens like Group B Streptococcus (GBS). Preclinical studies have elaborated on the mechanistic process of GBS-induced chorioamnionitis and its impact on the fetal programming of chronic neuropsychiatric diseases. GBS inoculation in rodents demonstrated the following: (i) silent and self-limited placental infection, similar to human chorioamnionitis; (ii) placental expression of chemokines attracting polymorphonuclear (PMN) cells; (iii) in vitro cytokine production; (iv) PMN infiltration in the placenta (histologic hallmark of human chorioamnionitis), linked to neurobehavioral impairments like cerebral palsy and autism spectrum disorders (ASD); (v) upregulation of interleukin-1β (IL-1β) in the placenta and fetal blood, associated with higher ASD risk in humans; (vi) sex-specific effects, with higher IL-1β release and PMN recruitment in male placenta; (vii) male offspring exhibiting ASD-like traits, while female offspring displayed attention deficit and hyperactivity disorder (ADHD)-like traits; (viii) IL-1 and/or NF-kB blockade alleviate placental and fetal inflammation, as well as subsequent neurobehavioral impairments. These findings offer potential therapeutic avenues, including sex-adapted anti-inflammatory treatment (e.g., blocking IL-1; repurposing of FDA-approved IL-1 receptor antagonist (IL-1Ra) treatment). Blocking the IL-1 pathway offers therapeutic potential to alleviate chorioamnionitis-related disabilities, presenting an opportunity for a human phase II RCT that uses IL-1 blockade added to the classic antibiotic treatment of chorioamnionitis.

Systemic juvenile idiopathic arthritis: The Great Ormond Street Hospital experience (2005-2021).

Systemic juvenile idiopathic arthritis (sJIA) is a complex, systemic inflammatory disorder driven by both innate and adaptive immunity. Improved understanding of sJIA pathophysiology has led to recent therapeutic advances including a growing evidence base for the earlier use of IL-1 or IL-6 blockade as first-line treatment. We conducted a retrospective case notes review of patients diagnosed with sJIA over a 16-year period (October 2005-October 2021) at Great Ormond Street Hospital for Children. We describe the clinical presentation, therapeutic interventions, complications, and remission rates at different timepoints over the disease course. We examined our data, which spanned a period of changing therapeutic landscape, to try and identify potential therapeutic signals in patients who received biologic treatment early in the disease course compared to those who did not. A total of 76-children (female n = 40, 53%) were diagnosed with sJIA, median age 4.5 years (range 0.6-14.1); 36% (27/76) presented with suspected or confirmed macrophage activation syndrome. A biologic disease-modifying anti-rheumatic drug (bDMARD) alone was commenced as first-line treatment in 28% (n = 21/76) of the cohort; however, at last review, 84% (n = 64/76) had received treatment with a bDMARD. Clinically inactive disease (CID) was achieved by 88% (n = 67/76) of the cohort at last review; however, only 32% (24/76) achieved treatment-free CID. At 1-year follow-up, CID was achieved in a significantly greater proportion of children who received treatment with a bDMARD within 3 months of diagnosis compared to those who did not (90% vs. 53%, p = 0.002). Based on an ever-increasing evidence base for the earlier use of bDMARD in sJIA and our experience of the largest UK single-centre case series described to date, we now propose a new therapeutic pathway for children diagnosed with sJIA in the UK based on early use of bDMARDs. Reappraisal of the current National Health Service commissioning pathway for sJIA is now urgently required.

Neuroinflammation, autoinflammation, splenomegaly and anemia caused by bi-allelic mutations in IRAK4.

We describe a novel, severe autoinflammatory syndrome characterized by neuroinflammation, systemic autoinflammation, splenomegaly, and anemia (NASA) caused by bi-allelic mutations in IRAK4. IRAK-4 is a serine/threonine kinase with a pivotal role in innate immune signaling from toll-like receptors and production of pro-inflammatory cytokines. In humans, bi-allelic mutations in IRAK4 result in IRAK-4 deficiency and increased susceptibility to pyogenic bacterial infections, but autoinflammation has never been described. We describe 5 affected patients from 2 unrelated families with compound heterozygous mutations in IRAK4 (c.C877T (p.Q293*)/c.G958T (p.D320Y); and c.A86C (p.Q29P)/c.161+1G>A) resulting in severe systemic autoinflammation, massive splenomegaly and severe transfusion dependent anemia and, in 3/5 cases, severe neuroinflammation and seizures. IRAK-4 protein expression was reduced in peripheral blood mononuclear cells (PBMC) in affected patients. Immunological analysis demonstrated elevated serum tumor necrosis factor (TNF), interleukin (IL) 1 beta (IL-1β), IL-6, IL-8, interferon α2a (IFN-α2a), and interferon β (IFN-β); and elevated cerebrospinal fluid (CSF) IL-6 without elevation of CSF IFN-α despite perturbed interferon gene signature. Mutations were located within the death domain (DD; p.Q29P and splice site mutation c.161+1G>A) and kinase domain (p.Q293*/p.D320Y) of IRAK-4. Structure-based modeling of the DD mutation p.Q29P showed alteration in the alignment of a loop within the DD with loss of contact distance and hydrogen bond interactions with IRAK-1/2 within the myddosome complex. The kinase domain mutation p.D320Y was predicted to stabilize interactions within the kinase active site. While precise mechanisms of autoinflammation in NASA remain uncertain, we speculate that loss of negative regulation of IRAK-4 and IRAK-1; dysregulation of myddosome assembly and disassembly; or kinase active site instability may drive dysregulated IL-6 and TNF production. Blockade of IL-6 resulted in immediate and complete amelioration of systemic autoinflammation and anemia in all 5 patients treated; however, neuroinflammation has, so far proven recalcitrant to IL-6 blockade and the janus kinase (JAK) inhibitor baricitinib, likely due to lack of central nervous system penetration of both drugs. We therefore highlight that bi-allelic mutation in IRAK4 may be associated with a severe and complex autoinflammatory and neuroinflammatory phenotype that we have called NASA (neuroinflammation, autoinflammation, splenomegaly and anemia), in addition to immunodeficiency in humans.

IL-1 blockade in cardiovascular disease: an appraisal of the evidence across different inflammatory paradigms.

Pre-clinical and clinical studies suggest a role for inflammation in the pathophysiology of cardiovascular (CV) diseases. The NLRP3 (NACHT, leucine-rich repeat, and pyrin domain-containing protein 3) inflammasome is activated during tissue injury and releases interleukin-1β (IL-1β). We describe three paradigms in which the NLRP3 inflammasome and IL-1β contribute to CV diseases. During acute myocardial infarction (AMI), necrotic cell debris, including IL-1α, induce NLRP3 inflammasome activation and further damage the myocardium contributing to heart failure (HF) (acute injury paradigm). In chronic HF, IL-1β is induced by persistent myocardial overload and injury, neurohumoral activation and systemic comorbidities favoring infiltration and activation of immune cells into the myocardium, microvascular inflammation, and a pro-fibrotic response (chronic inflammation paradigm). In recurrent pericarditis, an autoinflammatory response triggered by cell injury and maintained by the NLRP3 inflammasome/IL-1β axis is present (autoinflammatory disease paradigm). Anakinra, recombinant IL-1 receptor antagonist, inhibits the acute inflammatory response in patients with ST elevation myocardial infarction (STEMI) and acute HF. Canakinumab, IL-1β antibody, blunts systemic inflammation and prevents complications of atherosclerosis in stable patients with prior AMI. In chronic HF, anakinra reduces systemic inflammation and improves cardiorespiratory fitness. In recurrent pericarditis, anakinra and rilonacept, a soluble IL-1 receptor chimeric fusion protein blocking IL-1α and IL-1β, treat and prevent acute flares. In conclusion, the NLRP3 inflammasome and IL-1 contribute to the pathophysiology of CV diseases, and IL-1 blockade is beneficial with different roles in the acute injury, chronic inflammation and autoinflammatory disease paradigms. Further research is needed to guide the optimal use of IL-1 blockers in clinical practice.

Unexpected Clinical Lessons Learned From IL-4 and IL-13 Blockade.

In 2017, dupilumab became the first FDA approved systemic therapy for atopic dermatitis. Since its approval, extensive clinical experience and continued research have revealed a number of unexpected effects that are highly clinically relevant. We will review these clinical effects and the supporting evidence.J Drugs Dermatol. 2023;22(10):1007-1008 doi:10.36849/JDD.7249.

TNF-like weak inducer of apoptosis inhibition is comparable to IL-13 blockade in ameliorating atopic dermatitis inflammation.

Targeting IL-13 is highly efficacious in patients with Th2-biased atopic dermatitis (AD), but inhibition of other inflammatory molecules might also limit disease. We investigated the importance of the TNF family cytokine TNF-like weak inducer of apoptosis (TWEAK; TNFSF12) to keratinocyte dysregulation and the pathogenesis of AD in mice and also tested if blocking TWEAK has a similar therapeutic effect as targeting IL-13. Conditional knockout mice lacking Fn14 (TNFRSF12A), the receptor for TWEAK, only in keratinocytes, were repetitively sensitized with house dust mite allergen and analyzed for AD-like skin inflammation. To determine the translational potential, wild-type mice with AD were therapeutically treated with anti-TWEAK and/or anti-IL-13 antibodies, and skin inflammation was assessed. Mice deficient in Fn14 in keratinocytes were resistant to developing maximal clinical features of AD, exhibiting reduced epidermal hyperplasia and dermal thickening, less skin infiltration of immune cells, and downregulated inflammatory gene expression. Moreover, therapeutic neutralization of TWEAK in wild-type mice with AD reduced all of the pathological features to a comparable extent as blocking IL-13. The activity of TWEAK in keratinocytes contributes to AD development, and neutralizing TWEAK represents a future potential therapeutic option in human AD similar to targeting IL-13.

IL-33-induced neutrophilic inflammation and NETosis underlie rhinovirus-triggered exacerbations of asthma

Rhinovirus-induced neutrophil extracellular traps (NETs) contribute to acute asthma exacerbations; however, the molecular factors that trigger NETosis in this context remain ill-defined. Here, we sought to implicate a role for IL-33, an epithelial cell-derived alarmin rapidly released in response to infection. In mice with chronic experimental asthma (CEA), but not naïve controls, rhinovirus inoculation induced an early (1day post infection; dpi) inflammatory response dominated by neutrophils, neutrophil-associated cytokines (IL-1α, IL-1β, CXCL1), and NETosis, followed by a later, type-2 inflammatory phase (3-7 dpi), characterised by eosinophils, elevated IL-4 levels, and goblet cell hyperplasia. Notably, both phases were ablated by HpARI (Heligmosomoides polygyrus Alarmin Release Inhibitor), which blocks IL-33 release and signalling. Instillation of exogenous IL-33 recapitulated the rhinovirus-induced early phase, including the increased presence of NETs in the airway mucosa, in a PAD4-dependent manner. Ex vivo IL-33-stimulated neutrophils from mice with CEA, but not naïve mice, underwent NETosis and produced greater amounts of IL-1α/β, IL-4, and IL-5. In nasal samples from rhinovirus-infected people with asthma, but not healthy controls, IL-33 levels correlated with neutrophil elastase and dsDNA. Our findings suggest that IL-33 blockade ameliorates the severity of an asthma exacerbation by attenuating neutrophil recruitment and the downstream generation of NETs.

The paradigm of IL-23-independent production of IL-17F and IL-17A and their role in chronic inflammatory diseases.

Interleukin-17 family (IL-17s) comprises six structurally related members (IL-17A to IL-17F); sequence homology is highest between IL-17A and IL-17F, displaying certain overlapping functions. In general, IL-17A and IL-17F play important roles in chronic inflammation and autoimmunity, controlling bacterial and fungal infections, and signaling mainly through activation of the nuclear factor-kappa B (NF-κB) pathway. The role of IL-17A and IL-17F has been established in chronic immune-mediated inflammatory diseases (IMIDs), such as psoriasis (PsO), psoriatic arthritis (PsA), axial spondylarthritis (axSpA), hidradenitis suppurativa (HS), inflammatory bowel disease (IBD), multiple sclerosis (MS), and asthma. CD4+ helper T cells (Th17) activated by IL-23 are well-studied sources of IL-17A and IL-17F. However, other cellular subtypes can also produce IL-17A and IL-17F, including gamma delta (γδ) T cells, alpha beta (αβ) T cells, type 3 innate lymphoid cells (ILC3), natural killer T cells (NKT), or mucosal associated invariant T cells (MAIT). Interestingly, the production of IL-17A and IL-17F by innate and innate-like lymphocytes can take place in an IL-23 independent manner in addition to IL-23 classical pathway. This would explain the limitations of the inhibition of IL-23 in the treatment of patients with certain rheumatic immune-mediated conditions such as axSpA. Despite their coincident functions, IL-17A and IL-17F contribute independently to chronic tissue inflammation having somehow non-redundant roles. Although IL-17A has been more widely studied, both IL-17A and IL-17F are overexpressed in PsO, PsA, axSpA and HS. Therefore, dual inhibition of IL-17A and IL-17F could provide better outcomes than IL-23 or IL-17A blockade.

Interleukin-17-targeted treatment in patients with spondyloarthritis and associated cardiometabolic risk profile.

Spondyloarthritis is a group of immune-mediated rheumatic disorders that significantly impact patients' physical function and quality of life. Patients with spondyloarthritis experience a greater prevalence of cardiometabolic disorders, such as obesity, hypertension, dyslipidemia and diabetes mellitus, and these comorbidities are associated with increased spondyloarthritis disease activity and risk of cardiovascular events. This narrative review summarizes the evidence for a physiological link between inflammatory status and cardiometabolic comorbidities in spondyloarthritis, as well as the impact of interleukin (IL)-17 blockade versus other molecular mechanisms in patients with cardiometabolic conditions. The IL-23/IL-17 axis plays a pivotal role in the pathophysiology of spondyloarthritis by promoting inflammation and tissue remodeling at the affected joints and entheses. The importance of the IL-23/IL-17 signaling cascade in underlying sub-clinical inflammation in common cardiometabolic disorders suggests the existence of shared pathways between these processes and spondyloarthritis pathophysiology. Thus, a bidirectional relationship exists between the effects of biologic drugs and patients' cardiometabolic profile, which must be considered during treatment decision making. Biologic therapy may induce changes in patients' cardiometabolic status and cardiometabolic conditions may conversely impact the clinical response to biologic therapy. Available evidence regarding the impact of IL-17 blockade with secukinumab on cardiometabolic parameters suggests this drug does not interfere with traditional cardiovascular risk markers and could be associated with a decreased risk of cardiovascular events. Additionally, the efficacy and retention rates of secukinumab do not appear to be negatively affected by obesity, with somestudies reporting a positive impact on clinical outcomes, contrary to that described with other approaches, such as tumor necrosis factor blockade. Inthisarticle, we also review evidence for this bidirectional association with othertreatments for spondyloarthritis. Current evidence suggests that IL-17-targeted therapy with secukinumab is highly effective in spondyloarthritis patients with cardiometabolic comorbidities and may provide additional cardiometabolic benefits.

DP23 Paraprotein negative Schnitzler syndrome: a new clinical entity?

Abstract Schnitzler syndrome (SchS) is a rare autoinflammatory condition with prominent cutaneous features. The genetic basis of the condition is not understood. The Strasbourg Criteria outline the clinical diagnosis of SchS, requiring an IgM or IgG monoclonal gammopathy and an urticarial rash (Simon A, Asli B, Braun-Falco M et al. Schnitzler’s syndrome: diagnosis, treatment, and follow-up. Allergy 2013; 68:562–8). We report two cases of SchS, the first with a 5-year delay in the development of a paraprotein and the second with complete absence of a paraprotein, despite 12 years of symptoms. Case one was a 47-year-old female who attended with a 4-year history of a dusky-red urticarial rash and polyarthralgia. Inflammatory markers were persistently raised, in the absence of any identified cause. Investigations demonstrated thrombocytosis, hypocomplementaemia and an isolated elevated IgM (3.07 g L–1), with no monoclonal band. Serum free light chain κ : λ ratio was normal. The patient had a working diagnosis of hypocomplementaemic urticarial vasculitis, despite skin biopsy demonstrating a lack of fibrinoid necrosis. She failed to improve symptomatically on high-dose antihistamines, corticosteroids or azathioprine and had minimal improvement with omalizumab. Repeat serum electrophoresis identified the development of a new IgM κ paraprotein 5 years after the initial symptom onset. Interleukin (IL)-1 blockade resulted in rapid clinical and biochemical improvement. Case 2 was a 55-year-old woman with a 4-year history of recurrent urticaria. A diagnosis of urticarial vasculitis was made; skin biopsy was incongruent but displayed a neutrophilic infiltrate. She had a poor response to high-dose antihistamines and withdrew from services for 3 years. Subsequent therapy with ciclosporin, azathioprine, omalizumab, dapsone and colchicine yielded no clinical benefit. Laboratory investigations repeatedly showed elevated inflammatory markers and an elevated IgA (3.9 g L–1) in the context of inflammatory bowel disease but no IgM or IgM paraprotein. Serum free light chain κ : λ ratio was normal. Clinical suspicion of an autoinflammatory condition was high given the longstanding treatment-resistant urticaria and systemic inflammation. A trial of IL-1 blockade led to immediate clinical and biochemical resolution. This treatment was continued and has resulted in the eradication of a cumulative 12 years of symptoms. There are several reports of SchS with no monoclonal band responding to IL-1 antagonism. As these cases do not fulfil the obligatory criteria for SchS, we propose a new clinical entity, paraprotein-negative IL-1-mediated inflammatory dermatosis (PANID). It is not yet clear if PANID is a precursor to SchS, although published cases demonstrating delayed paraprotein development could support this. Clinicians should consider this diagnosis in patients with treatment-refractory urticaria and systemic inflammation.

Infections occurring following IL6 blockade for the management of cytokine release syndrome in onco-hematology patients.

Cytokine release syndrome (CRS) is a common adverse event of CAR T cell or bispecific antibody (bsAb) therapy. Anti-IL6/IL6R drugs are used in the management of auto-immune diseases. Some reports showed increased risk of bacterial infection in this context. In onco-hematology, there are few data about the occurrence of infection after administration of an anti-IL6/IL6R for CRS. We retrospectively reviewed all consecutive patients treated in Gustave Roussy Cancer Campus between 2018 and 2021, who received anti-IL6/IL6R for CRS due to bsAb in phase I clinical trials or adoptive cellular therapy (ACT). We constituted a control group including all the patients treated in the same clinical trials or standard of care ACT, naïve of anti-IL6/IL6R. Fifty-two patients have been included. In the anti-IL6/IL6R group (n = 26), five patients developed a grade 2 to 5 infection within a month after anti-IL6/IL6R treatment, including two grade 5 infections. In the control group (n = 26), only one patient had a grade 3 infection. The two patients who had grade 5 infections were treated for diffuse large B cell lymphoma (DLBCL), one with bsAb and the other with CAR T cell. Fifty percent (3/6) of DLBCL patients who received an anti-IL6/IL6R presented an infection, one of which was a grade 5. In solid tumor patients treated with bsAb and anti-IL6/IL6R, only one patient (/9, 11%) developed a grade 2 viral infection. It seems that the use of anti-IL6/IL6R in CRS secondary to bsAb administration in solid tumors patients does not significantly increase the risk of infection, as opposed to DLBCL patients where secondary infection might be a concern.

Rapid reduction in Staphylococcus aureus in atopic dermatitis subjects following dupilumab treatment

Atopic dermatitis (AD) is an inflammatory disorder characterized by dominant type 2 inflammation leading to chronic pruritic skin lesions, allergic comorbidities, and Staphylococcus aureus skin colonization and infections. S aureus is thought to play a role in AD severity. This study characterized the changes in the host-microbial interface in subjects with AD following type 2 blockade with dupilumab. Participants (n= 71) with moderate-severe AD were enrolled in a randomized (dupilumab vs placebo; 2:1), double-blind study at Atopic Dermatitis Research Network centers. Bioassays were performed at multiple time points: S aureus and virulence factor quantification, 16s ribosomal RNA microbiome, serum biomarkers, skin transcriptomic analyses, and peripheral blood T-cell phenotyping. At baseline, 100% of participants were S aureus colonized on the skin surface. Dupilumab treatment resulted in significant reductions in S aureus after only 3 days (compared to placebo), which was 11 days before clinical improvement. Participants with the greatest S aureus reductions had the best clinical outcomes, and these reductions correlated with reductions in serum CCL17 and disease severity. Reductions (10-fold) in S aureus cytotoxins (day 7), perturbations in TH17-cell subsets (day 14), and increased expression of genes relevant for IL-17, neutrophil, and complement pathways (day 7) were also observed. Blockade of IL-4 and IL-13 signaling, very rapidly (day 3) reduces S aureus abundance in subjects with AD, and this reduction correlates with reductions in the type 2 biomarker, CCL17, and measures of AD severity (excluding itch). Immunoprofiling and/or transcriptomics suggest a role for TH17 cells, neutrophils, and complement activation as potential mechanisms to explain these findings.

The Role of IL-17 in the Pathogenesis of Oral Squamous Cell Carcinoma.

Elucidating the inflammatory mechanisms underlying formation and progression of oral squamous cell carcinoma (OSCC) is crucial for discovering new targeted therapeutics. The proinflammatory cytokine IL-17 has proven roles in tumor formation, growth, and metastasis. The presence of IL-17 is demonstrated in both in vitro and in vivo models, and in OSCC patients, is mostly accompanied by enhanced proliferation and invasiveness of cancer cells. Here we review the known facts regarding the role of IL-17 in OSCC pathogenesis, namely the IL-17 mediated production of proinflammatory mediators that mobilize and activate myeloid cells with suppressive and proangiogenic activities and proliferative signals that directly induce proliferation of cancer cells and stem cells. The possibility of a potential IL-17 blockade in OSCC therapy is also discussed.