The role of IL-1 inhibition in systemic juvenile idiopathic arthritis: current status and future perspectives

Efficacy and safety of canakinumab in systemic juvenile idiopathic arthritis, the first Chinese experience

BACKGROUND

Systemic juvenile idiopathic arthritis (sJIA) is a severe form of juvenile arthritis that is characterized by chronic joint inflammation and systemic symptoms such as fever, rash, and organ involvement. Anti-IL-6 receptor monoclonal antibody tocilizumab is an effective treatment. However, some patients still experience persisting or recurrent symptoms and the real-world effectiveness of canakinumab in Chinese patients with sJIA has never been reported. Therefore, this study aimed to assess the efficacy and safety of canakinumab in Chinese patients with sJIA using real-world data.

METHODS

We conducted a retrospective study on children with active sJIA. Clinical features, laboratory data, corticosteroid dosage, and adverse events (AEs) were collected at baseline and at 4, 8, 12, and 24 weeks after initiating canakinumab treatment.

RESULTS

Seven female and four male patients were included in the study. All patients had previously been treated with tocilizumab and were administered canakinumab for 12.4 ± 3.4 months. Notably, significant improvements were observed in both clinical signs and symptoms as well as laboratory indicators. Four children under corticosteroid treatment were able to successfully discontinue their corticosteroid therapy: one at week 4, two at week 12, and one at week 24. Notably, there was a significant reduction in the number of tender and swollen joints (P = 0.0059) as well as the systemic juvenile arthritis disease activity score (P < 0.0001). The most common AE was infection, but no patients experienced serious AEs. No cases of macrophage activation syndrome or death were reported during the follow-up period.

CONCLUSIONS

Canakinumab was found to be potentially efficacious and safe in Chinese patients with sJIA. No new AEs were observed with canakinumab treatment.

Establishment and analysis of a novel diagnostic model for systemic juvenile idiopathic arthritis based on machine learning

BACKGROUND

Systemic juvenile idiopathic arthritis (SJIA) is a form of childhood arthritis with clinical features such as fever, lymphadenopathy, arthritis, rash, and serositis. It seriously affects the growth and development of children and has a high rate of disability and mortality. SJIA may result from genetic, infectious, or autoimmune factors since the precise source of the disease is unknown. Our study aims to develop a genetic-based diagnostic model to explore the identification of SJIA at the genetic level.

METHODS

The gene expression dataset of peripheral blood mononuclear cell (PBMC) samples from SJIA was collected from the Gene Expression Omnibus (GEO) database. Then, three GEO datasets (GSE11907-GPL96, GSE8650-GPL96 and GSE13501) were merged and used as a training dataset, which included 125 SJIA samples and 92 health samples. GSE7753 was used as a validation dataset. The limma method was used to screen differentially expressed genes (DEGs). Feature selection was performed using Lasso, random forest (RF)-recursive feature elimination (RFE) and RF classifier.

RESULTS

We finally identified 4 key genes (ALDH1A1, CEACAM1, YBX3 and SLC6A8) that were essential to distinguish SJIA from healthy samples. And we combined the 4 key genes and performed a grid search as well as 10-fold cross-validation with 5 repetitions to finally identify the RF model with optimal mtry. The mean area under the curve (AUC) value for 5-fold cross-validation was greater than 0.95. The model's performance was then assessed once more using the validation dataset, and an AUC value of 0.990 was obtained. All of the above AUC values demonstrated the strong robustness of the SJIA diagnostic model.

CONCLUSIONS

We successfully developed a new SJIA diagnostic model that can be used for a novel aid in the identification of SJIA. In addition, the identification of 4 key genes that may serve as potential biomarkers for SJIA provides new insights to further understand the mechanisms of SJIA.

Tmem178 Negatively Regulates IL-1β Production Through Inhibition of the NLRP3 Inflammasome

OBJECTIVE

Inflammasomes modulate the release of bioactive interleukin (IL)-1β. Excessive IL-1β levels are detected in patients with systemic juvenile idiopathic arthritis (sJIA) and cytokine storm syndrome (CSS) with mutated and unmutated inflammasome components, raising questions on the mechanisms of IL-1β regulation in these disorders.

METHODS

To investigate how the NLRP3 inflammasome is modulated in sJIA, we focused on Transmembrane protein 178 (Tmem178), a negative regulator of calcium levels in macrophages, and measured IL-1β and caspase-1 activation in wild-type (WT) and Tmem178-/- macrophages after calcium chelators, silencing of Stim1, a component of store-operated calcium entry (SOCE), or by expressing a Tmem178 mutant lacking the Stromal Interaction Molecule 1 (Stim1) binding site. Mitochondrial function in both genotypes was assessed by measuring oxidative respiration, mitochondrial reactive oxygen species (mtROS), and mitochondrial damage. CSS development was analyzed in Perforin-/- /Tmem178-/- mice infected with lymphocytic choriomeningitis virus (LCMV) in which inflammasome or IL-1β signaling was pharmacologically inhibited. Human TMEM178 and IL1B transcripts were analyzed in data sets of whole blood and peripheral blood monocytes from healthy controls and patients with active sJIA.

RESULTS

TMEM178 levels are reduced in whole blood and monocytes from patients with sJIA while IL1B levels are increased. Accordingly, Tmem178-/- macrophages produce elevated IL-1β compared with WT cells. The elevated intracellular calcium levels after SOCE activation in Tmem178-/- macrophages induce mitochondrial damage, release mtROS, and ultimately promote NLRP3 inflammasome activation. In vivo, inhibition of inflammasome or IL-1β neutralization prolongs Tmem178-/- mouse survival in LCMV-induced CSS.

CONCLUSION

Down-regulation of TMEM178 levels may represent a marker of disease activity and help identify patients who could benefit from inflammasome targeting.

Systemic Lupus Erythematosus and Cytokine Storm

Systemic lupus erythematosus (SLE) is the prototype of autoimmune diseases and can manifest with a plethora of clinical signs and symptoms associated with a myriad of laboratory abnormalities. An infrequent but potentially lethal complication of SLE is macrophage activation syndrome (MAS). The diagnosis of MAS in SLE can be very challenging due to similarities in presentation of both flares and infections, such as fever, lymphadenopathy, splenomegaly, and cytopenias. These aggravating factors contribute to the increased risk of poor outcomes in SLE-associated MAS. Indeed, at the moment MAS remains invariably lethal if untreated and still has a high mortality rate with treatment. In this chapter, we discuss several aspects of MAS in the context of SLE and in particular, the pathogenesis of MAS in SLE, how MAS presents in pediatric versus adult SLE, and, finally, MAS treatment in SLE and future directions.

Tmem178 negatively regulates IL-1β production through inhibition of the NLRP3 inflammasome

Objective

Inflammasomes modulate the release of bioactive IL-1β. Excessive IL-1β levels are detected in patients with systemic juvenile idiopathic arthritis (sJIA) and cytokine storm syndrome (CSS) with mutated and unmutated inflammasome components, raising questions on the mechanisms of IL-1β regulation in these disorders.

Methods

To investigate how the NLRP3 inflammasome is modulated in sJIA, we focused on Tmem178, a negative regulator of calcium levels in macrophages, and measured IL-1β and caspase-1 activation in wild-type (WT) and Tmem178 -/- macrophages following calcium chelators, silencing of Stim1, a component of store-operated calcium entry (SOCE), or by expressing a Tmem178 mutant lacking Stim1 binding site. Mitochondrial function in both genotypes was assessed by measuring oxidative respiration, mitochondrial reactive oxygen species (mtROS), and mitochondrial damage. CSS development was analyzed in Perforin -/- /Tmem178 -/- mice infected with LCMV in which inflammasome or IL-1 signaling was pharmacologically inhibited. Human TMEM178 and IL-1B transcripts were analyzed in a dataset of peripheral blood monocytes from healthy controls and active sJIA patients.

Results

TMEM178 levels are reduced in monocytes from sJIA patients while IL-1B show increased levels. Accordingly, Tmem178 -/- macrophages produce elevated IL-1β compared to WT cells. The elevated intracellular calcium levels following SOCE activation in Tmem178 -/- macrophages induce mitochondrial damage, release mtROS, and ultimately, promote NLRP3 inflammasome activation. In vivo , inhibition of inflammasome or IL-1 neutralization prolongs Tmem178 -/- mouse survival to LCMV-induced CSS.

Conclusion

Downregulation of Tmem178 levels may represent a new biomarker to identify sJIA/CSS patients that could benefit from receiving drugs targeting inflammasome signaling.

Evaluation of periodontal status and cytokine response in children with familial Mediterranean fever or systemic juvenile idiopathic arthritis

OBJECTIVES

Familial Mediterranean fever (FMF) and systemic juvenile idiopathic arthritis (sJIA) are chronic inflammatory diseases and anti-inflammatory agents are used in their treatment. This study evaluates the periodontal status and cytokine response in pediatric patients with FMF or sJIA.

MATERIALS AND METHODS

Forty-eight FMF/sJIA patients were under treatment/control and in attack-free period; 20 systemically healthy children participated in the study. FMF/sJIA patients were divided into two subgroups based on the treatment they received: receiving anti-IL-1 therapy (anti-IL-1 ( +)) and not receiving anti-IL-1 therapy (anti-IL-1 ( -)). The clinical periodontal indices were recorded. Gingival crevicular fluid (GCF) and serum samples were collected. Cytokine levels (IL-1β, IL-1α, TNF-α, IL-6, IL-8, IL-10, IL-17, IL-33) in GCF and serum were measured using ELISA kits.

RESULTS

There was no significant difference between the groups in terms of GCF IL-1β and IL-1α levels although, BoP and GI were significantly lower in the anti-IL-1 ( +) group compared to the control group. GCF IL-10 level was higher in the anti-IL-1 ( -) group than in the control group; GCF IL-8 levels were lower in both FMF/sJIA subgroups versus controls. There was no significant difference between serum cytokine levels of FMF/sJIA subgroups.

CONCLUSIONS

Considering the significant decrease in GI, BoP, and GCF IL-8 levels in the anti-IL-1 ( +) group, it can be concluded that anti-IL-1 medications may suppress periodontal inflammation clinically and immunologically.

CLINICAL RELEVANCE

Anti-IL agents are not currently used in periodontal therapy. However, this study demonstrated the positive effect of anti-IL-1 medications on periodontal inflammation in pediatric patients with FMF or sJIA.

Air pollution exposure and auto-inflammatory and autoimmune diseases of the musculoskeletal system: a review of epidemiologic and mechanistic evidence

Auto-inflammatory and autoimmune diseases of the musculoskeletal system can be perceived as a spectrum of rheumatic diseases, with the joints and connective tissues are eroded severely that progressively develop chronic inflammation and lesion. A wide range of risk factors represented by genetic and environmental factors have been uncovered by population-based surveys and experimental studies. Lately, the exposure to air pollution has been found to be potentially involved in the mechanisms of occurrence or development of such diseases, principally manifest in oxidative stress, local and systemic inflammation, and epigenetic modifications, as well as the mitochondrial dysfunction, which has been reported to participate in the intermediate links. The lungs might serve as a starting area of air pollutants, which would cause oxidative stress-induced bronchial-associated lymphoid tissue (iBALT) to further to influence T, B cells, and the secretion of pro-inflammatory cytokines. The binding of aromatic hydrocarbon receptor (AhR) to the corresponding contaminant ligands tends to regulate the reaction of Th17 and Tregs. Furthermore, air pollution components might spur on immune and inflammatory responses by damaging mitochondria that could interact with and exacerbate oxidative stress and pro-inflammatory cytokines. In this review, we focused on the association between air pollution and typical auto-inflammatory and autoimmune diseases of the musculoskeletal system, mainly including osteoarthritis (OA), rheumatoid arthritis (RA), spondyloarthritis (SpA) and juvenile idiopathic arthritis (JIA), and aim to collate the mechanisms involved and the potential channels. A complete summary and in-depth understanding of the autoimmune and inflammatory effects of air pollution exposure should hopefully contribute new perspectives on how to formulate better public health policies to alleviate the adverse health effects of air pollutants.

The hyperinflammatory spectrum: from defects in cytotoxicity to cytokine control

Cytotoxic lymphocytes kill target cells through polarized release of the content of cytotoxic granules towards the target cell. The importance of this cytotoxic pathway in immune regulation is evidenced by the severe and often fatal condition, known as hemophagocytic lymphohistiocytosis (HLH) that occurs in mice and humans with inborn errors of lymphocyte cytotoxic function. The clinical and preclinical data indicate that the damage seen in severe, virally triggered HLH is due to an overwhelming immune system reaction and not the direct effects of the virus per se. The main HLH-disease mechanism, which links impaired cytotoxicity to excessive release of pro-inflammatory cytokines is a prolongation of the synapse time between the cytotoxic effector cell and the target cell, which prompts the former to secrete larger amounts of cytokines (including interferon gamma) that activate macrophages. We and others have identified novel genetic HLH spectrum disorders. In the present update, we position these newly reported molecular causes, including CD48-haploinsufficiency and ZNFX1-deficiency, within the pathogenic pathways that lead to HLH. These genetic defects have consequences on the cellular level on a gradient model ranging from impaired lymphocyte cytotoxicity to intrinsic activation of macrophages and virally infected cells. Altogether, it is clear that target cells and macrophages may play an independent role and are not passive bystanders in the pathogenesis of HLH. Understanding these processes which lead to immune dysregulation may pave the way to novel ideas for medical intervention in HLH and virally triggered hypercytokinemia.

Inflammation context in Alzheimer's disease, a relationship intricate to define

Alzheimer's disease (AD), the most common form of dementia, is characterized by the accumulation of amyloid β (Aβ) and hyperphosphorylated tau protein aggregates. Importantly, Aβ and tau species are able to activate astrocytes and microglia, which release several proinflammatory cytokines, such as tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β), together with reactive oxygen (ROS) and nitrogen species (RNS), triggering neuroinflammation. However, this inflammatory response has a dual function: it can play a protective role by increasing Aβ degradation and clearance, but it can also contribute to Aβ and tau overproduction and induce neurodegeneration and synaptic loss. Due to the significant role of inflammation in the pathogenesis of AD, several inflammatory mediators have been proposed as AD markers, such as TNF-α, IL-1β, Iba-1, GFAP, NF-κB, TLR2, and MHCII. Importantly, the use of anti-inflammatory drugs such as NSAIDs has emerged as a potential treatment against AD. Moreover, diseases related to systemic or local inflammation, including infections, cerebrovascular accidents, and obesity, have been proposed as risk factors for the development of AD. In the following review, we focus on key inflammatory processes associated with AD pathogenesis.

Biomarkers in Systemic Juvenile Idiopathic Arthritis, Macrophage Activation Syndrome and Their Importance in COVID Era

Systemic juvenile idiopathic arthritis (sJIA) and its complication, macrophage activation syndrome (sJIA-MAS), are rare but sometimes very serious or even critical diseases of childhood that can occasionally be characterized by nonspecific clinical signs and symptoms at onset-such as non-remitting high fever, headache, rash, or arthralgia-and are biologically accompanied by an increase in acute-phase reactants. For a correct positive diagnosis, it is necessary to rule out bacterial or viral infections, neoplasia, and other immune-mediated inflammatory diseases. Delays in diagnosis will result in late initiation of targeted therapy. A set of biomarkers is useful to distinguish sJIA or sJIA-MAS from similar clinical entities, especially when arthritis is absent. Biomarkers should be accessible to many patients, with convenient production and acquisition prices for pediatric medical laboratories, as well as being easy to determine, having high sensitivity and specificity, and correlating with pathophysiological disease pathways. The aim of this review was to identify the newest and most powerful biomarkers and their synergistic interaction for easy and accurate recognition of sJIA and sJIA-MAS, so as to immediately guide clinicians in correct diagnosis and in predicting disease outcomes, the response to treatment, and the risk of relapses. Biomarkers constitute an exciting field of research, especially due to the heterogeneous nature of cytokine storm syndromes (CSSs) in the COVID era. They must be selected with utmost care-a fact supported by the increasingly improved genetic and pathophysiological comprehension of sJIA, but also of CSS-so that new classification systems may soon be developed to define homogeneous groups of patients, although each with a distinct disease.

IL-1 and autoinflammatory disease: biology, pathogenesis and therapeutic targeting

Over 20 years ago, it was first proposed that autoinflammation underpins a handful of rare monogenic disorders characterized by recurrent fever and systemic inflammation. The subsequent identification of novel, causative genes directly led to a better understanding of how the innate immune system is regulated under normal conditions, as well as its dysregulation associated with pathogenic mutations. Early on, IL-1 emerged as a central mediator for these diseases, based on data derived from patient cells, mutant mouse models and definitive clinical responses to IL-1 targeted therapy. Since that time, our understanding of the mechanisms of autoinflammation has expanded beyond IL-1 to additional innate immune processes. However, the number and complexity of IL-1-mediated autoinflammatory diseases has also multiplied to include additional monogenic syndromes with expanded genotypes and phenotypes, as well as more common polygenic disorders seen frequently by the practising clinician. In order to increase physician awareness and update rheumatologists who are likely to encounter these patients, this review discusses the general pathophysiological concepts of IL-1-mediated autoinflammation, the epidemiological and clinical features of specific diseases, diagnostic challenges and approaches, and current and future perspectives for therapy.

Anti-inflammatory Treatment of Kawasaki Disease: Comparison of Current Guidelines and Perspectives

Kawasaki disease (KD), an acute, generalized vasculitis, is associated with an increased risk of coronary heart disease and is the most common cause of acquired heart disease in childhood. The incidence of KD is increasing worldwide. There are numerous international treatment guidelines. Our study aims to perform the first one so far comparison of them. While the gold standard therapy remains still the same (intravenous immunoglobulins and aspirin), there is currently a lack of evidence for choosing optimal treatment for high-risk patients and refractory KD. In this review, we also discuss the treatment of complications of KD and Kawasaki-like phenotypes, present an anti-inflammatory treatment in the light of new scientific data, and present novel potential therapeutic targets for KD.

Key Factor Regulating Inflammatory Microenvironment, Metastasis, and Resistance in Breast Cancer: Interleukin-1 Signaling

Breast cancer is one of the top-ranked cancers for incidence and mortality worldwide. The biggest challenges in breast cancer treatment are metastasis and drug resistance, for which work on molecular evaluation, mechanism studies, and screening of therapeutic targets is ongoing. Factors that lead to inflammatory infiltration and immune system suppression in the tumor microenvironment are potential therapeutic targets. Interleukin-1 is known as a proinflammatory and immunostimulatory cytokine, which plays important roles in inflammatory diseases. Recent studies have shown that interleukin-1 cytokines drive the formation and maintenance of an inflammatory/immunosuppressive microenvironment through complex intercellular signal crosstalk and tight intracellular signal transduction, which were found to be potentially involved in the mechanism of metastasis and drug resistance of breast cancer. Some preclinical and clinical treatments or interventions to block the interleukin-1/interleukin-1 receptor system and its up- and downstream signaling cascades have also been proven effective. This study provides an overview of IL-1-mediated signal communication in breast cancer and discusses the potential of IL-1 as a therapeutic target especially for metastatic breast cancer and combination therapy and current problems, aiming at enlightening new ideas in the study of inflammatory cytokines and immune networks in the tumor microenvironment.

The cytokine storms of COVID-19, H1N1 influenza, CRS and MAS compared. Can one sized treatment fit all?

An analysis of published data appertaining to the cytokine storms of COVID-19, H1N1 influenza, cytokine release syndrome (CRS), and macrophage activation syndrome (MAS) reveals many common immunological and biochemical abnormalities. These include evidence of a hyperactive coagulation system with elevated D-dimer and ferritin levels, disseminated intravascular coagulopathy (DIC) and microthrombi coupled with an activated and highly permeable vascular endothelium. Common immune abnormalities include progressive hypercytokinemia with elevated levels of TNF-α, interleukin (IL)-6, and IL-1β, proinflammatory chemokines, activated macrophages and increased levels of nuclear factor kappa beta (NFκB). Inflammasome activation and release of damage associated molecular patterns (DAMPs) is common to COVID-19, H1N1, and MAS but does not appear to be a feature of CRS. Elevated levels of IL-18 are detected in patients with COVID-19 and MAS but have not been reported in patients with H1N1 influenza and CRS. Elevated interferon-γ is common to H1N1, MAS, and CRS but levels of this molecule appear to be depressed in patients with COVID-19. CD4+ T, CD8+ and NK lymphocytes are involved in the pathophysiology of CRS, MAS, and possibly H1N1 but are reduced in number and dysfunctional in COVID-19. Additional elements underpinning the pathophysiology of cytokine storms include Inflammasome activity and DAMPs. Treatment with anakinra may theoretically offer an avenue to positively manipulate the range of biochemical and immune abnormalities reported in COVID-19 and thought to underpin the pathophysiology of cytokine storms beyond those manipulated via the use of, canakinumab, Jak inhibitors or tocilizumab. Thus, despite the relative success of tocilizumab in reducing mortality in COVID-19 patients already on dexamethasone and promising results with Baricitinib, the combination of anakinra in combination with dexamethasone offers the theoretical prospect of further improvements in patient survival. However, there is currently an absence of trial of evidence in favour or contravening this proposition. Accordingly, a large well powered blinded prospective randomised controlled trial (RCT) to test this hypothesis is recommended.

Experiences with IL-1 blockade in systemic juvenile idiopathic arthritis - data from the German AID-registry

BACKGROUND

Systemic juvenile idiopathic arthritis (sJIA) is a complex disease with dysregulation of the innate immune system driven by cytokines. A major role is ascribed to interleukin-1β (IL-1β), supporting the autoinflammatory character of the disease and offering an effective blocking mechanism for treatment. Here we present clinical practice data from the German AID-registry for patients treated with IL-1 inhibition (IL-1i).

METHODS

In 2009 a clinical and research consortium (AID-Net) was established, including an online AID-registry. Patients with documented sJIA diagnosis were identified. Data for this retrospective IL-1i study were recorded by 17 centers. Response to treatment was evaluated according to Wallace criteria and additionally by an own classifying clinical response system.

RESULTS

In 6 years, 202 patients with confirmed sJIA were recorded in the AID-registry. Out of these, 111 children received therapy with Anakinra (ANA) (n = 84, 39 f) and/or Canakinumab (CANA) (n = 27, 15 f) at a median age of 8.7 y (range 0.6-19.1). During the first 12 months 75/111 (ANA 55, CANA 20) patients were evaluated according to Wallace criteria (achievement of inactive disease 28/55 and 17/20, remission over 6 months under medication 13/55 and 7/20 cases). Over the whole period of time, clinical response was preserved in the majority of patients (ANA 54/80, CANA 20/27). Arthritis mostly persisted in polyarticular (PA) courses. During treatment with IL-1i concomitant medication could be tapered in about 15%. IL-1i was discontinued in 59/111 patients. 45 (15) adverse events (AE)s in ANA (CANA) treated patients (19.7 (26.6) AE/100 ANA (CANA) exposure years, 95%CI: 14.4-26.4 (14.9-43.9)) were reported.

CONCLUSION

In a large cohort of sJIA patients from Germany, we can confirm an overall favorable clinical response to both available IL-1 blocking agents. IL-1i was well tolerated with acceptable safety and effectiveness in a real-life clinical setting.

Effects of familial Mediterranean fever on the middle ear

OBJECTIVE

To evaluate middle and inner ear function and hearing status of children with familial Mediterranean fever (FMF).

METHODS

We assigned 56 patients with FMF to the study group and 52 healthy volunteers to the control group. The mean age of patients in the study and control groups were 10.10 ± 3.70 and 9.77 ± 3.74 years, respectively. Physical examination and hearing evaluation were performed in both groups. The audiological test battery included 226-Hz tympanometry, pure tone audiometric evaluation, acoustic stapedial reflex measurements, distortion product otoacoustic emission recording, and wide-band tympanometry assessment.

RESULTS

The groups were similar in age and sex ratio (p > 0.05 for both comparisons). Pure tone audiogram and distortion product otoacoustic emission results were also similar for both groups (p > 0.05). The ipsilateral acoustic stapedial reflex were present in both of the groups and all participants had Type A tympanogram. The contralateral acoustic stapedial reflex thresholds were significantly higher in the familial Mediterranean fever group (p < 0.05 for all comparisons). The ambient and peak pressure absorbance values of wide-band tympanometry were significantly lower at 2000 Hz and significantly higher at 4000 Hz in the familial Mediterranean fever group (p < 0.05 for both comparisons). The severity and duration of disease adversely affected the absorbance values of wide-band tympanometry at 2000 and 4000 Hz (p < 0.05).

CONCLUSION

To our knowledge, this is the first study to demonstrate the adverse subclinical effects of familial Mediterranean fever on the middle ear. We recommend that children diagnosed with FMF should be closely monitored for future clinical middle ear pathologies.

Inflammasomes and Childhood Autoimmune Diseases: A Review of Current Knowledge

Inflammasomes are multiprotein complexes capable of sensing pathogen-associated molecular patterns (PAMPs), danger-associated molecular patterns (DAMPs), and cellular perturbations. Upon stimulation, the inflammasomes activate the production of the pro-inflammatory cytokines IL-1β and IL-18 and induce gasdermin D-mediated pyroptosis. Dysregulated inflammasome signaling could lead to hyperinflammation in response to environmental triggers, thus contributing to the pathogenesis of childhood autoimmune/autoinflammatory diseases. In this review, we group childhood rheumatic diseases into the autoinflammation to autoimmunity spectrum and discuss about the involvement of inflammasomes in disease mechanisms. Genetic mutations in inflammasome components cause monogenic autoinflammatory diseases, while inflammasome-related genetic variants have been implicated in polygenic childhood rheumatic diseases. We highlight the reported associations of inflammasome signaling-related genetic polymorphisms/protein levels with pediatric autoimmune disease susceptibility and disease course. Furthermore, we discuss about the use of IL-1 receptor antagonist as an adjunctive therapy in several childhood autoimmune diseases, including macrophage activation syndrome (MAS) and multisystem inflammatory syndrome in children (MIS-C) related to COVID-19. A comprehensive multi-cohort comparison on inflammasome gene expression profile in different pediatric rheumatic diseases is needed to identify patient subsets that might benefit from the adjunctive therapy of IL-1β inhibitors.

Coronavirus Desease 2019 (COVID-19) in Children: Lessons from Pediatric Rheumatology

The clinical presentation and outcomes of infection with the novel coronavirus (COVID-19) are characterized by exceptional variability in manifestations, which depend on many factors, one of which is the patient’s age. One of the severe life-threatening manifestations in adults is severe acute respiratory syndrome (SARS-CoV-2), in some cases accompanied by the development of multiple organ failure. During the first two to three months of the COVID-19 pandemic, the global medical community was of the opinion that this disease in children is usually mild and not fatal. However, with the accumulation of new information, it became clear that there is a growing recognition of the existence of multisystem inflammatory syndrome in children, chronologically associated with SARS-CoV-2, which can lead to serious consequences. The article presents the main epidemiological, clinical and laboratory characteristics of the syndrome, as well as discusses the issues of its pathogenesis, differential diagnosis with a number of other acute conditions associated with an dysbalance of cytokines.

Molecular and Cellular Mechanisms of Arthritis in Children and Adults: New Perspectives on Applied Photobiomodulation

Juvenile idiopathic arthritis and adult rheumatoid arthritis are two major groups with chronic joint pain and inflammation, extra-articular manifestations, and high risk of comorbidities, which can cause physical and ocular disability, as well as create great socio-economic pressure worldwide. The pathogenesis of arthritis manifested in childhood and adulthood is multifactorial, unclear, and overly complex, in which immunity plays an important role. Although there are more and more biological agents with different mechanisms of action for the treatment of arthritis, the results are not as expected, because there are partial responses or non-responsive patients to these compounds, high therapeutic costs, side effects, and so on; therefore, we must turn our attention to other therapeutic modalities. Updating knowledge on molecular and cellular mechanisms in the comparative pathogenesis of chronic arthritis in both children and adults is necessary in the early and correct approach to treatment. Photobiomodulation (PBM) represents a good option, offering cost-effective advantages over drug therapy, with a quicker, more positive response to treatment and no side effects. The successful management of PBM in arthritis is based on the clinician's ability to evaluate correctly the inflammatory status of the patient, to seek the optimal solution, to choose the best technology with the best physical parameters, and to select the mode of action to target very precisely the immune system and the molecular signaling pathways at the molecular level with the exact amount of quantum light energy in order to obtain the desired immune modulation and the remission of the disease. Light is a very powerful tool in medicine because it can simultaneously target many cascades of immune system activation in comparison with drugs, so PBM can perform very delicate tasks inside our cells to modulate cellular dysfunctions, helping to initiate self-organization phenomena and finally, healing the disease. Interdisciplinary teams should work diligently to meet these needs by also using single-cell imaging devices for multispectral laser photobiomodulation on immune cells.

Immature neutrophil signature associated with the sexual dimorphism of systemic juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) is a group of inflammatory conditions of unknown etiology whose incidence is sex dependent. Although several studies have attempted to identify JIA-related gene signatures, none have systematically assessed the impact of sex on the whole blood transcriptomes of JIA patients. By analyzing over 400 unique pediatric gene expression profiles, we characterized the sexual differences in leukocyte composition of systemic JIA patients and identified sex-specific gene signatures that were related to immature neutrophils. Female systemic JIA patients presented higher activation of immature neutrophil-related genes compared to males, and these genes were associated with the response to IL-1 receptor blockade treatment. Also, we found that this immature neutrophil signature is sexually dimorphic across human lifespan and in adults with rheumatoid arthritis and asthma. These results suggest that neutrophil maturation is sexually dimorphic in rheumatic inflammation, and that this may impact disease progression and treatment.

Canakinumab for Treatment of Adult-Onset Still's Disease to Achieve Reduction of Arthritic Manifestation (CONSIDER): phase II, randomised, double-blind, placebo-controlled, multicentre, investigator-initiated trial

BACKGROUND

Inhibition of interleukin (IL)-1 represents a promising treatment option in adult-onset Still's disease (AOSD).

OBJECTIVE

To investigate the efficacy and safety of canakinumab in patients with AOSD and active joint involvement by means of a multicentre, double-blind, randomised, placebo-controlled trial.

METHODS

Patients with AOSD and active joint involvement (tender and swollen joint counts of ≥4 each) were treated with canakinumab (4 mg/kg, maximum 300 mg subcutaneous every 4 weeks) or placebo. The primary endpoint was the proportion of patients with a clinically relevant reduction in disease activity at week 12 as determined by the change in disease activity score (ΔDAS28>1.2).

RESULTS

At enrolment, patients had high active disease with a mean DAS28(ESR) of 5.4 in the canakinumab and 5.3 in the placebo group, respectively. In the intention-to-treat analysis, 12 patients (67%) in the canakinumab group and 7 patients (41%) in the placebo group fulfilled the primary outcome criterion (p=0.18). In the per-protocol analysis, significantly higher American College of Rheumatology (ACR) 30% (61% vs 20%, p=0.033), ACR 50% (50% vs 6.7%, p=0.009) and ACR 70% (28% vs 0%, p=0.049) response rates were observed in the canakinumab group compared with the placebo group. Two patients in the canakinumab group experienced a serious adverse event.

CONCLUSION

Although the study was terminated prematurely and the primary endpoint was not achieved, treatment with canakinumab led to an improvement of several outcome measures in AOSD. The overall safety findings were consistent with the known profile of canakinumab. Thus, our data support indication for IL-1 inhibition with canakinumab in AOSD.

Efficacy and safety of canakinumab in systemic juvenile idiopathic arthritis: 48-week results from an open-label phase III study in Japanese patients

OBJECTIVES

To assess the efficacy and safety of canakinumab in Japanese patients with systemic juvenile idiopathic arthritis (sJIA).

METHODS

This was an open-label, single-arm active treatment study. sJIA patients, aged ≥2 to <20 years, were administered canakinumab 4 mg/kg every 4 weeks for ≤48 weeks. The co-primary endpoints were the proportion of patients who achieved an adapted American College of Rheumatology pediatric (ACR pedi) 30 criteria at week 8, and the proportion of patients who successfully tapered corticosteroids at week 28. Herein, the efficacy and safety results up to 48 weeks are reported.

RESULTS

Of the 19 patients enrolled, 15 (78.9%) had previously used tocilizumab. All patients achieved ACR pedi 30 at week 8 and 73.7% (14/19) successfully tapered corticosteroids at week 28. At week 48, ACR pedi 50/70/90/100 responses were achieved by 100.0%/100.0%/87.5%/68.8% of patients. The most common adverse events (AEs) were infections (271.6 patient-years), 42.1% (8/19) patients had serious AEs. Two potential cases of macrophage activation syndrome were identified. No deaths were reported.

CONCLUSION

Canakinumab was efficacious in Japanese patients with sJIA and was associated with substantial corticosteroid dose reduction in the majority of patients. The safety profile of canakinumab was consistent with that observed from previous studies.

CLINICALTRIALS.GOV (IDENTIFIER

NCT02396212).

Biologics in juvenile idiopathic arthritis-main advantages and major challenges: A narrative review

Juvenile idiopathic arthritis (JIA) is the most common rheumatic disease in childhood. The disease is divided in different subtypes based on main clinical features and disease course. Emergence of biological agents targeting specific pro-inflammatory cytokines responsible for the disease pathogenesis represents the revolution in the JIA treatment. Discovery and widespread usage of biological agents have led to significant improvement in JIA patients’ treatment, with evidently increased functionality and decreased disease sequel. Increased risk of infections remains the main discussion topic for years. Despite the slightly increased frequency of upper respiratory tract infections reported in some studies, the general safety of drugs is acceptable with rare reports of severe adverse effects (SAEs). Tuberculosis (TBC) represents the important threat in regions with increased TBC prevalence. Therefore, routine screening for TBC should not be neglected when prescribing and during the follow-up of biological treatment. Malignancy represents a hypothetical complication that sometimes causes hesitations for physicians and patients in its prescription and usage. On the other hand, current reports from the literature do not support the increased risk for malignancy among JIA patients treated with biological agents. A multidisciplinary approach including a pediatric rheumatologist and an infectious disease specialist is mandatory in the follow- up of JIA patients. Although the efficacy and safety of biological agents have been proven in different studies, there is still a need for long-term, multicentric evaluation providing relevant data.

Interleukin-1 Blockade in Systemic Juvenile Idiopathic Arthritis

Systemic juvenile idiopathic arthritis (sJIA) is a severe disorder now linked more to autoinflammation than to autoimmunity. Clinical and laboratory evidence support the pathogenetic role of interleukin-1 (IL-1), and blockade of this cytokine has proved to be very effective in the treatment of sJIA. There are now several agents that block IL-1 available on the market. This article reviews the efficacy and safety of these drugs for the treatment of sJIA on the basis of published data, and offers the current view on treating sJIA according to its different phenotypes. There are no head to head trials among the different IL-1 inhibitors, and although efficacy has been demonstrated for all of them, it is still unknown which one would be more appropriate for which particular situation. The presence of synovitis in addition to active systemic features might be relevant for these choices. In addition, complications such as macrophage activation syndrome can be important since, on one hand, it has been associated with biologic therapy administration and, on another, there have been some reports of this complication being treated with anti-IL-1. Current recommendations by the American College of Rheumatology are now outdated, and new ones are being prepared. In the meantime, basic and clinical research is advancing in order to identify new treatment targets and to evaluate the different protocols currently in use.

Vaccination for Children on Biologics

PURPOSE OF REVIEW

Several biologic drugs are available for treatment of immune-mediated diseases, and the number of children treated with biologics is increasing. This review summarises current knowledge about the safety and immunogenicity of vaccines in children treated with biologic therapy.

RECENT FINDINGS

A recent retrospective, multicentre study reported that the booster dose of live-attenuated vaccine (MMR/V) was safe for patients with rheumatic diseases treated with biologic therapy. Recent publications revealed that immunogenicity of vaccines in children treated with biologics was lower than in the healthy population, especially on long-term follow-up. Children treated with biologic therapy are at greater danger of infections, compared to the healthy population. Therefore, they should be vaccinated according to national guidelines. Regardless of the therapy, non-live vaccines are recommended. However, it is common practice to advise postponing vaccination with live-attenuated vaccines in children while they are on immunosuppressive therapy. Newly published data suggest that booster dose MMR/V is safe for children treated with biologic therapy.

Pyroptosis in Liver Disease: New Insights into Disease Mechanisms

There has been increasing interest in pyroptosis as a novel form of pro-inflammatory programmed cell death. The mechanism of pyroptosis is significantly different from other forms of cell death in its morphological and biochemical features. Pyroptosis is characterized by the activation of two different types of caspase enzymes—caspase-1 and caspase-4/5/11, and by the occurrence of a proinflammatory cytokine cascade and an immune response. Pyroptosis participates in the immune defense mechanisms against intracellular bacterial infections. On the other hand, excessive inflammasome activation can induce sterile inflammation and eventually cause some diseases, such as acute or chronic hepatitis and liver fibrosis. The mechanism and biological significance of this novel form of cell death in different liver diseases will be evaluated in this review. Specifically, we will focus on the role of pyroptosis in alcoholic and non-alcoholic fatty liver disease, as well as in liver failure. Finally, the therapeutic implications of pyroptosis in liver diseases will be discussed.

Autoinflammatory Disorders: A Review and Update on Pathogenesis and Treatment

The autoinflammatory diseases comprise a broad spectrum of disorders characterized by unchecked activation of the innate immune system. Whereas aberrations in adaptive immunity have long been identified in 'autoimmune' disorders, the concept of 'autoinflammation' emerged relatively recently, first describing a group of clinical disorders characterized by spontaneous episodes of systemic inflammation without manifestations typical of autoimmune disorders. Improved knowledge of innate immune mechanisms, coupled with remarkable progress in genomics and an expanding number of clinical cases, has since led to an increasing number of disorders classified as autoinflammatory or containing an autoinflammatory component. Biologic therapies targeting specific components of the innate immune system have provided immense clinical benefit, and have further elucidated the role of innate immunity in autoinflammatory disorders. This article reviews the basic mechanisms of autoinflammation, followed by an update on the pathophysiology and treatment of the monogenic and multifactorial autoinflammatory diseases, and the common dermatologic conditions in which autoinflammation plays a major role.

Disruption of the Blood-Brain Barrier During Neuroinflammatory and Neuroinfectious Diseases

As the organ of highest metabolic demand, utilizing over 25% of total body glucose utilization via an enormous vasculature with one capillary every 73 μm, the brain evolves a barrier at the capillary and postcapillary venules to prevent toxicity during serum fluctuations in metabolites and hormones, to limit brain swelling during inflammation, and to prevent pathogen invasion. Understanding of neuroprotective barriers has since evolved to incorporate the neurovascular unit (NVU), the blood-cerebrospinal fluid (CSF) barrier, and the presence of CNS lymphatics that allow leukocyte egress. Identification of the cellular and molecular participants in BBB function at the NVU has allowed detailed analyses of mechanisms that contribute to BBB dysfunction in various disease states, which include both autoimmune and infectious etiologies. This chapter will introduce some of the cellular and molecular components that promote barrier function but may be manipulated by inflammatory mediators or pathogens during neuroinflammation or neuroinfectious diseases.

Unveiling the Efficacy, Safety, and Tolerability of Anti-Interleukin-1 Treatment in Monogenic and Multifactorial Autoinflammatory Diseases

Autoinflammatory diseases (AIDs) are heterogeneous disorders characterized by dysregulation in the inflammasome, a large intracellular multiprotein platform, leading to overproduction of interleukin-1(IL-1)β that plays a predominant pathogenic role in such diseases. Appropriate treatment is crucial, also considering that AIDs may persist into adulthood with negative consequences on patients' quality of life. IL-1β blockade results in a sustained reduction of disease severity in most AIDs. A growing experience with the human IL-1 receptor antagonist, Anakinra (ANA), and the monoclonal anti IL-1β antibody, Canakinumab (CANA), has also been engendered, highlighting their efficacy upon protean clinical manifestations of AIDs. Safety and tolerability have been confirmed by several clinical trials and observational studies on both large and small cohorts of AID patients. The same treatment has been proposed in refractory Kawasaki disease, an acute inflammatory vasculitis occurring in children before 5 years, which has been postulated to be autoinflammatory for its phenotypical and immunological similarity with systemic juvenile idiopathic arthritis. Nevertheless, minor concerns about IL-1 antagonists have been raised regarding their employment in children, and the development of novel pharmacological formulations is aimed at minimizing side effects that may affect adherence to treatment. The present review summarizes current findings on the efficacy, safety, and tolerability of ANA and CANA for treatment of AIDs and Kawasaki vasculitis with a specific focus on the pediatric setting.

Are we aiming to miss in translational autoimmunity treatments?

Autoimmunity treatments, fruitfully pioneered in mouse models, can be disappointing or result in immunosuppression and opportunistic infections in translational trials. Many possible reasons exist, but one major, overlooked reason may be the treatment timing in relation to circadian oscillations of the immune system. Mice and humans both have immunological circadian clocks and experience the same circulatory oscillations of immune cells with regards to their sleep/wake phases, but have opposite sleep/wake phases with regard to the daylight cycle. Therefore, researchers mainly study mice and potential autoimmunity treatments during the murine sleep/rest phase, which is when pro-inflammatory mediators and more adaptive immune cells are prevalent in the circulation. In translational trials, however, treatment administration happens primarily during a patient's wake/activity phase, during the daytime, which is when more local and acute immune responses are active in the circulation. Therefore, we believe that the most opportune window for autoimmunity treatment may be missed in translational trials. Shifting the timing, and adjusting dosing to target only immune cells that are active at that time, may result in higher success with minimized immunosuppression or toxicities.

Use of synthetic and biologic DMARDs during pregnancy

Introduction: Since most of the autoimmune diseases (AID) affect mostly women in their fertile years, and fertility is in general preserved, the use of disease-modifying antirheumatic drugs (DMARDs) during conception, pregnancy, and lactation has been a matter of concern in the treatment of women affected by AID. Areas covered: We performed a comprehensive review of the latest and most relevant research papers published in the field and discussed different aspects related to the use of synthetic and biologic DMARDs and immunosuppressants in the preconceptional period, during pregnancy and lactation in AID patients, both in males and females. Expert commentary: Active AID impose an increased risk for adverse maternal and fetal outcomes, such as preeclampsia, miscarriage, intrauterine growth restriction, prematurity, low birth weight, and stillbirth. Family planning with proper contraception and shared decision-making on the ideal time to conceive with treatment adjustment must be a rule. One of the main challenges when counseling and/or adjusting treatment of patients that are planning a pregnancy is to provide a medication that is at the same time efficacious and safe at the conceptional period and to developing the fetus.

Plasma interleukin-37 is increased and inhibits the production of inflammatory cytokines in peripheral blood mononuclear cells in systemic juvenile idiopathic arthritis patients

Background

Interleukin (IL)-37 has emerged as a novel anti-inflammatory cytokine that play an immunosuppressive role in regulating inflammatory response. This study aimed to measure IL-37 levels in the plasma and peripheral blood mononuclear cells (PBMCs) of patients with systemic juvenile idiopathic arthritis (sJIA), and to establish the correlation between IL-37 levels and disease activity, laboratory parameters and inflammatory cytokines.

Methods

The mRNA levels of IL-37 in PBMCs and plasma IL-37 concentrations in 46 sJIA patients and 30 age- and sex-matched healthy controls were measured by real-time polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. The correlations between plasma IL-37 levels and disease activity, laboratory parameters and inflammatory cytokines in sJIA were analyzed by Spearman correlation test. PBMCs from the sJIA patients were stimulated with recombinant human IL-37 (rhIL-37) protein, expressions of IL-1β, IL-6, TNF-α and IL-17 were detected by RT-PCR and ELISA.

Results

Plasma levels of IL-37 and relative IL-37 mRNA expression were significantly elevated in sJIA patients, especially in active sJIA patients, when compared with the healthy controls (P < 0.001). Furthermore, patients with active disease showed higher IL-37 mRNAs and plasma protein levels than those with inactive disease as well as healthy controls. Plasma IL-37 levels were correlated with disease activity and inflammatory cytokines (IL-6, TNF-α, IL-17 and GM-CSF) in sJIA patients. The productions of inflammatory cytokines such as IL-6, TNF-α, IL-17 in PBMCs from sJIA patients were obviously decreased after recombinant IL-37 stimulation, whereas the production of IL-1β was not changed.

Conclusions

Our results demonstrate that levels of IL-37 were higher in sJIA patients, which were correlated with disease activity and sJIA related inflammatory cytokines. In addition, rhIL-37 down-regulates the expressions of inflammatory cytokines form PBMCs in sJIA patients, suggesting that IL-37 may have the potential role as a natural inhibitor for the pathogenesis and therapy of sJIA.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1655-8) contains supplementary material, which is available to authorized users.