Emergent high fatality lung disease in systemic juvenile arthritis

Unmet needs and research gaps in Still's disease across ages: proceedings from a pediatric and adult joint expert panel

BACKGROUND

Still's disease (SD), including systemic juvenile idiopathic arthritis (sJIA) and adult-onset SD (AOSD), is an inflammatory condition typically characterized by daily fever, arthritis, and skin rash together with neutrophilic leukocytosis, thrombocytosis, and increased acute phase reactants. The reported differences between sJIA and AOSD appear to reflect variations along an inflammatory spectrum influenced by age, rather than differences in the underlying pathology.

METHODS

In February 2023, an expert meeting, including pediatric and adult rheumatologists, was held in Rome, Italy, with the aim of defining more precise and timely strategies for disease management. The following four topics were discussed: (1) early recognition and diagnosis of SD; (2) pathogenetic pathways and possible biomarkers for diagnosis and response; (3) refractory disease and risk factors, and (4) treatment of SD and its complications.

RESULTS

The development of improved diagnostic criteria and validation of biomarkers are important steps towards achieving early diagnosis, although several biomarkers remain to be universally validated and available for clinical practice. Additionally, awareness of important complications of SD, including macrophage activation syndrome and lung disease, is crucial for improving patient outcomes, alongside an improved understanding of risk factors for the development of refractory disease. While interleukin (IL)-1 and IL-6 inhibitors have improved the treatment landscape of SD, harmonizing the therapeutic approach across centers and countries, together with developing treatment strategies for refractory patients, still represents a challenge.

CONCLUSIONS

Here, we summarize the results of discussions among experts, supplemented by relevant literature, and highlight unmet needs in the diagnosis and management of SD.

Allogeneic haematopoietic stem-cell transplantation for children with refractory systemic juvenile idiopathic arthritis and associated lung disease: outcomes from an international, retrospective cohort study

BACKGROUND

Systemic juvenile idiopathic arthritis-related lung disease (sJIA-LD) is a severe complication in patients with treatment-refractory systemic juvenile idiopathic arthritis (sJIA). The objective of this study was to evaluate the effect of allogeneic haematopoietic stem-cell transplantation (HSCT) in a cohort of children with sJIA-LD.

METHODS

This international, retrospective cohort study was performed in nine hospitals across the USA and Europe in children with sJIA-LD who had received allogeneic HSCT. Patients' medical charts were reviewed and their data extracted using a standardised form. The outcomes assessed were allogeneic HSCT outcomes (eg, engraftment and donor chimerism, and transplant-related complications), pulmonary outcomes (eg, oxygen dependence, chest CT findings, and pulmonary function test results), and overall outcomes (eg, death, complete response, or partial response). A complete response was defined as resolution of signs of sJIA without the need for systemic immunomodulatory therapy, in addition to discontinuation of supplemental oxygen.

FINDINGS

Between Jan 18, 2018, and Oct 17, 2022, 13 patients with sJIA-LD, who were refractory to immunosuppressive treatment and who had received an average of six different treatment agents, underwent allogeneic HSCT. Ten (77%) of 13 patients were female and three (23%) were male. The median age at diagnosis of sJIA-LD was 4·8 years (IQR 2·9-14·8) and the median age at transplantation was 9·0 years (5·0-19·0). Pre-HSCT chest CT revealed characteristic sJIA-LD. Five patients required supplemental oxygen before transplantation. Patients received various reduced toxicity or intensity conditioning regimens. Grafts were from 10/10 HLA-matched (n=6) or 9/10 HLA-mismatched (n=5) unrelated donors, a 7/10 related donor (n=1), and a matched sibling (n=1). All patients engrafted. One patient had secondary graft failure and received a second transplant from a different donor. Post-transplantation complications included acute graft-versus-host disease (n=5), bacteraemia (n=8), cytomegalovirus reactivation (n=6), and post-transplantation macrophage activation syndrome (n=3). Four patients died; two from cytomegalovirus pneumonitis, one from intracranial haemorrhage, and one from progressive sJIA-LD. At a median follow-up of 16 months (IQR 6-24), all nine surviving patients had a complete response, with no active features of sJIA, no biological therapy or corticosteroid use, and no supplemental oxygen dependence.

INTERPRETATION

Allogeneic HSCT might be a valuable treatment option for patients with refractory sJIA and sJIA-LD and should be considered for children with worsening oxygen dependence or severe treatment-related morbidity.

FUNDING

National Institute of Arthritis and Musculoskeletal and Skin Diseases (R01-AR079525).

Pediatric Pulmonology 2024 Year in Review: Rare and Diffuse Lung Disease

The field of pediatric rare and diffuse lung diseases continues to advance, with ongoing research deepening our understanding of the diagnosis and treatment of conditions such as children's interstitial and diffuse lung disease (chILD), non-cystic fibrosis (CF) bronchiectasis, and pulmonary complications of childhood cancer. Recent publications in Pediatric Pulmonology and other journals in 2024 have highlighted new insights into the pathophysiology, disease progression, and emerging diagnostic tools for these rare lung conditions, as well as innovative therapeutic approaches. This review features these important advancements within the context of current diagnostic practices and clinical care for pediatric patients with rare and diffuse lung diseases.

Long-term efficacy of MAS825, a bispecific anti-IL1β and IL-18 monoclonal antibody, in two patients with systemic JIA and recurrent episodes of macrophage activation syndrome

INTRODUCTION

Systemic JIA (sJIA), a multifaceted autoinflammatory disorder, can be complicated by life-threatening conditions such as macrophage activation syndrome (MAS) and interstitial lung disease. The management of these conditions presents a therapeutic challenge, underscoring the need for innovative treatment approaches.

OBJECTIVES

To report the possible role of MAS825, a bispecific anti-IL1β and IL-18 monoclonal antibody, in the treatment of multi-drug-resistant sJIA.

METHODS

We report two patients affected by sJIA with severe and refractory MAS and high serum IL-18 levels, responding to dual blockade of IL-1β and IL-18.

RESULTS

The first patient is a 20-year-old man, presenting a severe MAS complicated by thrombotic microangiopathy, following SARS-CoV-2 infection. He was treated with MAS825, with quick improvement. Eighteen months later, the patient is still undergoing biweekly treatment with MAS825, associated with MTX, ciclosporin and low-dose glucocorticoids, maintaining good control over the systemic features of the disease. The second patient, a 10-year-old girl, presented a severe MAS case, complicated by posterior reversible encephalopathy syndrome, following an otomastoiditis. The MAS was not fully controlled despite treatment with i.v. high-dose glucocorticoids, anakinra and ciclosporin. She began biweekly MAS825, which led to a prompt amelioration of MAS parameters. After 10 months, the patient continues to receive MAS825 and is in complete remission.

CONCLUSION

In light of the pivotal role of IL-1β and IL-18 in sJIA, MAS and interstitial lung disease, MAS825 might represent a possible valid and safe option in the treatment of drug-resistant sJIA, especially in the presence of high serum IL-18 levels.

Neonatal and Pediatric Pulmonary Vascular Disease

Pediatric patients are affected by a wide variety of pulmonary vascular diseases ranging from congenital anomalies diagnosed at birth to acquired diseases that present later in childhood and into adolescence. While some pulmonary vascular diseases present similarly to those seen in adults, other forms are unique to children. Knowledge of the characteristic imaging features of these diseases is essential to facilitate prompt diagnosis and guide clinical management.

Patients with Adult-Onset Still's Disease in Germany: A Retrospective Analysis of Clinical Characteristics and Treatment Practices Ahead of the Release of the German Recommendations

Background/Objectives: Adult-onset Still's disease (AOSD) is an autoinflammatory disorder that can be challenging to diagnose and manage. The aim of this study was to analyze retrospective data to provide insights into the clinical presentation, disease activity, and treatment patterns and outcomes of AOSD during routine clinical care prior to the release of new AOSD guidelines. Methods: This retrospective database analysis evaluated adult patients (≥18 years) with a diagnosis of AOSD who engaged in a clinical visit between 1 January 2010 and 31 December 2020. The evaluated outcomes included demographic characteristics, symptoms, disease activity, and treatment. Results: Our study included 120 patients (67 [55.8%] of whom were female) diagnosed with AOSD according to the Yamaguchi criteria at ten German rheumatology centers. The median (quartile [Q] 1, Q3) age was 51 (36, 62) years, and the median (Q1, Q3) time from diagnosis was 9 (4, 11) years. Approximately half (66 [55.0%]) had a polycyclic disease course. The most frequent symptoms at initial diagnosis were arthralgia (105 [87.5%]) and fever (86 [71.7%]), and these symptoms continued for a substantial proportion of patients at the current visit (35 [29.2%] and 22 [18.3%], respectively). High neutrophil and ferritin levels were also common. The mean Still Activity Score, a measure of disease activity, improved from 4.66 at initial diagnosis to 1.97 at the most recent visit. The treatments most frequently used at some point in the disease course were glucocorticoids (118 [98.3%]), interleukin (IL)-1 inhibitors (89 [74.2%]), and methotrexate (85 [70.8%]). The most common current treatments were IL-1 inhibitors (55 [45.8%]), followed by methotrexate (29 [24.2%}) and glucocorticoids (28 [23.3%]). Conclusions: Our cohort of patients with AOSD seen at German rheumatology clinics showed strong improvements in symptoms and disease activity from initial diagnosis, but a high symptom burden remained for some patients. Future studies may be able to build on our data to document the impact of new guidelines on treatment patterns.

EULAR/PReS recommendations for the diagnosis and management of Still's disease, comprising systemic juvenile idiopathic arthritis and adult-onset Still's disease

Systemic juvenile idiopathic arthritis (sJIA) and adult-onset Still's disease (AOSD) are considered the same disease, but a common approach for diagnosis and management is still missing.

METHODS

In May 2022, EULAR and PReS endorsed a proposal for a joint task force (TF) to develop recommendations for the diagnosis and management of sJIA and AOSD. The TF agreed during a first meeting to address four topics: similarity between sJIA and AOSD, diagnostic biomarkers, therapeutic targets and strategies and complications including macrophage activation syndrome (MAS). Systematic literature reviews were conducted accordingly.

RESULTS

The TF based their recommendations on four overarching principles, highlighting notably that sJIA and AOSD are one disease, to be designated by one name, Still's disease.Fourteen specific recommendations were issued. Two therapeutic targets were defined: clinically inactive disease (CID) and remission, that is, CID maintained for at least 6 months. The optimal therapeutic strategy relies on early use of interleukin (IL-1 or IL-6 inhibitors associated to short duration glucocorticoid (GC). MAS treatment should rely on high-dose GCs, IL-1 inhibitors, ciclosporin and interferon-γ inhibitors. A specific concern rose recently with cases of severe lung disease in children with Still's disease, for which T cell directed immunosuppressant are suggested. The recommendations emphasised the key role of expert centres for difficult-to-treat patients. All overarching principles and recommendations were agreed by over 80% of the TF experts with a high level of agreement.

CONCLUSION

These recommendations are the first consensus for the diagnosis and management of children and adults with Still's disease.

Interleukin (IL)-1/IL-6-Inhibitor-Associated Drug Reaction With Eosinophilia and Systemic Symptoms (DReSS) in Systemic Inflammatory Illnesses

BACKGROUND

After introducing IL-1/IL-6 inhibitors, some patients with Still and Still-like disease developed unusual, often fatal, pulmonary disease. This complication was associated with scoring as DReSS (drug reaction with eosinophilia and systemic symptoms) implicating these inhibitors, although DReSS can be difficult to recognize in the setting of systemic inflammatory disease.

OBJECTIVE

To facilitate recognition of IL-1/IL-6 inhibitor-DReSS in systemic inflammatory illnesses (Still/Still-like) by looking at timing and reaction-associated features. We evaluated outcomes of stopping or not stopping IL-1/IL-6 inhibitors after DReSS reaction began.

METHODS

In an international study collaborating primarily with pediatric specialists, we characterized features of 89 drug-reaction cases versus 773 drug-exposed controls and compared outcomes of 52 cases stopping IL-1/IL-6 inhibitors with 37 cases not stopping these drugs.

RESULTS

Before the reaction began, drug-reaction cases and controls were clinically comparable, except for younger disease-onset age for reaction cases with preexisting cardiothoracic comorbidities. After the reaction began, increased rates of pulmonary complications and macrophage activation syndrome differentiated drug-reaction cases from drug-tolerant controls (P = 4.7 × 10-35 and P = 1.1 × 10-24, respectively). The initial DReSS feature was typically reported 2 to 8 weeks after initiating IL-1/IL-6 inhibition. In drug-reaction cases stopping versus not stopping IL-1/IL-6-inhibitor treatment, reaction-related features were indistinguishable, including pulmonary complication rates (75% [39 of 52] vs 76% [28 of 37]). Those stopping subsequently required fewer medications for treatment of systemic inflammation, had decreased rates of macrophage activation syndrome, and improved survival (P = .005, multivariate regression). Resolution of pulmonary complications occurred in 67% (26 of 39) of drug-reaction cases who stopped and in none who continued inhibitors.

CONCLUSIONS

In systemic inflammatory illnesses, recognition of IL-1/IL-6-inhibitor-associated reactions followed by avoidance of IL-1/IL-6 inhibitors significantly improved outcomes.

Clinical characteristics and prognosis of interstitial lung disease in systemic juvenile idiopathic arthritis: a two-center retrospective observational cohort study

BACKGROUND

Interstitial lung disease (ILD) is a serious complication in systemic juvenile idiopathic arthritis (SJIA). This study aimed to identify the clinical characteristics and prognosis of SJIA-ILD.

METHODS

A two-center retrospective cohort study was conducted on patients newly diagnosed with SJIA in China from October 2010 to December 2021. Clinical characteristics, laboratory parameters, outcomes, and relapse rates were compared between ILD and non-ILD groups.

RESULTS

A total of 176 children with SJIA were included, including 35 in ILD group and 141 in non-ILD group. The median age at onset of SJIA was 5.8 years (range 4.4-9.5) in patients with SJIA-ILD. It exhibited higher incidences of cervical spine (28.6%) and hip involvement (40.0%) in ILD group (P = 0.031 and P = 0.029, respectively). The incidence of macrophage activation syndrome (MAS) in ILD group reached up to 40%, significantly elevated than that in non-ILD group (P = 0.047). Children with ILD demonstrated a stronger inflammatory response and were more prone to developing lymphopenia (P = 0.009), requiring more combination therapy (P = 0.006) to control disease activity. 54.3% of patients received biologic therapies, with only three patient receiving biologics (one with IL-6 blockade, two with TNF inhibitor) prior to ILD onset and none receiving IL-1 blockade. The median follow-up duration was 6.0 years (range 3.9-9.5). The proportions of patients with SJIA-ILD achieving clinical inactive disease without glucocorticoids within 6 to 12 months of the treatment were significantly lower than control group (45.7% vs. 70.2%, P = 0.006). In ILD group, only 54.3% of patients achieved complete remission, and 17.1% were in a non-remission state, among whom two deaths from respiratory failure. There was no significant difference in disease relapse rates between the two groups (P > 0.05).

CONCLUSIONS

Patients with SJIA-ILD exhibited heightened inflammation, increased hip joint and cervical spine involvement, and were more susceptible to developing lymphopenia and MAS, suggesting a relatively poor prognosis. They required a prolonged time to control inflammation and more aggressive treatment strategies to achieve inactive status. The unsatisfactory rate of complete remission highlighted an urgent need for focused clinical strategies.

Defining Criteria for Disease Activity States in Systemic Juvenile Idiopathic Arthritis Based on the Systemic Juvenile Arthritis Disease Activity Score

OBJECTIVE

Our objective was to develop and validate cutoff values in the systemic Juvenile Arthritis Disease Activity Score 10 (sJADAS10) that distinguish the states of inactive disease (ID), minimal disease activity (MDA), moderate disease activity (MoDA), and high disease activity (HDA) in children with systemic juvenile idiopathic arthritis, based on subjective disease state assessment by the treating pediatric rheumatologist.

METHODS

The cutoff definition cohort was composed of 400 patients enrolled at 30 pediatric rheumatology centers in 11 countries. Using the subjective physician rating as an external criterion, six methods were applied to identify the cutoffs: mapping, calculation of percentiles of cumulative score distribution, the Youden index, 90% specificity, maximum agreement, and receiver operating characteristic curve analysis. Sixty percent of the patients were assigned to the definition cohort, and 40% were assigned to the validation cohort. Cutoff validation was conducted by assessing discriminative ability.

RESULTS

The sJADAS10 cutoffs that separated ID from MDA, MDA from MoDA, and MoDA from HDA were ≤2.9, ≤10, and >20.6, respectively. The cutoffs discriminated strongly among different levels of pain, between patients with and without morning stiffness, and among patients whose parents judged their disease status as remission or persistent activity or flare or were satisfied or not satisfied with current illness outcome.

CONCLUSION

The sJADAS cutoffs revealed good metrologic properties in both definition and validation cohorts and are therefore suitable for use in clinical trials and routine practice.

A lifelong journey: Long-term perspectives on Juvenile Idiopathic Arthritis

Juvenile Idiopathic Arthritis (JIA) represents a diverse group of chronic inflammatory conditions that begin in childhood or adolescence and continue into adulthood, with varying severity and outcomes. This review discusses the complexities of transitioning JIA patients emphasizing that inadequate transition from pediatric to adult care leads to loss of follow-up, treatment discontinuation, and increased disease activity. Furthermore, challenges in disease classification hinder continuity of care across lifespan. It is also pointed out that predicting long-term outcomes in JIA remains complex due to heterogeneity and evolving phenotypes. Factors such as disease category, joint involvement, and treatment influence disease activity, functional disability, and quality of life. Despite advancements in treatment strategies, a substantial proportion of patients experience long-term disability and joint damage. Finally, it is underscored that optimising long-term outcomes in adults with JIA requires a multifaceted approach encompassing structured transition processes, personalised treatment strategies, and comprehensive management of comorbidities. Further research is needed to refine predictive models, enhance disease monitoring tools, and understand the complex interplay between disease activity, treatment response, and long-term outcomes.

Innovations in the care of childhood interstitial lung disease associated with connective tissue disease and immune-mediated disorders

Childhood interstitial lung disease (chILD) associated with connective tissue and immune mediated disorders is the second most common chILD diagnostic category. As knowledge of the molecular and genetic underpinnings of these rare disorders advances, the recognized clinical spectrum of associated pulmonary manifestations continues to expand. Pulmonary complications of these diseases, including ILD, confer increased risk for morbidity and mortality and contribute to increased complexity for providers tasked with managing the multiple organ systems that can be impacted in these systemic disorders. While pulmonologists play an important role in diagnosis and management of these conditions, thankfully they do not have to work alone. In collaboration with a multidisciplinary team of subspecialists, the pulmonary and other systemic manifestations of these conditions can be managed effectively together. The goal of this review is to familiarize the reader with the classic patterns of chILD and other pulmonary complications associated with primary immune-mediated disorders (monogenic inborn errors of immunity) and acquired systemic autoimmune and autoinflammatory diseases. In addition, this review will highlight current, emerging, and innovative therapeutic strategies and will underscore the important role of multidisciplinary management to improving outcomes for these patients.

New discoveries in the genetics and genomics of systemic juvenile idiopathic arthritis

INTRODUCTION

Systemic juvenile idiopathic arthritis (sJIA) is a severe inflammatory condition with onset in childhood. It is sporadic, but elements of its stereotypical innate immune responses are likely genetically encoded by both common variants with small effect sizes and rare variants with larger effects.

AREAS COVERED

Genomic investigations have defined the unique genetic architecture of sJIA. Identification of the class II HLA locus as the strongest sJIA risk factor for the first time brought attention to T lymphocytes and adaptive immune mechanisms in sJIA. The importance of the human leukocyte antigen (HLA) locus was reinforced by recognition that HLA-DRB1*15 alleles are strongly associated with development of drug reactions and sJIA-associated lung disease (sJIA-LD). At the IL1RN locus, genetic variation relates to both risk of sJIA and may also predict non-response to anakinra. Finally, rare genetic variants may have critical roles in disease complications, such as homozygous LACC1 mutations in families with an sJIA-like illness, and hemophagocytic lymphohistiocytosis (HLH) gene variants in some children with macrophage activation syndrome (MAS).

EXPERT OPINION

Genetic and genomic analysis of sJIA holds great promise for both basic discovery of the course and complications of sJIA, and may help guide personalized medicine and therapeutic decision-making.

Innovations in Childhood Interstitial and Diffuse Lung Disease

Children's interstitial and diffuse lung diseases (chILDs) are a heterogenous and diverse group of lung disorders presenting during childhood. Infants and children with chILD disorders present with respiratory signs and symptoms as well as diffuse lung imaging abnormalities. ChILD disorders are associated with significant health care resource utilization and high morbidity and mortality. The care of patients with chILD has been improved through multidisciplinary care, multicenter collaboration, and the establishment of patient research networks in the United Stated and abroad. This review details past and current innovations in the diagnosis and clinical care of children with chILD.

Severe Features of Systemic Juvenile Idiopathic Arthritis in Patients With Congenital Heart Disease

OBJECTIVE

To describe the clinical features of patients with congenital heart disease (CHD) who subsequently developed systemic juvenile idiopathic arthritis (sJIA).

METHODS

We conducted a retrospective review of patients diagnosed with CHD and sJIA at our institution. Detailed clinical, laboratory, and radiographic data were collected from the medical record and reviewed with each patient's primary medical team.

RESULTS

Five patients with sJIA and CHD were identified. Each child had a unique cardiac anatomy, but all the patients required surgical repair during the first year of life. Four children had thymectomies at the time of cardiac surgery. Classic signs of sJIA such as fever (n = 5), rash (n = 5), and arthritis (n = 4) developed after surgical intervention in all the patients. The individuals in this cohort displayed risk factors associated with severe sJIA, including disease onset before 2 years of age (n = 5), elevated interleukin 18 levels (n = 5), baseline eosinophilia prior to initiation of biologic disease-modifying antirheumatic drugs (n = 4), and positivity for HLA-DRB1*15:01 alleles (n = 4). Macrophage activation syndrome (MAS) occurred in 3 patients and sJIA-associated lung disease (sJIA-LD) was identified in 4 patients. Two children died from complications of their cardiac and/or pulmonary disease.

CONCLUSION

We identified an association between CHD and severe forms of sJIA. Although these findings will need to be confirmed in larger, multicenter cohorts, the results highlight the importance of considering a diagnosis of sJIA in children with CHD and remaining vigilant for complications such as MAS and sJIA-LD.

Tailoring the treatment of inflammatory rheumatic diseases by a better stratification and characterization of the clinical patient heterogeneity. Findings from a systematic literature review and experts' consensus

Inflammatory rheumatic diseases are different pathologic conditions associated with a deregulated immune response, codified along a spectrum of disorders, with autoinflammatory and autoimmune diseases as two-end phenotypes of this continuum. Despite pathogenic differences, inflammatory rheumatic diseases are commonly managed with a limited number of immunosuppressive drugs, sometimes with partial evidence or transferring physicians' knowledge in different patients. In addition, several randomized clinical trials, enrolling these patients, did not meet the primary pre-established outcomes and these findings could be linked to the underlying molecular diversities along the spectrum of inflammatory rheumatic disorders. In fact, the resulting patient heterogeneity may be driven by differences in underlying molecular pathology also resulting in variable responses to immunosuppressive drugs. Thus, the identification of different clinical subsets may possibly overcome the major obstacles that limit the development more effective therapeutic strategies for these patients with inflammatory rheumatic diseases. This clinical heterogeneity could require a diverse therapeutic management to improve patient outcomes and increase the frequency of clinical remission. Therefore, the importance of better patient stratification and characterization is increasingly pointed out according to the precision medicine principles, also suggesting a new approach for disease treatment. In fact, based on a better proposed patient profiling, clinicians could more appropriately balance the therapeutic management. On these bases, we synthetized and discussed the available literature about the patient profiling in regard to therapy in the context of inflammatory rheumatic diseases, mainly focusing on randomized clinical trials. We provided an overview of the importance of a better stratification and characterization of the clinical heterogeneity of patients with inflammatory rheumatic diseases identifying this point as crucial in improving the management of these patients.

The Systemic Score May Identify Life-Threatening Evolution in Still Disease: Data from the GIRRCS AOSD-Study Group and the AIDA Network Still Disease Registry

OBJECTIVE

We aimed to evaluate the clinical usefulness of the systemic score in the prediction of life-threatening evolution in Still disease. We also aimed to assess the clinical relevance of each component of the systemic score in predicting life-threatening evolution and to derive patient subsets accordingly.

METHODS

A multicenter, observational, prospective study was designed including patients included in the Gruppo Italiano Di Ricerca in Reumatologia Clinica e Sperimentale Adult-Onset Still Disease Study Group and the Autoinflammatory Disease Alliance Network Still Disease Registry. Patients were assessed to see if the variables to derive the systemic score were available. The life-threatening evolution was defined as mortality, whatever the clinical course, and/or macrophage activation syndrome, a secondary hemophagocytic lymphohistiocytosis associated with a poor prognosis.

RESULTS

A total of 597 patients with Still disease were assessed (mean ± SD age 36.6 ± 17.3 years; male 44.4%). The systemic score, assessed as a continuous variable, significantly predicted the life-threatening evolution (odds ratio [OR] 1.24; 95% confidence interval [CI] 1.07-1.42; P = 0.004). A systemic score ≥7 also significantly predicted the likelihood of a patient experiencing life-threatening evolution (OR 3.36; 95% CI 1.81-6.25; P < 0.001). Assessing the clinical relevance of each component of the systemic score, liver involvement (OR 1.68; 95% CI 1.48-2.67; P = 0.031) and lung disease (OR 2.12; 95% CI 1.14-4.49; P = 0.042) both significantly predicted life-threatening evolution. The clinical characteristics of patients with liver involvement and lung disease were derived, highlighting their relevance in multiorgan disease manifestations.

CONCLUSION

The clinical utility of the systemic score was shown in identifying Still disease at a higher risk of life-threatening evolution in a large cohort. Furthermore, the clinical relevance of liver involvement and lung disease was highlighted.

Initial Respiratory System Involvement in Juvenile Idiopathic Arthritis with Systemic Onset Is a Marker of Interstitial Lung Disease: The Results of Retrospective Cohort Study Analysis

Background: Pulmonary involvement in systemic juvenile idiopathic arthritis (SJIA) is a rare but dangerous complication. The main risk factors are already known, such as macrophage activation syndrome, a refractory course of systemic juvenile arthritis, infusion reaction to interleukin 1 and/or interleukin 6 blockers, trisomy 21, and eosinophilia. However, information about respiratory system involvement (RSI) at the onset of SJIA is scarce. Our study aimed to evaluate the specific features of children with SJIA with RSI and their outcomes. Methods: In a single-center retrospective cohort study, we compared the information from the medical records of 200 children with SJIA according to ILAR criteria or SJIA-like disease (probable/possible SJIA) with and without signs of RSI (dyspnea, shortness of breath, pleurisy, acute respiratory distress syndrome, and interstitial lung disease (ILD)) at the disease onset and evaluated their outcomes (remission, development of chronic ILD, clubbing, and pulmonary arterial hypertension). Results: A quarter (25%) of the SJIA patients had signs of the RSI at onset and they more often had rash; hepato- and splenomegaly; heart (pericarditis, myocarditis), central nervous system, and kidney involvement; hemorrhagic syndrome; macrophage activation syndrome (MAS, 44.4% vs. 9.0%, p = 0.0000001); and, rarely, arthritis with fewer active joints, compared to patients without RSI. Five patients (10% from the group having RSI at the onset of SJIA and 2.5% from the whole SJIA cohort) developed fibrosing ILD. All of them had a severe relapsed/chronic course of MAS; 80% of them had a tocilizumab infusion reaction and further switched to canakinumab. Unfortunately, one patient with Down's syndrome had gone. Conclusion: Patients with any signs of RSI at the onset of the SJIA are required to be closely monitored due to the high risk of the following fibrosing ILD development. They required prompt control of MAS, monitoring eosinophilia, and routine checks of night oxygen saturation for the prevention/early detection of chronic ILD.

Connective tissue disease-associated lung disease in children

Connective tissue diseases are a heterogeneous group of autoimmune diseases that can affect a variety of organ systems. Lung parenchymal involvement is an important contributor to morbidity and mortality in children with connective tissue disease. Connective tissue disease-associated lung disease in children often manifests as one of several radiologic-pathologic patterns of disease, with certain patterns having a propensity to occur in association with certain connective tissue diseases. In this article, key clinical, histopathologic, and computed tomography (CT) features of typical patterns of connective tissue disease-associated lung disease in children are reviewed, with an emphasis on radiologic-pathologic correlation, to improve recognition of these patterns of lung disease at CT and to empower the pediatric radiologist to more fully contribute to the care of pediatric patients with these conditions.

Systemic juvenile idiopathic arthritis-associated lung disease: A retrospective cohort study

BACKGROUND

Lung damage in systemic juvenile arthritis (sJIA) is one of the contemporary topics in pediatric rheumatology. Several previous studies showed the severe course and fatal outcomes in some patients. The information about interstitial lung disease (ILD) in the sJIA is scarce and limited to a total of 100 cases.

AIM

To describe the features of sJIA patients with ILD in detail.

METHODS

In the present retrospective cohort study, information about 5 patients less than 18-years-old with sJIA and ILD were included. The diagnosis of sJIA was made according to the current 2004 and new provisional International League of Associations for Rheumatology criteria 2019. ILD was diagnosed with chest computed tomography with the exclusion of other possible reasons for concurrent lung involvement. Macrophage activation syndrome (MAS) was diagnosed with HLH-2004 and 2016 EULAR/ACR/PRINTO Classification Criteria and hScores were calculated during the lung involvement.

RESULTS

The onset age of sJIA ranged from 1 year to 10 years. The time interval before ILD ranged from 1 mo to 3 years. The disease course was characterized by the prevalence of the systemic features above articular involvement, intensive rash (100%), persistent and very active MAS (hScore range: 194-220) with transaminitis (100%), and respiratory symptoms (100%). Only 3 patients (60%) developed a clubbing phenomenon. All patients (100%) had pleural effusion and 4 patients (80%) had pericardial effusion at the disease onset. Two patients (40%) developed pulmonary arterial hypertension. Infusion-related reactions to tocilizumab were observed in 3 (60%) of the patients. One patient with trisomy 21 had a fatal disease course. Half of the remaining patients had sJIA remission and 2 patients had improvement. Lung disease improved in 3 patients (75%), but 1 of them had initial deterioration of lung involvement. One patient who has not achieved the sJIA remission had the progressed course of ILD. No cases of hyper-eosinophilia were noted. Four patients (80%) received canakinumab and one (20%) tocilizumab at the last follow-up visit.

CONCLUSION

ILD is a severe life-threatening complication of sJIA that may affect children of different ages with different time intervals since the disease onset. Extensive rash, serositis (especially pleuritis), full-blown MAS with transaminitis, lymphopenia, trisomy 21, eosinophilia, and biologic infusion reaction are the main predictors of ILD. The following studies are needed to find the predictors, pathogenesis, and treatment options, for preventing and treating the ILD in sJIA patients.

Pediatric systemic juvenile idiopathic arthritis-related lung disease: Description of clinical cohort and review of management

CONTEXT

Since the early 2010s, there has been an increased awareness of interstitial lung disease in systemic juvenile idiopathic arthritis (sJIA-LD) in pediatric patients. Despite the increase in prevalence of sJIA-LD, little is known about this disease process and effective therapeutic management.

OBJECTIVES

To identify and characterize the disease process and management of interstitial lung disease related to systemic juvenile idiopathic arthritis.

STUDY DESIGN

In this single-center, retrospective case series of 9 patients, we analyze demographic, clinical, radiographic, and laboratory data to corroborate common clinical characteristics and describe an approach for diagnosis and monitoring of sJIA-LD.

DATA EXTRACTION

All data was extracted through electronic medical records and individually reviewed by two pediatric pulmonologists and two pediatric rheumatologists.

RESULTS

Our results were similar to other described cases of sJIA-LD as patients in our cohort were more likely to be younger, have a history of macrophage activation syndrome and prior use of biologic therapies. In contrast to prior studies, they did not present with peripheral lymphadenopathy and hepatosplenomegaly.

LIMITATIONS

The cohort size was small and data is reflective of one center's approach to management of a rare lung disease process.

CONCLUSION

Interstitial lung disease due to sJIA is rare and management can be difficult in these complex patients.More research is necessary to understand the increased incidence and treatment of sJIA-LD in pediatric population.

Disease Course, Treatments, and Outcomes of Children With Systemic Juvenile Idiopathic Arthritis-Associated Lung Disease

OBJECTIVE

Systemic juvenile idiopathic arthritis-associated lung disease (SJIA-LD) is a life-threatening disease complication. Key questions remain regarding clinical course and optimal treatment approaches. The objectives of the study were to detail management strategies after SJIA-LD detection, characterize overall disease courses, and measure long-term outcomes.

METHODS

This was a prospective cohort study. Clinical data were abstracted from the electronic medical record, including current clinical status and changes since diagnosis. Serum biomarkers were determined and correlated with presence of LD.

RESULTS

We enrolled 41 patients with SJIA-LD, 85% with at least one episode of macrophage activation syndrome and 41% with adverse reactions to a biologic. Although 93% of patients were alive at last follow-up (median 2.9 years), 37% progressed to requiring chronic oxygen or other ventilator support, and 65% of patients had abnormal overnight oximetry studies, which changed over time. Eighty-four percent of patients carried the HLA-DRB1*15 haplotype, significantly more than patients without LD. Patients with SJIA-LD also showed markedly elevated serum interleukin-18 (IL-18), variable C-X-C motif chemokine ligand 9 (CXCL9), and significantly elevated matrix metalloproteinase 7. Treatment strategies showed variable use of anti-IL-1/6 biologics and addition of other immunomodulatory treatments and lung-directed therapies. We found a broad range of current clinical status independent of time from diagnosis or continued biologic treatment. Multidomain measures of change showed imaging features were the least likely to improve with time.

CONCLUSION

Patients with SJIA-LD had highly varied courses, with lower mortality than previously reported but frequent hypoxia and requirement for respiratory support. Treatment strategies were highly varied, highlighting an urgent need for focused clinical trials.

Diagnosing and Treating Systemic Juvenile Idiopathic Arthritis and Adult-Onset Still's Disease as Part of the Still's Disease Continuum

Aim

We have summarised the existing evidence supporting the concept that systemic juvenile idiopathic arthritis (sJIA) and adult-onset Still's disease (AOSD) are part of the same Still's disease spectrum.

Methods

A PubMed/Embase database search was conducted using specific search strings and free text words to screen for relevant articles. The search was limited to studies in humans, published up to June 2023, in English-language.

Summary

sJIA and AOSD are rare autoinflammatory disorders that have similar pathophysiological and clinical features. The clinical presentations of sJIA and AOSD are highly variable, with differential diagnoses that include a broad range of malignancies, infectious diseases, and autoimmune disorders, which contribute to delays in diagnosis. Several sets of classification exist to help diagnose patients in clinical practice; the International League of Associations for Rheumatology criteria for sJIA and the Yamaguchi and Fautrel criteria for AOSD are the most-used criteria. The therapeutic strategy for Still's disease aims to relieve signs and symptoms, prevent irreversible joint damage and potentially life-threatening complications, and avoid deleterious side effects of treatment. Recently, targeted therapies such as interleukin (IL)-1 and IL-6 inhibitors have become available for the treatment of sJIA and AOSD. While these biologics were originally largely reserved for patients in whom non-steroidal anti-inflammatory drugs, corticosteroids and conventional synthetic disease-modifying anti-rheumatic drugs had failed, they are increasingly used earlier in the treatment paradigm. Among IL-1 inhibitors, canakinumab is the only biologic approved in the US for the treatment of both sJIA and AOSD.

From Sand to Excellence: A Deep Dive into Abu Dhabi's Rheumatology Landscape

The Emirate of Abu Dhabi (AD) is the capital and largest emirate of the United Arab Emirates (UAE). The emirate's economic significance stems from non-oil and oil contributions to GDP. The 2022 GDP of Abu Dhabi was USD 230 billion. The government provides services to its residents through digital platforms such as official websites. The Abu Dhabi Health Insurance Law No. 23 of 2005 mandates that residents have access to necessary medical care and services. There is a paucity in the literature on the available rheumatology services in the Arab region. This review article aims to explore the status of rheumatology services in AD for both residents and visitors. It will include an overview of paediatric and adult rheumatology care, accessibility of diagnostic procedures, the integration of electronic medical records, access to medications, the status of postgraduate education, research, and suggestions on how to enhance rheumatology services in AD as a destination for medical tourism.

Single-cell RNA sequencing in juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) is one of the most common chronic inflammatory rheumatic diseases in children, with onset before age 16 and lasting for more than 6 weeks. JIA is a highly heterogeneous condition with various consequences for health and quality of life. For some JIA patients, early detection and intervention remain challenging. As a result, further investigation of the complex and unknown mechanisms underlying JIA is required. Advances in technology now allow us to describe the biological heterogeneity and function of individual cell populations in JIA. Through this review, we hope to provide novel ideas and potential targets for the diagnosis and treatment of JIA by summarizing the current findings of single-cell RNA sequencing studies and understanding how the major cell subsets drive JIA pathogenesis.

Recent advances and evolving concepts in Still's disease

Still's disease is a rare inflammatory syndrome that encompasses systemic juvenile idiopathic arthritis and adult-onset Still's disease, both of which can exhibit life-threatening complications, including macrophage activation syndrome (MAS), a secondary form of haemophagocytic lymphohistiocytosis. Genetic insights into Still's disease involve both HLA and non-HLA susceptibility genes, suggesting the involvement of adaptive immune cell-mediated immunity. At the same time, phenotypic evidence indicates the involvement of autoinflammatory processes. Evidence also implicates the type I interferon signature, mechanistic target of rapamycin complex 1 signalling and ferritin in the pathogenesis of Still's disease and MAS. Pathological entities associated with Still's disease include lung disease that could be associated with biologic DMARDs and with the occurrence of MAS. Historically, monophasic, recurrent and persistent Still's disease courses were recognized. Newer proposals of alternative Still's disease clusters could enable better dissection of clinical heterogeneity on the basis of immune cell profiles that could represent diverse endotypes or phases of disease activity. Therapeutically, data on IL-1 and IL-6 antagonism and Janus kinase inhibition suggest the importance of early administration in Still's disease. Furthermore, there is evidence that patients who develop MAS can be treated with IFNγ antagonism. Despite these developments, unmet needs remain that can form the basis for the design of future studies leading to improvement of disease management.

Imaging of pulmonary fibrosis in children: A review, with proposed diagnostic criteria

Computed tomography (CT) imaging findings of pulmonary fibrosis are well established for adults and have been shown to correlate with prognosis and outcome. Recognition of fibrotic CT findings in children is more limited. With approved treatments for adult pulmonary fibrosis, it has become critical to define CT criteria for fibrosis in children, to identify patients in need of treatment and those eligible for clinical trials. Understanding how pediatric fibrosis compares with idiopathic pulmonary fibrosis and other causes of fibrosis in adults is increasingly important as these patients transition to adult care teams. Here, we review what is known regarding the features of pulmonary fibrosis in children compared with adults. Pulmonary fibrosis in children may be associated with genetic surfactant dysfunction disorders, autoimmune systemic disorders, and complications after radiation, chemotherapy, transplantation, and other exposures. Rather than a basal-predominant usual interstitial pneumonia pattern with honeycombing, pediatric fibrosis is primarily characterized by reticulation, traction bronchiectasis, architectural distortion, or cystic lucencies/abnormalities. Ground-glass opacities are more frequent in children with fibrotic interstitial lung disease than adults, and disease distribution appears more diffuse, without clearly defined axial or craniocaudal predominance. Following discussion and consensus amongst a panel of expert radiologists, pathologists and physicians, distinctive disease features were integrated to develop criteria for the first global Phase III trial in children with pulmonary fibrosis.

Case report: Suspected transfusion-related acute lung injury type II in a child with refractory systemic juvenile idiopathic arthritis complicated by macrophage activation syndrome

Introduction

Transfusion-related acute lung injury is a rare but potentially fatal complication, which may appear during or post-transfusion of blood products. Patients with macrophage activation syndrome, a serious life-threatening complication associated with systemic juvenile idiopathic arthritis, often require transfusion or administration of blood products for correction of cytopenia, coagulopathy and hypofibrinogenemia.

Case report

A 6-year-old girl with a past medical history of systemic juvenile idiopathic arthritis had the first relapse of the disease during which she developed macrophage activation syndrome. During this life-threatening complication, she received a second dose of whole blood derived filtered and irradiated platelets from a single male donor due to profound thrombocytopenia. Approximately one hour post-infusion, the patient developed progressive dyspnea, hypoxemia and bilateral pulmonary edema. She was promptly intubated and placed on mechanical ventilation for 40 h. Clinical, laboratory and radiological findings, as well as the success of supportive ventilation therapy were highly suggestive of transfusion-related acute lung injury, a life-threatening complication that occurs within six hours of blood component transfusion. Blood immunology showed no presence of anti-human neutrophil antigen and anti-leukocyte antigen class I and class II antibodies in the donor's or patient's plasma.

Conclusion

To the best of our knowledge, we report the first case of a child with systemic juvenile idiopathic arthritis complicated with macrophage activation syndrome who developed type II transfusion-related acute lung injury following platelet transfusion. It is important to consider transfusion-related acute lung injury in transfusion settings in these children and apply critical and restrictive approach for platelet transfusion.

The 4th NextGen therapies for SJIA and MAS: part 2 phenotypes of refractory SJIA and the landscape for clinical trials in refractory SJIA

Although the introduction of the IL-1 and IL-6 inhibiting biologics in 2012 has revolutionized the treatment and markedly improved outcomes for many patients with SJIA, about 20% of these patients continue to have active disease, have markedly decreased quality of life and high disease activity as well as treatment-related morbidity and mortality. There is a clear need to define these disease states, and then use these definitions as the basis for further studies into the prevalence, clinical features, and pathophysiologic mechanisms. While such patients are most likely to benefit from novel therapies, they are very difficult to enroll in the ongoing clinical trials given the unique features of their disease and large numbers of background medications. The discussions at the NextGen 2022 conference focused on strategies to overcome these obstacles and accelerate studies in refractory SJIA.

The 4th NextGen therapies of SJIA and MAS, part 4: it is time for IL-18 based trials in systemic juvenile idiopathic arthritis?

Since IL-18 has recently emerged as a biomarker associated with refractory disease course in SJIA, the focus of the discussion was the feasibility of the biomarker-driven drug development to SJIA. Overall, there was broad agreement on the conclusion that IL-18 is a uniquely specific biomarker for many of the subsets of SJIA most in need of new therapies, and it may define a class of diseases mediated by IL-18 excess. The consensus was that leveraging IL-18 remains our most promising "lead" for use in refractory SJIA as it may mechanistically explain the disease pathophysiology and lead to more targeted therapies.

The 4th NextGen therapies for SJIA and MAS: part 3 clinical trials in refractory SJIA: historic controls as an alternative to a withdrawal design study

The substantial morbidity and mortality associated with refractory systemic JIA underlies the need for new treatment approaches. However, progress in this area has been limited by the difficulty of enrolling these patients in clinical trials with traditional designs, particularly in patients presenting with the life-threatening macrophage activation syndrome. At the NextGen 2022 conference, there was group consensus that using historical cohorts as a control group to avoid the need for a placebo-arm or drug withdrawal was highly desirable and might be acceptable for clinical trials in MAS to support medication efficacy and safety. However, if historic controls were used in a trial, it would be important to ensure that the historic cohort matches the study group in terms of clinical characteristics (such as disease severity and exposure to other medications), and that disease outcome in both groups is assessed using the same outcome measures. The discussions at the NextGen 2022 conference focused on the potential strategies to achieve these goals.

[Lung involvement in autoinflammatory diseases]

Genetic autoinflammatory diseases are now a recognized and rapidly expanding group. The lung involvement historically associated with autoinflammatory diseases is inflammatory seritis, primarily seen in familial Mediterranean fever and other interleukin-1 mediated diseases. Over the last ten years, pulmonary involvement has been the core presentation of two autoinflammatory diseases associated with constitutive type I interferon activation, i.e. SAVI and COPA syndrome. Most patients with these diseases usually develop early progression to pulmonary fibrosis, which is responsible for high rates of morbidity and mortality. Other rare autoinflammatory diseases are associated with alveolar proteinosis, particularly when related to MARS mutations. Additionally, in adults, VEXAS is frequently associated with pulmonary involvement, albeit without prognosis effect. A molecular approach to autoinflammatory diseases enables not only the definition of biomarkers for diagnosis, but also the identification of targeted treatments. Examples include JAK inhibitors in SAVI and COPA syndrome, even though this therapy does not prevent progression to pulmonary fibrosis. Another illustrative example is the efficacy of methionine supplementation in alveolar proteinosis linked to MARS mutations. Overall, in autoinflammatory diseases the lung is now emerging as a possible affected organ. Continuing discovery of new autoinflammatory diseases is likely to uncover further pathologies involving the lung. Such advances are expected to lead to the development of novel therapeutic perspectives.

Recombinant Interleukin-1 Receptor Antagonist Is an Effective First-Line Treatment Strategy in New-Onset Systemic Juvenile Idiopathic Arthritis, Irrespective of HLA-DRB1 Background and IL1RN Variants

OBJECTIVE

Human leukocyte antigen (HLA)-DRB1*15:01 has been recently associated with interstitial lung disease (LD), eosinophilia, and drug reactions in systemic juvenile idiopathic arthritis (sJIA). Additionally, genetic variants in IL1RN have been linked to poor response to anakinra. We sought to reproduce these findings in a prospective cohort study of patients with new-onset sJIA treated with anakinra as first-line therapy.

METHODS

HLA and IL1RN risk alleles were identified via whole-genome sequencing. Treatment responses and complications were compared between carriers versus noncarriers.

RESULTS

Seventeen of 65 patients (26%) carried HLA-DRB1*15:01, comparable with the general population, and there was enrichment for HLA-DRB1*11:01, a known risk locus for sJIA. The rates of clinical inactive disease (CID) at 6 months, 1 year, and 2 years were generally high, irrespective of HLA-DRB1 or IL1RN variants, but significantly lower in carriers of an HLA-DRB1*11:01 allele. One patient, an HLA-DRB1*15:01 carrier, developed sJIA-LD. Of the three patients with severe drug reactions to biologics, one carried HLA-DRB1*15:01. The prevalence of eosinophilia did not significantly differ between HLA-DRB1*15:01 carriers and noncarriers at disease onset (6.2% vs 14.9%, P = 0.67) nor after the start of anakinra (35.3% vs 37.5% in the first 2 years of disease).

CONCLUSION

We observed high rates of CID using anakinra as first-line treatment irrespective of HLA-DRB1 or IL1RN variants. Only one of the 17 HLA-DRB1*15:01 carriers developed sJIA-LD, and of the three patients with drug reactions to biologics, only one carried HLA-DRB1*15:01. Although thorough monitoring for the development of drug hypersensitivity and refractory disease courses in sJIA, including sJIA-LD, remains important, our data support the early start of biologic therapy in patients with new-onset sJIA irrespective of HLA-DRB1 background or IL1RN variants.

IL-1 Family Blockade in Cytokine Storm Syndromes

Interleukin-1 is a prototypic proinflammatory cytokine that is elevated in cytokine storm syndromes (CSSs), such as secondary hemophagocytic lymphohistiocytosis (sHLH) and macrophage activation syndrome (MAS). IL-1 has many pleotropic and redundant roles in both innate and adaptive immune responses. Blockade of IL-1 with recombinant human interleukin-1 receptor antagonist has shown efficacy in treating CSS. Recently, an IL-1 family member, IL-18, has been demonstrated to be contributory to CSS in autoinflammatory conditions, such as in inflammasomopathies (e.g., NLRC4 mutations). Anecdotally, recombinant IL-18 binding protein can be of benefit in treating IL-18-driven CSS. Lastly, another IL-1 family member, IL-33, has been postulated to contribute to CSS in an animal model of disease. Targeting of IL-1 and related cytokines holds promise in treating a variety of CSS.

Cytokine Storm Syndrome Associated with Systemic Juvenile Idiopathic Arthritis

The cytokine storm syndrome (CSS) associated with systemic juvenile idiopathic arthritis (sJIA) has widely been referred to as macrophage activation syndrome (MAS). In this chapter, we use the term sJIA-associated CSS (sJIA-CSS) when referring to this syndrome and use the term MAS when referencing publications that specifically report on sJIA-associated MAS.

Biological and clinical roles of IL-18 in inflammatory diseases

Several new discoveries have revived interest in the pathogenic potential and possible clinical roles of IL-18. IL-18 is an IL-1 family cytokine with potent ability to induce IFNγ production. However, basic investigations and now clinical observations suggest a more complex picture. Unique aspects of IL-18 biology at the levels of transcription, activation, secretion, neutralization, receptor distribution and signalling help to explain its pleiotropic roles in mucosal and systemic inflammation. Blood biomarker studies reveal a cytokine for which profound elevation, associated with detectable 'free IL-18', defines a group of autoinflammatory diseases in which IL-18 dysregulation can be a primary driving feature, the so-called 'IL-18opathies'. This impressive specificity might accelerate diagnoses and identify patients amenable to therapeutic IL-18 blockade. Pathogenically, human and animal studies identify a preferential activation of CD8+ T cells over other IL-18-responsive lymphocytes. IL-18 agonist treatments that leverage the site of production or subversion of endogenous IL-18 inhibition show promise in augmenting immune responses to cancer. Thus, the unique aspects of IL-18 biology are finally beginning to have clinical impact in precision diagnostics, disease monitoring and targeted treatment of inflammatory and malignant diseases.

The latest advances in the use of biological DMARDs to treat Still's disease

INTRODUCTION

Currently, the therapeutic management of Still's disease, a multisystemic inflammatory rare disorder, is directed to target the inflammatory symptoms and signs of patients. The treatment varies from glucocorticoids to disease-modifying antirheumatic drugs (DMARDs), both conventional synthetic and biological (bDMARDs). Usually, in refractory patients, bDMARDs are administered.

AREAS COVERED

Among bDMARDs, IL-1 and IL-6 inhibitors are frequently used, as data reported from both clinical trials and 'real-life' experiences. Recently, innovative therapeutic strategies have suggested an early administration of bDMARDs to increase the rate of clinical response and drug-free remission. Some new targets have been also proposed targeting IL-18, IFN-γ, and JAK/STAT pathway, which could be applied to Still's disease and its life-threatening evolution.

EXPERT OPINION

Many lines of evidence improved the knowledge about the therapeutic management of Still's disease with bDMARDs. However, many unmet needs may be still highlighted which could provide the basis to arrange further specific research in increasing the rate of clinical response. In fact, Still's disease remains a highly heterogeneous disease suggesting possible diverse underlying pathogenic mechanisms, at least partially, and consequent different therapeutic strategies. A better patient stratification may help in arranging specific studies to improve the long-term outcome of Still's disease.

Treatment of systemic juvenile idiopathic arthritis

Systemic juvenile idiopathic arthritis (sJIA) is an inflammatory disease with hallmarks of severe systemic inflammation, which can be accompanied by arthritis. Contemporary scientific insights set this paediatric disorder on a continuum with its counterpart, adult-onset Still disease (AOSD). Patients with sJIA are prone to complications, including life-threatening hyperinflammation (macrophage activation syndrome (sJIA-MAS)) and sJIA-associated lung disease (sJIA-LD). Meanwhile, the treatment arsenal in sJIA has expanded markedly. State-of-the-art therapeutic approaches include biologic agents that target the IL-1 and IL-6 pathways. Beyond these, a range of novel agents are on the horizon, some of them already being used on a compassionate use basis, including JAK inhibitors and biologic agents that target IL-18, IFNγ, or IL-1β and IL-18 simultaneously. However, sJIA, sJIA-MAS and sJIA-LD still pose challenging conundrums to rheumatologists treating paediatric and adult patients worldwide. Although national and international consensus treatment plans exist for the treatment of 'classic' sJIA, the treatment approaches for early sJIA without arthritis, and for refractory or complicated sJIA, are not well defined. Therefore, in this Review we outline current approaches for the treatment of sJIA and provide an outlook on knowledge gaps.

Population-level single-cell genomics reveals conserved gene programs in systemic juvenile idiopathic arthritis

Systemic autoimmune and autoinflammatory diseases are characterized by genetic and cellular heterogeneity. While current single-cell genomics methods provide insights into known disease subtypes, these analysis methods do not readily reveal novel cell-type perturbation programs shared among distinct patient subsets. Here, we performed single-cell RNA-Seq of PBMCs of patients with systemic juvenile idiopathic arthritis (SJIA) with diverse clinical manifestations, including macrophage activation syndrome (MAS) and lung disease (LD). We introduced two new computational frameworks called UDON and SATAY-UDON, which define patient subtypes based on their underlying disrupted cellular programs as well as associated biomarkers or clinical features. Among twelve independently identified subtypes, this analysis uncovered what we believe to be a novel complement and interferon activation program identified in SJIA-LD monocytes. Extending these analyses to adult and pediatric lupus patients found new but also shared disease programs with SJIA, including interferon and complement activation. Finally, supervised comparison of these programs in a compiled single-cell pan-immune atlas of over 1,000 healthy donors found a handful of normal healthy donors with evidence of early inflammatory activation in subsets of monocytes and platelets, nominating possible biomarkers for early disease detection. Thus, integrative pan-immune single-cell analysis resolved what we believe to be new conserved gene programs underlying inflammatory disease pathogenesis and associated complications.

Molecular Pathways in the Pathogenesis of Systemic Juvenile Idiopathic Arthritis

Systemic juvenile idiopathic arthritis (sJIA) is a rare childhood chronic inflammatory disorder with risk for life-threatening complications including macrophage activation syndrome and lung disease. At onset, sJIA pathogenesis resembles that of the autoinflammatory periodic fever syndromes with marked innate immune activation, expansion of neutrophils and monocytes, and high levels of interleukin-18. Here, we review the current conceptual understanding of sJIA pathogenesis with a focus on both innate and adaptive immune pathways. Finally, we consider how recent progress toward understanding the immunologic basis of sJIA may support new therapies for refractory disease courses.

Derivation and validation of four patient clusters in Still's disease, results from GIRRCS AOSD-study group and AIDA Network Still Disease Registry

BACKGROUND

Different patient clusters were preliminarily suggested to dissect the clinical heterogeneity in Still's disease. Thus, we aimed at deriving and validating disease clusters in a multicentre, observational, prospective study to stratify these patients.

METHODS

Patients included in GIRRCS AOSD-study group and AIDA Network Still Disease Registry were assessed if variables for cluster analysis were available (age, systemic score, erythrocyte sedimentation rate (ESR), C reactive protein (CRP) and ferritin). K-means algorithm with Euclidean metric and Elbow plot were used to derive an adequate number of clusters.

RESULTS

K-means clustering assessment provided four clusters based on means standardised according to z-scores on 349 patients. All clusters mainly presented fever, skin rash and joint involvement. Cluster 1 was composed by 115 patients distinguished by lower values of age and characterised by skin rash myalgia, sore throat and splenomegaly. Cluster 2 included 128 patients identified by lower levels of ESR, ferritin and systemic score; multiorgan manifestations were less frequently observed. Cluster 3 comprised 31 patients categorised by higher levels of CRP and ferritin, they were characterised by fever and joint involvement. Cluster 4 contained 75 patients derived by higher values of age and systemic score. Myalgia, sore throat, liver involvement and life-threatening complications, leading to a high mortality rate, were observed in these patients.

CONCLUSIONS

Four patient clusters in Still's disease may be recognised by a multidimensional characterisation ('Juvenile/Transitional', 'Uncomplicated', 'Hyperferritinemic' and 'Catastrophic'). Of interest, cluster 4 was burdened by an increased rate of life-threatening complications and mortality, suggesting a more severe patient group.

The clinical and experimental treatment of Juvenile Idiopathic Arthritis

Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatic disease in children and comprises of multiple subtypes. The most relevant disease subtypes, grouped upon current insight in disease mechanisms, are nonsystemic (oligo- and polyarticular) JIA and systemic JIA (sJIA). In this review, we summarize some of the main proposed mechanisms of disease in both nonsystemic and sJIA and discuss how current therapeutic modalities target some of the pathogenic immune pathways. Chronic inflammation in nonsystemic JIA is the result of a complex interplay between effector and regulatory immune cell subsets, with adaptive immune cells, specifically T-cell subsets and antigen-presenting cells, in a central role. There is, however, also innate immune cell contribution. SJIA is nowadays recognized as an acquired chronic inflammatory disorder with striking autoinflammatory features in the first phase of the disease. Some sJIA patients develop a refractory disease course, with indications for involvement of adaptive immune pathways as well. Currently, therapeutic strategies are directed at suppressing effector mechanisms in both non-systemic and sJIA. These strategies are often not yet optimally tuned nor timed to the known active mechanisms of disease in individual patients in both non-systemic and sJIA. We discuss current treatment strategies in JIA, specifically the 'Step-up' and 'Treat to Target approach' and explore how increased insight into the biology of disease may translate into future more targeted strategies for this chronic inflammatory disease at relevant time points: preclinical disease, active disease, and clinically inactive disease.