Pulmonary hypertension and other potentially fatal pulmonary complications in systemic juvenile idiopathic arthritis

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.

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.

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.

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.

Part 5: Allogeneic HSCT in refractory SJIA with lung disease; recent cases from centers in North America & Europe

It has been increasingly recognized that there is a subset of patients with refractory systemic JIA, who have failed all available medications and may benefit from HSCT. The increasing experience with HSCT in SJIA, suggests that despite the complicated post-HSCT course, short-term, the transplanted patients either achieved SJIA remission or reduced burden of disease. Longer follow-up, however, is needed to better define the long-term outcomes. The discussion at the NextGen 2022 conference was focused on the optimal timing for the procedure, the need for a good control of inflammatory SJIA activity prior to HSCT, and the role of the reduced intensity conditioning regimens as there was a remote concern that such regimens might increase the risk of SJIA relapse after the transplantation. There was unanimous agreement about the importance of long-term registries to address these questions.

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.

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.

Diagnosis and Management of the Systemic Juvenile Idiopathic Arthritis Patient with Emerging Lung Disease

Chronic lung disease in children with systemic juvenile idiopathic arthritis (SJIA-LD) is an emerging and potentially life-threatening disease complication. Despite recent descriptions of its clinical spectrum, preliminary immunologic characterization, and proposed hypotheses regaarding etiology, optimal approaches to diagnosis and management remain unclear. Here, we review the current clinical understanding of SJIA-LD, including the potential role of biologic therapy in disease pathogenesis, as well as the possibility of drug reactions with eosinophilia and systemic symptoms (DRESS). We discuss approaches to evaluation of children with suspected SJIA-LD, including a proposed algorithm to risk-stratify all SJIA patients for screening to detect LD early. We review potential pharmacologic and non-pharmacologic treatment approaches that have been reported for SJIA-LD or utilized in interstitial lung diseases associated with other rheumatic diseases. This includes lymphocyte-targeting therapies, JAK inhibitors, and emerging therapies against IL-18 and IFNγ. Finally, we consider urgent unmet needs in this area including in basic discovery of disease mechanisms and clinical research to improve disease detection and patient outcomes.

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.

Seven Additional Patients with SOX17 Related Pulmonary Arterial Hypertension and Review of the Literature

Pulmonary arterial hypertension (PAH) is an infrequent disorder characterized by high blood pressure in the pulmonary arteries. It may lead to premature death or the requirement for lung and/or heart transplantation. Genetics plays an important and increasing role in the diagnosis of PAH. Here, we report seven additional patients with variants in SOX17 and a review of sixty previously described patients in the literature. Patients described in this study suffered with additional conditions including large septal defects, as described by other groups. Collectively, sixty-seven PAH patients have been reported so far with variants in SOX17, including missense and loss-of-function (LoF) variants. The majority of the loss-of-function variants found in SOX17 were detected in the last exon of the gene. Meanwhile, most missense variants were located within exon one, suggesting a probable tolerated change at the amino terminal part of the protein. In addition, we reported two idiopathic PAH patients presenting with the same variant previously detected in five patients by other studies, suggesting a possible hot spot. Research conducted on PAH associated with congenital heart disease (CHD) indicated that variants in SOX17 might be particularly prevalent in this subgroup, as two out of our seven additional patients presented with CHD. Further research is still necessary to clarify the precise association between the biological pathway of SOX17 and the development of PAH.

Incidence and Risk Factors for Eosinophilia and Lung Disease in Biologic-Exposed Children With Systemic Juvenile Idiopathic Arthritis

OBJECTIVE

Although interleukin-1 (IL-1)/IL-6 inhibitors are effective therapies for systemic juvenile idiopathic arthritis (JIA), some patients develop eosinophilia and lung disease during treatment. This study was undertaken to retrospectively evaluate incidence and risk factors for eosinophilia and describe lung disease outcomes in IL-1/IL-6 inhibitor-exposed patients with systemic JIA.

METHODS

Among JIA patients at our institution exposed to interleukin-1 (IL-1)/IL-6 inhibitors (1995-2022), we compared incidence rate of eosinophilia in systemic JIA compared to other JIA, stratified by medication class (IL-1/IL-6 inhibitors, other cytokine inhibitors, methotrexate). We used Cox models to identify predictors of eosinophilia during IL-1/IL-6 inhibitor use and summarized treatment changes and outcomes after eosinophilia, including lung disease. HLA typing was performed on a clinical or research basis.

RESULTS

There were 264 new medication exposures in 75 patients with systemic JIA and 41 patients with other JIA. A total of 49% of patients with systemic JIA with HLA typing (n = 45) were positive for HLA-DRB1*15 alleles. Eosinophilia was common during IL-1/IL-6 inhibitor use and did not differ by systemic JIA compared to other JIA (0.08 and 0.07 per person-year, respectively; P = 0.30). Among systemic JIA patients, pretreatment macrophage activation syndrome (MAS) was associated with a higher rate of subsequent eosinophilia on biologic therapy (unadjusted hazard ratio 3.2 [95% confidence interval 1.2-8.3]). A total of 4 of 5 patients who switched therapy within 10 weeks of eosinophilia experienced disease flare compared to none of the patients who continued the original therapy. A total of 8 of 25 patients with pulmonary evaluations had lung disease, and all had severe manifestations of systemic JIA (MAS, intensive care unit stay). One death was attributed to systemic JIA-lung disease.

CONCLUSION

Eosinophilia is common in JIA patients using IL-1/IL-6 inhibitors. Severe disease may be associated with eosinophilia and lung disease in systemic JIA.

HLA-DRB1*15 and Eosinophilia Are Common Among Patients With Systemic Juvenile Idiopathic Arthritis

OBJECTIVE

Concern exists that medications used to treat patients with systemic juvenile idiopathic arthritis (JIA), particularly interleukin (IL)-1 and IL-6 blocking agents, might be causing adverse drug reactions and lung disease (systemic JIA-LD). Carriage of HLA-DRB1*15 has been reported as a risk factor for adverse drug reactions among patients with systemic JIA. We performed a retrospective chart review to evaluate these factors at our center.

METHODS

We reviewed the records of 86 subjects with systemic JIA followed for at least 6 months between 1996 and 2022. HLA typing was performed in 23 of the subjects. We compared characteristics of patients with or without eosinophilia. Among patients with HLA typing, we compared clinical characteristics of subjects with or without DRB1*15 and with or without systemic JIA-LD.

RESULTS

Among the 23 patients with HLA typing, 74% carried DRB1*15, and 63% of patients without systemic JIA-LD carried DRB1*15. Seven subjects had systemic JIA-LD, all of whom carried DRB1*15. Patients with systemic JIA-LD were younger at the time of diagnosis and more likely to have had macrophage activation syndrome. Exposure to IL-1 and IL-6 blockers was common, occurring in 95% of patients. Eosinophilia occurred in 39% of patients with systemic JIA, often before IL-1 or IL-6 blockade. Eosinophilia was associated with adverse drug reactions and macrophage activation syndrome. There was 1 death, unrelated to active systemic JIA disease.

CONCLUSION

Carriage of DRB1*15 was more common in this cohort of patients with systemic JIA than in the general population. Eosinophilia and systemic JIA-LD were more common among patients with severe systemic JIA complicated by macrophage activation syndrome.

Development of a Screening Algorithm for Lung Disease in Systemic Juvenile Idiopathic Arthritis

OBJECTIVE

Lung disease (LD) is an increasingly recognized complication of systemic juvenile idiopathic arthritis (sJIA). As there are no currently available guidelines for pulmonary screening in sJIA, we sought to develop such an algorithm at our institution.

METHODS

A multidisciplinary workgroup was convened, including members representing rheumatology, pulmonary, stem cell transplantation, and patient families. The workgroup leaders drafted an initial algorithm based on published literature and experience at our center. A modified Delphi approach was used to achieve agreement through three rounds of anonymous, asynchronous voting and a consensus meeting. Statements approved by the workgroup were rated as appropriate with moderate or high levels of consensus. These statements were organized into the final approved screening algorithm for LD in sJIA.

RESULTS

The workgroup ultimately rated 20 statements as appropriate with a moderate or high level of consensus. The approved algorithm recommends pulmonary screening for newly diagnosed patients with sJIA with clinical features that the workgroup agreed may confer increased risk for LD. These "red flag features" include baseline characteristics (young age of sJIA onset, human leukocyte antigen type, trisomy 21), high disease activity (macrophage activation syndrome [MAS], sJIA-related ICU admission, elevated MAS biomarkers), respiratory symptoms or abnormal pulmonary examination findings, and features of drug hypersensitivity-like reactions (eosinophilia, atypical rash, anaphylaxis). The workgroup achieved consensus on the recommended pulmonary work-up and monitoring guidelines.

CONCLUSION

We developed a pulmonary screening algorithm for sJIA-LD through a multidisciplinary consensus-building process, which will be revised as our understanding of sJIA-LD continues to evolve.

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

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

New developments related to lung complications in pediatric rheumatic disease

PURPOSE OF REVIEW

While substantial progress has been made understanding lung disease in adult patients with rheumatic disease, pediatric lung disease has not been well addressed. Several recent studies provide new insights into diagnosis, management and treatment of lung disease in children with rheumatic disease.

RECENT FINDINGS

Building on previous research, newly diagnosed patients may have abnormalities in pulmonary function tests and chest computed tomography imaging even when asymptomatic. New guidelines for screening for rheumatic-associated lung disease provide important recommendations for clinicians. New theories have been proposed about immunologic shifts leading to the development of lung disease in children with systemic juvenile idiopathic arthritis. Additionally, there are new antifibrotic agents that are being explored as treatments in pediatric patients with fibrotic lung diseases.

SUMMARY

Patients appear to have frequent lung function abnormalities while being clinically asymptomatic, emphasizing importance for rheumatologists to refer for pulmonary function tests and imaging at diagnosis. New advances are helping define optimal approaches to treatment of lung disease, including use of biologic agents and antifibrotic medicines for pediatric patients with rheumatologic diseases.

Lung Ultrasound in Children With Systemic Juvenile Idiopathic Arthritis-Associated Interstitial Lung Disease

OBJECTIVE

Systemic juvenile idiopathic arthritis (JIA) associated with lung disease (JIA-LD) is a potentially life threating complication in children with systemic JIA. Although high-resolution computed tomography (HRCT) is considered the gold standard imaging modality for evaluating interstitial lung disease (ILD), lung ultrasound (US) has shown utility for ILD screening in adults with connective tissue diseases at lower cost and without using ionizing radiation. The goals of this pilot study were to describe lung US features in children with known systemic JIA-LD and to assess the feasibility of lung US in this population.

METHODS

Children age <18 years with systemic JIA-LD and healthy controls were enrolled. Lung US acquisition was performed at 14 lung positions. Demographic, clinical, and HRCT data were collected and reviewed. Feasibility was assessed through patient surveys. Lung US findings were qualitatively and semiquantitatively assessed and compared to HRCT findings.

RESULTS

Lung US was performed in 9 children with systemic JIA-LD and 6 healthy controls and took 12 minutes on average to perform. Lung US findings in systemic JIA-LD included focal to diffuse pleural irregularity, granularity, and thickening, with associated scattered or coalesced B-lines, and subpleural consolidations. Lung US findings appeared to correspond to HRCT findings.

CONCLUSION

Lung US in systemic JIA-LD reveals highly conspicuous abnormalities in the pleura and subpleura that appear to correlate with peripheral lung findings on HRCT. Lung US is a feasible imaging tool in children even from an early age. This study suggests a potential role of lung US in systemic JIA-LD screening, diagnosis, and/or prognostication.

Rescue of Pap-Mas in Systemic JIA Using Janus Kinase Inhibitors, Case Report and Systematic Review

INTRODUCTION

Biological disease-modifying anti-rheumatic drugs (bDMARDs) targeting interleukin (IL)-6 and IL-1β represent a steroid-sparing first-line therapy used in systemic-onset juvenile idiopathic arthritis (sJIA). Recently, the occurrence of pulmonary alveolar proteinosis (PAP) in sJIA patients was reported with early-onset and exposure to bDMARDs as potential risk factors. We report on a new case with longitudinal immunomonitoring successfully treated by Janus Kinase inhibitors (JAKi) and review past clinical descriptions of this new entity.

METHODS

We report one case of pulmonary alveolar proteinosis and macrophage activation syndrome (PAP-MAS) with longitudinal immunomonitoring. We then conducted a review of the literature of seven publications reporting 107 cases of PAP-MAS sJIA, and included the main characteristics and evolution under treatment.

RESULTS

Of the seven articles analyzed, the incidence of PAP-MAS among sJIA patients varied from 1.28% to 12.9%. We report here a single case among a cohort of 537 sJIA patients followed in the pediatric department of the Hospices Civils de Lyon over the last 15 years. This child presented with all clinical and immunological characteristics of PAP-MAS. After several lines of treatment, he benefited from JAKi and improved with respect to both systemic symptoms and lung disease. In the literature, strategies with monoclonal antibodies targeting either INF-γ or IL-1β/IL-18 have been tested with variable results. Orally taken JAKi presents the advantage of targeting multiple cytokines and avoiding parenteral injections of monoclonal antibodies that may contribute to the pathogenesis.

CONCLUSIONS

JAKi represent a promising option in the treatment of lung disease associated with sJIA.

Mouse models of systemic juvenile idiopathic arthritis and macrophage activation syndrome

Macrophage activation syndrome (MAS) is a life-threatening complication of pediatric rheumatic diseases, occurring most commonly in children with systemic juvenile idiopathic arthritis (SJIA). Despite several classes of currently available treatment options for SJIA, including biologic agents targeting IL-1 or IL-6, there remain severe cases suffering from refractory disease and recurrent MAS. The phenotype of MAS is similar to hemophagocytic lymphohistiocytosis (HLH), but the underlying pathophysiology of MAS complicating SJIA or other disorders has not been fully clarified. These facts make it challenging to develop and utilize animal models to study MAS. To date, there is no "perfect" model replicating MAS, but several models do demonstrate aspects of SJIA and/or MAS. In this review, we examine the proposed animal models of SJIA and MAS, focusing on how they reflect these disorders, what we have learned from the models, and potential future research questions. As we better understand the key features of each, animal models can be powerful tools to further define the pathophysiology of SJIA and MAS, and develop new treatment targets and strategies.

Clinical Presentation and Treatment of Juvenile Idiopathic Arthritis Combined with Lung Disease: A Narrative Review

Juvenile idiopathic Arthritis (JIA) is a common rheumatic disorder in children that can cause multiple systems to be affected simultaneously, leading to severe clinical symptoms and a high mortality rate in those with pulmonary involvement. Pleurisy is the most common manifestation of pulmonary involvement. At the same time, other conditions, such as pneumonia, interstitial lung disease, occlusive bronchiectasis, and alveolar protein deposition, have been increasingly reported in recent years. This review aims to provide an overview of the clinical manifestations of JIA lung damage and the current treatment options to assist in identifying and treating JIA lung involvement.

Fatal Pulmonary Veno-Occlusive Disease and Systemic Juvenile Idiopathic Arthritis: Case Report and Literature Review

Systemic juvenile idiopathic arthritis (sJIA) is a chronic childhood inflammatory disease. SJIA accounts for approximately 5-15 per cent of all cases of JIA and has a high morbidity and mortality rate. In this disease, pulmonary complications (PC) other than pleuritis are much less frequent and not easily recognised by clinicians. Pulmonary hypertension, the most severe PC, is associated with uncontrolled disease and use of biologic therapies. We present a case of a school-age female with sJIA who died of acute cardiopulmonary instability secondary to pulmonary venous-occlusive disease demonstrated by necropsy. We describe her clinical evolution. We also undertook a narrative review of the literature about PC in sJIA to discuss the current state of the art regarding this complication. High disease activity and the use of multiple therapies include disease-modifying anti-rheumatic drugs should be a red flag for clinicians when discounting PC and pulmonary hypertension. The combination of chest X-ray, electrocardiogram and echocardiogram appear to be the best tests to achieve an early diagnosis.

Therapeutic plasma exchange in refractory macrophage activation syndrome complicating systemic juvenile idiopathic arthritis: a case-based review

Juvenile idiopathic arthritis (JIA) is a heterogeneous group of arthritis of autoimmune aetiology. Systemic-onset juvenile idiopathic arthritis (soJIA) presents with fever, transient erythematous rash, hepatomegaly, splenomegaly, lymphadenopathy, and serositis. SoJIA presents multiple complications, and the most severe is the macrophage activation syndrome (MAS); the timely treatment of MAS must be established early and aggressively to avoid a fatal outcome. Therapeutic plasma exchange has anecdotally been used in refractory cases. A 66-month-old male with a 1-year illness characterized by evening-predominant, intermittent fever, adenomegalies, urticarial-like rash, arthralgia, and arthritis. Biochemical analysis revealed anaemia, leukocytosis, neutrophilia, hypertriglyceridemia, hyperferritinemia, and hypofibrinogenemia; bone marrow aspirate showed hemophagocytosis. He was diagnosed with SoJIA complicated with MAS. He received multiple treatments with IV human gammaglobulin, cyclosporine, dexamethasone, and tocilizumab without improvement. Plasma replacement treatment was performed. Afterwards, he presented significant improvement. After 3-year-follow-up, he remains in good general condition. We present a refractory case of soJIA complicated with MAS successfully treated with plasma exchange.

Improvement of Refractory Systemic Juvenile Idiopathic Arthritis-Associated Lung Disease with Single-Agent Blockade of IL-1β and IL-18

Systemic juvenile idiopathic arthritis associated with interstitial lung disease (SJIA-LD) represents a highly morbid subset of SJIA for which effective therapies are lacking. We report the case of a patient with refractory SJIA-LD who underwent treatment with MAS-825, an investigational bispecific monoclonal antibody targeting IL-1β and IL-18. MAS-825 treatment was associated with a marked reduction in total IL-18 and free IL-18 in both serum and bronchoalveolar lavage fluid (BAL). Baseline oxygen saturation, exercise tolerance, and quality of life metrics improved after treatment with MAS-825, while pulmonary function testing remained stable. Following treatment, the BAL showed no evidence of pulmonary alveolar proteinosis and inflammatory infiltrates were markedly reduced, reflected by decreased numbers of CD4 T-cells, CD8 T-cells, and macrophages. The patient was able to wean entirely off systemic corticosteroids and other biologics after 10 months of treatment with MAS-825 and experienced no side effects of the drug. This case demonstrates improvement in pulmonary symptoms, lung inflammation, and burden of immunomodulatory therapy after treatment with MAS-825 and suggests that simultaneous targeting of both IL-1β and IL-18 may be a safe and effective treatment strategy in SJIA-LD.

Case report: Emapalumab for active disease control prior to hematopoietic stem cell transplantation in refractory systemic juvenile idiopathic arthritis complicated by macrophage activation syndrome

Introduction

Macrophage activation syndrome (MAS), a secondary form of hemophagocytic lymphohistiocytosis, is a serious life-threatening complication associated with systemic juvenile idiopathic arthritis (sJIA). MAS is characterized by fever, hepatosplenomegaly, liver dysfunction, cytopenias, coagulation abnormalities, and hyperferritinemia and may progress to multiple organ failure and death. Overproduction of interferon-gamma is a major driver of hyperinflammation in murine models of MAS and primary hemophagocytic lymphohistiocytosis. A subset of patients with sJIA may develop progressive interstitial lung disease, which is often difficult to manage. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) can potentially be a curative immunomodulatory strategy for patients with sJIA refractory to conventional therapy and/or complicated by MAS. The use of emapalumab (anti-interferon gamma antibody) for the active control of MAS in refractory cases of sJIA and associated lung disease has not been reported. Herein we report a patient with refractory sJIA complicated by recurrent MAS and lung disease that was managed with emapalumab and ultimately followed by an allo-HSCT, which resulted in permanent correction of the underlying immune dysregulation and improvement of lung disease.

Case Report

We present a 4-year-old girl with sJIA complicated by recurrent MAS and progressive interstitial lung disease. She developed a progressively worsening disease that was refractory to glucocorticoids, anakinra, methotrexate, tocilizumab, and canakinumab. She had a chronic elevation of serum inflammatory markers, notably soluble interleukin-18, and CXC chemokine ligand 9 (CXCL9). Emapalumab, initiated at 6 mg/kg (1 dose) and continued at 3 mg/kg twice weekly for a total of 4 weeks, resulted in MAS remission along with normalization of inflammatory markers. The patient received a matched sibling donor allo-HSCT after a reduced-intensity conditioning regimen with fludarabine/melphalan/thiotepa and alemtuzumab, along with tacrolimus and mycophenolate mofetil for graft-vs.-host disease prophylaxis. At 20 months following her transplant, she has maintained a full donor engraftment with complete donor-derived immune reconstitution. She had complete resolution of sJIA symptoms including marked improvement in her lung disease along with normalization of serum interleukin-18 and CXCL9 levels.

Conclusion

The use of emapalumab followed by allo-HSCT could help achieve a complete response in refractory cases of sJIA complicated by MAS who have failed standard treatment.

First-line options for systemic juvenile idiopathic arthritis treatment: an observational study of Childhood Arthritis and Rheumatology Research Alliance Consensus Treatment Plans

BACKGROUND

The Childhood Arthritis and Rheumatology Research Alliance (CARRA) developed consensus treatment plans (CTPs) to compare treatment initiation strategies for systemic juvenile idiopathic arthritis (sJIA). First-line options for sJIA treatment (FROST) was a prospective observational study to assess CTP outcomes using the CARRA Registry.

METHODS

Patients with new-onset sJIA were enrolled if they received initial treatment according to the biologic CTPs (IL-1 or IL-6 inhibitor) or non-biologic CTPs (glucocorticoid (GC) monotherapy or methotrexate). CTPs could be used with or without systemic GC. Primary outcome was achievement of clinical inactive disease (CID) at 9 months without current use of GC. Due to the small numbers of patients in the non-biologic CTPs, no statistical comparisons were made between the CTPs.

RESULTS

Seventy-three patients were enrolled: 63 (86%) in the biologic CTPs and 10 (14%) in the non-biologic CTPs. CTP choice appeared to be strongly influenced by physician preference. During the first month of follow-up, oral GC use was observed in 54% of biologic CTP patients and 90% of non-biologic CTPs patients. Five (50%) non-biologic CTP patients subsequently received biologics within 4 months of follow-up. Overall, 30/53 (57%) of patients achieved CID at 9 months without current GC use.

CONCLUSION

Nearly all patients received treatment with biologics during the study period, and 46% of biologic CTP patients did not receive oral GC within the first month of treatment. The majority of patients had favorable short-term clinical outcomes. Increased use of biologics and decreased use of GC may lead to improved outcomes in sJIA.

Lung Involvement in Systemic Juvenile Idiopathic Arthritis: A Narrative Review

Systemic juvenile idiopathic arthritis associated with lung disorders (sJIA-LD) is a subtype of sJIA characterized by the presence of chronic life-threatening pulmonary disorders, such as pulmonary hypertension, interstitial lung disease, pulmonary alveolar proteinosis and/or endogenous lipoid pneumonia, which were exceptionally rare before 2013. Clinically, these children show a striking dissociation between the relatively mild clinical manifestations (tachypnoea, clubbing and chronic cough) and the severity of the pulmonary inflammatory process. Our review describes sJIA-LD as having a reported prevalence of approximately 6.8%, with a mortality rate of between 37% and 68%. It is often associated with an early onset (<2 years of age), macrophage activation syndrome and high interleukin (IL)-18 circulating levels. Other risk factors may be trisomy 21 and a predisposition to adverse reactions to biological drugs. The most popular hypothesis is that the increase in the number of sJIA-LD cases can be attributed to the increased use of IL-1 and IL-6 blockers. Two possible explanations have been proposed, named the “DRESS hypothesis” and the “cytokine plasticity hypothesis”. Lung ultrasounds and the intercellular-adhesion-molecule-5 assay seem to be promising tools for the early diagnosis of sJIA-LD, although high resolution computed tomography remains the gold standard. In this review, we also summarize the treatment options for sJIA-LD, focusing on JAK inhibitors.

Rare, rarer, lung involvement in adult-onset Still's disease: A mini-review

Adult-onset Still's disease (AOSD) is a polygenic systemic autoinflammatory disease which is associated with increased morbidity and mortality. Pulmonary involvement is a rare, but serious complication of AOSD. As in AOSD, IL-1b, IL-18, and IL-6 dominate the molecular pathogenesis, which mediate a type 1 and type 3 inflammatory signature of the adaptive immune system. This is evidenced by the success of IL-1- and IL-6 inhibition in the management of AOSD. However, anaphylactic reactions to treatment with IL-1- or IL-6-inhibitors is currently being discussed as a potential trigger for lung involvement inf AOSD, while genetic risk factors have also been identified. Clinically, pulmonary involvement in AOSD can manifest in many different forms. Parenchymal inflammation with peripheral consolidations is the most frequent form while PAH is less common, but often very difficult to manage. This mini-review provides an overview of the pathophysiology as well as the clinical presentation and the diagnostic features of pulmonary involvement in AOSD.

AOSD Endotypes based on immune cell profiles: patient stratification with hierarchical clustering analysis

OBJECTIVES

This study aimed to analyse the immune cell profiles of adult-onset Still's disease (AOSD) and to stratify disease-associated endotypes.

METHODS

We included 95 cases of treatment-naïve patients with AOSD and 66 cases of healthy controls (HCs). Patients with AOSD were classified via an unbiased hierarchical cluster analysis based on circulating immune cells. Their clinical and laboratory characteristics, treatment management, systemic scores, and outcomes were then analysed.

RESULTS

The proportions of neutrophils and CD8+ T cells were significantly higher while monocytes and natural killer and CD4+ T cells were decreased in patients with AOSD (all p < 0.005). Unbiased hierarchical cluster analysis classified 95 AOSD into three endotype-based groups: group 1 had the highest percentage of neutrophils (Neu-dominant group), group 2 had the highest percentage of monocytes (Mono-dominant group), and group 3 had the highest percentage of CD8+ T cells (CD8-dominant group). Patients in group 3 had the highest systemic score at diagnosis and were more likely to have pulmonary infiltrates, pericarditis, splenomegaly, and poorer treatment responses. A correlation study revealed that the CD4 to CD8 ratio was negatively correlated with the systemic score and positively correlated with treatment response in patients with AOSD (p = 0.001 and p = 0.0091). During the 24.6 ± 15.2 months of follow-up, the highest total number of disease flares occurred in group 3 (p < 0.0001).

CONCLUSION

Hierarchical cluster analysis of peripheral immune cells classified AOSD into three disease-related endotypes. Group 3 showed higher systemic score and poorer treatment responses.

The Conundrum of Lung Disease and Drug Hypersensitivity-like Reactions in Systemic Juvenile Idiopathic Arthritis

An unusual form of lung disease has begun to affect some children with systemic juvenile idiopathic arthritis (JIA), coincident with increasing utilization of interleukin-1 (IL-1) and IL-6 antagonists. Many children with systemic JIA-associated lung disease (SJIA-LD) have a history of clinical and laboratory features resembling drug reaction with eosinophilia and systemic symptoms (DRESS), a presentation now convincingly associated with HLA-DRB1*15. Treatment of DRESS typically requires drug discontinuation, a daunting prospect for clinicians and families who rely upon these agents. Here we review SJIA-LD and its associated DRESS-like phenotype. We suggest an alternative explanation, the cytokine plasticity hypothesis, proposing that IL-1 and IL-6 blockers modulate the milieu in which T cells develop, leading to a pathologic immune response triggered through exposure to common microbes, or to other exogenous or endogenous antigens, rather than to the drugs themselves. This hypothesis differs from DRESS in mechanism but also in clinical implications, predicting that control of pathogenic T cells could permit continued use of IL-1 and IL-6 antagonists in some individuals. The spectrum posed by these two hypotheses provides a conceptual framework that will guide investigation into the pathogenesis of SJIA-LD and may open up new therapeutic avenues for patients with systemic JIA.

Anakinra in Patients With Systemic Juvenile Idiopathic Arthritis: Long-term Safety From the Pharmachild Registry

OBJECTIVE

To evaluate the long-term safety profile of anakinra in patients with systemic juvenile idiopathic arthritis (sJIA).

METHODS

Data from patients with sJIA enrolled in the Pharmachild registry (ClinicalTrials.gov: NCT03932344) prior to September 30, 2018, and treated with anakinra were analyzed. The study endpoints were the occurrence of non-serious adverse events (SAEs) of at least moderate severity and SAEs, including macrophage activation syndrome (MAS), and the duration of anakinra treatment with reasons for discontinuation. All endpoints were analyzed overall by 6-month time windows, and in different treatment sets represented by those patients treated continuously with anakinra for at least 12, 18, and 24 months (set-12, -18, and -24, respectively).

RESULTS

Three hundred six patients were enrolled. Of these patients, 46%, 34%, and 28% had been treated for at least 12, 18, and 24 months, respectively. Two hundred and one AEs, mostly represented by infections, were reported for 509.3 patient-years (PY) with an overall incidence rate (IR) of 39.5 per 100 PY. Among 56 SAEs (IR 11.0/100 PY), 23.2% were infections and 19.6% MAS episodes. The IR of AEs was higher during the first 6 months of anakinra treatment, followed by decreasing IRs in the long-term treatment sets. Treatment discontinuation occurred in 76% of patients, most frequently in the first 6 months, because of inefficacy (43%), remission (31%), or AEs/intolerance (15%). No deaths or malignancies occurred during anakinra treatment.

CONCLUSION

The results of the present study confirm the long-term safety profile of anakinra in patients with sJIA and demonstrate an overall decreasing incidence of AEs over time. [ClinicalTrials.gov: NCT01399281 and NCT03932344].

Severe delayed hypersensitivity reactions to IL-1 and IL-6 inhibitors link to common HLA-DRB1*15 alleles

OBJECTIVES

Drug reaction with eosinophilia and systemic symptoms (DRESS) is a severe, delayed hypersensitivity reaction (DHR). We observed DRESS to inhibitors of interleukin 1 (IL-1) or IL-6 in a small group of patients with Still's disease with atypical lung disease. We sought to characterise features of patients with Still's disease with DRESS compared with drug-tolerant Still's controls. We analysed human leucocyte antigen (HLA) alleles for association to inhibitor-related DHR, including in a small Kawasaki disease (KD) cohort.

METHODS

In a case/control study, we collected a multicentre series of patients with Still's disease with features of inhibitor-related DRESS (n=66) and drug-tolerant Still's controls (n=65). We retrospectively analysed clinical data from all Still's subjects and typed 94/131 for HLA. European Still's-DRESS cases were ancestry matched to International Childhood Arthritis Genetics Consortium paediatric Still's cases (n=550) and compared for HLA allele frequencies. HLA association also was analysed using Still's-DRESS cases (n=64) compared with drug-tolerant Still's controls (n=30). KD subjects (n=19) were similarly studied.

RESULTS

Still's-DRESS features included eosinophilia (89%), AST-ALT elevation (75%) and non-evanescent rash (95%; 88% involving face). Macrophage activation syndrome during treatment was frequent in Still's-DRESS (64%) versus drug-tolerant Still's (3%; p=1.2×10-14). We found striking enrichment for HLA-DRB1*15 haplotypes in Still's-DRESS cases versus INCHARGE Still's controls (p=7.5×10-13) and versus self-identified, ancestry-matched Still's controls (p=6.3×10-10). In the KD cohort, DRB1*15:01 was present only in those with suspected anakinra reactions.

CONCLUSIONS

DRESS-type reactions occur among patients treated with IL-1/IL-6 inhibitors and strongly associate with common HLA-DRB1*15 haplotypes. Consideration of preprescription HLA typing and vigilance for serious reactions to these drugs are warranted.

Serum proteome analysis of systemic JIA and related lung disease identifies distinct inflammatory programs and biomarkers

OBJECTIVES

Recent observations in systemic Juvenile Idiopathic Arthritis (sJIA) suggest an increasing incidence of high-mortality interstitial lung disease (sJIA-LD) often characterized by a variant of pulmonary alveolar proteinosis (PAP). Co-occurrence of macrophage activation syndrome (MAS) and PAP in sJIA suggested a shared pathology, but sJIA-LD patients also commonly experience features of drug reaction such as atypical rashes and eosinophilia. We sought to investigate immunopathology and identify biomarkers in sJIA, MAS, and sJIA-LD.

METHODS

We used SOMAscan to measure >1300 analytes in sera from healthy controls and patients with sJIA, MAS, sJIA-LD and other related diseases. We verified selected findings by ELISA and lung immunostaining. Because the proteome of a sample may reflect multiple states (sJIA, MAS, sJIA-LD), we used regression modeling to identify subsets of altered proteins associated with each state. We tested key findings in a validation cohort.

RESULTS

Proteome alterations in active sJIA and MAS overlapped substantially, including known sJIA biomarkers like SAA and S100A9, and novel elevations of heat shock proteins and glycolytic enzymes. IL-18 was elevated in all sJIA groups, particularly MAS and sJIA-LD. We also identified an MAS-independent sJIA-LD signature notable for elevated ICAM5, MMP7, and allergic/eosinophilic chemokines, which have been previously associated with lung damage. Immunohistochemistry localized ICAM5 and MMP7 in sJIA-LD lung. ICAM5's ability to distinguish sJIA-LD from sJIA/MAS was independently validated.

CONCLUSION

Serum proteins support an sJIA-to-MAS continuum, help distinguish sJIA, sJIA/MAS, and sJIA-LD and suggest etiologic hypotheses. Select biomarkers, such as ICAM5, could aid in early detection and management of sJIA-LD.

The Role of Anti-IL-1 Medications in Autoinflammatory Disease

The interleukin (IL) -1 family of cytokines are involved in different aspects of inflammation with IL-1 beta being the best known and most powerful proinflammatory cytokine. Dysregulation of IL-1 beta and other family members results in autoinflammatory conditions such as systemic juvenile idiopathic arthritis and familial Mediterranean fever. The growing understanding and knowledge of the pathophysiology of many autoinflammatory diseases have led to the development and use of IL-1 blocking medications for many chronic and disabling diseases. In this article, we present the anti-IL-1 agents and their major indications in pediatric rheumatology. [Pediatr Ann. 2022;51(2):e72-e76.].

Pathogenesis and Treatment of Refractory Disease Courses in Systemic Juvenile Idiopathic Arthritis: Refractory Arthritis, Recurrent Macrophage Activation Syndrome and Chronic Lung Disease

Systemic juvenile idiopathic arthritis is a distinct and heterogeneous disease presently classified under the umbrella of juvenile idiopathic arthritis, with some patients following a monophasic remitting course, whereas others have persistent disease with chronic organ- and life-threatening complications. Although biologic therapies have revolutionized treatment, recent follow-up studies report significant numbers of children with persistently active disease on long term follow-up. This review focuses on refractory disease courses, specifically refractory arthritis, systemic juvenile idiopathic arthritis with recurrent, or longstanding signs of macrophage activation syndrome, and systemic juvenile idiopathic arthritis associated with suspected, probable, or definite lung disease.

Consensus-Based Guidelines for the Recognition, Diagnosis, and Management of Hemophagocytic Lymphohistiocytosis in Critically Ill Children and Adults

OBJECTIVE

Hemophagocytic lymphohistiocytosis is a hyperinflammatory syndrome that often requires critical care support and remains difficult to diagnose. These guidelines are meant to aid in the early recognition, diagnosis, supportive care, and treatment of patients with hemophagocytic lymphohistiocytosis in ICUs.

DATA SOURCES

The literature searches were performed with PubMed (MEDLINE).

STUDY SELECTION

Keywords and medical subject headings terms for literature search included "macrophage activation syndrome," hemophagocytic lymphohistiocytosis," and "hemophagocytic syndrome."

DATA EXTRACTION

The Histiocyte Society developed these consensus recommendations on the basis of published reports and expert opinions with level of evidence provided for each recommendation. They were endorsed by the Society of Critical Care Medicine.

DATA SYNTHESIS

Testing for hemophagocytic lymphohistiocytosis should be initiated promptly in all patients admitted to ICUs with an unexplained or disproportionate inflammatory response, especially those with rapid clinical deterioration. Meeting five or more of eight hemophagocytic lymphohistiocytosis 2004 diagnostic criteria serves as a valuable diagnostic tool for hemophagocytic lymphohistiocytosis. Early aggressive critical care interventions are often required to manage the multisystem organ failure associated with hemophagocytic lymphohistiocytosis. Thorough investigation of the underlying triggers of hemophagocytic lymphohistiocytosis, including infections, malignancies, and autoimmune/autoinflammatory diseases, is essential. Early steroid treatment is indicated for patients with familial hemophagocytic lymphohistiocytosis and is often valuable in patients with acquired hemophagocytic lymphohistiocytosis (i.e., secondary hemophagocytic lymphohistiocytosis) without previous therapy, including macrophage activation syndrome (hemophagocytic lymphohistiocytosis secondary to autoimmune/autoinflammatory disease) without persistent or relapsing disease. Steroid treatment should not be delayed, particularly if organ dysfunction is present. In patients with macrophage activation syndrome, whose disease does not sufficiently respond, interleukin-1 inhibition and/or cyclosporine A is recommended. In familial hemophagocytic lymphohistiocytosis and severe, persistent, or relapsing secondary macrophage activation syndrome, the addition of prompt individualized, age-adjusted etoposide treatment is recommended.

CONCLUSIONS

Further studies are needed to determine optimal treatment for patients with hemophagocytic lymphohistiocytosis in ICUs, including the use of novel and adjunct therapies.

Interstitial lung disease occurring shortly after tocilizumab infusion in a patient with polyarticular juvenile idiopathic arthritis: a case report

Background

Tocilizumab has been shown to be effective for treatment of juvenile idiopathic arthritis (JIA). To our knowledge, this is the first reported case of interstitial lung disease occurring shortly after tocilizumab infusion in a patient with JIA.

Case presentation

A 14-year-old female patient with polyarticular JIA developed interstitial lung disease after intravenous and subcutaneous administration of tocilizumab. Her condition improved with glucocorticoid therapy.

Conclusion

Our results suggest that increased interleukin-6 levels in the blood following tocilizumab treatment may be linked to development of interstitial lung disease.

Interfering with interferons: targeting the JAK-STAT pathway in complications of systemic juvenile idiopathic arthritis (SJIA)

Systemic JIA (SJIA) is distinguished from other forms of JIA by the prevalence of the severe, life-threatening complications macrophage activation syndrome (SJIA-MAS) and lung disease (SJIA-LD). Alternative therapeutics are urgently needed, as disease pathogenesis diverges from what is observed in SJIA, and currently available biologics are insufficient. SJIA-MAS, defined by a cytokine storm and dysregulated proliferation of T-lymphocytes, and SJIA-LD which presents with lymphocytic interstitial inflammation and pulmonary alveolar proteinosis, are both thought to be driven by IFNs, in particular the type II IFN-γ. Involvement of IFNs and a possible crosstalk of type I IFNs with existing biologics indicate a distinct role for the JAK-STAT signalling pathway in the pathogenesis of SJIA-MAS and SJIA-LD. Here, we review this role of JAK-STATs and IFNs in SJIA complications and discuss how new insights of ongoing research are shaping future therapeutic advances in the form of JAK inhibitors and antibodies targeting IFNs.

Adverse effects of biologic anti-inflammatory agents on the respiratory system: A review

The therapy of autoimmune rheumatological conditions has undergone significant changes with the introduction of biologic antiinflammatory agents including cytokine antagonists and agents that interfere with the function of T and B cells or those that inhibit intracellular enzymes such as Janus kinase (JAK). Although useful to control inflammation, these agents may be associated with druginduced lung disease, which may be difficult to differentiate from pulmonary disorders caused by the underlying autoimmune diseases. This review aims to provide a description of lung disease, both infectious and non-infectious, that may be induced by the administration of biologic anti-inflammatory agents with emphasis on inhibitors of tumour necrosis factor, interleukin-1, interleukin-6 and JAK.

IFN-γ is essential for alveolar macrophage driven pulmonary inflammation in macrophage activation syndrome

Macrophage activation syndrome (MAS) is a life-threatening cytokine storm complicating systemic juvenile idiopathic arthritis (SJIA) driven by IFNγ. SJIA and MAS are associated with an unexplained emerging lung disease (SJIA-LD), with our recent work supporting pulmonary activation of IFNγ pathways pathologically linking SJIA-LD and MAS. Our objective was to mechanistically define the novel observation of pulmonary inflammation in the TLR9 mouse model of MAS. In acute MAS, lungs exhibit mild but diffuse CD4-predominant, perivascular interstitial inflammation with elevated IFNγ, IFN-induced chemokines, and AMΦ expression of IFNγ-induced genes. Single-cell RNA-sequencing confirmed IFN-driven transcriptional changes across lung cell types with myeloid expansion and detection of MAS-specific macrophage populations. Systemic MAS resolution was associated with increased AMΦ and interstitial lymphocytic infiltration. AMΦ transcriptomic analysis confirmed IFNγ-induced proinflammatory polarization during acute MAS, which switches towards an anti-inflammatory phenotype after systemic MAS resolution. Interestingly, recurrent MAS led to increased alveolar inflammation and lung injury, and reset AMΦ polarization towards a proinflammatory state. Furthermore, in mice bearing macrophages insensitive to IFNγ, both systemic feature of MAS and pulmonary inflammation were attenuated. These findings demonstrate that experimental MAS induces IFNγ-driven pulmonary inflammation replicating key features of SJIA-LD, and provides a model system for testing novel treatments directed towards SJIA-LD.

Lung Functioning and Inflammation in a Mouse Model of Systemic Juvenile Idiopathic Arthritis

Systemic juvenile idiopathic arthritis (sJIA) is an immune disorder characterized by fever, skin rash, arthritis and splenomegaly. Recently, increasing number of sJIA patients were reported having lung disease. Here, we explored lung abnormalities in a mouse model for sJIA relying on injection of IFN-γ deficient (IFN-γ KO) mice with complete Freund's adjuvant (CFA). Monitoring of lung changes during development of sJIA using microcomputer tomography revealed a moderate enlargement of lungs, a decrease in aerated and increase in non-aerated lung density. When lung function and airway reactivity to methacholine was assessed, gender differences were seen. While male mice showed an increased tissue hysteresivity, female animals were characterized by an increased airway hyperactivity, mirroring ongoing inflammation. Histologically, lungs of sJIA-like mice showed subpleural and parenchymal cellular infiltrates and formation of small granulomas. Flow cytometric analysis identified immature and mature neutrophils, and activated macrophages as major cell infiltrates. Lung inflammation in sJIA-like mice was accompanied by augmented expression of IL-1β and IL-6, two target cytokines in the treatment of sJIA. The increased expression of granulocyte colony stimulating factor, a potent inducer of granulopoiesis, in lungs of mice was striking considering the observed neutrophilia in patients. We conclude that development of sJIA in a mouse model is associated with lung inflammation which is distinct to the lung manifestations seen in sJIA patients. Our observations however underscore the importance of monitoring lung disease during systemic inflammation and the model provides a tool to explore the underlying mechanism of lung pathology in an autoinflammatory disease context.

Pulmonary Manifestations of Rheumatic Diseases in Children

Children with rheumatic disease have rare pulmonary manifestations that may cause significant morbidity and mortality. These children are often clinically asymptomatic until disease has significantly progressed, so they should be screened for pulmonary involvement. There has been recent recognition of a high mortality-related lung disease in systemic-onset juvenile idiopathic arthritis; risk factors include onset of juvenile idiopathic arthritis less than 2 years of age, history of macrophage activation syndrome, presence of trisomy 21, and history of anaphylactic reaction to biologic therapy. Early recognition and treatment of lung disease in children with rheumatic diseases may improve outcomes.