Neutrophils From Children With Systemic Juvenile Idiopathic Arthritis Exhibit Persistent Proinflammatory Activation Despite Long-Standing Clinically Inactive Disease

Background: Systemic juvenile idiopathic arthritis (SJIA) is a chronic childhood arthropathy with features of autoinflammation. Early inflammatory SJIA is associated with expansion and activation of neutrophils with a sepsis-like phenotype, but neutrophil phenotypes present in longstanding and clinically inactive disease (CID) are unknown. The objective of this study was to examine activated neutrophil subsets, S100 alarmin release, and gene expression signatures in children with a spectrum of SJIA disease activity.Methods: Highly-purified neutrophils were isolated using a two-step procedure of density-gradient centrifugation followed by magnetic-bead based negative selection prior to flow cytometry or cell culture to quantify S100 protein release. Whole transcriptome gene expression profiles were compared in neutrophils from children with both active SJIA and CID.Results: Patients with SJIA and active systemic features demonstrated a higher proportion of CD16+CD62Llo neutrophil population compared to controls. This neutrophil subset was not seen in patients with CID or patients with active arthritis not exhibiting systemic features. Using imaging flow cytometry, CD16+CD62Llo neutrophils from patients with active SJIA and features of macrophage activation syndrome (MAS) had increased nuclear hypersegmentation compared to CD16+CD62L+ neutrophils. Serum levels of S100A8/A9 and S100A12 were strongly correlated with peripheral blood neutrophil counts. Neutrophils from active SJIA patients did not show enhanced resting S100 protein release; however, regardless of disease activity, neutrophils from SJIA patients did show enhanced S100A8/A9 release upon PMA stimulation compared to control neutrophils. Furthermore, whole transcriptome analysis of highly purified neutrophils from children with active SJIA identified 214 differentially expressed genes (DEG) compared to neutrophils from healthy controls. The most significantly upregulated gene pathway was Immune System Process, including AIM2, IL18RAP, and NLRC4. Interestingly, this gene set showed intermediate levels of expression in neutrophils from patients with long-standing CID yet persistent serum IL-18 elevation. Indeed, all patient samples regardless of disease activity demonstrated elevated inflammatory gene expression, including inflammasome components and S100A8.Conclusion: We identify features of neutrophil activation in SJIA patients with both active disease and CID, including a proinflammatory gene expression signature, reflecting persistent innate immune activation. Taken together, these studies expand understanding of neutrophil function in chronic autoinflammatory disorders such as SJIA

Efficacy and safety of emapalumab in macrophage activation syndrome

OBJECTIVES: Macrophage activation syndrome (MAS) is a severe, life-threatening complication of systemic juvenile idiopathic arthritis (sJIA) and adult-onset Still's disease (AOSD). The objective of this study was to confirm the adequacy of an emapalumab dosing regimen in relation to interferon-γ (IFNγ) activity by assessing efficacy and safety. The efficacy outcome was MAS remission by week 8, based on clinical and laboratory criteria. METHODS: We studied emapalumab, a human anti-IFNγ antibody, administered with background glucocorticoids, in a prospective single-arm trial involving patients who had MAS secondary to sJIA or AOSD and had previously failed high-dose glucocorticoids, with or without anakinra and/or ciclosporin. The study foresaw 4-week treatment that could be shortened or prolonged based on investigator's assessment of response. Patients entered a long-term (12 months) follow-up study. RESULTS: Fourteen patients received emapalumab. All patients completed the trial, entered the long-term follow-up and were alive at the end of follow-up. The investigated dosing regimen, based on an initial loading dose followed by maintenance doses, was appropriate, as shown by rapid neutralisation of IFNγ activity, demonstrated by a prompt decrease in serum C-X-C motif chemokine ligand 9 (CXCL9) levels. By week 8, MAS remission was achieved in 13 of the 14 patients at a median time of 25 days. Viral infections and positive viral tests were observed. CONCLUSIONS: Neutralisation of IFNγ with emapalumab was efficacious in inducing remission of MAS secondary to sJIA or AOSD in patients who had failed high-dose glucocorticoids. Screening for viral infections should be performed, particularly for cytomegalovirus. TRIAL REGISTRATION NUMBER: NCT02069899 and NCT03311854

Increase in pediatric recurrent fever evaluations during the first year of the COVID-19 pandemic in North America

The impact of the COVID-19 pandemic on new diagnoses of recurrent fevers and autoinflammatory diseases is largely unknown. The Childhood Arthritis and Rheumatology Research Alliance (CARRA) PFAPA/AID Working Group aimed to investigate the impact of the COVID-19 pandemic on the number of pediatric patients evaluated for recurrent fevers and autoinflammatory diseases in North America. The absolute number of new outpatient visits and the proportion of these visits attributed to recurrent fever diagnoses during the pre-pandemic period (1 March 2019–29 February 2020) and the first year of the COVID-19 pandemic (1 March 2020–28 February 2021) were examined. Data were collected from 27 sites in the United States and Canada. Our results showed an increase in the absolute number of new visits for recurrent fever evaluations in 21 of 27 sites during the COVID-19 pandemic compared to the pre-pandemic period. The increase was observed across different geographic regions in North America. Additionally, the proportion of new visits to these centers for recurrent fever in relation to all new patient evaluations was significantly higher during the first year of the pandemic, increasing from 7.8% before the pandemic to 10.9% during the pandemic year (p < 0.001). Our findings showed that the first year of the COVID-19 pandemic was associated with a higher number of evaluations by pediatric subspecialists for recurrent fevers. Further research is needed to understand the reasons behind these findings and to explore non-infectious triggers for recurrent fevers in children

American College of Rheumatology Provisional Criteria for Clinically Relevant Improvement in Children and Adolescents With Childhood-Onset Systemic Lupus Erythematosus

10.1002/acr.23834ARTHRITIS CARE & RESEARCH715579-59

Complications of complications: diagnosis and treatment of recurrent macrophage activation syndrome in a patient with well-controlled systemic juvenile idiopathic arthritis

Macrophage activation syndrome (MAS) is a subtype of haemophagocytic lymphohistiocytosis (HLH), and a well-described complication of systemic juvenile idiopathic arthritis (SJIA), triggered by disease onset or flare, infection, or some medications. Here, we report a 20-year-old man with previously well-controlled SJIA, who developed first time MAS after acute Epstein-Barr virus (EBV) infection, with MAS recurrence due to a drug reaction, ‘3-week sulfasalazine syndrome’, secondary to prophylactic trimethoprim/sulfamethoxazole. Both episodes of MAS were minimally responsive to pulse corticosteroids. Initial EBV-driven MAS was treated with multiple doses of emapalumab prior to resolution, while MAS secondary to sulfasalazine-induced 3-week syndrome required the initiation of ruxolitinib. This case exhibits two rare but life-threatening causes of MAS/secondary HLH in a single patient and the difficulties in their diagnosis and management

Systemic autoinflammation with intractable epilepsy managed with interleukin-1 blockade

Abstract Background Autoinflammatory disorders are distinguished by seemingly random episodes of systemic hyperinflammation, driven in particular by IL-1. Recent pre-clinical work has shown a key role for IL-1 in epilepsy in animal models, and therapies for autoinflammation including IL-1 blockade are proposed for refractory epilepsy. Case presentation Here, we report an adolescent female with signs of persistent systemic inflammation and epilepsy unresponsive to multiple anti-epileptic drugs (AED). She was diagnosed with generalized epilepsy with a normal brain MRI and an electroencephalogram (EEG) showing occasional generalized spike and slow wave discharges. Her diagnostic evaluation showed no signs of autoimmunity or genetic causes of epilepsy or periodic fever syndromes but persistently elevated serum inflammatory markers including S100 alarmin proteins. She experienced prompt clinical response to IL-1 blockade with first anakinra and then canakinumab, with near complete resolution of clinical seizures. Additionally, she displayed marked improvements in quality of life and social/academic functioning. Baseline gene expression studies on peripheral blood mononuclear cells (PBMC) from this patient showed significantly activated gene pathways suggesting systemic immune activation, including focal adhesion, platelet activation, and Rap1 signaling, which is an upstream regulator of IL-1β production by the NLRP3 inflammasome. It also showed activation of genes that characterize inflammasome-mediated autoinflammatory disorders and no signs of interferon activation. This gene expression signature was largely extinguished after anakinra treatment. Conclusions Together, these findings suggest that patients with epilepsy responsive to immune modulation may have distinct autoinflammatory features supporting IL-1 blockade. As such, IL-1 blockade may be highly efficacious adjunctive medication for certain refractory epilepsy syndromes

Polymicrogyria and Congenital Parvovirus B19 Infection

Fetal parvovirus B19 infection causes anemia, hydrops, and pregnancy loss but is generally not considered teratogenic. Nevertheless, disturbances of neuronal migration have been described with congenital parvovirus infection. We evaluated a term infant with congenital parvovirus disease and polymicrogyria. We compared this case with four other reports of central nervous system disease after birth to parvovirus-infected mothers. After an extensive diagnostic evaluation, this infant was found to have congenital parvovirus disease with severe anemia and nonimmune hydrops as well as extensive polymicrogyria. Although rare, this report and literature review suggest that parvovirus B19 has the potential to disrupt normal neurodevelopment. We suggest that infants with severe congenital parvovirus infection have close developmental surveillance and if symptomatic undergo neuroimaging to assess for disorders of neuromigration