Humoral and cellular immunogenicity, effectiveness and safety of COVID-19 mRNA vaccination in patients with pediatric rheumatic diseases: A prospective cohort study.

OBJECTIVES: To evaluate immunogenicity, effectiveness and safety of COVID-19 vaccination in patients with pediatric autoimmune inflammatory rheumatic disease (pedAIIRD). METHODS: A prospective cohort study was performed at the pediatric rheumatology department of the Wilhelmina Children's Hospital in Utrecht, the Netherlands. Vaccination dates, COVID-19 cases and vaccine-related adverse events (AEs) were registered for all pedAIIRD patients during regular clinic visits from March 2021 - August 2022. SARS-CoV-2 IgG antibody levels and T-cell responses were measured from serum samples after vaccination, and clinical and drug therapy data were collected from electronic medical records. Rate of COVID-19 disease was compared between vaccinated and unvaccinated patients in a time-varying Cox regression analysis. RESULTS: A total of 157 patients were included in this study and 88 % had juvenile idiopathic arthritis (JIA). One hundred thirty-seven patients were fully vaccinated, of which 47 % used biological agents at the time of vaccination, and 20 patients were unvaccinated. Geometric mean concentrations (GMCs) of post-vaccine antibody levels against SARS-CoV-2 were above the threshold for positivity in patients who did and did not use biological agents at the time of vaccination, although biological users demonstrated significantly lower antibody levels (adjusted GMC ratio: 0.38, 95 % CI: 0.21 - 0.70). T-cell responses were adequate in all but two patients (9 %). The adjusted rate of reported COVID-19 was significantly lower for fully vaccinated patients compared to non-vaccinated patients (HR: 0.53, 95 % CI: 0.29 - 0.97). JIA disease activity scores were not significantly different after vaccination, and no serious AEs were reported. CONCLUSIONS: COVID-19 mRNA vaccines were immunogenic (both cellular and humoral), effective and safe in a large cohort of pedAIIRD patients despite their use of immunosuppressive medication.

NRF2/Itaconate Axis Regulates Metabolism and Inflammatory Properties of T Cells in Children with JIA.

BACKGROUND: CD4+ T cells critically contribute to the initiation and perturbation of inflammation. When CD4+ T cells enter inflamed tissues, they adapt to hypoxia and oxidative stress conditions, and to a reduction in nutrients. We aimed to investigate how this distinct environment regulates T cell responses within the inflamed joints of patients with childhood rheumatism (JIA) by analyzing the behavior of NRF2-the key regulator of the anti-oxidative stress response-and its signaling pathways. METHODS: Flow cytometry and quantitative RT-PCR were used to perform metabolic profiling of T cells and to measure the production of inflammatory cytokines. Loss of function analyses were carried out by means of siRNA transfection experiments. NRF2 activation was induced by treatment with 4-octyl-Itaconate (4-OI). RESULTS: Flow cytometry analyses revealed a high metabolic status in CD4+ T cells taken from synovial fluid (SF) with greater mitochondrial mass, and increased glucose and fatty acid uptake. This resulted in a heightened oxidative status of SF CD4+ T cells. Despite raised ROS levels, expression of NRF2 and its target gene NQO1 were lower in CD4+ T cells from SF than in those from blood. Indeed, NRF2 activation of CD4+ T cells downregulated oxidative stress markers, altered the metabolic phenotype and reduced secretion of IFN-γ. CONCLUSION: NRF2 could be a potential regulator in CD4+ T cells during chronic inflammation and could instigate a drift toward disease progression or regression, depending on the inflammatory environment.

Long-term efficacy and safety of canakinumab in patients with mevalonate kinase deficiency: results from the randomised Phase 3 CLUSTER trial.

OBJECTIVES: To evaluate the long-term efficacy and safety of canakinumab in patients with mevalonate kinase deficiency during the open label extension (weeks 41-113) of the randomized controlled CLUSTER trial. METHODS: During a 72-week period, patients received open-label canakinumab 150 or 300 mg, every 4 or 8 weeks. The disease activity was evaluated every 8 weeks using physician global assessment and counting the number of flares. Concentrations of CRP and serum amyloid A protein were measured. The safety was studied by determination and classification of observed adverse events. The safety and efficacy were analysed separately in three subgroups of patients receiving a cumulative dose of less than <35 mg/kg, ≥35 to <70 mg/kg or ≥70 mg/kg. RESULTS: Of the 74 patients who started the CLUSTER study, 66 entered Epoch 4 and 65 completed it. During the 72-week period, 42 (64%) patients experienced no flares, while 13 (20%) had one flare, as compared with a median of 12 flares per year reported at baseline. Low physician global assessment scores were seen at the end of the study for all groups with >90% reporting minimal disease activity or none at all. Median CRP concentrations were consistently equal or lower than 10 mg/l, while median serum amyloid A concentrations remained only slightly above the normal range of 10 mg/l. The study showed no new or unexpected adverse events. CONCLUSION: Canakinumab proved effective to control disease activity and prevent flares in mevalonate kinase deficiency during the 72-week study period. No new safety concerns were reported. TRIAL REGISTRATION: NCT02059291. https://clinicaltrials.gov.

Immunometabolic factors in adolescent chronic disease are associated with Th1 skewing of invariant Natural Killer T cells.

Invariant Natural Killer T (iNKT) cells respond to the ligation of lipid antigen-CD1d complexes via their T-cell receptor and are implicated in various immunometabolic diseases. We considered that immunometabolic factors might affect iNKT cell function. To this end, we investigated iNKT cell phenotype and function in a cohort of adolescents with chronic disease and immunometabolic abnormalities. We analyzed peripheral blood iNKT cells of adolescents with cystic fibrosis (CF, n = 24), corrected coarctation of the aorta (CoA, n = 25), juvenile idiopathic arthritis (JIA, n = 20), obesity (OB, n = 20), and corrected atrial septal defect (ASD, n = 25) as controls. To study transcriptional differences, we performed RNA sequencing on a subset of obese patients and controls. Finally, we performed standardized co-culture experiments using patient plasma, to investigate the effect of plasma factors on iNKT cell function. We found comparable iNKT cell numbers across patient groups, except for reduced iNKT cell numbers in JIA patients. Upon ex-vivo activation, we observed enhanced IFN-γ/IL-4 cytokine ratios in iNKT cells of obese adolescents versus controls. The Th1-skewed iNKT cell cytokine profile of obese adolescents was not explained by a distinct transcriptional profile of the iNKT cells. Co-culture experiments with patient plasma revealed that across all patient groups, obesity-associated plasma factors including LDL-cholesterol, leptin, and fatty-acid binding protein 4 (FABP4) coincided with higher IFN-γ production, whereas high HDL-cholesterol and insulin sensitivity (QUICKI) coincided with higher IL-4 production. LDL and HDL supplementation in co-culture studies confirmed the effects of lipoproteins on iNKT cell cytokine production. These results suggest that circulating immunometabolic factors such as lipoproteins may be involved in Th1 skewing of the iNKT cell cytokine response in immunometabolic disease.

Antigen-driven PD-1+ TOX+ BHLHE40+ and PD-1+ TOX+ EOMES+ T lymphocytes regulate juvenile idiopathic arthritis in situ.

T lymphocytes accumulate in inflamed tissues of patients with chronic inflammatory diseases (CIDs) and express pro-inflammatory cytokines upon re-stimulation in vitro. Further, a significant genetic linkage to MHC genes suggests that T lymphocytes play an important role in the pathogenesis of CIDs including juvenile idiopathic arthritis (JIA). However, the functions of T lymphocytes in established disease remain elusive. Here we dissect the transcriptional and the clonal heterogeneity of synovial T lymphocytes in JIA patients by single-cell RNA sequencing combined with T cell receptor profiling on the same cells. We identify clonally expanded subpopulations of T lymphocytes expressing genes reflecting recent activation by antigen in situ. A PD-1+ TOX+ EOMES+ population of CD4+ T lymphocytes expressed immune regulatory genes and chemoattractant genes for myeloid cells. A PD-1+ TOX+ BHLHE40+ population of CD4+ , and a mirror population of CD8+ T lymphocytes expressed genes driving inflammation, and genes supporting B lymphocyte activation in situ. This analysis points out that multiple types of T lymphocytes have to be targeted for therapeutic regeneration of tolerance in arthritis.

Whole Transcriptome Analysis Reveals Heterogeneity in B Cell Memory Populations in Patients With Juvenile Idiopathic Arthritis-Associated Uveitis.

Purpose: Patients with juvenile idiopathic arthritis (JIA) are prone to developing chronic anterior uveitis (JIA-U+). Although several risk factors for JIA-U+ have been identified, the underlying etiology is poorly understood. Histopathological studies demonstrate B cell infiltrates in eye tissues of patients with JIA-U+. Methods: We performed transcriptome profiling of peripheral blood CD19-positive B cells taken from 14 cases with JIA-U+, 13 JIA cases without uveitis (JIA-U-), and five healthy controls. Deconvolution-based estimation was used to determine the immune cell fractions for each sample. Results: Deconvolution results revealed that naive B cells made up on average 71% of the CD19-positive cell fractions analyzed. Differential expression analysis identified 614 differentially expressed genes (DEGs) between the groups at nominal significance and six genes at a false discovery rate of 5% (FDR < 0.05). Head-to-head comparison of all JIA-U- versus JIA-U+ revealed no DEGs in the CD19+ B cell pool (FDR < 0.05). However, principal component analysis based on a panel of key genes for B cell subsets revealed that JIA-U+ cases bifurcate into distinct clusters, characterized by markedly disparate expression for genes associated with specific memory B cell populations. CIBERSORT analysis of the overall transcriptome of the new uveitis cluster identified an increased proportion of memory B cells. Conclusion: These data show that JIA-U- and JIA-U+ have a globally similar transcriptome considering the global peripheral CD19-positive B cell pool. However, heterogeneity in B cell memory genes among cases with uveitis suggests a role for specific memory B cell subsets in the etiology of JIA-U+.

European consensus-based recommendations for diagnosis and treatment of immunoglobulin A vasculitis-the SHARE initiative.

OBJECTIVES: IgA vasculitis (IgAV, formerly known as Henoch-Schönlein purpura) is the most common cause of systemic vasculitis in childhood. To date, there are no internationally agreed, evidence-based guidelines concerning the appropriate diagnosis and treatment of IgAV in children. Accordingly, treatment regimens differ widely. The European initiative SHARE (Single Hub and Access point for paediatric Rheumatology in Europe) aims to optimize care for children with rheumatic diseases. The aim therefore was to provide internationally agreed consensus recommendations for diagnosis and treatment for children with IgAV. METHODS: Recommendations were developed by a consensus process in accordance with the EULAR standard operating procedures. An extensive systematic literature review was performed, and evidence-based recommendations were extrapolated from the included papers. These were evaluated by a panel of 16 international experts via online surveys and subsequent consensus meeting, using nominal group technique. Recommendations were accepted when ⩾80% of experts agreed. RESULTS: In total, 7 recommendations for diagnosis and 19 for treatment of paediatric IgAV were accepted. Diagnostic recommendations included: appropriate use of skin and renal biopsy, renal work-up and imaging. Treatment recommendations included: the importance of appropriate analgesia and angiotensin-converting enzyme inhibitor use and non-renal indications for CS use, as well as a structured approach to treating IgAV nephritis, including appropriate use of CS and second-line agents in mild, moderate and severe disease along with use of angiotensin-converting enzyme inhibitors and maintenance therapy. CONCLUSION: The SHARE initiative provides international, evidence-based recommendations for the diagnosis and treatment of IgAV that will facilitate improvement and uniformity of care.

European consensus-based recommendations for the diagnosis and treatment of Kawasaki disease - the SHARE initiative.

OBJECTIVES: The European Single Hub and Access point for paediatric Rheumatology in Europe initiative aimed to optimize care for children with rheumatic diseases. Kawasaki disease (KD) is the most common cause of acquired heart disease in children and an important cause of long-term cardiac disease into adulthood. Prompt diagnosis and treatment of KD is difficult due to the heterogeneity of the disease but is crucial for improving outcome. To date, there are no European internationally agreed, evidence-based guidelines concerning the diagnosis and treatment of KD in children. Accordingly, treatment regimens differ widely. The aim of this study is to provide consensus-based, European-wide evidence-informed recommendations for diagnosis and treatment of children with KD. METHODS: Recommendations were developed using the EULAR's standard operating procedures. An extensive systematic literature search was performed, and evidence-based recommendations were extrapolated from the included papers. These were evaluated by a panel of international experts via online surveys and subsequently discussed in three consensus meetings, using nominal group technique. Recommendations were accepted when ⩾80% agreed. RESULTS: In total, 17 recommendations for diagnosis and 14 for treatment of KD in children were accepted. Diagnostic recommendations included laboratory and imaging workup for complete as well as incomplete KD. Treatment recommendations included the importance of early treatment in both complete and incomplete KD, use of intravenous immunoglobulin, aspirin, corticosteroids for high-risk cases, and other treatment options for those with resistant disease. CONCLUSION: The Single Hub and Access point for paediatric Rheumatology in Europe initiative provides international evidence-based recommendations for diagnosing and treating KD in children, facilitating improvement and uniformity of care.

European consensus-based recommendations for the diagnosis and treatment of rare paediatric vasculitides - the SHARE initiative.

OBJECTIVES: The European initiative Single Hub and Access point for paediatric Rheumatology in Europe (SHARE) aimed to optimize care for children with rheumatic diseases. Systemic vasculitides are very rare in children. Consequently, despite recent advances, paediatric-specific information is sparse. The lack of evidence-based recommendations is an important, unmet need. This study aimed to provide recommendations for diagnosing and treating children with rare forms of childhood systemic vasculitis. METHODS: Recommendations were developed by a consensus process in accordance with the European League Against Rheumatism standard operating procedures. A systematic literature review informed the recommendations, which were devised and evaluated by a panel of experts via an online survey, and two consensus meetings using nominal group technique. Recommendations were accepted when ⩾ 80% of experts agreed. RESULTS: Ninety-three relevant articles were found, and 78 recommendations were accepted in the two consensus meetings. General, cross-cutting recommendations and disease-specific statements regarding the diagnosis and treatment of childhood-onset PAN, granulomatosis with polyangiitis, microscopic polyangiitis, eosinophilic granulomatosis with polyangiitis, and Takayasu arteritis are provided. CONCLUSION: These Single Hub and Access point for paediatric Rheumatology in Europe recommendations were formulated through an evidence-based consensus process to support uniform, high-quality standard of care for children with rare forms of paediatric systemic vasculitis.

Transcription factor motif enrichment in whole transcriptome analysis identifies STAT4 and BCL6 as the most prominent binding motif in systemic juvenile idiopathic arthritis.

BACKGROUND: The term systemic juvenile idiopathic arthritis (sJIA) describes an autoinflammatory condition characterized by arthritis and severe systemic inflammation, which in later stages can transform into interleukin (IL)-17-driven autoimmune arthritis. IL-1 antagonists have been used with good efficacy in the early stages of sJIA. METHODS: A whole transcriptome analysis of peripheral blood RNA samples was performed in six patients with sJIA and active systemic disease, before initiating treatment with the IL-1ß receptor antagonist anakinra, and after induction of inactive disease, compared with a single-sample control cohort of 21 patients in several clinical stages of sJIA activity. Whole transcriptomes were compared longitudinally and interindividually including gene ontology and motif enrichment analysis of differentially expressed genes. RESULTS: There were 741 transcripts were identified using a threshold with a p value <0.01 and a fold change > 2. HLADRB1 and CD74 were identified as the most strongly upregulated genes in inactive compared to active disease; CD177 expression was significantly enhanced in active disease compared to inactive disease. Motif enrichment analysis revealed STAT4, BCL6, and STAT3 as the most prominent transcription factors that were present during active disease. In addition, strong upregulation of the major histocompatability complex II (MHCII) ligand CD74 was found in both active and inactive sJIA compared to healthy controls. CONCLUSION: Using transcription factor motif enrichment, this study identifies novel putative pathways in sJIA (STAT4, BCL6) implicating B cell activation at an earlier stage than predicted in refractory disease. The implication of BCL-6 dependent pathways argues for occurrence of autoimmunity early within the process of sJIA chronification. Transcriptional regulation of HLA-DRB1, a recently described independent genetic risk factor, in combination with its cooperating partner CD74 in patients where sJIA is confirmed, supports pathogenic involvement in alterations in antigen presentation during sJIA.

European evidence-based recommendations for the diagnosis and treatment of childhood-onset lupus nephritis: the SHARE initiative.

Lupus nephritis (LN) occurs in 50%-60% of patients with childhood-onset systemic lupus erythematosus (cSLE), leading to significant morbidity. Timely recognition of renal involvement and appropriate treatment are essential to prevent renal damage. The Single Hub and Access point for paediatric Rheumatology in Europe (SHARE) initiative aimed to generate diagnostic and management regimens for children and adolescents with rheumatic diseases including cSLE. Here, we provide evidence-based recommendations for diagnosis and treatment of childhood LN. Recommendations were developed using the European League Against Rheumatism standard operating procedures. A European-wide expert committee including paediatric nephrology representation formulated recommendations using a nominal group technique. Six recommendations regarding diagnosis and 20 recommendations covering treatment choices and goals were accepted, including each class of LN, described in the International Society of Nephrology/Renal Pathology Society 2003 classification system. Treatment goal should be complete renal response. Treatment of class I LN should mainly be guided by other symptoms. Class II LN should be treated initially with low-dose prednisone, only adding a disease-modifying antirheumatic drug after 3 months of persistent proteinuria or prednisone dependency. Induction treatment of class III/IV LN should be mycophenolate mofetil (MMF) or intravenous cyclophosphamide combined with corticosteroids; maintenance treatment should be MMF or azathioprine for at least 3 years. In pure class V LN, MMF with low-dose prednisone can be used as induction and MMF as maintenance treatment. The SHARE recommendations for diagnosis and treatment of LN have been generated to support uniform and high-quality care for all children with SLE.

European evidence-based recommendations for diagnosis and treatment of childhood-onset systemic lupus erythematosus: the SHARE initiative.

Childhood-onset systemic lupus erythematosus (cSLE) is a rare, multisystem and potentially life-threatening autoimmune disorder with significant associated morbidity. Evidence-based guidelines are sparse and management is often based on clinical expertise. SHARE (Single Hub and Access point for paediatric Rheumatology in Europe) was launched to optimise and disseminate management regimens for children and young adults with rheumatic diseases like cSLE. Here, we provide evidence-based recommendations for diagnosis and treatment of cSLE. In view of extent and complexity of cSLE and its various manifestations, recommendations for lupus nephritis and antiphospholipid syndrome will be published separately. Recommendations were generated using the EULAR (European League Against Rheumatism) standard operating procedure. An expert committee consisting of paediatric rheumatologists and representation of paediatric nephrology from across Europe discussed evidence-based recommendations during two consensus meetings. Recommendations were accepted if >80% agreement was reached. A total of 25 recommendations regarding key approaches to diagnosis and treatment of cSLE were made. The recommendations include 11 on diagnosis, 9 on disease monitoring and 5 on general treatment. Topics included: appropriate use of SLE classification criteria, disease activity and damage indices; adequate assessment of autoantibody profiles; secondary macrophage activation syndrome; use of hydroxychloroquine and corticosteroid-sparing regimens; and the importance of addressing poor adherence. Ten recommendations were accepted regarding general diagnostic strategies and treatment indications of neuropsychiatric cSLE. The SHARE recommendations for cSLE and neuropsychiatric manifestations of cSLE have been formulated by an evidence-based consensus process to support uniform, high-quality standards of care for children with cSLE.

Update on research and clinical translation on specific clinical areas from biology to bedside: Unpacking the mysteries of juvenile idiopathic arthritis pathogenesis.

In the past decades, we have gained important insights into the mechanisms of disease and therapy underlying chronic inflammation in juvenile idiopathic arthritis (JIA). These insights have resulted in several game-changing therapeutic modalities for many patients. However, additional progress still has to be made with regard to efficacy, cost reduction, minimization of side effects, and dose-tapering and stop strategies of maintenance drugs. Moreover, to really transform the current therapeutic strategies into personalized medicine, we need validated biomarkers to translate increased insights into clinical practice. In this article, we describe recent developments in JIA research and outline how clinical innovations need to go hand in hand with basic discoveries to really effect care for patients. Facilitating the transition from bench to bedside is crucial for addressing the major current challenges in JIA management. When successful, it will set new standards for a safe, targeted, and personalized medicine in JIA.

Time to share.

In the following a brief commentary is given on a new European project that aims to provide the European countries with recommendations for the care of children and yound adults with rheumatic diseases. These recommendations will be based on surveys sent to PRINTO members and systematic literature reviews. Surveys on current local standard of care and best practice will be send to PRINTO members in EU member states. The success of this project largely largely depends on information provided by individual centers from our existing PRINTO and PReS networks. We would therefore like to ask your collaboration in completing and returning these surveys which will be circulated March April 2013.

Functional human regulatory T cells fail to control autoimmune inflammation due to PKB/c-akt hyperactivation in effector cells.

During the last decade research has focused on the application of FOXP3(+) regulatory T cells (Tregs) in the treatment of autoimmune disease. However, thorough functional characterization of these cells in patients with chronic autoimmune disease, especially at the site of inflammation, is still missing. Here we studied Treg function in patients with juvenile idiopathic arthritis (JIA) and observed that Tregs from the peripheral blood as well as the inflamed joints are fully functional. Nevertheless, Treg-mediated suppression of cell proliferation and cytokine production by effector cells from the site of inflammation was severely impaired, because of resistance to suppression. This resistance to suppression was not caused by a memory phenotype of effector T cells or activation status of antigen presenting cells. Instead, activation of protein kinase B (PKB)/c-akt was enhanced in inflammatory effector cells, at least partially in response to TNFα and IL-6, and inhibition of this kinase restored responsiveness to suppression. We are the first to show that PKB/c-akt hyperactivation causes resistance of effector cells to suppression in human autoimmune disease. Furthermore, these findings suggest that for a Treg enhancing strategy to be successful in the treatment of autoimmune inflammation, resistance because of PKB/c-akt hyperactivation should be targeted as well.

Autologous stem cell transplantation for autoimmunity induces immunologic self-tolerance by reprogramming autoreactive T cells and restoring the CD4+CD25+ immune regulatory network.

Despite a rapidly accumulating clinical experience with autologous stem cell transplantation (ASCT) as a treatment for severe refractory autoimmune disease, data on the mechanisms by which ASCT induces immune tolerance are still very scarce. In this study it is shown that ASCT restores immunologic self-tolerance in juvenile idiopathic arthritis (JIA) via 2 mechanisms. First, ASCT induces a restoration of the frequency of FoxP3 expressing CD4+CD25bright regulatory T cells (Tregs) from severely reduced numbers before ASCT to normal levels after ASCT. This recovery is due to a preferential homeostatic expansion of CD4+CD25+ Tregs during the lymphopenic phase of immunereconstitution, as measured by Ki67 and CD44 expression, and to a renewed thymopoiesis of naive mRNA FoxP3 expressing CD4+CD25+ Tregs after ASCT. Second, using artificial antigen-presenting cells to specifically isolate self-reactive T cells, we demonstrate that ASCT induces autoimmune cells to deviate from a proinflammatory phenotype (mRNA interferon-gamma [IFN-gamma] and T-bet high) to a tolerant phenotype (mRNA interleukin-10 [IL-10] and GATA-3 high). These data are the first to demonstrate the qualitative immunologic changes that are responsible for the induction of immune tolerance by ASCT for JIA: the restoration of the CD4+CD25+ immune regulatory network and reprogramming of autoreactive T cells.