Proteomic mapping identifies serum marker signatures associated with MIS-C specific hyperinflammation and cardiovascular manifestation.

Multisystem inflammatory syndrome in children (MIS-C) shares several clinical and immunological features with Kawasaki Disease (KD) and pediatric hyperinflammation, but the immuno-phenotypic overlap among these clinical mimics is still incompletely understood. Here we analyzed serum samples from treatment-naïve patients with MIS-C (n = 31) and KD (n = 11), pediatric hyperinflammation (n = 13) and healthy controls (HC, n = 10) by proximity extension assay (PEA) to profile 184 blood biomarkers. Collectively, immunophenotypic overlap between MIS-C and hyperinflammation exceeds overlap with KD. Overexpression of IL-17A in MIS-C and KD could best separate these conditions from hyperinflammatory conditions, while those were hallmarked by overabundance of adenosin deaminase and IL-18. Depletion in serum TNF-related subfamily member 9 (TNFRSF9) and apoptosis inducing ligand (TRAIL) linked with cardiovascular manifestations and myocarditis in MIS-C. Altogether, our analysis highlights important differences in molecular marker signatures also across different MIS-C and KD cohorts and suggests several previously unidentified molecular associations in context of cardiovascular inflammation.

Autoantibody-Mediated Depletion of IL-1RA in Still's Disease and Potential Impact of IL-1 Targeting Therapies.

BACKGROUND: Adult-onset Still's disease (AOSD) and systemic juvenile idiopathic arthritis (sJIA) resemble a continuum of a rare, polygenic IL-1ß-driven disease of unknown etiology. OBJECTIVE: In the present study we sought to investigate a potential role of recently described autoantibodies neutralizing the interleukin-1(IL-1)-receptor antagonist (IL-1-Ra) in the pathogenesis of Still's disease. METHODS: Serum or plasma samples from Still's disease patients (AOSD, n = 23; sJIA, n = 40) and autoimmune and/or inflammatory disease controls (n = 478) were analyzed for autoantibodies against progranulin (PGRN), IL-1Ra, IL-18 binding protein (IL-18BP), and IL-36Ra, as well as circulating IL-1Ra and IL-36Ra levels by ELISA. Biochemical analyses of plasma IL-1Ra were performed by native Western blots and isoelectric focusing. Functional activity of the autoantibodies was examined by an in vitro IL-1ß-signaling reporter assay. RESULTS: Anti-IL-1-Ra IgG were identified in 7 (27%) out of 29 Still's disease patients, including 4/23 with AOSD and 3/6 with sJIA and coincided with a hyperphosphorylated isoform of endogenous IL-1Ra. Anti-IL-36Ra antibodies were found in 2 AOSD patients. No anti-PGRN or anti-IL-18BP antibodies were detected. Selective testing for anti-IL-1Ra antibodies in an independent cohort (sJIA, n = 34) identified 5 of 34 (14.7%) as seropositive. Collectively, 8/12 antibody-positive Still's disease patients were either new-onset active disease or unresponsive to IL-1 blocking drugs. Autoantibody-seropositivity associated with decreased IL-1Ra plasma/serum levels. Seropositive plasma impaired in vitro IL-1Ra bioactivity, which could be reversed by anakinra or canakinumab treatment. CONCLUSION: Autoantibodies neutralizing IL-1Ra may represent a novel patho-mechanism in a subgroup of Still's disease patients, which is sensitive to high-dose IL-1 blocking therapy.

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

Systemic juvenile idiopathic arthritis (sJIA) and adult-onset Still's disease (AOSD) are considered the same disease, but a common approach for diagnosis and management is still missing. METHODS: In May 2022, EULAR and PReS endorsed a proposal for a joint task force (TF) to develop recommendations for the diagnosis and management of sJIA and AOSD. The TF agreed during a first meeting to address four topics: similarity between sJIA and AOSD, diagnostic biomarkers, therapeutic targets and strategies and complications including macrophage activation syndrome (MAS). Systematic literature reviews were conducted accordingly. RESULTS: The TF based their recommendations on four overarching principles, highlighting notably that sJIA and AOSD are one disease, to be designated by one name, Still's disease.Fourteen specific recommendations were issued. Two therapeutic targets were defined: clinically inactive disease (CID) and remission, that is, CID maintained for at least 6 months. The optimal therapeutic strategy relies on early use of interleukin (IL-1 or IL-6 inhibitors associated to short duration glucocorticoid (GC). MAS treatment should rely on high-dose GCs, IL-1 inhibitors, ciclosporin and interferon-γ inhibitors. A specific concern rose recently with cases of severe lung disease in children with Still's disease, for which T cell directed immunosuppressant are suggested. The recommendations emphasised the key role of expert centres for difficult-to-treat patients. All overarching principles and recommendations were agreed by over 80% of the TF experts with a high level of agreement. CONCLUSION: These recommendations are the first consensus for the diagnosis and management of children and adults with Still's disease.

P2RX7 gene variants associate with altered inflammasome assembly and reduced pyroptosis in chronic nonbacterial osteomyelitis (CNO).

Chronic nonbacterial osteomyelitis (CNO), an autoinflammatory bone disease primarily affecting children, can cause pain, hyperostosis and fractures, affecting quality-of-life and psychomotor development. This study investigated CNO-associated variants in P2RX7, encoding for the ATP-dependent trans-membrane K+ channel P2X7, and their effects on NLRP3 inflammasome assembly. Whole exome sequencing in two related transgenerational CNO patients, and target sequencing of P2RX7 in a large CNO cohort (N = 190) were conducted. Results were compared with publicly available datasets and regional controls (N = 1873). Findings were integrated with demographic and clinical data. Patient-derived monocytes and genetically modified THP-1 cells were used to investigate potassium flux, inflammasome assembly, pyroptosis, and cytokine release. Rare presumably damaging P2RX7 variants were identified in two related CNO patients. Targeted P2RX7 sequencing identified 62 CNO patients with rare variants (32.4%), 11 of which (5.8%) carried presumably damaging variants (MAF <1%, SIFT "deleterious", Polyphen "probably damaging", CADD >20). This compared to 83 of 1873 controls (4.4%), 36 with rare and presumably damaging variants (1.9%). Across the CNO cohort, rare variants unique to one (Median: 42 versus 3.7) or more (≤11 patients) participants were over-represented when compared to 190 randomly selected controls. Patients with rare damaging variants more frequently experienced gastrointestinal symptoms and lymphadenopathy while having less spinal, joint and skin involvement (psoriasis). Monocyte-derived macrophages from patients, and genetically modified THP-1-derived macrophages reconstituted with CNO-associated P2RX7 variants exhibited altered potassium flux, inflammasome assembly, IL-1ß and IL-18 release, and pyroptosis. Damaging P2RX7 variants occur in a small subset of CNO patients, and rare P2RX7 variants may represent a CNO risk factor. Observations argue for inflammasome inhibition and/or cytokine blockade and may allow future patient stratification and individualized care.

Current treatment in macrophage activation syndrome worldwide: a systematic literature review to inform the METAPHOR project.

OBJECTIVE: To assess current treatment in macrophage activation syndrome (MAS) worldwide and to highlight any areas of major heterogeneity of practice. METHODS: A systematic literature search was performed in both Embase and PubMed databases. Paper screening was done by two independent teams based on agreed criteria. Data extraction was standardized following the PICO framework. A panel of experts assessed paper validity, using the Joanna Briggs Institute appraisal tools and category of evidence (CoE) according to EULAR procedure. RESULTS: Fifty-seven papers were finally included (80% retrospective case-series), describing 1148 patients with MAS: 889 systemic juvenile idiopathic arthritis (sJIA), 137 systemic lupus erythematosus (SLE), 69 Kawasaki disease (KD) and 53 other rheumatologic conditions. Fourteen and 11 studies specified data on MAS associated to SLE and KD, respectively. All papers mentioned glucocorticoids (GCs), mostly methylprednisolone and prednisolone (90%); dexamethasone was used in 7% of patients. Ciclosporin was reported in a wide range of patients according to different cohorts. Anakinra was used in 179 MAS patients, with a favourable outcome in 83% of sJIA-MAS. Etoposide was described by 11 studies, mainly as part of HLH-94/04 protocol. Emapalumab was the only medication tested in a clinical trial in 14 sJIA-MAS, with 93% of MAS remission. Ruxolitinib was the most reported JAK-inhibitor in MAS. CONCLUSION: High-dose GCs together with IL-1 and IFNγ inhibitors have shown efficacy in MAS, especially in sJIA-associated MAS. However, global level of evidence on MAS treatment, especially in other conditions, is still poor and requires standardized studies to be confirmed.

Inflammatory Biomarkers Can Differentiate Acute Lymphoblastic Leukemia with Arthropathy from Juvenile Idiopathic Arthritis Better Than Standard Blood Tests.

OBJECTIVE: To evaluate the predictive value of biomarkers of inflammation like phagocyte-related S100 proteins and a panel of inflammatory cytokines in order to differentiate the child with acute lymphoblastic leukemia (ALL) from juvenile idiopathic arthritis (JIA). STUDY DESIGN: In this cross-sectional study, we measured S100A9, S100A12, and 14 cytokines in serum from children with ALL (n = 150, including 27 with arthropathy) and JIA (n = 236). We constructed predictive models computing areas under the curve (AUC) as well as predicted probabilities in order to differentiate ALL from JIA. Logistic regression was used for predictions of ALL risk, considering the markers as the respective exposures. We performed internal validation using repeated 10-fold cross-validation and recalibration, adjusted for age. RESULTS: In ALL, the levels of S100A9, S100A12, interleukin (IL)-1 beta, IL-4, IL-13, IL-17, matrix metalloproteinase-3, and myeloperoxidase were low compared with JIA (P < .001). IL-13 had an AUC of 100% (95% CI 100%-100%) due to no overlap between the serum levels in the 2 groups. Further, IL-4 and S100A9 had high predictive performance with AUCs of 99% (95% CI 97%-100%) and 98% (95% CI 94%-99%), respectively, exceeding both hemoglobin, platelets, C-reactive protein, and erythrocyte sedimentation rate. CONCLUSIONS: The biomarkers S100A9, IL-4, and IL-13 might be valuable markers to differentiate ALL from JIA.

Biologics with or without methotrexate in treatment of polyarticular juvenile idiopathic arthritis: effectiveness, safety and drug survival.

OBJECTIVE: To investigate the impact of additionally given MTX on biologic treatment of polyarticular JIA in terms of effectiveness, safety and drug survival. METHODS: Patients suffering from polyarticular JIA and treated with either monotherapy with a first biologic or a combination of a biologic and MTX were selected from the BIKER registry. The TNF-α inhibitors (TNFi) adalimumab, etanercept and golimumab and the IL-6 inhibitor tocilizumab were considered. Upon a non-randomized study design, we adjusted the different cohorts using propensity score matching to improve comparability. RESULTS: A total of 2148 patients entered the analysis, who were treated by either combination therapy (n = 1464) or monotherapy (n = 684). Disease activity declined significantly more in patients upon combination therapy than upon biologic monotherapy. Comparison of adjusted cohorts revealed that patients who received TNFi gained more benefit from additionally given MTX than patients treated with tocilizumab. Median survival time of therapy with biologics was significantly longer upon combination therapy (3.1 years) than with monotherapy (2.7 years), as demonstrated by a Kaplan-Meier analysis (log rank test: P = 0.002). The safety profile was moderately affected by additional MTX due to increased incidence of gastrointestinal and hepatic adverse events. Serious adverse events occurred at an equal rate of 3.6 events per 100 patient-years in both cohorts. CONCLUSION: Additionally given MTX improves the effectiveness of biologic treatment in polyarticular JIA without seriously compromising treatment safety. Especially TNFi benefit from combination, while no improvement in outcome has been observed by combining tocilizumab with MTX.

Incident psoriasis under treatment with tumor necrosis factor-α inhibitors in juvenile idiopathic arthritis patients-analysis of the BiKeR registry.

The efficacy of tumor necrosis factor inhibitors (TNFi) for the treatment of psoriasis is well established, but patients may develop psoriasis for the first time while on TNFi as a paradoxical effect. Limited data on this association in patients with juvenile idiopathic arthritis (JIA) are available. Safety data from patients registered to the German Biologics registry (BiKeR) were analyzed. Patients were grouped by treatment regime: single TNFi, multiple TNFi, non-TNFi biologics or bDMARD-naïve control group receiving methotrexate. TNFi-associated psoriasis was defined as incident diagnosis of psoriasis after starting TNFi treatment. Patients with a history of psoriasis or psoriasis arthritis prior to TNFi therapy were excluded. Event rates using AEs reported after first dose were compared by Wald's test. A total of 4149 patients were treated with a TNFi (etanercept, adalimumab, golimumab, infliximab), 676 with a non-TNFi biologic (tocilizumab, abatacept, anakinra, canakinumab) and 1692 with methotrexate only. A total of 31 patients were diagnosed with incident psoriasis while on one of the above treatments. Compared with methotrexate, psoriasis was more frequent in the TNFi cohorts (RR 10.8, p = 0.019), specifically in the subgroup of TNF antibodies (RR 29.8, p = 0.0009), whereas no significant signal was observed with etanercept. Also, non-TNFi-treated patients presented high incident psoriasis rates (RR 25.0, p = 0.003). Our findings indicate a higher rate of incident psoriasis in JIA patients treated with TNFi monoclonal antibodies or non-TNFi biologic treatment. JIA patients receiving monoclonal antibody TNFi or non-TNFi bDMARD should be monitored for incident psoriasis. Medication change, if topical skin treatment remains insufficient, may be considered.

An Immunological Axis Involving Interleukin 1ß and Leucine-Rich-α2-Glycoprotein Reflects Therapeutic Response of Children with Kawasaki Disease: Implications from the KAWAKINRA Trial.

PURPOSE: A recent phase II open-label study of the interleukin 1 (IL-1) receptor antagonist (IL-1Ra) anakinra in treating IVIG-resistant Kawasaki disease (KD) patients reported promising results. Here, we aimed to characterize the immunological impact of IL-1 blockade in this unique study population. METHODS: Patients' and control sera and supernatants of cells (whole blood, neutrophils, coronary artery endothelial cells) stimulated with recombinant IL-1ß were analyzed for single or multiple marker (n = 22) expression by ELISA or multiplexed bead array assay. Data were analyzed using unsupervised hierarchical clustering, multiple correlation, and multi-comparison statistics and were compared to retrospective analyses of KD transcriptomics. RESULTS: Inflammation in IVIG-resistant KD (n = 16) is hallmarked by over-expression of innate immune mediators (particularly IL-6 > CXCL10 > S100A12 > IL-1Ra). Those as well as levels of immune or endothelial cell activation markers (sICAM-1, sVCAM-1) declined most significantly in course of anakinra treatment. Prior as well as following IL-1R blockade, over-expression of leucine-rich-α2-glycoprotein 1 (LRG1) associated best with remnant inflammatory activity and the necessity to escalate anakinra dosage and separated inflammatory KD patients from sJIA-MAS (n = 13) and MIS-C (n = 4). Protein as well as retrospective gene expression analyses indicated tight association of LRG1 with IL-1ß signaling and neutrophilia, while particularly neutrophil stimulation with recombinant IL-1ß resulted in concentration-dependent LRG1 release. CONCLUSION: Our study identifies LRG1 as known trigger of endothelial activation and cardiac re-modeling to associate with IL-1ß signaling in KD. Besides a potential patho-mechanistic implication of these findings, our data suggest blood leukocyte and neutrophil counts to best predict response to IL-1Ra treatment in IVIG-resistant KD.

Independent risk factors for myasthenic crisis and disease exacerbation in a retrospective cohort of myasthenia gravis patients.

BACKGROUND: Myasthenic crisis (MC) and disease exacerbation in myasthenia gravis (MG) are associated with significant lethality and continue to impose a high disease burden on affected patients. Therefore, we sought to determine potential predictors for MC and exacerbation as well as to identify factors affecting outcome. METHODS: We examined a retrospective, observational cohort study of patients diagnosed with MG between 2000 and 2021 with a mean follow-up of 62.6 months after diagnosis from eight tertiary hospitals in Germany. A multivariate Cox regression model with follow-up duration as the time variable was used to determine independent risk factors for MC and disease exacerbation. RESULTS: 815 patients diagnosed with MG according to national guidelines were included. Disease severity at diagnosis (quantitative MG score or Myasthenia Gravis Foundation of America class), the presence of thymoma and anti-muscle specific tyrosine kinase-antibodies were independent predictors of MC or disease exacerbation. Patients with minimal manifestation status 12 months after diagnosis had a lower risk of MC and disease exacerbation than those without. The timespan between diagnosis and the start of immunosuppressive therapy did not affect risk. Patients with a worse outcome of MC were older, had higher MGFA class before MC and at admission, and had lower vital capacity before and at admission. The number of comorbidities, requirement for intubation, prolonged mechanical ventilation, and MC triggered by infection were associated with worse outcome. No differences between outcomes were observed comparing treatments with IVIG (intravenous immunoglobulin) vs. plasma exchange vs. IVIG together with plasma exchange. CONCLUSIONS: MC and disease exacerbations inflict a substantial burden of disease on MG patients. Disease severity at diagnosis and antibody status predicted the occurrence of MC and disease exacerbation. Intensified monitoring with emphasis on the prevention of infectious complications could be of value to prevent uncontrolled disease in MG patients.

Prevention of disease flares by risk-adapted stratification of therapy withdrawal in juvenile idiopathic arthritis: results from the PREVENT-JIA trial.

OBJECTIVES: To investigate the ability of high-sensitivity C-reactive protein (hsCRP) and S100A12 to serve as predictive biomarkers of successful drug withdrawal in children with clinical remission of juvenile idiopathic arthritis (JIA). METHODS: This multicentre trial (PREVENT-JIA) enrolled 119 patients with JIA in clinical remission, and 100 patients reached the intervention phase in which the decision whether to continue or stop treatment was based on S100A12 and hsCRP levels. Patients were monitored for 12 months after stopping medication for flares of disease. Results were compared with withdrawal of therapy without biomarker-based stratification in patients from the German Biologika in der Kinderrheumatologie (BiKeR) pharmacovigilance registry. RESULTS: In the PREVENT-JIA group, 49 patients had a flare, and 45% of patients stopping medication showed flares within the following 12 months. All patients (n=8) continuing therapy due to permanently elevated S100A12/hsCRP at more than one visit flared during the observation phase. In the BiKeR control group, the total flare rate was 62%, with 60% flaring after stopping medication. The primary outcome, time from therapy withdrawal to first flare (cumulative flare rate after therapy withdrawal), showed a significant difference in favour of the PREVENT-JIA group (p=0.046; HR 0.62, 95% CI 0.38 to 0.99). As additional finding, patients in the PREVENT-JIA trial stopped therapy significantly earlier. CONCLUSION: Biomarker-guided strategies of therapy withdrawal are feasible in clinical practice. This study demonstrates that using predictive markers of subclinical inflammation is a promising tool in the decision-making process of therapy withdrawal, which translates into direct benefit for patients. TRIAL REGISTRATION NUMBER: ISRCTN69963079.

The 2021 EULAR/American College of Rheumatology points to consider for diagnosis, management and monitoring of the interleukin-1 mediated autoinflammatory diseases: cryopyrin-associated periodic syndromes, tumour necrosis factor receptor-associated periodic syndrome, mevalonate kinase deficiency, and deficiency of the interleukin-1 receptor antagonist.

BACKGROUND: The interleukin-1 (IL-1) mediated systemic autoinflammatory diseases, including the cryopyrin-associated periodic syndromes (CAPS), tumour necrosis factor receptor-associated periodic syndrome (TRAPS), mevalonate kinase deficiency (MKD) and deficiency of the IL-1 receptor antagonist (DIRA), belong to a group of rare immunodysregulatory diseases that primarily present in early childhood with variable multiorgan involvement. When untreated, patients with severe clinical phenotypes have a poor prognosis, and diagnosis and management of these patients can be challenging. However, approved treatments targeting the proinflammatory cytokine IL-1 have been life changing and have significantly improved patient outcomes. OBJECTIVE: To establish evidence-based recommendations for diagnosis, treatment and monitoring of patients with IL-1 mediated autoinflammatory diseases to standardise their management. METHODS: A multinational, multidisciplinary task force consisting of physician experts, including rheumatologists, patients or caregivers and allied healthcare professionals, was established. Evidence synthesis, including systematic literature review and expert consensus (Delphi) via surveys, was conducted. Consensus methodology was used to formulate and vote on statements to guide optimal patient care. RESULTS: The task force devised five overarching principles, 14 statements related to diagnosis, 10 on therapy, and nine focused on long-term monitoring that were evidence and/or consensus-based for patients with IL-1 mediated diseases. An outline was developed for disease-specific monitoring of inflammation-induced organ damage progression and reported treatments of CAPS, TRAPS, MKD and DIRA. CONCLUSION: The 2021 EULAR/American College of Rheumatology points to consider represent state-of-the-art knowledge based on published data and expert opinion to guide diagnostic evaluation, treatment and monitoring of patients with CAPS, TRAPS, MKD and DIRA, and to standardise and improve care, quality of life and disease outcomes.

Soluble interleukin-2 receptor serum levels facilitate prediction of relapses in subgroups of patients with juvenile idiopathic arthritis.

OBJECTIVES: JIA is characterised by a chronic disease course. Once patients achieve a state of inactive disease, there are no established biomarkers to predict the further course of inflammation for these patients. Therefore, the purpose of this study was to quantify serum biomarkers during quiescent disease to evaluate their use in identifying JIA patients at risk for future disease flare. METHODS: Patients with non-systemic JIA reaching inactive disease status were divided into two groups: 92 patients with future active disease after a median period of 6 months (range 3-9) and 80 patients with persistent inactive disease for the following period (median 11 months, range 7-16) according to the juvenile arthritis DAS (JADAS). Clinical parameters and serum levels of various biomarkers were measured in the state of inactive disease using immunoassays in both groups and were analysed for their potential to predict the further course of disease. RESULTS: Soluble interleukin-2 receptor (sIL-2R) serum levels were significantly higher in patients with future active disease (P = 0.021), which especially applied to patients with RF-negative polyarticular and extended oligoarticular JIA (P < 0.001). Higher sIL-2R serum levels during inactive disease were associated with a greater number of active joints at future active disease. CONCLUSION: Patients without clinical signs of disease activity already presented with increased sIL-2R serum levels several months before disease relapses, whereas conventional inflammation parameters were not elevated. Determination of sIL-2R serum levels during inactive disease may facilitate identifying patients with subclinical disease activity at risk for future active disease.

miR-23a contributes to T cellular redox metabolism in juvenile idiopathic oligoarthritis.

OBJECTIVE: JIA is a chronic inflammatory disease of unknown origin. The regulation of inflammatory processes involves multiple cellular steps including mRNA transcription and translation. Different miRNAs control these processes tightly. We aimed to determine the roles of specific miRNAs within JIA pathogenesis. METHODS: We performed a global miRNA expression analysis in parallel in cells from the arthritic joint and peripheral blood of oligoarticular JIA patients and healthy controls. Quantitative RT-PCR analysis was used to verify expression of miRNA in T cells. Ex vivo experiments and flow cytometric analyses were used to analyse proliferation and redox metabolism. RESULTS: Global miRNA expression analysis demonstrated a different composition of miRNA expression at the site of inflammation compared with peripheral blood. Bioinformatic analysis of predicted miRNA target genes suggest a huge overrepresentation of genes involved in metabolic and oxidative stress pathways in the inflamed joint. Despite enhanced reactive oxygen species (ROS) levels within the local inflammatory milieu, JIA T cells are hyperproliferative and reveal an overexpression of miR-23a, which is an inhibitor of Peptidyl-prolyl isomerase F (PPIF), the regulator of mitochondrial ROS escape. Mitochondrial ROS escape is diminished in JIA T cells, resulting in their prolonged survival. CONCLUSION: Our data suggest that miRNA-dependent mitochondrial ROS shuttling might be a mechanism that contributes to T cell regulation in JIA at the site of inflammation.

MRP8/14 serum levels as diagnostic markers for systemic juvenile idiopathic arthritis in children with prolonged fever.

OBJECTIVES: Differential diagnosis in children with prolonged fever is challenging. In particular, differentiating systemic-onset JIA (SJIA) from infectious diseases is difficult. Biomarkers are needed that support the diagnostic work-up. The aim of this study was to validate the usefulness of Myeloid-related protein 8/14 (MRP8/14) measurements in the diagnostic work-up of febrile children and to transfer it to clinical practice. METHODS: Data for 1110 paediatric patients were included and divided into two cohorts: (cohort A) for validation of MRP8/14 test performance with three different testing systems: the experimental ELISA, commercial ELISA and an innovative (point-of-care test) lateral flow immunoassay (LFIA); (cohort B) to validate the diagnostic accuracy with the two latter assays. RESULTS: In cohort A (n = 940), MRP8/14 was elevated in SJIA (12 110 ± 2650 ng/ml mean ± 95% CI) compared with other diagnoses (including infections and autoinflammatory diseases; 2980 ± 510 ng/ml) irrespective of fever and anti-inflammatory treatment (P < 0.001). In untreated patients with fever (n = 195) MRP8/14 levels in SJIA (19 740 ± 5080 ng/ml) were even higher compared with other diagnoses (4590 ± 1160 ng/ml) (P < 0.001, sensitivity 73%, specificity 90%). In group B1, the performance of the tests was confirmed in untreated patients with fever (n = 170): commercial ELISA (sensitivity 79%, specificity 89%) and LFIA (sensitivity 84%, specificity 81%). Compared with ferritin, IL-18, ESR, soluble IL-2 receptor and procalcitonin, MRP8/14 showed the best accuracy. CONCLUSION: MRP8/14 serum analyses have been validated as a helpful tool supporting the diagnosis of SJIA in febrile children. The results could be confirmed with commercial ELISA and LFIA enabling a rapid diagnostic point-of-care screening test.

Patient parameters and response after administration of rituximab in pediatric mature B-cell non-Hodgkin lymphoma.

BACKGROUND: Mature aggressive B-cell lymphomas are heterogenous malignancies that make up more than half of all diagnosed non-Hodgkin lymphoma in children and adolescents. The overall survival rate increased over the last decades to 80%-90% due to fine tuning of polychemotherapy. However, new therapeutic implications are needed to further increase the overall survival. Current clinical trials analyze the therapeutic effect of rituximab in pediatric patients, while the mechanism of action in vivo is still not fully understood. METHODS: Effector molecules important for tumor defense were analyzed before and at day 5 after rituximab treatment via flow cytometry. Serum rituximab levels were measured with an ELISA. RESULTS: We evaluated patient parameters that may affect treatment response in relation to rituximab administration and serum rituximab levels. We indeed found a reduction of Fcγ receptor (FcγR) II levels after rituximab treatment in monocyte subtypes, whereas FcγRI expression was significantly increased. Serum levels of proinflammatory marker proteins S100A8/A9 and S100A12 significantly decreased after treatment to normal levels from an overall proinflammatory state before treatment. CD57, perforin, and granzyme B expression decreased after treatment, comprising a less cytolytic natural killer (NK) cell population. CONCLUSION: The highlighted effects of rituximab treatment on patient's immune response help in understanding the biology behind tumor defense mechanisms and effector function. After subsequent studies, these novel insights might be translated into patient care and could contribute to improve treatment of pediatric patients with mature aggressive B-cell lymphoma.

Cord Blood Low-Density Granulocytes Correspond to an Immature Granulocytic Subset with Low Expression of S100A12.

Although substantial progress has been achieved concerning neonatal sepsis, its lethality remains considerably high, and further insights into peculiarities and malfunctions of neonatal immunity are needed. This study aims to contribute to a better understanding of the role of human neonatal granulocyte subpopulations and calgranulin C (S100A12). For this purpose, we gathered 136 human cord blood (CB) samples. CD66b+ CB low-density granulocytes (LDG) and CB normal-density granulocytes were isolated and functionally and phenotypically compared with healthy adult control granulocytes. We could identify CB-LDG as CD66bbright CD64high CD16low CD35low CD10low S100A12med-low and, based on these markers, recovered in whole CB stainings. Consistent with flow cytometric findings, microscopic imaging supported an immature phenotype of CB-LDG with decreased S100A12 expression. In CB serum of healthy neonates, S100A12 was found to be higher in female newborns when compared with males. Additionally, S100A12 levels correlated positively with gestational age independently from sex. We could solidify functional deficits of CB-LDG concerning phagocytosis and generation of neutrophil extracellular traps. Our study reveals that previously described suppressive effects of CB-LDG on CD4+ T cell proliferation are exclusively due to phagocytosis of stimulation beads used in cocultures and absent when using soluble or coated Abs. In conclusion, we characterize CB-LDG as immature neutrophils with functional deficits and decreased expression and storage of S100A12. Concerning their cross-talk with the adaptive immunity, we found no direct inhibitory effect of LDG. Neonatal LDG may thus represent a distinct population that differs from LDG populations found in adults.

A dysregulated interleukin-18-interferon-γ-CXCL9 axis impacts treatment response to canakinumab in systemic juvenile idiopathic arthritis.

OBJECTIVES: The monoclonal IL-1ß antibody canakinumab is approved for the treatment of systemic juvenile idiopathic arthritis (SJIA). Its efficacy has been proven in several trials, but not all patients show a complete and sustained response to therapy. We aimed to analyse the association of baseline serum biomarkers with treatment outcome in patients with SJIA treated with canakinumab. METHODS: Serum samples from 54 patients with active SJIA without recent macrophage activation syndrome (MAS) treated with canakinumab in an open-label response characterization study were subjected to a multiplexed bead array assay. Interesting targets from these analyses were validated by ELISA. Clinical treatment outcomes included modified paediatric ACR (pACR) 30 and 90 responses, clinically inactive disease (CID) within 15 days of treatment and sustained complete response, defined as pACR100 or CID within 15 days of treatment plus no future flare or MAS. RESULTS: In canakinumab-naïve patients most biomarkers were elevated when compared with healthy controls at baseline and some rapidly decreased by day 15 [IL-1 receptor antagonist (IL-1RA), IL-6, IL-18 and S100A12]. Responders had higher IL-18 and IFN-γ levels and lower chemokine (C-X-C motif) ligand 9 (CXCL9) levels at baseline, emphasized by the IL-18: CXCL9 and IFN-γ: CXCL9 ratios. These ratios had significant accuracy in predicting treatment responses. CONCLUSION: Differential regulation of the IL-18-IFN-γ-CXCL9 axis is observed in patients with SJIA. Higher IL-18: CXCL9 and IFN-γ: CXCL9 ratios at baseline are associated with a better clinical response to canakinumab treatment in SJIA. Future studies are needed to validate these findings and determine their generalizability to patients with recent MAS.

Consumer perspective on healthcare services for juvenile idiopathic arthritis: results of a multicentre JIA inception cohort study.

OBJECTIVES: To evaluate healthcare services for patients with juvenile idiopathic arthritis (JIA) from the parent-proxy perspective and to identify factors associated with perceived deficits in care. METHODS: Patients with JIA from 11 paediatric rheumatology units were enrolled in an inception cohort within the first 12 months after diagnosis. Healthcare services were assessed using The Child Healthcare Questionnaire on satisfaction, utilisation and needs. Factors associated with deficits in care were identified by logistic regression analysis. RESULTS: Data from parents of 835 JIA-patients were included in the analysis. At the assessment (4.7 months after diagnosis), 85% of the patients received drug treatment, and 50% had received multi-professional care. The most frequently used services were physiotherapy (84%), occupational therapy (23%), and telephone counselling (17%). Almost one-third of families reported that they had not received the services that they needed, with health education being the most frequently reported need. Most parents (93%) were satisfied with the overall healthcare provided for their children, especially regarding doctors' behaviour. However, approximately 1 in 3 consumers were dissatisfied with the time to JIA diagnosis and the school services. The lower the child's quality of life, the higher the chance was that the child and the family received multi-professional care, perceived unmet needs, and were dissatisfied with care. CONCLUSIONS: According to parents' experience and satisfaction with their child's care, performance at the system level can be further improved by diagnosing JIA earlier, providing additional information at disease onset, and ensuring that the child's social environment is taken into account.

Impact of chorioamnionitis on maternal and fetal levels of proinflammatory S100A12.

Histologic chorioamnionitis (HCA) may lead to the fetal inflammatory response syndrome (FIRS). The aim of this pilot study was to evaluate S100A12, a marker of innate immune activation, in mothers with or without HCA and in their infants. Concentrations of S100A12, interleukin 6 (IL-6), and C-reactive protein (CRP) were evaluated in maternal, cord, and neonatal blood of very preterm infants. Histologic examinations of the placenta and umbilical cords were performed. The 48 mother-neonate pairs enrolled were subdivided into two groups: HCA group (N = 15) and control group without HCA (N = 33). Maternal S100A12 levels were similar between HCA and control group. Similarly, S100A12 concentrations in cord and neonatal blood did not differ between the groups. However, high S100A12 concentrations were detected in cord and neonatal blood of two out of three neonates exposed to HCA associated with advanced funisitis. Concentrations of IL-6 and CRP were higher in maternal blood of the HCA group compared with controls (p < 0.05, p < 0.001; respectively), but no differences in cord or neonatal blood was found.Conclusion:S100A12 did neither identify mothers with HCA nor very preterm infants exposed to HCA. It is currently unknown if S100A12 may identify neonates with FIRS. What is known: • Histologic chorioamnionitis (HCA) may lead to the fetal inflammatory response syndrome (FIRS). • S100A12 represents an early, sensitive, and specific diagnostic marker of inflammatory processes. What is new: • S100A12 did neither identify mothers with HCA nor very preterm infants exposed to HCA. • It is currently still unclear if S100A12 has a potential in identifying preterm infants with FIRS.