Persistently active interferon-γ pathway and expansion of T-bet+ B cells in a subset of patients with childhood-onset systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is an autoimmune disease causing significant morbidity and mortality, despite important improvements in its management in the last decades. The objective of this work is to investigate the role of IFN-γ in the pathogenesis of childhood-onset systemic lupus erythematosus (cSLE), evaluating the crosstalk between IFN-α and IFN-γ and the expression of T-bet, a transcription factor induced by IFN-γ, in B cells of patients with cSLE. Expression levels of both IFN-α and IFN-γ-induced genes were upregulated in patients with cSLE. We found increased serum levels of CXCL9 and CXCL10 in patients with cSLE. Type I IFN score decreased with initiation of immunosuppressive treatment; conversely, type II IFN score and levels of CXCL9 were not significantly affected by immunosuppressive treatment. Type II IFN score and CXCL9 were significantly higher in patients with lupus nephritis. We observed the expansion of a population of naïve B cells expressing T-bet in a cluster of patients with cSLE. IFN-γ, but not IFN-α, induced the expression of T-bet in B cells. Our data suggest that IFN-γ is hyperactive in cSLE, especially in patients with lupus nephritis, and it is not modulated by therapy. Our data reinforce the potential of IFN-γ as a therapeutic target in SLE.

The HyperPed-COVID international registry: Impact of age of onset, disease presentation and geographical distribution on the final outcome of MIS-C.

OBJECTIVES: The aim of the study was to establish an international multicenter registry to collect data on patients with Multisystem Inflammatory Syndrome in Children (MIS-C), in order to highlight a relationship between clinical presentation, age of onset and geographical distribution on the clinical outcome. STUDY DESIGN: Multicenter retrospective study involving different international societies for rare immunological disorders.1009 patients diagnosed with MIS-C between March and September 2022, from 48 centers and 22 countries were collected. Five age groups (<1, 1-4, 5-11, 12-16, >16 years) and four geographic macro-areas, Western Europe, Central-Eastern Europe, Latin America, Asian-African resource-limited countries (LRC), were identified. RESULTS: Time to referral was significantly higher in LRC. Intensive anti-inflammatory treatment, including biologics, respiratory support and mechanic ventilation were more frequently used in older children and in European countries. The mortality rate was higher in very young children (<1 year), in older patients (>16 years of age) and in LRC. Multivariate analysis identified the residence in LRC, presence of severe cardiac involvement, renal hypertension, lymphopenia and non-use of heparin prophylaxis, as the factors most strongly associated with unfavorable outcomes. CONCLUSIONS: The stratification of patients by age and geographic macro-area provided insights into the clinical presentation, treatment and outcome of MIS-C. The mortality and sequelae rates exhibited a correlation with the age and geographical areas. Patients admitted and treated in LRC displayed more severe outcomes, possibly due to delays in hospital admission and limited access to biologic drugs and to intensive care facilities.

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.

Expansion of CD4dimCD8+ T cells characterizes macrophage activation syndrome and other secondary HLH.

CD8+ T-cell activation has been demonstrated to distinguish patients with primary and infection-associated hemophagocytic lymphohistiocytosis (HLH) from patients with early sepsis. We evaluated the activation profile of CD8+ T cells in patients with various forms of secondary HLH (sHLH), including macrophage activation syndrome (MAS). Peripheral blood mononuclear cells from children with inactive systemic juvenile idiopathic arthritis (sJIA, n = 17), active sJIA (n = 27), MAS in sJIA (n = 14), infection-associated HLH (n = 7), and with other forms of sHLH (n = 9) were analyzed by flow cytometry. Compared with patients with active sJIA, in patients with MAS and sHLH of different origins, beside a significant increase in the frequency of CD38high/HLA-DR+CD8+ T cells, we found a significant increase in the frequency of CD8+ T cells expressing the CD4 antigen (CD4dimCD8+ T cells). These cells expressed high levels of the activation markers CD38 and HLA-DR, suggesting they were a subset of CD38high/HLA-DR+CD8+ T cells, as well as of the activation/exhaustion markers CD25, PD1, CD95, and interferon-γ. The frequency of CD4dimCD8+ T cells strongly correlated with most of the laboratory parameters of MAS severity and with circulating levels of CXCL9 and interleukin-18. These findings were confirmed in a prospective replication cohort in which no expansion of any particular T-cell receptor Vß family in CD3+ T cells of patients with sHLH was found. Finally, frequency of CD4dimCD8+, but not of CD38high/HLA-DR+CD8+ T cells, significantly correlated with a clinical severity score, further supporting the involvement of these cells in MAS/sHLH pathogenesis.

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.

Reduced digestion of circulating genomic DNA in systemic sclerosis patients with the DNASE1L3 R206C variant.

OBJECTIVES: Polymorphism in a coding region of deoxyribonuclease I-like III (DNASE1L3), causing amino acid substitution of Arg-206 to Cys (R206C), is a robustly replicated heritable risk factor for SSc and other autoimmune diseases. DNASE1L3 is secreted into the circulation, where it can digest genomic DNA (gDNA) in apoptosis-derived membrane vesicles (AdMVs). We sought to determine the impact of DNASE1L3 R206C on digestion of circulating gDNA in SSc patients and healthy controls (HCs). METHODS: The ability of DNASE1L3 to digest AdMV-associated gDNA was tested in vitro. The effect of R206C substitution on extracellular secretion of DNASE1L3 was determined using a transfected cell line and primary monocyte-derived dendritic cells from SSc patients. Plasma samples from SSc patients and HCs with DNASE1L3 R206C or R206 wild type were compared for their ability to digest AdMV-associated gDNA. The digestion status of endogenous gDNA in plasma samples from 123 SSc patients and 74 HCs was determined by measuring the proportion of relatively long to short gDNA fragments. RESULTS: The unique ability of DNASE1L3 to digest AdMV-associated gDNA was confirmed. Extracellular secretion of DNASE1L3 R206C was impaired. Plasma from individuals with DNASE1L3 R206C had reduced ability to digest AdMV-associated gDNA. The ratio of long: short gDNA fragments was increased in plasma from SSc patients with DNASE1L3 R206C, and this ratio correlated inversely with DNase activity. CONCLUSION: Our results confirm that circulating gDNA is a physiological DNASE1L3 substrate and show that its digestion is reduced in SSc patients with the DNASE1L3 R206C variant.

Performance of the 2016 ACR-EULAR myositis response criteria in juvenile dermatomyositis therapeutic trials and consensus profiles.

OBJECTIVES: The 2016 ACR-EULAR Response Criteria for JDM was developed as a composite measure with differential weights of six core set measures (CSMs) to calculate a Total Improvement Score (TIS). We assessed the contribution of each CSM, representation of muscle-related and patient-reported CSMs towards improvement, and frequency of CSM worsening across myositis response criteria (MRC) categories in validation of MRC. METHODS: Data from JDM patients in the Rituximab in Myositis trial (n = 48), PRINTO JDM trial (n = 139), and consensus patient profiles (n = 273) were included. Observed vs expected CSM contributions were compared using Sign test. Characteristics of MRC categories were compared by Wilcoxon tests with Bonferroni adjustment. Spearman correlation of changes in TIS and individual CSMs were examined. Agreement between physician-assessed change and MRC categories was evaluated by weighted Cohen's kappa. RESULTS: Of 457 JDM patients with IMACS CSMs and 380 with PRINTO CSMs, 9-13% had minimal, 19-23% had moderate and 41-50% had major improvement. The number of improved and absolute percentage change of CSMs increased by MRC improvement level. Patients with minimal improvement by MRC had a median of 0-1 CSM worsened, and those with moderate/major improvement had a median of zero worsening CSMs. Of patients improved by MRC, 94-95% had improvement in muscle strength and 93-95% had improvement in ≥1 patient-reported CSM. IMACS and PRINTO CSMs performed similarly. Physician-rated change and MRC improvement categories had moderate-to-substantial agreement (Kappa 0.5-0.7). CONCLUSION: The ACR-EULAR MRC perform consistently across multiple studies, supporting its further use as an efficacy end point in JDM trials.

Haematological and other manifestations in the presence of antiphospholipid antibodies in a multicentric paediatric cohort.

OBJECTIVES: To identify the variables associated with the development of haematological manifestations in the presence of antiphospholipid antibodies (aPLs) in a paediatric cohort. METHODS: We conducted a multicentric retrospective cohort study of children under the age of 18 years. RESULTS: One hundred and thirty-four children were included; 12.2% had at least one thrombotic event (TE) and 67% at least one non-criterion manifestation. Of them, 90% did not develop any TE. Haematological manifestations were the most frequent (42%), followed by neurological (19.8%), cutaneous (17.6%), cardiac (16.8%) and renal (1.5%) manifestations. In those children with haematological disorders, the aPLs positivity rate was: 67.3% LA, 65.6% aß2GPI, 60% aCL, 45.5% single, 23.6% double and 30.9% triple. A univariate analysis showed that children with IgM aCL+, IgM aß2GPI+, triple positivity and with a SLE diagnosis had a significantly higher frequency of haematological manifestations (p<0.05). Finally, a stepwise regression analysis identified IgG aß2GPI positivity [OR 2.91, 95% CI (1.26-6.74), p=0.013], SLE [OR 2.67, 95% CI (1.13-6.3), p=0.026] and LA positivity [OR 2.53, 95% CI (1.08-5.94), p=0.033] as independent risk factors for the development of haematological manifestations. CONCLUSIONS: Non-criteria manifestations and among them haematological disorders, are the most frequent events in the presence of aPLs and/or LA in our paediatric cohort. Children with SLE, LA and/or IgG aß2GPI positivity showed a higher risk of haematological manifestations.

Hyperinflammatory syndrome in a paediatric patient with a recent diagnosis of HIV/AIDS infection: hemophagocytic lymphohistiocytosis or immune reconstitution syndrome?

INTRODUCTION: Haemophagocytic lymphohistiocytosis is a rare and life-threatening condition caused by uncontrolled immune activation leading to excessive inflammation and tissue destruction. It could either be due to a primary genetic defect or be triggered by secondary causes such as infections, autoimmune diseases, rheumatological diseases or post-transplant immunosuppression. We here report the case of a 4-year-old child with a recent AIDS diagnosis who developed a severe systemic inflammation. CASE REPORT: We here report the case of a 4-year-old child with a recent AIDS diagnosis who was admitted to the ER with acute respiratory failure due to Pneumocystis jiroveci infection and Aspergillosis; the following microbiological assessment also showed a CMV, HSV, EBV and HHV-7 coinfection. On the 51st day after she'd started antiretroviral therapy, 39th after she'd followed a course of Bactrim and Caspofungin for PJI and Ambisome for pulmonary Aspergillosis, she started presenting fever, unresponsive to broad-spectrum antibiotic therapy. She also presented worsening of her clinical conditions, with evidence at the laboratory assessments of progressive raise in inflammatory indexes, coagulopathy, trilinear cytopenia and hyperferritinemia. To perform the differential diagnosis between IRIS and HLH, HLA-DR on T cells was studied, turning out negative for IRIS. Therefore, in the suspicion of HLH, a bone marrow aspirate and biopsy were performed with evidence of trilinear cytopenia, prevalence of T-cells and macrophages with signs of phagocytosis. She was started on high-dose steroids and Anakinra for a total of 29 days, resulting in prompt apyrexia and progressive improvement of her clinical conditions and laboratory results. CONCLUSION: To the best of our knowledge there is poor literature available about the differential diagnosis of HLH and IRIS, therefore medical management in the concurrence of these two conditions needs to be further investigated, especially in a setting where immunological testing is not quickly available. The clinical differences between these pathologies are blurred and the bone marrow biopsy within marker for IRIS helped us to distinguish these two entities.

Canakinumab in systemic juvenile idiopathic arthritis: real-world data from a retrospective Italian cohort.

OBJECTIVE: The objective of this study was to use real-world data to evaluate the effectiveness and safety of canakinumab in Italian patients with systemic JIA (sJIA). METHODS: A retrospective multicentre study of children with sJIA was performed. Clinical features, laboratory parameters and adverse events were collected at baseline, and 6 and 12 months after starting canakinumab. The primary outcome measure of effectiveness was clinically inactive disease (CID) off glucocorticoids (GCs) treatment at 6 months. RESULTS: A total of 80 children from 15 Italian centres were analysed. Of the 12 patients who started canakinumab in CID while receiving anakinra, all maintained CID. Of the 68 with active disease at baseline, 57.4% achieved CID off GCs at 6 months and 63.8% at 12 months. In univariate analysis, the variables significantly related to non-response were number of active joints (NAJs) ≥5, history of macrophage activation syndrome (MAS) and disease duration. Multivariate analysis confirmed the association between non-response and NAJs ≥5 [odds ratio (OR) 6.37 (95% CI: 1.69, 24.02), P = 0.006] and between non-response and history of MAS [OR 3.53 (95% CI: 1.06, 11.70), P = 0.039]. No serious adverse events were recorded in this series. There were two cases of MAS during canakinumab, leading to a rate of 2.9 episodes per 100 patient years. CONCLUSION: We have confirmed, using real-world data, the efficacy of canakinumab in sJIA in a multicentric cohort. History of MAS and higher NAJ were associated with lower probability of achieving CID.

Common bone marrow signature in COVID-19-associated multisystem inflammatory syndrome in children: A first-wave small case series experience.

The hyper-inflammatory response, also known as multisystem inflammatory syndrome in children (MIS-C), represents a major concern in children with SARS-CoV-2 infection. We report bone marrow features of three patients with MIS-C who were diagnosed during the first wave of the SARS-CoV-2 pandemic. A bone marrow evaluation was performed at onset of the inflammatory condition in order to exclude secondary hemophagocytic lymphohistiocytosis (sHLH). The bone marrows of the patients presented common features: the erythroid and megakaryocytic lineages were prominently affected and hemophagocytosis was moderately increased, differently than observed in sHLH. Megakaryocytopoiesis was increased, representing a peculiar feature of MIS-C differing from sHLH. SARS-CoV-2 RT-PCR and viral panel were studied in bone marrow aspiration samples. MIS-C is a rare complication of SARS-CoV-2 infections in children. An immuno-dysregulation considering both innate and adaptive immunity together with vascular inflammation and endothelial dysfunction play a major role. Our observations, although limited due to the small sample size, suggest that there are unique features in the bone marrow of patients with MIS-C that are likely secondary to immuno-dysregulation, and there are notable differences in bone marrow features compared to those reported in sHLH.

Hemoperfusion with CytoSorb to Manage Multiorgan Dysfunction in the Spectrum of Hemophagocytic Lymphohistiocytosis Syndrome in Critically Ill Children.

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening condition characterized by a state of hyperinflammation. Blood purification techniques can blunt the inflammatory process with a rapidly relevant nonselective effect on the cytokine storm, thus potentially translating into survival benefit for these patients. In this cohort, we evaluated the impact of hemoadsorption with CytoSorb combined with continuous kidney replacement therapy used as adjunctive therapy in 6 critically ill children with multiple organ dysfunction due to HLH. In our series, we found a reduction in inflammatory biomarkers in patients with HLH secondary to infection. Ferritin, one of the most important bedside biomarkers of HLH, showed a reduction in most of the treated patients. The same results were found measuring interleukin-6 and interleukin-10. The same patients showed hemodynamic stabilization measured by the Vasopressor-Inotropic-Score, and reduction in the organ disease score measured with the Pediatric Logistic Organ Dysfunction score. In our cohort, mortality was less than expected based on the Pediatric Index of Mortality 3 score at pediatric intensive care unit admission. Our study shows that hemoperfusion could be a valuable therapeutic option in HLH: stronger scientific evidence is needed to confirm our preliminary experience.

Auricular leishmaniasis in a child successfully treated with intralesional amphotericin B.

Cutaneous leishmaniasis (CL) is the most frequent form of leishmaniasis. The auricle is an extremely rare site for CL in the Old World. Auricular CL may be mistaken for other entities, such as relapsing polychondritis (RP). Here we report a pediatric case of Old World auricular CL mimicking RP in a child successfully treated with intralesional liposomal amphotericin B.

Thrombotic Microangiopathy Associated with Macrophage Activation Syndrome: A Multinational Study of 23 Patients.

OBJECTIVE: To describe the clinical characteristics, treatment, and outcomes of a multinational cohort of patients with macrophage activation syndrome (MAS) and thrombotic microangiopathy (TMA). STUDY DESIGN: International pediatric rheumatologists were asked to collect retrospectively the data of patients with the co-occurrence of MAS and TMA. Clinical and laboratory features of patients with systemic juvenile idiopathic arthritis (sJIA)-associated MAS and TMA were compared with those of an historical cohort of patients with sJIA and MAS. RESULTS: Twenty-three patients with MAS and TMA were enrolled: 17 had sJIA, 2 systemic lupus erythematosus, 1 juvenile dermatomyositis, 1 mixed connective tissue disease, and 2 undifferentiated connective tissue disease. Compared with the historical cohort of MAS, patients with sJIA with coexistent MAS and TMA had higher frequencies of renal failure and neurologic involvement, hemorrhage, jaundice, and respiratory symptoms, as well as more severe anemia and thrombocytopenia, higher levels of alanine aminotransferase, lactate dehydrogenase, bilirubin and D-dimer, and lower levels of albumin and fibrinogen. They also required admission to the intensive care unit more frequently. Among patients tested, complement abnormalities and reduced ADAMTS13 activity were observed in 64.3% and 44.4% of cases, respectively. All patients received glucocorticoids. Treatment for TMA included plasma-exchange, eculizumab, and rituximab. CONCLUSIONS: The possible coexistence of MAS and TMA in rheumatic diseases may be underrecognized. This association should be considered in patients with MAS who develop disproportionate anemia, thrombocytopenia, and lactate dehydrogenase increase, or have multiorgan failure.

Childhood Sjögren syndrome: features of an international cohort and application of the 2016 ACR/EULAR classification criteria.

OBJECTIVE: Sjögren syndrome in children is a poorly understood autoimmune disease. We aimed to describe the clinical and diagnostic features of children diagnosed with Sjögren syndrome and explore how the 2016 ACR/EULAR classification criteria apply to this population. METHODS: An international workgroup retrospectively collected cases of Sjögren syndrome diagnosed under 18 years of age from 23 centres across eight nations. We analysed patterns of symptoms, diagnostic workup, and applied the 2016 ACR/EULAR classification criteria. RESULTS: We identified 300 children with Sjögren syndrome. The majority of patients n = 232 (77%) did not meet 2016 ACR/EULAR classification criteria, but n = 110 (37%) did not have sufficient testing done to even possibly achieve the score necessary to meet criteria. Even among those children with all criteria items tested, only 36% met criteria. The most common non-sicca symptoms were arthralgia [n = 161 (54%)] and parotitis [n = 140 (47%)] with parotitis inversely correlating with age. CONCLUSION: Sjögren syndrome in children can present at any age. Recurrent or persistent parotitis and arthralgias are common symptoms that should prompt clinicians to consider the possibility of Sjögren syndrome. The majority of children diagnosed with Sjögren syndromes did not meet 2016 ACR/EULAR classification criteria. Comprehensive diagnostic testing from the 2016 ACR/EULAR criteria are not universally performed. This may lead to under-recognition and emphasizes a need for further research including creation of paediatric-specific classification criteria.

IgM on the surface of T cells: a novel biomarker of pediatric-onset systemic lupus erythematosus.

BACKGROUND: Children with systemic lupus erythematosus (SLE) frequently have kidney involvement. Lupus nephritis sometimes presents alone, without systemic SLE features, representing the so-called full-house nephropathy (FHN). Distinguishing patients with SLE or FHN has therapeutic and prognostic implications. METHODS: In this retrospective observational study, we determined the presence of IgM on the surface of T cells (T cell IgM) by flow cytometry and characterized its ability in distinguishing SLE and FHN patients in a large pediatric cohort (n = 84). Fifty-seven patients with SLE (≥ 4 SLICC criteria at disease onset or during the follow-up) and 27 patients with FHN (3 or less SLICC criteria) were enrolled. RESULTS: Elevated T cell IgM levels were found in 24/25 SLE patients in active phase of disease and in 29/45 SLE patients in remission. In contrast, among FHN patients, only 1/9 presented this characteristic in active phase of disease and 0/20 in remission. Compared with standardized SLICC laboratory parameters, i.e., autoantibody titers and hypocomplementemia, T cell IgM positivity showed an extremely high sensitivity and specificity for the diagnosis of SLE, with the highest area under the curve (0.97, p < 0.001) by receiver operating characteristic analysis, similar to ANA (0.96, p < 0.001) and anti-dsDNA (0.90, p < 0.001) autoantibodies. CONCLUSIONS: Altogether, our data indicate that T cell IgM intensity may be a useful tool to correctly classify patients with lupus nephritis as SLE or FHN since disease onset.

Development and initial validation of a composite disease activity score for systemic juvenile idiopathic arthritis.

OBJECTIVE: To develop a composite disease activity score for systemic JIA (sJIA) and to provide preliminary evidence of its validity. METHODS: The systemic Juvenile Arthritis Disease Activity Score (sJADAS) was constructed by adding to the four items of the original JADAS a fifth item that aimed to quantify the activity of systemic features. Validation analyses were conducted on patients with definite or probable/possible sJIA enrolled at first visit or at the time of a flare, who had active systemic manifestations, which should include fever. Patients were reassessed 2 weeks to 3 months after baseline. Three versions were examined, including ESR, CRP or no acute-phase reactant. RESULTS: A total of 163 patients were included at 30 centres in 10 countries. The sJADAS was found to be feasible and to possess face and content validity, good construct validity, satisfactory internal consistency (Cronbach's alpha 0.64-0.65), fair ability to discriminate between patients with different disease activity states and between those whose parents were satisfied or not satisfied with illness outcome (P < 0.0001 for both), and strong responsiveness to change over time (standardized response mean 2.04-2.58). Overall, these properties were found to be better than those of the original JADAS and of DAS for RA and of Puchot score for adult-onset Still's disease. CONCLUSION: The sJADAS showed good measurement properties and is therefore a valid instrument for the assessment of disease activity in children with sJIA. The performance of the new tool should be further examined in other patient cohorts that are evaluated prospectively.

Acute rheumatic fever prophylaxis in high-income countries: clinical observations from an Italian multicentre, retrospective study.

OBJECTIVES: The aim of the study is to evaluate the compliance rate to secondary prophylaxis and the presence of rheumatic heart disease (RHD) in a cohort of Italian patients with acute rheumatic fever (ARF). METHODS: This is a multicentre retrospective study. The patients were divided into two groups by the presence or absence at last follow-up of RHD. Clinical features, ARF recurrences and the rate of compliance to secondary prophylaxis were evaluated. RESULTS: Two-hundred and ninety patients were enrolled (137 females; 153 males). Carditis at onset was present in 244 patients (84.7%). At the end of follow-up, 173 patients manifested RHD. Adherence to secondary prophylaxis was low in 26% of patients. The presence of RHD at follow-up was associated with the presence of carditis and its severity at onset (p=0.001), but it was not related to secondary prophylaxis adherence (p=NS). No association between prophylaxis adherence and ARF recurrence was found (p=NS) nor between ARF recurrence and RHD at the end of follow-up (p=NS). CONCLUSIONS: Poor adherence to secondary prophylaxis does not seem to be associated with increased risk of RHD in developed countries. Further studies are needed to confirm our data in a larger population.

Interleukin-18 in pediatric rheumatic diseases.

PURPOSE OF REVIEW: IL-18 is a pleiotropic cytokine involved in the regulation of innate and adaptive immune responses. IL-18 pro-inflammatory activities are finely regulated in vivo by the inhibitory effects of the soluble IL-18-binding protein (IL-18BP). The elevation of circulating levels of IL-18 has been described in children with systemic juvenile idiopathic arthritis (sJIA). In the recent years, the role of IL-18 in the pathogenesis of secondary haemophagocytic lymphohistiocytosis (sHLH), also referred to as macrophage activation syndrome (MAS), in the context of autoinflammatory diseases, including sJIA, is emerging. RECENT FINDINGS: A large number of studies in patients and animal models pointed to the imbalance in IL-18/IL-18BP levels, causing increased systemic levels of free bioactive IL-18, as a predisposing factor in the development of MAS. Although the exact mechanisms involved in the development of MAS are not clearly understood, increasing evidence demonstrate the role of IL-18 in upregulating the production of interferon (IFN)-γ. SUMMARY: On the basis of the first emerging data on the possibility of blocking IL-18, we here discuss the scientific rationale for neutralizing the IL-18/IFNγ axis in the prevention and treatment of sHLH and MAS.