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.

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.

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.

Subcutaneous dosing regimens of tocilizumab in children with systemic or polyarticular juvenile idiopathic arthritis.

OBJECTIVES: To determine s.c. tocilizumab (s.c.-TCZ) dosing regimens for systemic JIA (sJIA) and polyarticular JIA (pJIA). METHODS: In two 52-week phase 1 b trials, s.c.-TCZ (162 mg/dose) was administered to sJIA patients every week or every 2 weeks (every 10 days before interim analysis) and to pJIA patients every 2 weeks or every 3 weeks with body weight ≥30 kg or <30 kg, respectively. Primary end points were pharmacokinetics, pharmacodynamics and safety; efficacy was exploratory. Comparisons were made to data from phase 3 trials with i.v. tocilizumab (i.v.-TCZ) in sJIA and pJIA. RESULTS: Study participants were 51 sJIA patients and 52 pJIA patients aged 1-17 years who received s.c.-TCZ. Steady-state minimum TCZ concentration (Ctrough) >5th percentile of that achieved with i.v.-TCZ was achieved by 49 (96%) sJIA and 52 (100%) pJIA patients. In both populations, pharmacodynamic markers of disease were similar between body weight groups. Improvements in Juvenile Arthritis DAS-71 were comparable between s.c.-TCZ and i.v.-TCZ. By week 52, 53% of sJIA patients and 31% of pJIA patients achieved clinical remission on treatment. Safety was consistent with that of i.v.-TCZ except for injection site reactions, reported by 41.2% and 28.8% of sJIA and pJIA patients, respectively. Infections were reported in 78.4% and 69.2% of patients, respectively. Two sJIA patients died; both deaths were considered to be related to TCZ. CONCLUSION: s.c.-TCZ provides exposure and risk/benefit profiles similar to those of i.v.-TCZ. S.c. administration provides an alternative administration route that is more convenient for patients and caregivers and that has potential for in-home use. TRIAL REGISTRATION: ClinicalTrials.gov, http://clinicaltrials.gov, NCT01904292 and NCT01904279.

Chronic nonbacterial osteomyelitis - clinical and magnetic resonance imaging features.

BACKGROUND: Chronic nonbacterial osteomyelitis (CNO) is a rare autoinflammatory bone disorder. Little information exists on the use of imaging techniques in CNO. MATERIALS AND METHODS: We retrospectively reviewed clinical and MRI findings in children diagnosed with CNO between 2012 and 2018. Criteria for CNO included unifocal or multifocal inflammatory bone lesions, symptom duration >6 weeks and exclusion of infections and malignancy. All children had an MRI (1.5 tesla) performed at the time of diagnosis; 68 of these examinations were whole-body MRIs including coronal short tau inversion recovery sequences, with additional sequences in equivocal cases. RESULTS: We included 75 children (26 boys, or 34.7%), with mean age 10.5 years (range 0-17 years) at diagnosis. Median time from disease onset to diagnosis was 4 months (range 1.5-72.0 months). Fifty-nine of the 75 (78.7%) children presented with pain, with or without swelling or fever, and 17 (22.7%) presented with back pain alone. Inflammatory markers were raised in 46/75 (61.3%) children. Fifty-four of 75 (72%) had a bone biopsy. Whole-body MRI revealed a median number of 6 involved sites (range 1-27). Five children (6.7%) had unifocal disease. The most commonly affected bones were femur in 46 (61.3%) children, tibia in 48 (64.0%), pelvis in 29 (38.7%) and spine in 20 (26.7%). Except for involvement of the fibula and spine, no statistically significant differences were seen according to gender. CONCLUSION: Nearly one-fourth of the children presented with isolated back pain, particularly girls. The most common sites of disease were the femur, tibia and pelvic bones. Increased inflammatory markers seem to predict the number of MRI sites involved.

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.

Prevalence of cranial involvement in a cohort of Italian patients with chronic non-bacterial osteomyelitis.

OBJECTIVES: Chronic non-bacterial osteomyelitis (CNO) is a non-infectious inflammatory disease characterised by uni- or multi-focal bone lytic lesions. CNO mainly affects metaphysis of long bones, pelvis and shoulder girdle. Neurocranium lesions are extremely rare. The objective of the study is to describe the prevalence and clinical manifestations of CNO patients with neurocranium involvement in an Italian cohort of CNO patients. METHODS: This is a retrospective study. Medical records of patients with CNO admitted to eight paediatric rheumatology centres were reviewed. RESULTS: Among 86 patients with CNO enrolled in the study, three of them were female and presented neurocranium involvement - multifocal lesions. Two out of the 3 patients were completely asymptomatic for cranial involvement, while one of the 3 complained of cranial bossing. Cranial involvement was detected with bone scintigraphy and then confirmed by magnetic resonance imaging and/or computed tomography. Two patients presented fever and two with skin manifestations. Laboratory inflammatory markers were increased in two of them. All patients underwent bone biopsy confirming the diagnosis. They all received NSAIDs. Two patients received corticosteroids and then methotrexate and achieved clinical remission, while one patient received pamidronate. CONCLUSIONS: This is the first report of neurocranium involvement in a cohort of patients affected by CNO. In our cohort no patient showed significant signs attributable to cranial involvement.

ADA2 deficiency (DADA2) as an unrecognised cause of early onset polyarteritis nodosa and stroke: a multicentre national study.

OBJECTIVES: To analyse the prevalence of CECR1 mutations in patients diagnosed with early onset livedo reticularis and/or haemorrhagic/ischaemic strokes in the context of inflammation or polyarteritis nodosa (PAN). Forty-eight patients from 43 families were included in the study. METHODS: Direct sequencing of CECR1 was performed by Sanger analysis. Adenosine deaminase 2 (ADA2) enzymatic activity was analysed in monocyte isolated from patients and healthy controls incubated with adenosine and with or without an ADA1 inhibitor. RESULTS: Biallelic homozygous or compound heterozygous CECR1 mutations were detected in 15/48 patients. A heterozygous disease-associated mutation (p.G47V) was observed in two affected brothers. The mean age of onset of the genetically positive patients was 24 months (6 months to 7 years). Ten patients displayed one or more cerebral strokes during their disease course. Low immunoglobulin levels were detected in six patients. Thalidomide and anti-TNF (tumour necrosis factor) blockers were the most effective drugs. Patients without CECR1 mutations had a later age at disease onset, a lower prevalence of neurological and skin manifestations; one of these patients displayed all the clinical features of adenosine deaminase 2deficiency (DADA2) and a defective enzymatic activity suggesting the presence of a missed mutation or a synthesis defect. CONCLUSIONS: DADA2 accounts for paediatric patients diagnosed with PAN-like disease and strokes and might explain an unrecognised condition in patients followed by adult rheumatologist. Timely diagnosis and treatment with anti-TNF agents are crucial for the prevention of severe complications of the disease. Functional assay to measure ADA2 activity should complement genetic testing in patients with non-confirming genotypes.

Haematological involvement associated with a mild autoinflammatory phenotype, in two patients carrying the E250K mutation of PSTPIP1.

OBJECTIVES: Hyperzincaemia/hypercalprotectinemia (Hz/Hc) syndrome is a recently described condition caused by a specific de novo mutation (E250K) affecting PSTPIP1 gene. It has a phenotype distinct from classical pyogenic arthritis, pyoderma gangrenosum, and acne (PAPA) syndrome that includes severe systemic and cutaneous inflammation, hepatosplenomegaly, arthritis without sequelae, pancytopenia and failure to thrive. METHODS: We describe an 8-year-old boy who presented recurrent right knee swelling mimicking septic arthritis and persistent bone marrow involvement, without cutaneous involvement. RESULTS: Molecular analysis of the PSTPIP1 gene revealed the presence of a heterozygous E250K mutation. No growth failure was detected nor in the patient neither in his mother, carrying the same variant. Blood zinc and calprotectin MRP8/14 concentrations of the patient were found to be markedly increased. Therapy with anakinra was started with rapid disappearance of clinical symptoms and normalization of CRP levels in 24 hours, but persistence of bone marrow involvement. CONCLUSIONS: The patient described has a milder phenotype, with no skin features, minor episodes of arthritis with no sequelae and normal growth. Compared to the patients with de novo mutations described in the literature, familial cases seem to have a milder phenotype. Our case further confirms the lack of efficacy of anakinra on bone marrow involvement.

A novel mutation in the CIAS1/NLRP3 gene associated with an unexpected phenotype of cryopyrin-associated periodic syndromes.

OBJECTIVES: Cryopyrin-associated periodic syndromes (CAPS) comprise a spectrum of distinct, rare, autosomal dominant autoinflammatory disorders of increasing severity caused by NLRP3 gene mutations. METHODS: We describe a 13-year-old female who presented, in the initial phase of the disease, recurrent episodes of high fever, pericarditis, arthralgia, arthritis of the knees, abdominal pain and marked increase in inflammatory markers. In the subsequent months she developed recurrent episodes of chest pain, skin rash and swelling of the subcutaneous tissue, without fever, and with spontaneous resolution. RESULTS: Molecular analysis of the CIAS1 gene revealed the presence of the Q703K variant and also a c.1105C>A mutation in the heterozygous state, that predicts a L369M amino acid substitution. The latter variant has never been reported. The L369M mutation was predicted to significantly affect protein structure (scoring as 'dangerous' and 'deleterious') by the Variant Effect Predictor tool. Therapy with anakinra was started with rapid disappearance of clinical symptoms and normalization of CRP levels in 24 hours. CONCLUSIONS: The rapid response to IL-1 inhibition suggests that the disease of this patient is driven by IL-1 and supports the conclusion that this novel mutation is pathogenic and may be associated with a new CAPS phenotype. The role played by the concomitant presence of the mutation Q703K remains to be clarified.

Defining Criteria for Disease Activity States in Systemic Juvenile Idiopathic Arthritis Based on the Systemic Juvenile Arthritis Disease Activity Score.

OBJECTIVE: Our objective was to develop and validate cutoff values in the systemic Juvenile Arthritis Disease Activity Score 10 (sJADAS10) that distinguish the states of inactive disease (ID), minimal disease activity (MDA), moderate disease activity (MoDA), and high disease activity (HDA) in children with systemic juvenile idiopathic arthritis, based on subjective disease state assessment by the treating pediatric rheumatologist. METHODS: The cutoff definition cohort was composed of 400 patients enrolled at 30 pediatric rheumatology centers in 11 countries. Using the subjective physician rating as an external criterion, six methods were applied to identify the cutoffs: mapping, calculation of percentiles of cumulative score distribution, the Youden index, 90% specificity, maximum agreement, and receiver operating characteristic curve analysis. Sixty percent of the patients were assigned to the definition cohort, and 40% were assigned to the validation cohort. Cutoff validation was conducted by assessing discriminative ability. RESULTS: The sJADAS10 cutoffs that separated ID from MDA, MDA from MoDA, and MoDA from HDA were ≤2.9, ≤10, and >20.6, respectively. The cutoffs discriminated strongly among different levels of pain, between patients with and without morning stiffness, and among patients whose parents judged their disease status as remission or persistent activity or flare or were satisfied or not satisfied with current illness outcome. CONCLUSION: The sJADAS cutoffs revealed good metrologic properties in both definition and validation cohorts and are therefore suitable for use in clinical trials and routine practice.

Necrosis of the tongue as first symptom of Polyarteritis Nodosa (PAN): unusual presentation of a rare disease in children.

Polyarteritis or panarteritis nodosa (PAN) is a necrotizing, focal segmental vasculitis that affects predominantly medium-sized arteries in many different organ systems. It is extremely rare in childhood. Involvement of the oral mucosa at diagnosis is uncommon in PAN. Here, we report a case of a pediatric patient with tongue necrosis.

Feasibility of Conducting Comparative Effectiveness Research and Validation of a Clinical Disease Activity Score for Chronic Nonbacterial Osteomyelitis.

OBJECTIVE: Prospective comparative effectiveness research (CER) in chronic nonbacterial osteomyelitis (CNO) is lacking. Our objectives were to (1) determine the use and safety of each consensus treatment plan (CTP) regimen for CNO, (2) assess the feasibility of using the Chronic Nonbacterial Osteomyelitis International Registry (CHOIR) data for CER, and (3) develop and validate a CNO clinical disease activity score (CDAS) using CHOIR. METHODS: Consenting children or young adults with CNO were enrolled into CHOIR. Demographic, clinical, and imaging data were prospectively collected. The CNO CDAS was developed through a Delphi survey and nominal group technique. External validation surveys were administered to CHOIR participants. RESULTS: One hundred forty (78.2%) CHOIR participants enrolled between August 2018 and September 2020 received at least 1 CTP regimen. Baseline characteristics from different CTP groups were well matched. Patient pain, patient global assessment, and clinical CNO lesion count were key variables included in the CNO CDAS. The CDAS showed a strong correlation with patient/parent report of difficulty using a limb, back, or jaw and patient/parent report of disease severity, but a weak correlation with patient/parent report of fatigue, sadness, and worry. The change in CDAS was significant in patients reporting disease worsening or improvement (P < 0.001). The CDAS significantly decreased after initiating second-line treatments from median 12.0 (IQR 8.0-15.5) to 5.0 (IQR 3.0-12.0; P = 0.002). Although second-line treatments were well tolerated, psoriasis was the most common adverse event. CONCLUSION: The CNO CDAS was developed and validated for disease monitoring and assessment of treatment effectiveness. CHOIR provided a comprehensive framework for future CER.

Anakinra as first-line disease-modifying therapy in systemic juvenile idiopathic arthritis: report of forty-six patients from an international multicenter series.

OBJECTIVE: To examine the safety and efficacy of the interleukin-1 (IL-1) receptor antagonist anakinra as first-line therapy for systemic juvenile idiopathic arthritis (JIA). METHODS: Patients with systemic JIA receiving anakinra as part of initial disease-modifying antirheumatic drug (DMARD) therapy were identified from 11 centers in 4 countries. Medical records were abstracted using a standardized instrument, and resulting data were analyzed to characterize concomitant therapies, clinical course, adverse events, and predictors of outcome. RESULTS: Among 46 patients meeting inclusion criteria, anakinra monotherapy was used in 10 patients (22%), while 67% received corticosteroids and 33% received additional DMARDs. Outcomes were evaluated at a median followup interval of 14.5 months. Fever and rash resolved within 1 month in >95% of patients, while C-reactive protein and ferritin normalized within this interval in >80% of patients. Active arthritis persisted at 1 month in 39% of patients, at 3 months in 27%, and at >6 months of followup in 11%. Approximately 60% of patients, including 8 of 10 receiving anakinra monotherapy, attained a complete response without escalation of therapy. Disease characteristics and treatment were similar in partial and complete responders, except that partial responders were markedly younger at onset (median age 5.2 years versus 10.2 years; P = 0.004). Associated adverse events included documented bacterial infection in 2 patients and hepatitis in 1 patient. Tachyphylaxis was not observed. CONCLUSION: Anakinra as first-line therapy for systemic JIA was associated with rapid resolution of systemic symptoms and prevention of refractory arthritis in almost 90% of patients during the interval examined. These results justify further study of IL-1 inhibition as first-line, rather than rescue, therapy in systemic JIA.

Priming of hematopoietic progenitor cells by plerixafor and filgrastim in children with previous failure of mobilization with chemotherapy and/or cytokine treatment.

Plerixafor has been recently approved by the European Medicines Agency for adult patients who have failed other mobilization strategies. Experience in children, however, is extremely limited. We describe the experience of the use of this drug in 8 children under a compassionate-use program in 3 Italian and 2 Spanish centers. Plerixafor was generally well tolerated; only 2 of 8 children reported adverse effects, and these were mild in intensity. Peripheral blood progenitor cell priming was improved with plerixafor in 6 of 8 patients. In the remaining 2 patients, the target CD34+ cell count was below the target of 2 × 10(6) cells/kg, although in these patients cell counts before collection were good enough for leukapheresis. Plerixafor, therefore seems to be safe and effective for peripheral blood progenitor cell mobilization in children. Adverse events were comparable with those described with filgrastim alone.

Kawasaki syndrome and concurrent Coxsackie virus B3 infection.

We describe two previously healthy children who were hospitalized in the same period in different departments of our University with clinical signs of Kawasaki syndrome, which were treated with intravenous immunoglobulins and acetylsalicylic acid: in both cases, Coxsackie virus infection was concurrently demonstrated by enzyme-linked immunosorbent assay, and complement fixation test identified antibodies to serotype B3. In the acute phase, both patients presented hyperechogenic coronary arteries, but no cardiologic sequels in the mid term. The etiological relationship between Kawasaki syndrome and Coxsackie viruses is only hypothetical; however, the eventual identification of ad hoc environmental triggers is advisable in front of children with Kawasaki syndrome, with the aim of optimizing epidemiological surveillance and understanding the intimate biological events of this condition.