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.

Prognostic Factors and Long-Term Outcome with ANCA-Associated Kidney Vasculitis in Childhood.

BACKGROUND AND OBJECTIVES: ANCA-associated vasculitis is extremely rare in children. We report the clinicopathologic features, long-term outcomes, and prognostic factors of a large pediatric cohort of patients with ANCA-associated kidney vasculitis. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This retrospective study included 85 consecutive patients with kidney biopsy specimen-proven ANCA-associated vasculitis from tertiary referral centers in Italy and Canada. Kidney biopsy specimens were categorized as focal, crescentic, sclerotic, or mixed, according to the Berden classification. The prognostic significance of baseline clinical, laboratory, and histologic findings was analyzed with respect to kidney failure or CKD stage 3-5/kidney failure. RESULTS: A total of 53 patients had microscopic polyangiitis (62%), and 32 had granulomatosis with polyangiitis (38%). Rapidly progressive GN was the most frequent presentation (39%); a third of the patients also had nephrotic-range proteinuria. Kidney biopsy specimens were classified as focal in 21% of the patients, crescentic in 51%, sclerotic in 15%, and mixed in 13%. Remission-induction therapies included cyclophosphamide in 78% of patients. A total of 25 patients (29%) reached kidney failure. The median (interquartile range) time to kidney failure or last follow-up was 35 (6-89) months in the whole cohort, and 73 (24-109) months among the patients who did not reach this outcome. Patients whose biopsy specimens showed sclerotic histology had significantly shorter kidney survival (hazard ratio, 11.80; 95% confidence interval, 2.49 to 55.99) and survival free of CKD stage 3-5 (hazard ratio, 8.88; 95% confidence interval, 2.43 to 32.48), as compared with those with focal/mixed histology. Baseline eGFR, low serum albumin, hypertension, central nervous system complications, and sclerotic histology, which reflected severe kidney involvement, were associated with both kidney failure and CKD stage 3-5/kidney failure at unadjusted analysis; no independent prognostic factors emerged at multivariable analysis. CONCLUSIONS: Children with ANCA-associated kidney vasculitis often have aggressive presentation; a third of such children progress to kidney failure and this usually occurs early during follow-up. A severe clinical presentation is associated with the development of CKD or kidney failure.

Early Treatment and IL1RN Single-Nucleotide Polymorphisms Affect Response to Anakinra in Systemic Juvenile Idiopathic Arthritis.

OBJECTIVE: To evaluate the impact of early treatment and IL1RN genetic variants on the response to anakinra in systemic juvenile idiopathic arthritis (JIA). METHODS: Response to anakinra was defined as achievement of clinically inactive disease (CID) at 6 months without glucocorticoid treatment. Demographic, clinical, and laboratory characteristics of 56 patients were evaluated in univariate and multivariate analyses as predictors of response to treatment. Six single-nucleotide polymorphisms (SNPs) in the IL1RN gene, previously demonstrated to be associated with a poor response to anakinra, were genotyped by quantitative polymerase chain reaction (qPCR) or Sanger sequencing. Haplotype mapping was performed with Haploview software. IL1RN messenger RNA (mRNA) expression in whole blood from patients, prior to anakinra treatment initiation, was assessed by qPCR. RESULTS: After 6 months of anakinra treatment, 73.2% of patients met the criteria for CID without receiving glucocorticoids. In the univariate analysis, the variable most strongly related to the response was disease duration from onset to initiation of anakinra treatment, with an optimal cutoff at 3 months (area under the curve 84.1%). Patients who started anakinra treatment ≥3 months after disease onset had an 8-fold higher risk of nonresponse at 6 months of treatment. We confirmed that the 6 IL1RN SNPs were inherited as a common haplotype. We found that homozygosity for ≥1 high-expression SNP correlated with higher IL1RN mRNA levels and was associated with a 6-fold higher risk of nonresponse, independent of disease duration. CONCLUSION: Our findings on patients with systemic JIA confirm the important role of early interleukin-1 inhibition and suggest that genetic IL1RN variants predict nonresponse to therapy with anakinra.

The interferon-gamma pathway is selectively up-regulated in the liver of patients with secondary hemophagocytic lymphohistiocytosis.

Aim of this study was to investigate the activation of the IFNγ pathway in the affected liver and in the blood of patients with secondary hemophagocytic lymphohistiocytosis (sHLH). To this purpose, the mRNA expression levels of IFNG and IFNγ-inducible genes as well as Tyrosine (701)-phosphorylated signal transducer and activator of transcription 1 (STAT1) protein levels were evaluated in the liver and in peripheral blood mononuclear cells (PBMCs) of three patients with sHLH with predominant liver involvement. The mRNA expression levels of IFNG and IFNγ-inducible genes were markedly higher in patient livers compared to control livers and to one disease control liver. Conversely, slight differences in the expression levels of Type I IFN-inducible genes and other classical inflammatory cytokine genes were found. Further supporting the activation of the IFNγ pathway, higher protein levels of phosphorylated and total STAT1 were detected in patient livers compared to control livers. When the expression of the same genes analysed in liver tissues was evaluated in PBMCs collected from 2 out of 3 patients before the liver biopsy, we found that mRNA levels of IFNγ-inducible genes were markedly increased. Accordingly, high circulating levels of IFNγ-inducible CXCL9 were observed in patients. Altogether, these data demonstrate the selective and marked up-regulation of the IFNγ pathway in the liver tissue and blood of patients with active sHLH. Finally, we show that measurement of circulating CXCL9 levels and evaluation of IFNγ-inducible gene expression levels in PBMCs may represent a new valid tool to better identify patients with suspected HLH with predominant liver involvement.

An unusual presentation of purine nucleoside phosphorylase deficiency mimicking systemic juvenile idiopathic arthritis complicated by macrophage activation syndrome.

BACKGROUND: Systemic juvenile idiopathic arthritis (sJIA) is an inflammatory condition that presents with fever, rash and arthritis. At onset systemic features are predominant and the diagnosis may be a challenge. Secondary hemophagocytic lymphohistiocytosis (sHLH) forms may be associated with different disorders, including rheumatic diseases, and this form is called macrophage activation syndrome (MAS). CXCL9 levels, a chemokine induced by IFNγ, are significantly elevated in patients with sHLH or MAS and are correlated with laboratory features of disease activity. High levels of IL-18 have been reported in patients with MAS during sJIA, as well as in some patients with sHLH and IL-18 is indeed known to induce IFNγ production. FINDINGS: We report a patient with a clinical presentation highly suggestive for systemic juvenile idiopathic arthritis (sJIA) onset complicated by MAS, and was later diagnosed with purine nucleoside phosphorylase (PNP)-deficiency with HLH. Some unusual features appeared when HLH was controlled and further investigations provided the correct diagnosis. Serum CXCL9 and IL-18 levels were found markedly elevated at disease onset, during the active phase of MAS and decreased progressively during the course. CONCLUSION: The reported case underlines the potential difficulties in discriminating sJIA from other causes of systemic inflammation. Furthermore, this supports the notion that especially in young children with a sJIA-like disease other mimicking conditions should be actively sought for. CXCL9 and IL-18 levels suggested that patients with PNP-deficiency may have a subclinical activation of the IFNγ pathway and indeed they are predisposed to develop sHLH.

Kawasaki disease: guidelines of Italian Society of Pediatrics, part II - treatment of resistant forms and cardiovascular complications, follow-up, lifestyle and prevention of cardiovascular risks.

This second part of practical Guidelines related to Kawasaki disease (KD) has the goal of contributing to prompt diagnosis and most appropriate treatment of KD resistant forms and cardiovascular complications, including non-pharmacologic treatments, follow-up, lifestyle and prevention of cardiovascular risks in the long-term through a set of 17 recommendations.Guidelines, however, should not be considered a norm that limits the treatment options of pediatricians and practitioners, as treatment modalities other than those recommended may be required as a result of peculiar medical circumstances, patient's condition, and disease severity or individual complications.

Kawasaki disease: guidelines of the Italian Society of Pediatrics, part I - definition, epidemiology, etiopathogenesis, clinical expression and management of the acute phase.

The primary purpose of these practical guidelines related to Kawasaki disease (KD) is to contribute to prompt diagnosis and appropriate treatment on the basis of different specialists' contributions in the field. A set of 40 recommendations is provided, divided in two parts: the first describes the definition of KD, its epidemiology, etiopathogenetic hints, presentation, clinical course and general management, including treatment of the acute phase, through specific 23 recommendations.Their application is aimed at improving the rate of treatment with intravenous immunoglobulin and the overall potential development of coronary artery abnormalities in KD. Guidelines, however, should not be considered a norm that limits treatment options of pediatricians and practitioners, as treatment modalities other than those recommended may be required as a result of peculiar medical circumstances, patient's condition, and disease severity or complications.

ANCA-associated vasculitis in childhood: recent advances.

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides are rare systemic diseases that usually occur in adulthood. They comprise granulomatosis with polyangiitis (GPA, Wegener's), microscopic polyangiitis (MPA) and eosinophilic granulomatosis with polyangiitis (EGPA, Churg-Strauss syndrome). Their clinical presentation is often heterogeneous, with frequent involvement of the respiratory tract, the kidney, the skin and the joints. ANCA-associated vasculitis is rare in childhood but North-American and European cohort studies performed during the last decade have clarified their phenotype, patterns of renal involvement and their prognostic implications, and outcome. Herein, we review the main clinical and therapeutic aspects of childhood-onset ANCA-associated vasculitis, and provide preliminary data on demographic characteristics and organ manifestations of an Italian multicentre cohort.