Flora Magnotti

Biological treatments: new weapons in the management of monogenic autoinflammatory disorders

Treatment of monogenic autoinflammatory disorders, an expanding group of hereditary diseases characterized by apparently unprovoked recurrent episodes of inflammation, without high-titre autoantibodies or antigen-specific T cells, has been revolutionized by the discovery that several of these conditions are caused by mutations in proteins involved in the mechanisms of innate immune response, including components of the inflammasome, cytokine receptors, receptor antagonists, and oversecretion of a network of proinflammatory molecules. Aim of this review is to synthesize the current experience and the most recent evidences about the therapeutic approach with biologic drugs in pediatric and adult patients with monogenic autoinflammatory disorders.

First Report of Circulating MicroRNAs in Tumour Necrosis Factor Receptor-Associated Periodic Syndrome (TRAPS)

Tumor necrosis factor-receptor associated periodic syndrome (TRAPS) is a rare autosomal dominant autoinflammatory disorder characterized by recurrent episodes of long-lasting fever and inflammation in different regions of the body, such as the musculo-skeletal system, skin, gastrointestinal tract, serosal membranes and eye. Our aims were to evaluate circulating microRNAs (miRNAs) levels in patients with TRAPS, in comparison to controls without inflammatory diseases, and to correlate their levels with parameters of disease activity and/or disease severity. Expression levels of circulating miRNAs were measured by Agilent microarrays in 29 serum samples from 15 TRAPS patients carrying mutations known to be associated with high disease penetrance and from 8 controls without inflammatory diseases. Differentially expressed and clinically relevant miRNAs were detected using GeneSpring GX software. We identified a 6 miRNAs signature able to discriminate TRAPS from controls. Moreover, 4 miRNAs were differentially expressed between patients treated with the interleukin (IL)-1 receptor antagonist, anakinra, and untreated patients. Of these, miR-92a-3p and miR-150-3p expression was found to be significantly reduced in untreated patients, while their expression levels were similar to controls in samples obtained during anakinra treatment. MiR-92b levels were inversely correlated with the number of fever attacks/year during the 1st year from the index attack of TRAPS, while miR-377-5p levels were positively correlated with serum amyloid A (SAA) circulating levels. Our data suggest that serum miRNA levels show a baseline pattern in TRAPS, and may serve as potential markers of response to therapeutic intervention.

The labyrinth of autoinflammatory disorders: a snapshot on the activity of a third-level center in Italy

Autoinflammatory disorders (AIDs) are a novel class of diseases elicited by mutations in genes regulating the homeostasis of innate immune complexes, named inflammasomes, which lead to uncontrolled oversecretion of the proinflammatory cytokine interleukin-1β. Protean inflammatory symptoms are variably associated with periodic fever, depicting multiple specific conditions. Childhood is usually the lifetime in which most hereditary AIDs start, though still a relevant number of patients may experience a delayed disease onset and receive a definite diagnosis during adulthood. As a major referral laboratory for patients with recurrent fevers, we have tested samples from 787 patients in the period September 2007–March 2014, with a total of 1,328 AID-related genes evaluated and a gene/patient ratio of 1.69. In this report, we describe our experience in the clinical approach to AIDs, highlight the most striking differences between child and adult-onset AIDs, and shed an eye-opening insight into their diagnostic process.

Weekly oral alendronate in mevalonate kinase deficiency

BackgroundMevalonate kinase deficiency (MKD) is caused by mutations in the MVK gene, encoding the second enzyme of mevalonate pathway, which results in subsequent shortage of downstream compounds, and starts in childhood with febrile attacks, skin, joint, and gastrointestinal symptoms, sometimes induced by vaccinations.MethodsFor a history of early-onset corticosteroid-induced reduction of bone mineral density in a 14-year-old boy with MKD, who also had presented three bone fractures, we administered weekly oral alendronate, a drug widely used in the management of osteoporosis and other high bone turnover diseases, which blocks mevalonate and halts the prenylation process.ResultsAll of the patient’s MKD clinical and laboratory abnormalities were resolved after starting alendronate treatment.ConclusionsThis observation appears enigmatic, since alendronate should reinforce the metabolic block characterizing MKD, but is crucial because of the ultimate improvement shown by this patient. The anti-inflammatory properties of bisphosphonates are a new question for debate among physicians across various specialties, and requires further biochemical and clinical investigation.

Working the endless puzzle of hereditary autoinflammatory disorders

Abstract Hereditary autoinflammatory disorders encompass manifold dysfunctions of innate immunity caused by mutations in genes coding for the main characters of the inflammatory scene: most of these conditions have an early onset, ranging from the first days of life to the first decades, and include hereditary periodic fevers, NLRP-related diseases, granulomatous and pyogenic syndromes, which are basically characterized by upturned inflammasome activity and overproduction of bioactive interleukin (IL)-1β and other proinflammatory cytokines. The discovery of a causative link between autoinflammation and IL-1β release has improved our understanding of the intimate mechanisms of innate immunity, and has likewise led to the identification of extraordinary treatments for many of these disorders.

Immunometabolic biomarkers of inflammation in Behçet's disease: relationship with epidemiological profile, disease activity and therapeutic regimens

Behcets disease (BD) is a systemic inflammatory disease with a still unclear pathogenesis. Although several inflammatory molecules have been studied, current biomarkers are largely insensitive in BD and unable to predict disease progression and response to treatment. Our primary aim was to explore serum levels of soluble CD40 L (sCD40L), soluble intracellular adhesion molecule (sICAM‐1), monocyte chemoattractant protein‐1 (MCP‐1), myeloperoxidase (MPO), leptin, resistin, osteoprotegerin (OPG), soluble type 1 tumour necrosis factor receptor (sTNFR), interleukin (IL)−6 and serum amyloid A (SAA) serum concentration in a cohort of 27 BD patients. The secondary aim was to evaluate potential correlations between the putative circulating biomarkers, demographic profile of patients, the status of disease activity, the specific organ involvement at the time of sample collection and different therapeutic regimens. Serum concentrations of sTNFR (P = 0·008), leptin (P = 0·0011), sCD40L (P < 0·0001) and IL‐6 (P = 0·0154) were significantly higher in BD patients than in HC, while no difference was found in MCP‐1, MPO and resistin serum levels. Moreover, we observed significantly higher sTNFR serum concentrations in BD patients presenting inactive disease than HC (P = 0·0108). A correlation between sTNFR and age was also found, with higher levels in patients over 40 years than HC (P = 0·0329). Although further research is warranted to elucidate the role of circulating biomarkers, some of that may contribute to the understanding of the physiopathology processes underlying BD activity and damage as well as to provide useful tools for prognostic purposes and a personalized treatment approach.

Differential impact of high and low penetrance TNFRSF1A gene mutations on conventional and regulatory CD4+ T cell functions in TNFR1-associated periodic syndrome

TNFR‐associated periodic syndrome is an autoinflammatory disorder caused by autosomal‐dominant mutations in TNFRSF1A, the gene encoding for TNFR superfamily 1A. The lack of knowledge in the field of TNFR‐associated periodic syndrome biology is clear, particularly in the context of control of immune self‐tolerance. We investigated how TNF‐α/TNFR superfamily 1A signaling can affect T cell biology, focusing on conventional CD4+CD25− and regulatory CD4+CD25+ T cell functions in patients with TNFR‐associated periodic syndrome carrying either high or low penetrance TNFRSF1A mutations. Specifically, we observed that in high penetrance TNFR‐associated periodic syndrome, at the molecular level, these alterations were secondary to a hyperactivation of the ERK1/2, STAT1/3/5, mammalian target of rapamycin, and NF‐κB pathways in conventional T cells. In addition, these patients had a lower frequency of peripheral regulatory T cells, which also displayed a defective suppressive phenotype. These alterations were partially found in low penetrance TNFR‐associated periodic syndrome, suggesting a specific link between the penetrance of the TNFRSF1A mutation and the observed T cell phenotype. Taken together, our data envision a novel role for adaptive immunity in the pathogenesis of TNFR‐associated periodic syndrome involving both CD4+ conventional T cells and Tregs, suggesting a novel mechanism of inflammation in the context of autoinflammatory disorders.

Familial Mediterranean fever mutations are hypermorphic mutations that specifically decrease the activation threshold of the Pyrin inflammasome

Objectives FMF is the most frequent autoinflammatory disease and is associated in most patients with bi-allelic MEFV mutations. MEFV encodes Pyrin, an inflammasome sensor activated following RhoGTPase inhibition. The functional consequences of MEFV mutations on the ability of Pyrin variants to act as inflammasome sensors are largely unknown. The aim of this study was to assess whether MEFV mutations affect the ability of Pyrin to detect RhoGTPase inhibition and other inflammasome stimuli. Methods IL-1β and IL-18 released by monocytes from healthy donors (HDs) and FMF patients were measured upon specific engagement of the Pyrin, NLRP3 and NLRC4 inflammasomes. Cell death kinetics following Pyrin activation was monitored in real time. Results Monocytes from FMF patients secreted significantly more IL-1β and IL-18 and died significantly faster than HD monocytes in response to low concentrations of Clostridium difficile toxin B (TcdB), a Pyrin-activating stimulus. Monocytes from patients bearing two MEFV exon 10 pathogenic variants displayed an increased Pyrin inflammasome response compared with monocytes from patients with a single exon 10 pathogenic variant indicating a gene-dosage effect. Using a short priming step, the response of monocytes from FMF patients to NLRP3- and NLRC4-activating stimuli was normal indicating that MEFV mutations trigger a specific hypersensitivity of monocytes to low doses of a Pyrin-engaging stimulus. Conclusion Contrary to the NLRP3 mutations described in cryopyrin-associated periodic syndrome, FMF-associated MEFV mutations do not lead to a constitutive activation of Pyrin. Rather, FMF-associated mutations are hypermorphic mutations that specifically decrease the activation threshold of the Pyrin inflammasome without affecting other canonical inflammasomes.

Role of polymorphonucleates in the pathogenesis of systemic juvenile idiopathic arthritis and Still's disease: a proof of concept study.

Background Systemic juvenile idiopathic arthritis (sJIA) and adult-onset Still9s disease (AOSD) are autoinflammatory disorders characterized by neutrophilia and abnormal innate immunity response [1]. It has been hypothesized a pathogenic role of neutrophils, because of patients neutrophilia, maybe related to the typical higher production of pro-inflammatory cytokines, like IL-1β, whose role in these disorders should explain the efficacy of IL-1 blockers [2, 3]. IL-1β is synthesized as inactive form and its activation is mediated by the NLRP3 inflammasome [4]. Increased release of this cytokine in the extracellular environment lead to a positive feedback loop that perpetuates and amplifies itself stimulation [5]. This mechanism as well as neutrophils9 activation state could be modified in sJIA and AOSD. Objectives Our aim was to verify possible differences between sJIA and Still9s patients compared to healthy donors, in term of PMNs responsiveness to the extracellular environment and activation state. Methods PMNs were obtained from heparinised venous blood of sJIA patients (n=6), AOSD patients (n=4) and healthy controls (HC, n=8). All patients9 samples were collected during stages of active or non-active disease, according to international disease activity criteria used for the assessment of each disease. After lipopolysaccharide (LPS) treatment, IL-1β content in PMNs supernatants was measured by ELISA assay. CD11b expression levels were measured by flow cytometry, together with intracellular ROS levels through the H 2 DCFDA ROS-indicator. Results In comparison with HC, sJIA PMNs showed an increased IL-1β secretion after LPS stimulation (p Conclusions Data from our proof of concepts study suggest a possible involvement of PMNs in the pathogenesis of sJIA and AOSD, since they seem more active respect healthy ones and more sensitive to pro-inflammatory stimuli. Although further studies are necessary to confirm and validate this hypothesis, the trend observed may have a potential role in the direction of future therapeutic studies. References Pay, S., et al., A multicenter study of patients with adult-onset Still9s disease compared with systemic juvenile idiopathic arthritis. Clin Rheumatol, 2006. 25(5): p. 639-44. Mellins, E.D., et al., Pathogenesis of systemic juvenile idiopathic arthritis: some answers, more questions. Nat Rev Rheumatol, 2011. 7(7): p. 416-26. Mavragani, C.P., et al., Adult-Onset Still9s Disease: From Pathophysiology to Targeted Therapies. Int J Inflam, 2012. 2012: p. 879020. Martinon, F., et al., The inflammasomes: guardians of the body. Annu Rev Immunol, 2009. 27: p. 229-65. Frosch, M., et al., The myeloid-related proteins 8 and 14 complex, a novel ligand of toll-like receptor 4, and interleukin-1beta form a positive feedback mechanism in systemic-onset juvenile idiopathic arthritis. Arthritis Rheum, 2009. 60(3): p. 883-91. Disclosure of Interest None declared

OR10-004 - Circulating micrornas in TRAPS

To the best of our knowledge circulating miRNAs in TRAPS, as well as in other monogenic autoinflammatory disorders have never been investigated.