Monogenic autoinflammatory disease-associated cardiac damage.

Autoinflammatory diseases are systemic disorders caused by genetic or acquired abnormalities in certain signaling pathways of the innate immune system. Dysregulated activation of the inflammasome, i.e. molecular platforms responsible for the activation of caspase-1 and production of interleukin-1β, causes autoinflammation. Familial Mediterranean fever (FMF), the most common genetic autoinflammatory disease, is characterized by a periodic fever and serositis. The complex and heterogeneous genetic background of Japanese FMF patients, accompanied by potential overlap with other rheumatic diseases, suggests crosstalk between genetic and environmental factors. Recently, FMF has been recognized as being part of a spectrum of autoinflammatory syndromes named pyrin-associated autoinflammatory diseases. The discovery of a new monogenic autoinflammatory disease, A20 haploinsufficiency, may provide novel insights into early-onset Behçet's-like diseases. In contrast, adult-onset Still's disease and Schnitzler's syndrome are acquired autoinflammatory diseases without a monogenic abnormality. Although the concept of autoinflammatory diseases originally applied to monogenic hereditary recurrent fevers, it has been expanded to include non-genetic complex autoinflammatory diseases. Information concerning monogenic autoinflammatory diseases may prove useful for elucidating the molecular mechanisms underlying non-genetic autoinflammatory diseases.

The Genetic Basis for Periodic Fever

Gastrointestinal (GI) manifestations, such as abdominal pain, nausea, vomiting, and diarrhea, are common autoinflammatory disease (AID) symptoms. The abdominal symptomatology reflecting serositis is one of the most important classification and diagnostic criteria for the classic monogenic AID (MAID) – familial Mediterranean fever (FMF). Failure to timely diagnose FMF frequently leads to unjustified surgical interventions. Other periodic fevers may also present as abdominal symptoms; however, the latter are outside their diagnostic features. These diseases include, first of all, tumor necrosis factor receptor-associated periodic syndrome (TRAPS). Interleukin 1 (IL1) inhibitors serve as the major targeted drugs for the treatment of TRAPS. Russia has registered the IL1 inhibitor canakinumab that prevents the development of organ damages, including those in the GI tract. The paper describes a clinical case of the classic manifestations of TRAPS (fever, rash, periorbital edema, arthritis, and elevated levels of acutephase inflammatory markers) concurrent with severe abdominalgia during attacks and with the development of severe peritoneal adhesions, which led to bowel perforation and emergency surgical intervention. The prolonged persistence of inflammatory attacks before the initiation of therapy, as well as violation of the IL1 inhibitor administration regimen facilitated the development of an urgent exacerbation. Thus, TRAPS should be included in the differential diagnostic circle for patients with severe gastrointestinal manifestations characterized by an attack-like course. These patients need timely prescription of targeted therapy, strict adherence to the dosing and intervals between drug administrations, and careful monitoring to prevent serious complications with the visceral organs, including the gastrointestinal tract, and their immediate correction.

SP0009 The Expanding Spectrum of Autoinflammation

AB0749 LABORATORY MARKERS OF INFLAMMATORY ACTIVITY IN PATIENTS WITH MONOGENIC AND POLYGENIC AUTOINFLAMMATORY DISEASES

Therapy of autoinflammatory syndromes

Genetic and clinical features of familial mediterranean fever (FMF) in a homogeneous cohort of patients from South-Eastern Italy

Although colchicine is the mainstay of familial Mediterranean fever (FMF) treatment, 5-10% of patients are considered to have colchicine resistance (CR). However, there is no globally agreed CR definition or indications for biological disease-modifying anti-rheumatic drugs (bDMARDs). A survey on 'Biologics in Monogenic Autoinflammatory Diseases', part of the 'Clinical Practice Strategies' (CLiPS) initiative, was conducted by a JIR cohort-initiated eCOST network among expert participants worldwide. Our primary aim was to provide a flowchart reflecting the different CR definitions and present data regarding bDMARD indications. The secondary aim was to determine how specific biases influence clinical approaches. We analysed the CliPS according to the experience levels of physicians, country-specific FMF prevalence, countries' gross domestic product, bDMARD availability and reimbursement policies of the countries. A total of 223 responses from 46 countries were included in the study. Almost half of the respondents (73/160, 45.6%) indicated that three to four attacks within the preceding 6 months were necessary for their CR definition. The most frequently used acute-phase reactant was C-reactive protein (157/164, 95.7%). Almost three-fourths of the respondents (74%, n=165) considered that supplementary factors, including complications of FMF, attack severity, elevated activity scores, patient-reported outcome and quality of life scales, influenced their CR definition. We present a novel flowchart describing physicians' general attitudes and unique findings regarding management strategies for colchicine-resistant FMF and shifting trends influenced by epidemiological and socioeconomic factors.

OP0174 Exome sequencing identifies a hypermorphic missense mutation in the PLCG2 gene as the cause of a dominantly inherited autoinflammatory disease with immunodeficiency

Introduction: Periodic fever syndrome (PFS) is a rare monogenic autoinflammatory disease group. The innate immune system abnormalities have a characteristic onset and spontaneous inflammation without any infectious or autoimmune trigger. It differs from autoimmune disorders (e.g., systemic lupus erythematosus (SLE)) occurring due to a defect in the adaptive immune system with auto-antibodies. Case Presentation: The clinical features of three patients presented with a periodic pattern of fever and a different constellation of symptoms were investigated. The final diagnosis of Periodic fever syndrome was reached based on standard diagnostic criteria and genetic testing. All three cases were observed to present with recurrent fever episodes at an interval of 6 - 12 weeks, 3 - 4 weeks, and one month, respectively. The first patient, presenting with a diffuse erythematous plaque-like lesion along the calf with severe calf pain and tenderness with signs of meningeal irritation, was diagnosed with a tumor necrosis factor receptor-associated periodic fever syndrome (TRAPS) like phenotype. The genetic panel was negative in this case. The second patient presenting with recurrent pharyngitis, cervical adenitis, and tonsillitis unresponsive to antibiotics was diagnosed with periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome. The last patient presenting with recurrent monoarthritis, hepatosplenomegaly, and a positive Mediterranean fever (MEFV) gene mutation was diagnosed with familial Mediterranean fever (FMF). All three patients had normal growth and development. Conclusions: Although periodic fever syndrome was an uncommon entity, it was recommended that this syndrome should be considered when a patient presented with recurring fever episodes with a characteristic constellation of symptoms.

Monogenic autoinflammatory diseases (mAIDs) are inherited errors of innate immunity characterized by systemic inflammation recurring with variable frequency and involving the skin, serosal membranes, synovial membranes, joints, the gastrointestinal tube, and/or the central nervous system, with reactive amyloidosis as a potential severe long-term consequence. Although individually uncommon, all mAIDs set up an emerging chapter of internal medicine: recent findings have modified our knowledge regarding mAID pathophysiology and clarified that protean inflammatory symptoms can be variably associated with periodic fevers, depicting multiple specific conditions which usually start in childhood, such as familial Mediterranean fever, tumor necrosis factor receptor-associated periodic syndrome, cryopyrin-associated periodic syndrome, and mevalonate kinase deficiency. There are no evidence-based studies to establish which potential genotype analysis is the most appropriate in adult patients with clinical phenotypes suggestive of mAIDs. This review discusses genetic and clinical hints for an ideal diagnostic approach to mAIDs in adult patients, as their early identification is essential to prompt effective treatment and improve quality of life, and also highlights the most recent developments in the diagnostic work-up for the most frequent hereditary periodic febrile syndromes worldwide.

The term autoinflammation was initially introduced to denote a group of diseases that lacked the usual features of autoimmunity (high-titer autoantibodies and antigenspecific T cells), and were subsequently recognized as disorders of the innate immune system. Patients with autoinflammatory disorders present with chronic and recurrent bouts of systemic inflammation that are mediated by the cells of the innate immune system such as neutrophils and macrophages. The concept of autoinflammation started with hereditary recurrent fevers, but has grown substantially to include both monogenic and polygenic diseases. Hereditary recurrent fevers are the prototypic monogenic disorders, whereas Behcet disease, Crohn disease, gout, spondyloarthropathies, type-2 diabetes are all considered complex autoinflammatory diseases. The monogenic autoinflammatory diseases are inherited in an autosomal-recessive or autosomaldominant fashion, and many of disease-causing mutations are found in genes that regulate the IL-1 signaling pathway. More recently, new pathways such as the IL-36, immunoproteasome, HOIL-1 deficiency, and phospholipase Cg2 pathways have been identified in the pathogenesis of autoinflammation. Some of these new autoinflammatory diseases and relevant pathways will be discussed at the meeting. Despite major advances, a substantial number of patients have no mutations in the known autoinflammatory genes. The present challenge is how to find the as-yet undiscovered genes, considering that most cases are sporadic or occur in small families that are not suit-able for linkage analysis. New approaches and tools such as next-generation sequencing are the most likely methods to be successful. Such research might require collabora-tive studies in order to increase the number of patients presenting with a rare phenotype. Disclosure of interest None declared.

Autoinflammatory diseases (AIDs) are disorders characterised by recurrent inflammatory episodes in charge of different organs with no apparent involvement of autoantibodies or antigen-specific T lymphocytes. Few common clinical features have been identified among all monogenic AIDs (mAIDs), while the search for a common molecular pattern is still ongoing. The aim of this study was to increase knowledge on the inflammatory pathways in the development of mAIDs in order to identify possible predictive or diagnostic biomarkers for each disease and to develop future preventive and therapeutic strategies. Using protein array-based systems, we evaluated two signalling pathways known to be involved in inflammation and a wide range of inflammatory mediators (pro-inflammatory cytokines and chemokines) in a cohort of 23 patients affected by different mAIDs, as FMF, TRAPS, MKD, Blau syndrome (BS), and NLRP12D. Overall, we observed upregulation of multiple signalling pathway intermediates at protein levels in mAIDs patients’ PBMCs, compared with healthy controls, with significant differences also between patients. FMF, TRAPS, and BS presented also peculiar activations of inflammatory pathways that can distinguish them. MAPK pathway activation, however, seems to be a common feature. The serum level of cytokines and chemokines produced clear differences between patients with distinct diseases, which can help distinguish each autoinflammatory disease. The FMF cytokine production profile appears broader than that of TRAPS, which, in turn, has higher cytokine levels than BS. Our findings suggest an ongoing subclinical inflammation related to the abnormal and constitutive signalling pathways and define an elevated inflammatory cytokine signature. Moreover, the upregulation of Th17-related cytokines emphasises the important role for Th17 and/or Th17-like cells also in monogenic AIDs.

25-Year-Old Woman With Increasing Abdominal Girth and Shortness of Breath

SAT0541 THE SEVERITY OF FMF MAY BE ASSOCIATED WITH CO-MORBIDITIES