s accepted for publication onlyP01 In pursuit of colchicine resistance prediction in familial mediterranean fever: exploring a novel scoring model and simultaneous validationN. Aktay Ayaz1, F. G. Demirkan1, T. Coskuner2, F. Demir2, A. Tanatar1, M. Çakan3, S. G. Karadag4, G. Otar Yener5, S. Caglayan6, K. Ulu7, B. Sozeri2, H. E. Sonmez8 1Pediatric Rheumatology, Istanbul University, Istanbul Faculty of Medicine; 2Pediatric Rheumatology, University of Health Sciences, Umraniye Research and Training Hospital; 3Pediatric Rheumatology, University of Health Sciences, Zeynep Kamil Women and Children's Diseases Training and Research Hospital; 4Pediatric Rheumatology, University of Health Sciences, Bakırkoy Dr. Sadi Konuk Training and Research Hospital, Istanbul; 5Pediatric Rheumatology, Sanlıurfa Training and Research Hospital, Sanlıurfa, Sanlıurfa; 6Pediatric Rheuamtology, University of Health Sciences, Umraniye Research and Training Hospital; 7Pediatric Rheumatology, University of Health Sciences, Umraniye Research and Training Hospital, Istanbul, Istanbul; 8Pediatric Rheumatology, Kocaeli University, Kocaeli School of Medicine, Kocaeli, Kocaeli, Turkey Correspondence: N. Aktay AyazIntroduction: Over the years, definition and prediction of colchicine resistance have been the most intriguing issues of researches concerning familial Mediterranean fever (FMF).1,2Objectives: The aim of this study is to develop a novel scoring system based on the initial clinical features and laboratory findings via synchronous validation of it in an independent group for predicting colchicine resistance in children with FMF.Methods: The medical records of the cases with FMF who applied to the pediatric rheumatology outpatient clinic were evaluated retrospectively. To define the predictive factors for colchicine resistance, baseline clinical and laboratory findings prior to initiation of colchicine were evaluated. After generating a predictive score in the initial cohort, it was applied to an independent cohort in the database of Pediatric Rheumatology Academy (PeRA)-research group (RG) established in 20193, for external validation of effectiveness and reliability.Results: A total of 327 patients with FMF were included in the study. Among them, 78 (23.9%) (Group I) were colchicine resistant (cr)-FMF patients and 249 (76.1%) (Group II) were colchicine responsive. Erysipelas-like erythema (ELE), myalgia, arthritis, chronic arthritis, protracted febrile myalgia, amyloidosis, vasculitis, anemia, and proteinuria were more common in patients who were in group I than those in group II. A logistic regression model was used to estimate a model to predict the colchicine resistance in FMF patients. According to the regression analysis, recurrent arthritis, protracted febrile myalgia, presence of ELE, chronic anemia and elevated serum amyloid A levels in the attack-free period were determined as the scoring parameters for predicting patients with cr-FMF (Table 1). Scores were assigned according to β coefficients in the final model. The cut-off value of predictor score as 4.5 was 88% sensitive and 82% specific to foresee the risk of colchicine resistance in the ROC.The predictive score was applied to 374 patients (colchicine resistant = 75, colchicine responsive = 299) which were registered to PeRA-RG database up to December 2020. Sixty-five (86.6%) cr-FMF patients and 3 (1%) colchicine responsive patients had a total score of more than 4.5. The cut-off value of the score as 4.5 was 86.6% sensitive and 99% specific to identify the risk of colchicine resistance in the ROC.Conclusion: In advance of the previous studies, we intended to design a composite predictive scoring system to foresee unresponsive patients.4 By constructing this novel reliable predictor tool, we enunciate that physicians will be capable of anticipating drug resistance in children with FMF at the initiation of the disease and, thereby have a chance to interfere timely before the emergence of complications during the disease course.Key Words: Familial Mediterranean fever, predictive score, colchicine resistance REFERENCES 1. Ozen S, Kone-Paut I, Gül A. Colchicine resistance and intolerance in familial mediterranean fever: Definition, causes, and alternative treatments. Seminars in arthritis and rheumatism. 2017;47(1):115-20.2. Babaoglu H, Armagan B, Bodakci E, Satis H, Atas N, Sari A, et al. Predictors of persistent inflammation in familial Mediterranean fever and association with damage. Rheumatology (Oxford, England). 2021;60(1):333-9.3. Betul Sozeri HES, Ferhat Demir, Mustafa Çakan, Kübra Öztürk, Semanur Özdel, Gulcin Otar Yener, Şerife Gül Karadağ, Nuray Aktay Ayaz. Time to collaborate: Objectives, Design, and Methodology of PeRA-Research Group. The North Clinics of Istanbul. 2020.4. Özçakar ZB, Elhan AH, Yalçınkaya F. Can colchicine response be predicted in familial Mediterranean fever patients? Rheumatology (Oxford, England). 2014;53(10):1767-72. Disclosure of Interest None DeclaredTable 1 (abstract P01). Multivariate logistic regression analysis of prediction of colchicine resistance and scoring systemFull size tableP02 Diagnostic delay in a rare autoinflammatory syndromeF. Annunziata1, M. L. Pennacchio1, M. Tardi2, F. Paciello1, R. Borrelli2, R. Naddei1, M. Alessio1, L. Martemucci2, F. Orlando2 1Department of Translational Medical Sciences, Section of Pediatrics, University of Naples Federico II; 2Pediatrics, AORN Santobono Pausilipon, Naples, Italy Correspondence: F. AnnunziataIntroduction: TRNT1 is a nuclear gene encoding a ubiquitous enzyme (CCA-adding tRNA nucleotidyltransferase enzyme) necessary for aminoacylation of both mitochondrial and cytosolic tRNA. Mutations of that gene lead to heterogeneous phenotypes and systemic involvement of variable severity and progression.Objectives: To consider mutations of TRNT1 as an important differential diagnosis in patients with overlap of immunodeficiency and autoinflammatory features to avoid diagnostic delay.Methods: A 10-year-old female admitted to our rheumatology pediatric unit of Santobono Children's Hospital of Naples for febrile illness associated with vomit and diarrhoea, evolved in shock. She was treated in intensive care with broad spectrum antibiotics and cardiovascular support.Results: The anamnesis revealed recurrent fever accompanied by vomit, metabolic acidosis, dyselectrolytemia and increase of inflammatory markers, without evidence of infective causes, since second month of life. Even in the absence of evidence of infective origins, these febrile episodes were often treated with systemic antibiotic therapy with poor clinical response. However, it was observed resolution of symptoms after steroids therapy. She presented to our attention with following clinical conditions: microcytic anaemia (requiring blood transfusion),bilateral cataract, hypotonia, intellectual disability andhypogammaglobulinemia. Physical examination documented occurrence of facial dysmorphisms,brittle hair and intellectual disability. At the admission, laboratory assessment showed: white blood cell 4920/ul (n.v. 5-19), Haemoglobin 9.4 g/dl (n.v. 10.18), MCV 60.9 fL (85-120), RDW 43 fL (n.v. 38.7-45.1), Platlets 119000/ul (n.v. 140-440), Neutrophiles 3870/uL (n.v. 1300-8500), Lymphocytes 619/uL (n.v.1300-8500), Eosinophiles50/uL (n.v. 0-80), C Reactive Protein 324 mg/l (n.v. 0.5), Procalcitonin 610 ng/ml (n.v. <0.5), Ferritin 2071 ng/ml (n.v. 6-67), lactic dehydrogenase 1198 U/l (n.v. 230-500). Immunological screening was performed, showing hypogammaglobulinemia, with IgA <0.22 g/l (n.v 0.5-3) and IgG 6,3 g/dl (n.v. 7-15), and low levels of T total (TCD3 49%, n.v.55-78%) and T helper lymphocites (TCD4 29%, n.v. 27-53%). No infective causes were found. Because of the history characterized by recurrent fever, immunological alterations and dismorphic appearance, TRNT1 mutation associated disease was suspected. Genetic analysis was done, confirming our suspicion.Based on case reports available in literature, after the molecular diagnosisshe started onanti-TNF alfa (Etanercept) therapy.Conclusion: The presence of recurrent fever associated with elevation of inflammatory indexes, without evidence of infections, led to consider TRNT1 mutation related disease as an autoinflammatory syndrome. Currently, 49 case are reported in literature. This condition was firstly associated to congenital sideroblastic anaemia with immunodeficiency, fevers, and developmental delay (SIFD) but over the years phenotypic heterogeneity was described. Due to the rarity of that syndrome, dignostic delay is observed, as in our patient. Early diagnosis of this condition would enable patients to promptly access to therapies. Symptomatic treatments, including red blood cells transfusions, immunoglobulin replacement therapy and steroids, are the most used; however, mortality is high. Etanercept has been recently described as effective treatment. TNFa inhibitors can lead to a significative response for those patients who can benefit early in life. Our patient started that treatment but we are still waiting to define the clinical benefits of this therapy. Disclosure of Interest None DeclaredP03 Long-term efficacy and safety of canakinumab in patients with traps (tumor necrosis factor receptor-associated periodic syndrome) - interim analysis of the reliance registryN. Blank1, J. Henes2, T. Kallinich3, P. T. Oommen4, C. Schuetz5, M. Borte6, J. Weber-Arden7, J. Kuemmerle-Deschner2 1University Hospital, Heidelberg; 2University Hospital, Tuebingen; 3Charité University Medicine, Berlin; 4University Hospital, Duesseldorf; 5Medizinische Fakultaet Carl Gustav Carus, Dresden; 6Hospital St. Georg gGmbH, Leipzig; 7NOVARTIS PHARMA, Nürnberg, Germany Correspondence: N. BlankIntroduction: Tumor necrosis factor receptor-associated periodic syndrome (TRAPS) is a rare autoinflammatory condition characterized by severe systemic and organ inflammation. In clinical trials TRAPS patients have been successfully treated with the interleukin-1β inhibitor canakinumab. Canakinumab has been approved and applied for the treatment of TRAPS patients since 2017.Objectives: The present study explores the long-term efficacy and safety of canakinumab under routine clinical practice conditions in pediatric (age ≥2 years) and adult TRAPS patients.Methods: RELIANCE is a prospective, non-interventional, multi-center, observational study based in Germany with a 3-year follow-up period. Patients with clinically confirmed diagnoses of TRAPS who routinely receive canakinumab are enrolled in order to evaluate efficacy and safety of canakinumab under standard clinical practice conditions. Inflammatory markers, disease activity and remission by physician assessment, disease activity and fatigue by patient assessment, were assessed at baseline and at 6-monthly intervals. Results: The interim analysis of TRAPS patients enrolled by December 2020 includes baseline (N=16, including 1 patient with atypical TRAPS) and preliminary 18-month data. Mean age in this cohort was 23 years (3-43 years) and the median duration of prior CAN treatment was 1.0 year (0-4 years). All patients already were on canakinumab when being enrolled. Prior treatments were colchicin (N=2), anakinra (N=10) and tocilizumab (N=1).Physician assessment indicated 60-80% remission and laboratory parameters were within normal range. Disease control by patient assessment showed no major changes regarding the analyzed parameters (table 1). Of the three serious adverse events reported none was classified as drug-related.Conclusion: Preliminary analysis of 18-month interim data of TRAPS patients treated with CAN available from the RELIANCE study indicate stable efficacy and safety of CAN long-term treatment. Table 1 (abstract P03). Baseline characteristics and interim analysis data of patients with TRAPSFull size table Disclosure of Interest N. Blank Grant /Research support from: Novartis, Sobi, Consultant for: Novartis, Sobi, Lilly, Pfizer, Abbvie, BMS, MSD, Actelion, UCB, Boehringer-Ingelheim, Roche, J. Henes Grant /Research support from: Novartis, Roche, Consultant for: Novartis, AbbVie, Sobi, Roche, Janssen, Boehringer-Ingelheim, T. Kallinich Grant /Research support from: Novartis, Consultant for: Sobi, Novartis, Roche, P. T. Oommen Grant /Research support from: Novartis, C. Schuetz: None Declared, M. Borte: None Declared, J. Weber-Arden Employee of: Novartis, J. Kuemmerle-Deschner: None DeclaredP04 Evaluation of E148Q and concomitant AA amyloidosis secondary to familial mediterranean fever after adjusted clinical-demographic characteristicsThis abstract has not been included here as it has been previously publishedP05 Non-urticarial Muckle-Wells syndrome and mitochondrial cytopathy – hand-in-hand in the NLRP3 inflammasomeA. Lamas1, D. G Oliveira1,2, M. Rodrigues3, R. Faria2,4 1Medicine, Centro Hospitalar e Universitário do Porto; 2UMIB, ICBAS - Universidade do Porto, Porto; 3Neurology Department, Hospital de Braga, Braga; 4Consulta de Sindromas Autoinflamatórios, Unidade de Imunologia Clínica, Centro Hospitalar e Universitário do Porto, Porto, Portugal Correspondence: D. G OliveiraIntroduction: Muckle-Wells syndrome (MWS) is a rare inherited cryopyrin-associated periodic syndrome (CAPS) with NLRP3 gain-of-function mutations. Although urticaria is a prominent clinical feature, cases have been reported with systemic and neurological involvement without cutaneous manifestations. Inflammasome activation is a complex process and there is mounting evidence of the key role played by mitochondria.Objectives: To describe the clinical phenotype of two adult sisters harbouring a heterozygous NLRP3 mutation (c.2582A>G p.(Tyr861Cys) and a homoplasmic MT-TS2 mitochondrial variant of uncertain significance (VOUS) (m.12236G>A).Results: The patients described are siblings from a sibship of 5 (1 male and 4 females), in a family with a history of sensorineural deafness (SND) (at least 3 generations affected, onset during adolescence). A niece was diagnosed with MWS without mitochondrial mutation at another centre.Patient 1: a 52-year-old woman with a history of SND and chronic headaches (onset at age 10), associated with nausea, vomiting and fever (mostly concomitant with headaches), recurrent aseptic meningitis and stroke-like episodes. Other features included recurrent conjunctivitis, polyarthritis, inflammatory/iron deficiency anaemia and accelerated atherosclerosis (myocardial infarction at age 43). There was no history of cutaneous involvement. Patient 2: a 46-year-old woman with a history of SND (onset at age 18), presented with chronic recurrent headaches (onset at age 15), with concomitant nausea, vomiting and fever, with documentation of aseptic meningitis, and stroke-like episodes. Polyarthritis, synovitis and enthesopathy were more severe, and clinodactyly was present. There was no history of cutaneous involvement. Other features included recurrent conjunctivitis and inflammatory/iron deficiency anaemia.Both presented with markedly elevated serum amyloid A, erythrocyte sedimentation rate and C-reactive protein. Serum lactate levels were normal. Cerebrospinal fluid analysis revealed elevated protein levels, with associated pleocytosis. Electromyography was normal and muscle biopsy showed no evidence of mitochondrial myopathy. Abdominal fat biopsy showed no evidence of amyloid deposition.PCR and Sanger sequencing detected a homoplasmic mitochondrial VOUS in MT-TS2 gene (m.12236G>A) and a heterozygous missense NLRP3 mutation (c.2582A>G p.Tyr861Cys, Y861c or previously known as Y859c – in mice). Extensive genetic studies for the exclusion of other mitochondrial cytopathies were performed.A diagnosis of MWS syndrome was assumed and treatment started with IL-1 receptor antagonist (anakinra), with significant clinical improvement (headaches, fever, arthritis) and inflammatory marker remission.Conclusion: The clinical features fulfil diagnostic criteria for CAPS, as proposed by Kuemmerle-Deschner et al. (2016). They are also compatible with the phenotype previously described for this exon 6 missense mutation, coding for a protein at Y861, a dephosphorylation site in the leucine-rich repeat (LRR) domain of NLRP3. Phosphorylation/dephosphorylation of NLRP3 at key sites, as Y861, has been shown to be an essential step for the regulation of the NLRP3 inflammasome, with Y861c mutation leading to spontaneous inflammasome activation and interleukin-1β hyperproduction.The mitochondrial VOUS m.12236G>A is associated with non-syndromic SND, MELAS syndrome (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes) and respiratory chain deficiency (affecting complexes I, III and IV). Both patients did not fulfil diagnostic criteria for MELAS syndrome (Hirano et al. (1992) or Yatsuga et al. (2012)), an insufficient hypothesis to explain all the clinical manifestations. Mitochondrial dysfunction with increased production of reactive oxygen species and oxidized mitochondrial DNA (mtDNA) may act synergically in NLRP3 activation, autoinflammation and “inflammaging”. This case illustrates the intricacies of NLRP3 inflammasome hyperactivation through a rare mutation in exon 6, resulting in a distinct clinical phenotype. It also underlines the complex interplay between mitochondria and NLRP3 activation, and its potential role in the modulation/definition of clinical phenotypes. Disclosure of Interest None DeclaredP06 Long-term safety and effectiveness of canakinumab in patients with familial mediterranean fever (FMF) interim analysis of the reliance registryJ. Henes1, J. Kümmerle-Deschner2, T. Kallinich3, F. Dressler4, F. Weller-Heinemann5, B. Kortus-Goetze6, I. Foeldvari7, G. Horneff8, M. Hufnagel9, F. Meier10, J. Weber-Arden11, N. Blank12 1University Hospital, Tuebingen, Germany; 2Pediatric Department, University Hospital, Tuebingen; 3Charité University Medicine, Berlin; 4Hannover Medical School, Hannover; 5Prof. Hess Kinderklinik, Bremen; 6University Hospital, Marburg; 7Centre for Pediatric and Adolescence Rheumatology Hamburg, Hamburg; 8Asklepios Clinic , Sankt Augustin; 9University Hospital, Freiburg; 10University Hospital, Frankfurt; 11NOVARTIS PHARMA, Nürnberg; 12University Hospital, Heidelberg, Germany Correspondence: J. HenesIntroduction: Familial Mediterranean Fever (FMF) is characterized by recurrent attacks of fever and serositis as well as elevated inflammatory markers. FMF treatment goals according to EULAR are to control acute attacks and subclinical inflammation and to improve patients´ quality of life.Objectives: The present study explores the long-term efficacy and safety of canakinumab (CAN) in routine clinical practice in pediatric (age ≥2 years) and adult FMF patients.Methods: RELIANCE is a prospective, non-interventional, multi-center, observational study based in Germany for patients with clinically confirmed FMF who routinely receive CAN. Disease activity parameters by physicians´ and patients’ assessment were recorded at baseline and were assessed at 6-monthly intervals.Results: This interim analysis of FMF patients (N=54) enrolled by December 2020 includes baseline as well as 6-, 12- and 18-month data. Mean age in this cohort was 25 years (4-56 years) and the proportion of female patients was 46 % (N=25). At baseline, median duration of prior CAN treatment was 2.0 years (0-6 years). 34 patients (63%) were concomitantly treated with colchicine.While physician ratings report around 62% of patients in disease remission, 52% with absent and 34% with mild-moderate disease activity, patient-reported disease activity decreased during the observation period, especially in patients without prior CAN therapy (table 1). A total of 11 serious adverse events was reported, of which one case of tonsillectomy in a 6-year-old patient was classified as drug-related.Conclusion: Interim data of FMF patients from the RELIANCE study confirm efficacy and safety of long-term CAN treatment. Table 1 (abstarct P06). Baseline characteristics and third interim analysis data of patients with FMFFull size table Disclosure of Interest J. Henes Grant /Research support from: Novartis, Roche, Consultant for: Novartis, AbbVie, Sobi, Roche, Janssen, Boehringer-Ingelheim, J. Kümmerle-Deschner Grant /Research support from: Novartis, AbbVie, Sobi, Consultant for: Novartis, AbbVie, Sobi, T. Kallinich: None Declared, F. Dressler Grant /Research support from: Novartis, Consultant for: Abbvie, Mylan, Novartis, Pfizer, F. Weller-Heinemann: None Declared, B. Kortus-Goetze Consultant for: Novartis, I. Foeldvari Consultant for: Novartis, G. Horneff Grant /Research support from: AbbVie, Chugai, Merck Sharp & Dohme, Novartis, Pfizer, Roche, Speaker bureau of: AbbVie, Bayer, Chugai, Merck Sharp & Dohme, Novartis, Pfizer, Roche, M. Hufnagel Grant /Research support from: Novartis, F. Meier Speaker bureau of: Novartis, J. Weber-Arden Employee of: Novartis, N. Blank Grant /Research support from: Novartis, Sobi, Consultant for: Novartis, Sobi, Lilly, Pfizer, Abbvie, BMS, MSD, Actelion, UCB, Boehringer-Ingelheim, RocheP07 A family with an autosomal dominant CDC42-mutation covering the full clinical spectrum from developmental defects to autoinflammationV. Hentgen1, B. Bekhouche 2, A. Terre-Becker2, J. Cherfils3, M. Andre4, S. Georgin-Lavialle5, G. Boursier6, A. Smahi2 1Reference Center for AutoInflammatory diseases and amyloidosis, Versailles Hospital, Le Chesnay; 2INSERM U1163, Imagine Institute, Paris; 3Laboratoire d’Enzymologie et Biochimie Structurales, CNRS, Gif-sur-Yvette; 4Service de médecine interne, Montpied Hospital, Clermont-Ferrand; 5Reference Center for AutoInflammatory diseases and amyloidosis, Tenon Hospital, Paris; 6Laboratory of Rare and Autoinflammatory Genetic Diseases, CHRU Montpellier, Montpellier, France Correspondence: V. HentgenIntroduction: The CDC42 (Cell Division Cycle 42) gene product, CDC42, is a member of the family of small Rho GTPases, which are implicated in a broad spectrum of physiological functions in cell cycle regulation. Missense variants in CDC42 underlie a clinically heterogeneous group of phenotypes characterized by variable neurodevelopmental, growth, hematological, and immunological disorders.Objectives: Here, we report a family of 4 affected members with a dominant missense mutation in the CDC42 gene and analyze the pathophysiological mechanisms explaining a large part of the phenotypeMethods: The family (a mother with 3 of her children) was referred to our reference center for a suspected tumor necrosis factor receptor-associated periodic syndrome. No pathogenic variant was identified in 8 autoinflammation-related genes including TNFRSF1A, NLRP3 and MVK. Affected members presented with recurrent fevers lasting several weeks, severe arthromyalgias, arthritis and splenomegaly. Two children had in addition labio-palatine cleft and one developmental delay. All the affected members presented with other slight dysmorphic signs: hypertelorism, wide nasal bridge and mouth with widely spaced teeth. Inflammatory manifestations responded remarkably well to IL-1beta inhibition. Patients were included to the France Genomique research program allowing us to perform whole genome sequencing in trio and investigate the pathophysiological mechanisms.Results: A novel heterozygous p.Thr43Ile mutation in the CDC42 gene was identified in all affected family members. In silico modelisation predicted no structural change of CDC42, but a probable impaired interaction with DOCK proteins, a family of proteins involved in intracellular signaling networks. Fibroblasts as well as Peripheral Blood Mononuclear cells (PBMC) from the patients showed an inflammatory signature with an increased expression of IL-1β, IL-6, TNFα, IL-8 and IL-18 on a basal state in the untreated patient and after stimulation in treated ones. In respect to PBMC controls, patients showed an over-activation of both pyrine and NLRP3 inflammasomes using both agonist triggers and specific inibitors (NLRP3 inflammasome inhibitor MCC 112 and pro-caspase-1 inhibitor Z-VAD).The spontaneous increased ASC/Speck aggregation in mutated PBMCs confirms this observation strongly.These observations allow us to hypothesize that the inflammatory profile of the CDC42 mutations, passes through abnormal activation of the pyrin and probably the NLRP3 inflammasome thus linking the CDC42 abnormalities to the same inflammatory pathways than familial Mediterranean fever and mevalonate kinase deficiency.Conclusion: We describe in four affected members of the same family a novel heterozygous dominant p.Thr43Ile mutation in the CDC42 gene. CDC42 encodes a small GTPase of the Rho subfamily, playing a pivotal role in cell cycle regulation. In the family studied, diverse clinical manifestations compose a syndromic phenotype with autoinflammation, facial dysmorphism and neurodevelopmental delay. The pathophysiological assessment showed that the inflammatory profile of the p.Thr43Ile CDC42 mutation is linked to the pyrin and to a lesser extend to the NLRP3 inflammasome, unravelling a heretofore-unrecognized connection between seemingly unrelated autoinflammatory diseases. CDC42 mutations should be searched for USAID patients with splenomegaly, recurrent arthralgia and a clinical response to IL1 blockers, sporadic or dominant transmission. Disclosure of Interest None DeclaredP08 Evaluation of fatigue level and sleep quality in patients with familial mediterranean feverÇ. İncesu1, G. Kavrul Kayaalp2, F. G. Demirkan2, O. Köker2, F. Çakmak2, Ö. Akgün2, N. Aktay Ayaz2, R. Eker Ömeroğlu2 1Pediatrics; 2Pediatric Rheumatology, Istanbul University, Faculty of Medicine, İstanbul, Turkey Correspondence: G. Kavrul KayaalpIntroduction: Familial Mediterranean fever (FMF) is the most prevalent hereditary autoinflammatory disease. It is characterized by recurrent inflammatory episodes of fever and serositis. Its lifelong and inflammatory nature can cause detrimental effects on all aspects of patients' quality of life. Sleep quality and fatigue are essential factors affecting quality of life, which may be impaired in FMF patients due to recurrent episodes or ongoing subclinical inflammation.Objectives: In this study, it is aimed to evaluate whether sleep quality and fatigue level are affected in children with FMF compared to healthy children and to assess the parameters that may affect sleep quality and fatigue status in FMF patients.Methods: 225 children aged 7- 18 years who are followed up with the diagnosis of FMF in Istanbul University Faculty of Medicine Pediatric Rheumatology Clinic were included in the study. 182 age matched healthy peers were included as control group. Demographic features, family history, MEFV gene mutations, medications and The International Severity Score for FMF (ISSF) scores of the patients were recorded. The PedsQL Multidimensional Fatigue Scale module which consists of three parts as general fatigue, sleep/rest-related fatigue and cognitive fatigue was used to assess fatigue. Five answer options were offered and raw scores were extrapolated to a scale of 0 to 100 reversely (0 converted to 100, 1 to 75, 2 to 50, 3 to 25 and 4 to 0). Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep quality. The scores ranged 0 to 21were calculated according to the calculation sheet. A total score of 5 and above was considered as poor sleep quality.Results: Gender distribution was 59.3% female and 40.7% male in the patient group and 51.6% female, 48.4% male in the control group. The mean age was 12.2 ± 2.4 years, and 12.1 ± 3.3 years in the patient and control groups respectively. Mean ISSF score was 2.2 ± 1.1 points. Medications of the patients were 88.4% colchicine, 11.6% colchicine and anti IL-1 treatment (canakinumab or anakinra). The MEFV mutations were homozygous in 25.8%, heterozygous in 38.2%, compound heterozygous in 28% of the patients group. In the last year 13.3% of the patients didn’t have any attack, 86.7% had at least 1 attack. The median PSQI score was significantly higher in the patient group (5.1±2.3 in the patient group, 3.2±1,3 in the control group; p <0.05) and the median PEDsQL score was significantly higher in the control group (66.0±17.3 in the patient group, 70.4±15.9 in the control group; p <0.05). A significant positive correlation was observed between the number of attacks in the last 1 year and the PSQI score (r=0.721, p <0.05). There was no significant difference in terms of ISSF score, PSQI score, PEDsQL score, general fatigue score, sleep/rest fatigue score, and thought fatigue score between homozygous, heterozygous and compound heterozygous groups.Conclusion: This study demonstrates that children with FMF have lower sleep quality and higher fatigue levels compared to their healthy peers. The disease activity also effects the sleep quality and fatigue status of FMF patients. Maintaining low disease activity in the of the patients with FMF and evaluation of sleep quality in the routine follow-ups can improve the quality of life of the patients. Disclosure of Interest None DeclaredP09 Next generation sequencing in diagnosis of periodic fevers: one center experienceZ. Korobova1,2, I. Svitina2, K. Belozerov2, A. Tumakova2, A. Romanko3, E. Suspitsyn2,3, M. Kostik2,4 1Saint Petersburg Pasteur Institiute; 2Saint Petersburg State Pediatric Medical University; 3N.N. Petrov National Medical Research Center of Oncology; 4Almazov National Medical Research Centre, Saint-Petersburg, Russian Federation Correspondence: Z. KorobovaIntroduction: Periodic fever syndromes (PFS) is a group of disorders characterized by recurrent attacks of systemic and organ-specific inflammation. Establishing a reliable diagnosis on clinical and laboratory grounds is difficult due to non-specific clinical presentation. Besides monogenic autoinflammatory conditions periodic fevers may be a component of other primary immunodeficiency syndrome (PIDs), rheumati