THU0524 ARE CHILDREN AND ADULTS HAVING DIFFERENT PHENOTYPE AND GENOTYPE OF FMF?
Authors: Nuray Aktay Ayaz, Cemal Bes, Hafize Emine Sonmez, Ayşe Tanatar, Şerife Gül Karadağ, Nilüfer Alpay Kanıtez, Selda Çelik, Ozan Cemal İçaçan, Mustafa Çakan, Figen Çakmak
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background</h3> Familial Mediterranean fever (FMF) is an autosomal recessively inherited autoinflammatory disease and begins in childhood. In nearly 60% of patients, the first attack occurs before the age of 10, and in 90% of them before the age of 20 years. There isn't a prospective study designed for comparing childhood onset and adult onset FMF. <h3>Objectives</h3> To compare the demographic data, clinical features, genetic analysis, laboratory values and severity scores of both childhood and adult onset FMF. Compliance and resistance to colchicine, presence of accompanying diseases and complications due to FMF were also analyzed and reviewed. <h3>Methods</h3> The patients were divided into two groups; group I: children with FMF (symptoms begin before 18 years of age) and group II: adults with FMF (symptoms begin after 18 years of age). A questionnaire for collecting age at disease onset, sex, age at diagnosis, delay at diagnosis and duration of the disease, family history of FMF, consanguinity and accompanying diseases were filled. The questions were asked by an adult and pediatric rheumatologist to both groups by face to face interviews. Genetic analysis results and treatment protocols were taken from patient's charts. Laboratory data concerning complete blood count, ratio of urine protein to creatinine, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), serum amyloid A (SAA) levels were obtained during their routine follow-up at attack-free period. <h3>Results</h3> There were 178 (60.3%) children with the diagnosis of FMF; 73 female and 104 male and 117 (39.7%) adults diagnosed as FMF after 18 years of age; 69 female and 48 male. The mean±SD age at symptom onset, at the diagnosis and current age was 4.92±3.03, 6.45±3.61, 11.59±4.38 for group I and was 18.35±10.34, 32.23±11.62, 38±11.64 for group II, respectively. Consanguinity was significantly more frequent among children with FMF (36.1%). A positive family history of FMF was similarly present in 102 (57.6%) of group I and 66 (56.4%) of group II. Twelve (10.2%) adult patient have FMF at their children. Family history of amyloidosis was equally distributed between groups; 6.2% in group I and 6.8% in group II. The median number of FMF attacks per year was 18 in children and 15 in adults. While children were having significantly more frequent attacks, the duration of attacks were longer in adults compared to children (p&lt;0.001). The most frequent symptom was fever (91.5%) in children and abdominal pain (96.5%) in adults. Arthritis, chest pain and erysipelas like rash were seen similarly in both cohorts. Sacroileitis (10.2%), amyloidosis (5.1%) and chronic renal insufficiency (5.1%) were significantly more common in patients with FMF diagnosed after 18 years of age. Colchicine resistance and compliance were evenly distributed among groups. In genotypic evaluation, groups were compared for homozygotes, compound heterozygotes and heterozygotes and had put forth similar results. Attack free acute phase reactants like CRP; median 2.8 mg/dl and SAA; median 3.86 mg/dl were significantly higher in group I. <h3>Conclusion</h3> Both clinical features and acute phase response in FMF were less pronounced in patients diagnosed at adulthood. Children were having more frequent attacks,but accompanying diseases were more common in adults. While following patients taking age of the patient in to account will help to better understand the disease course. <h3>Reference</h3> [1] Yasar Bilge NS, Sari I, Solmaz D, et al. Comparison of early versus late onset familial Mediterranean fever. Int J Rheum Dis. 2018 Apr;21(4):880-884. doi: 10.1111/1756-185X.13259. Epub 2018 Jan 5. <h3>Acknowledgement</h3> None <h3>Disclosure of Interests</h3> None declared