BackgroundFamilial Mediterranean fever (FMF) is an inherited autoinflammatory disease characterized by recurrent episodes of fever and serositis. Arthritis is one of the most common attack manifestations. Arthritis in FMF is usually in the form of acute mono- or oligoarthritis of the large joints of the lower extremities. While acute attacks of arthritis usually heal without causing permanent deformity, the severe, long-lasting form of chronic arthritis can last for months or even years and result in permanent deformity.ObjectivesIn this study, we described the characteristics of joint involvement in FMF in a single cohort.MethodsThe medical records of patients with joint involvement from our cohort of 2350 patients who were diagnosed with familial Mediterranean fever were retrospectively scanned through the files and hospital database. The prevalence, demographic information, genetic test results, clinical features, features of joint involvement, treatments and responses, acute phase values in the attack and remission periods, and family history of patients with joint involvement were recorded.Results953 patients (n=953) from a total of 2350 patients had arthralgia or arthritis (40%). In our study, the male/female ratio was found to be 0.49 (male n=316, female n=637). The number of patients who underwent genetic testing was 787 (82%), and 702 (89%) of these patients had mutations in the MEFV gene. The most common pathogenic mutation is the M694V mutation with a rate of 43%. Concomitant diseases and their frequencies are shown in Table 1, the most common accompanying disease was spondylarthritis at a rate of 27%. Arthritis was present in the first attack in 55% (n=531), while arthritis was found in the ongoing attacks in 45%. The duration of the attack was between 24-96 hours in 77% (n=837) of the patients, and the duration was longer than 96 hours in 23% (n=116). The most common finding accompanying the attacks was exercise-related leg pain. Family history was present in 61% (n=580). 73% of the patients (n=696) were involved in the ankle and 51% were involved in the knee (n=492). The incidence of sacroiliitis was 14% (n=142). As for the number of joints, 91% of the patients had mono- and oligoarthritis. Asymmetric involvement was detected in 77% of the patients. Red arthritis was present in %73 of our study group. HLA-B27 was examined in 185 patients, 24 of them were positive (12%). It was found that 43% of the patients had treatment changes due to arthritis. Colchicine dose increases and changes were performed in 32% of these patients. NSAIDs were started in 21%, corticosteroids in 15%, DMARDs in 12%, anti-TNF in 10%, and anti-IL-1 in 8%. The mean dose of colchicine was as 1.56 ± 0.5 mg. Unresponsiveness to colchicine was found in 21% (n=122).Table 1.Concomitant diseases of our FMF cohortConclusionFMF diagnosis should definitely be considered in people with red mono-oligoarthritis in the large joints of the lower extremities. One of the most important features of joint involvement in FMF patients is the short duration of arthritis. The accompanying effort-related leg pain is an important symptom that should suggest FMF. In patients with a diagnosis of FMF and arthritis, the required colchicine dose in the treatment and the rate of colchicine unresponsiveness are higher than in other attack types. The incidence of sacroiliitis and spondyloarthropathy increases in patients with FMF, and joint involvement features are similar. FMF should be considered in the differential diagnosis of patients with inflammatory low back pain.Disclosure of InterestsNone declared

BackgroundFamilial Mediterranean fever (FMF) is a rare hereditary autoinflammatory disease with disease onset in childhood in most cases. Although autoinflammatory disease awareness is increasing among physicians, delayed diagnosis is still prevalent as a cause of greater morbidity[1].ObjectivesWe aimed to study the characteristics of FMF patients diagnosed between 2000-2010 and 2011-2021 and to see if there was a difference in diagnostic delay.MethodsWe retrospectively evaluated the medical records of the FMF patients followed up in our rheumatology clinic that were diagnosed between 2000-2021 and split them into two groups according to the year they received their diagnosis. There were 1151 patients diagnosed between 2000-2010 (Group 1) and 821 patients diagnosed between 2011-2021 (Group 2). The data studied included gender, age of onset, diagnostic delay, attack characteristics, MEFV mutation, and family history.ResultsThe median current age of patients in Group 1 is 37 years (IQR:30-46) and the median current age of the patients in Group 2 is 36 years (IQR:29-44). The female to male ratio was 1.57 in Group 1 and 1.75 in Group 2, with no significant difference between the groups. Group 2 had later disease onset (p<0.001) and later diagnosis (p<0.001) than Group 1 as shown in the Table 1. The proportion of patients with at least one M694V mutation was higher in Group 2 (p<0.001). The attack durations did not vary between the groups. There was no significant difference in the prevalence of abdominal pain, fever, arthritis, and arthralgia between Group 1 and Group 2. Chest pain (p=0.005), myalgia (p<0.001), and erysipelas-like erythema (p=0.041) were more common in Group 2 than Group 1. Patients with positive family history were more frequent in Group 2 than Group 1 (p=0.046).Table 1.Group 1 (2000-2010, n=1151)Group 2 (2011-2021, n=821)pFemale/Male, n704/447522/2990.275Age at onset, median (IQR) years13 (7-21)18 (12-26)<0.001Delay in diagnosis, median (IQR) years4 (1-11)5,5(2-15)<0.001Attack duration, median (IQR) years3(2-4)3(2-4)0.325Presence of at least one M694V mutation (%)526(46%)390(60%)<0.001Presence of abdominal pain in the initial attack (%)936(81%)669(81%)0.926Presence of fever in the initial attack (%)855(74%)592(72%)0.281Presence of chest pain in the initial attack (%)218(19%)199(24%)0.005Presence of arthritis in the initial attack (%)330(29%)215(26%)0.224Presence of arthralgia in the initial attack (%)213(19%)170(21%)0.223Presence of myalgia in the initial attack (%)45(4%)65(8%)<0.001Presence of erysipelas like erythema in the initial attack (%)31(3%)36(4%)0.041Presence of positive family history (%)652(57%)502(61%)0.046ConclusionThere was some increase in the diagnostic delay in 2011-2021 compared to 2000-2010. This may be partly due to the later onset of symptoms in patients diagnosed in 2011-2021, which could have led the physicians to consider other differential diagnoses. Nevertheless, diagnostic delay in FMF still seems a prevalent problem that should be addressed to prevent excess morbidity and mortality.References[1]Erdogan M, Ugurlu S, Ozdogan H, Seyahi E. Familial Mediterranean fever: misdiagnosis and diagnostic delay in Turkey. Clin Exp Rheumatol. 2019;37 Suppl 121(6):119-124.Disclosure of InterestsNone declared

BackgroundFamilial Mediterranean Fever (FMF) is the most common hereditary monogenic fever syndrome characterized by recurrent attacks of fever and polyserositis. Types and frquencies of attacks can change throughout the life of patients. The course of disease is affected by pathophysiological changes due to aging, increased comorbid diseases and multiple drug use.ObjectivesThe objective of this study was to understand the effect of aging on clinical features and disease course in patients with Familial Mediterranean Fever.Methods343 patients who were followed up with the diagnosis of FMF between 2005 to 2020 and were over 50 years old as of 2022 were included. The demographic characteristics of the patients, MEFV mutations, attack characteristics and the treatments they received were analyzed retrospectively. Attack characteristics, frequency of attacks and VAS scores of the patients were also analyzed and compared as pre-treatment, post-treatment, and most recent attacks.ResultsFemale to male ratio was 1.8:1. The mean age of patients was 57.6±6.5 (50-84) years. Age of symptoms started, age at diagnosis and delay at diagnosis were compared between the female and male patients. At the age of symptoms started, no significant difference was detected between the two groups, while the age at diagnosis was later and the time of delay at diagnosis was longer in female patients (p=0.006 and p=0.001).Number and frequencies of attacks and VAS scores were compared as attacks before treatment, attacks after treatment and attacks in the last year, a significant decrease was found in the last attacks (p<0.001). The frequency of fever, abdominal pain, arthritis and chest pain was significantly lower in the most recent attacks when compared to pre-treatment and post-treatment (p<0.001). The last attacks of the patients were mostly in the form of abdominal pain. Patients were compared as those who did not have an attack in the last year and who had an attack, it was seen that the mean age was lower in the group that had an attack (p<0.005). The mean of current colchicine dose was 1.29±0.43 mg, the mean dose of colchicine at diagnosis was 1.37±0.36 mg and the mean of maximum colchicine dose was 1.6±0.43 mg.Conclusion:Demographic Status, Patients (n:343)Male/female, n 119/224Age of onset, mean (S.D.), years 57.6 (6.5)Age at diagnosis, mean (S.D.), years 40.8 (10.8)Age of symptoms started, mean (S.D), years 24 (14.4)Delay at diagnosis, mean (S.D.), years 16.8 (14.5)Clinical features, n (%)Pre-Treatmentn (%)Post-Treatmentn (%)Recent Attacksn (%)p valueFeverAbdominal Pain266 (77.6)253 (73.8)52 (15)<0.001Arthralgia293 (85.4)299 (87.2)223 (65)<0.001Arthritis56 (16.3)82 (23.9)33 (9.6)<0.001Chest pain87 (25.4)100 (29.2)32 (9.3)<0.001Myalgia71 (20)79 (23)24 (7)<0.001Erysipelas-like23 (6.7)34 (9.9)46 (13.5)0.14erythema11 (3.2)12 (3.5)7 (2)0.487Number of attacks, mean (S.D.), years15.0 (11.9)3.04 (6.46)2 (3.67)<0.001VAS ScoresPre-treatment, mean (S.D.)8.05 (1.78)<0.001Post-treatment, mean (S.D.)2.91 (2.53)Recent, mean (S.D.)1.75 (2.38)It has been shown that there is a decrease in disease activity, frequency of attacks and the dose of colchicine used in FMF with aging.References[1] Ozen S, Bilginer Y (2014) A clinical guide to autoinflammatory diseases: familial Mediterranean fever and next-of-kin. Nat Rev Rheumatol 10:135-147[2] van der Hilst J, Moutschen M, Messiaen PE, Lauwerys BR, Vanderschueren S (2016) Efficacy of anti-IL-1 treatment in familial Mediterranean fever: a systematic review of the literature. Biologics 10:75-80[3]Siegal S (1949) Benign paroxysmal peritonitis. Gastroenterology 12:234-247[4]Reimann HA (1951) Periodic disease. Medicine (Baltimore) 30:219-245[5]Heller H, Sohar E, Sherf L (1958) Familial Mediterranean fever. AMA Arch Intern Med 102:50-71Acknowledgements:NIL.Disclosure of InterestsNone Declared.