AB1323 THE MYSTERY OF FAMILIAL MEDITERRANEAN FEVER: IS THERE ANY FACTOR TRIGGERING THE ATTACKS?

Abstract

BackgroundFamilial Mediterranean Fever (FMF) is an autoinflammatory disease characterized by recurrent episodes of fever and serositis. Although it is known that the attack frequency differs among patients carrying different mutant genotypes [1], whether physical and environmental factors play a role in triggering attacks or whether they have an influence on timing of attacks remains to be elucidated.ObjectivesWe aimed to identify different conditions causing flare-ups in FMF course and to investigate if there is a significant difference between patients carrying distinct mutations, regarding the distribution of the factors mentioned.MethodsTwo hundred patients were randomly selected among individuals who were routinely followed-up with FMF diagnosis in our centre. Individuals carrying only a variant of unknown significance or polymorphism such as R202Q, according to Infevers database, were excluded in order to gather a cohort consisting of patients with definite FMF. An inquiry was made based upon triggering factors determined by the patients themselves. The patients were classified into subgroups by their sex and mutation genotype. Since M694V variant is responsible for pronounced FMF course [2], we sorted the patients according to their status for M694V mutant allele. Group A included patients carrying M694V homozygously. Group B included patients carrying at least one M694V mutant allele whereas Group C consisted of patients who were non-M694V carriers. Chi-square test was performed to assess distribution of the trigger factors in terms of establishing its significance.ResultsDetailed distribution of trigger factors is shown in Table 1. 144 out of 200 patients described a culprit condition. Patients usually stated more than one factor, however some patients reported only one. The most-reported trigger factors by the cohort are summarized as following: 76 emotional stress (38%), 60 menstruation (30%), 40 cold exposure (20%), 34 fatigue (17%), 13 seasonal changes (6.5%). The distribution of trigger factors between Group A, B, and C were non-significant (p=0.88).Table 1.The distribution of triggering factors in subgroups.GroupTotal(%)Reported trigger factor (%)Mens- truation(%)Emotionalstress(%)Cold exposure(%)Fatigue(%)Seasonalchanges(%)Others(%)Female12397 (78.8)60 (48.8)47 (38.2)24 (19.5)19 (15.4)7 (5.7)6 (4.9)Male7747 (61)-29 (37.7)16 (20.8)15 (19.5)6 (7.8)7 (9.1)Group A6144 (72.1)14 (23)24 (39.3)13 (21.3)12 (19.7)4 (6.6)6 (9.8)Group B165120 (72.7)49 (29.7)66 (40)34 (20.6)29 (17.6)13 (7.9)11 (6.6)Group C3524 (68.6)11 (31.4)10 (28.6)6 (17.1)5 (14.3)01 (2.8)Group A: M694V homozygous patients, Group B: patients with at least one M694V allele, Group C: non-M694V carriersConclusionWe concluded that trigger factors did not vary between distinct mutant genotypes. Although emotional stress is the most reported trigger factor by the participants, one should bear in mind that emotional stress influences most chronic diseases negatively. We also observed that menstruation overtly triggers an FMF attack. Additionally, cold exposure should be considered as a notable trigger factor. It is still unclear what triggers an FMF attack in 28% of the patients, remains a mystery.