General characteristics of patients followed by Familial Mediterranean Fever

General Characteristics of Patients Followed by Familial Mediterranean Fever Aim: Familial Mediterranean fever (FMF) is an autosomal recessive inherited hereditary autoinflammatory disease. It is characterized by recurrent fever and serositis attacks and may show different clinical course in patients with the same genotype. A single mutation in the MEFV gene represents a significant portion of FMF patients. The pathogenetic mechanisms in these patients are not clearly known. miRNAs are defined as small, regulatory RNA molecules that play an important role in development, differentiation, cell proliferation, apoptosis, stress response and many physiological and pathological events and regulate the expression of target genes. Modifying factors and miRNAs (miRNAs) involved in the pathogenesis of FMF have not yet been clearly identified. In this study, we aimed to determine the general characteristics, genotypes and miRNAs involved in pathogenesis of disease in childhood FMF patients. Material and Methods: This study was conducted in Çukurova University Medical Faculty Pediatric Rheumatology outpatient department. Pediatric FMF patients admitted to the relevant polyclinic between March 2017 and July 2017 were included in the study. All patients' files were screened for demographic, clinical features and mutations. Analysis of 33 miRNAs, which were found to be particularly associated with apoptosis, were performed in 191 patients and 31 healthy controls who agreed to participate in the study. Results: Among 351 FMF patients included in the study, we found R202Q allele frequency (38.5%), higher than M694V mutation allele frequency (29.5%). However, we found the M694V homozygous patient group with younger age of disease-onset and less complete response to colchicine. The number of annual episodes after treatment, arthritis frequency, extremity pain with effort, AFR height at last control, family history of AAA disease, parental consanguinity and use of biological agents were also significantly higher in the M694V Homozygote group. As a result of miRNA analysis, the expression profile of 14 miRNAs was statistically different from the control group. The level of 4 miRNA expression was found to be higher than that of the control group (miR.365a.3p, miR.181c.5p, miR.181a.5p, miR.15a.5p). 10 miRNAs' (miR.27a.3p, let7.5.5p, miR.146a.5p, miR.30a.5p, let7a.5p, miR.30e.5p, let7C, miR.30d.5p, miR .25.3p, miR.29c.3p) expression levels were lower than the control group. Conclusion: We speculate that apoptosis-associated miRNAs may play a role in FMF pathogenesis. However, owing the reason that miRNAs may be affected by factors such as genotype, use of colchicine and biological agents, attack frequency and acute phase reactant elevation, more detailed and extensive research is needed in this topic. Keywords: Familial Mediterranean Fever, R202Q, M694V, miRNA