Late-Onset Famılıal Medıterranean Fever: Sıngle-Center Experıence And Lıterature Revıew

Introduction: Familial Mediterranean Fever (FMF) is an autoinflammatory disease characterized by recurrent fever and serositis attacks. The disease onset occurs before 20 years of age in 90% of patients. Rarely, the disease onset occurs after 40 years of age. Aim: We aimed to compare the patients with early and late-onset of disease. Methods: We did a retrospective analysis of 2020 patients registered in our FMF center in the years 2008-2017. Patients with disease onset after the age of 40 (Group 1) were collected. The control group (Group 2), disease onset before the age of 20, was randomly selected with twice amount of the study group. Demographic, clinical and genetic data were recorded. Results: Out of 2020 patients, 41 were in group 1 (2.02%). The male to female ratio was 1:1.7 in both groups. The delay of diagnosis was 5.6±5.75 years in group 1, 10.7±12.3 years in group 2. In terms of clinical features, the only significant difference between two groups belonged to fever seen in 26 (63.4%) patients in group 1 and 67 (81.7%) patients in group 2 (p=0,026). M694V mutation frequency was higher in group 2 whereas exon 2 mutation frequency was higher in group 1. The mean colchicine dose in the 6 months was 1.38±0.64 mg in group 1, 1.61±0.47 mg in group 2. Discussion: In patients with late disease onset, the results of decreased mean colchicine dose during the last 6 months, decreased fever ratio, and increased exon 2 mutation frequency might point out to mild disease severity. Keywords: Familial Mediterranean Fever, late-onset, early-onset, MEFV mutation, colchicine