Ab0026 Features of Familial Mediterranean Fever After Age 65: Retrospective Study of 59 French Patients From the Jir Cohort

Background: Familial Mediterranean fever (FMF) is the most common monogenic autoinflammatory disease associated with MEFV mutations and characterized by recurrent attacks of fever. FMF almost always begins in childhood, but the natural history of FMF in elderly patients is not well known. Objectives: To describe the clinical features of FMF after 65 years of age and to look for associations with other comorbidities. Methods: A monocentric retrospective study was performed at the French adult reference center for FMF at the Tenon University Hospital in Paris, focusing on patients older than 65 years. Results: Of the 638 FMF patients followed at the French Adult Centre for FMF, 59 elderly patients consisting of 32 women and 27 men, were included. Their median age was 73 years. The majority were homozygous for M694V in MEFV (71%). The median age at diagnosis and colchicine initiation was 28 and 35.5 years, respectively. The median delay between symptom onset and colchicine initiation was 28 years. The median year of colchicine initiation was 1980, and the mean colchicine dose was 1.23 mg/day. Only 55% of patients had a complete clinical response to colchicine, and subclinical inflammation persisted despite colchicine in 73% of patients. Nineteen percent of patients were prescribed an increase in colchicine dose and 37% received an interleukin-1 inhibitor after the age of 65 years old. The prevalence of AA amyloidosis was 10%. Common comorbidities were cardiovascular (n = 35, 59% of patients), hepatic (n = 22, 37%, mainly liver cirrhosis, n=16, 27%) and renal (n = 14, 24%; kidney disease caused by AA amyloidosis n=5, 8%). Fifteen percent of patients (n=9) died at a median age of 76.5 years. Two deaths were related to complications of FMF (AA amyloidosis, peritoneal mesothelioma), five to infections (Covid-19 n =2, undocumented bacterial pneumonia n=1, candidemia complicating chronic glucocorticoid use n=1), two to liver cirrhosis (NASH n=1, cryptogenic cirrhosis n=1). Conclusion: FMF remains a significant cause of morbidity in a group of patients over 65 years of age who, for historical reasons, were started on colchicine late in life. Follow-up of this population is therefore warranted. Interleukin-1 inhibitors are well tolerated after the age of 65 and should be prescribed for FMF complications or subclinical inflammation. The high prevalence of unexplained cirrhosis and persistent chronic inflammation in our study raises the question of a possible association with FMF, especially in elderly patients. REFERENCES: NIL. Acknowledgements: JIR cohort. Disclosure of Interests: None declared.