Predictors of persistent inflammation in familial Mediterranean fever and association with damage.

Objective: Persistent inflammation is an insidious and less studied feature of FMF. We investigated clinical determinants of persistent inflammation and its associations with individual damage items.

Methods: This is a cross-sectional analysis of 917 FMF patients, who fulfilled the Tel Hashomer criteria and had at least 6 months' follow-up. Patients were stratified based on whether they had persistent inflammation. We used logistic regression analysis to investigate independent predictors of persistent inflammation and the associated individual damage items.

Results: One hundred and forty-two (15%) patients had persistent inflammation. Active FMF (54%) was the most prominent reason for the persistent inflammation. Spondylarthritis (16%), other inflammatory arthritis (8%) and IBD (2%) were other frequent reasons. Male gender, history of exertional leg pain, inflammatory comorbidities, M694V homozygosity, colchicine resistance, lower education levels and musculoskeletal attack dominance were found to be the independent predictors of persistent inflammation. Earlier disease onset led to a tendency towards persistent inflammation. Patients with persistent inflammation were more likely to suffer damage. There is an increased risk of developing proteinuria, amyloidosis and renal insufficiency.

Conclusion: We identified, for the first time, the predictors of persistent inflammation in adult FMF patients and related individual damage items of the Autoinflammatory Disease Damage Index. Persistent inflammation is insidious and one of the chief causes of damage; therefore, especially patients with these predictors should be followed up more closely. If detected, underlying inflammatory comorbidities should be assessed meticulously as early detection and proper treatment strategies may favourably impact the natural history of the disease.