Objectives: Defining predictors of damage would improve patient care. We applied damage indexes to patients with familial Mediterranean fever (FMF) and identified the predictors of damage.
Methods: This is a cross-sectional analysis of 926 FMF patients, who fulfilled the Tel-Hashomer criteria and had at least six months of follow-up. Patients were stratified according to their damage status (damage vs. no damage) defined with autoinflammatory disease damage index (ADDI) and modified ADDI (excluding musculoskeletal pain). We used logistic regression analysis to investigate independent predictors of damage for both indexes.
Results: Mean disease duration was 21.6±11.9 years. 527 patients (57%) had damage according to ADDI. Median ADDI score was 1 (0-11). Most common FMF-related damages were observed in musculoskeletal, reproductive and kidney domains. Female gender, inflammatory comorbidity, colchicine resistance, colchicine nonadherence, musculoskeletal attack dominance, diagnostic delay, follow-up time, and smoking history remained independent predictors of damage according to ADDI score. The rate of patients with damage defined by modified ADDI was only to 23%. M694V/M694V homozygosity, female gender, musculoskeletal attack dominance, colchicine resistance, persistent inflammation, follow up time and family history of amyloidosis were found to be predictors of damage according to modified ADDI score.
Conclusions: Our study is the first to apply comprehensive damage indexes to FMF patients and identified predictors of damage. Factors linked to a severe FMF phenotype, including M694V homozygosity and persistent inflammation, were associated with only modified ADDI. Our findings justify the concerns about musculoskeletal pain and might point to the need for re-evaluation of ADDI for FMF patients.