Effects of interleukin-1 antagonists on de novo and pre-existing damage in patients with familial Mediterranean fever

Objective Colchicine is the mainstay of familial Mediterranean fever treatment and interleukin (IL-1) antagonists are the treatment of choice in resistant patients. We aimed to investigate efficacy of IL-1 antagonists in the prevention of damage, as well as the causes of treatment failure.Methods A total of 111 patients fulfilling Euro fever and Tel-Hashomer criteria and treated with IL-1 antagonists were included in the study. Patients were grouped according to their recent damage status: no damage, pre-existing damage and de novo damage that developed under IL-1 antagonist treatment. The degree of damage was determined using the Auto Inflammatory Disease Damage Index (ADDI). Total damage score was calculated separately as its original definition and with excluding chronic musculoskeletal pain, creating the modified ADDI (mADDI).Results Forty-six patients (43,2 %) had damage according to the mADDI. Damage was commonly observed at musculoskeletal, renal and reproductive domains. Median duration of treatment was forty-five months. Two patients developed de novo damage: one musculoskeletal and one reproductive in this time-period. Five patients had a worsening of their damage while using IL-1 antagonists. De novo damage with IL-1 antagonist treatment was associated with acute phase protein levels.Conclusion We evaluated change in damage accrual while using IL-1 antagonists in patients with FMF. Physicians should pay attention to controlling inflammation to prevent further damage, especially in those with pre-existing damage.