Table 1 Demographic and baseline characteristics of the study population

Age of diagnosis (years) median (min-max)

3.66 (0.9–17.5)

Current age (years) median (min-max)

15.2 (3.5–21)

Follow up duration (months) median (min-max)

90 (24–223)

Follow up duration after initiating canakinumab (months) median (min-max)

25 (9–56)

Parental consanguinity n (%)

16 (35.6)

Family history of FMF n (%)

30 (66.7)

Family history of amyloidosis n (%)

4 (8.9)

Characteristics during FMF attacks

Abdominal pain n (%)

45 (100)

Arthritis n (%)

24 (53.3)

Chest pain n (%)

14 (31.1)

Pericarditis n (%)

3 (6.7)

Fever n (%)

45 (100)

Erysipelas-like erythema n (%)

12 (26.7)

Protracted febrile myalgia n (%)

3 (6.7)

Laboratory characteristics before initiation of anti IL-1 therapy

Hemoglobin (g/dl) median (min-max)

11.8 (8.2–14.6)

Platelet count (10³ cells/µl) median (min-max)

311 (139–653)

WBC count (cells/µl) median (min-max)

9700 (3650–18,000)

SAA (mg/L) median (min-max)

127 (1-970)

CRP (mg/L) median (min-max)

32.0 (0.2–346.0)

ESR (mm/h) median (min-max)

27 (4–88)

Number of attacks in the last 6 months median (min-max)

6 (2–24)

Duration of attacks in the last 6 months (day) median (min-max)

3 (2–5)

AIDAI score of the last month before biologic treatment median (min-max)

16 (2–40)

Anakinra use prior to canakinumab n (%)

23 (51.1)

Duration of anakinra use prior to canakinumab (months) median (min-max)

3 (1–23)

MEVF sequence variants

p.(Met694Val) homozygous n

40

p.(Met694Val)/ p.(Met680Ile) compound heterozygous n

3

p.(Met680Ile)/ p.(Val726Ala) compound heterozygous n

1

p.(Met694Val) heterozygous n

1