[Use of IL-1 inhibitors in the treatment of familial Mediterranean fever in pediatric rheumatology].

backgroundFamilial Mediterranean fever (FMF) is the most frequent monogenic autoinflammatory disease in Germany. Genetic testing for Mediterranean FeVer (MEFV) variants is essential for diagnostic confirmation, although its impact on therapeutic decisions remains largely unclear.

objectiveInvestigation of the correlation between MEFV variant type and disease course as well as the need for treatment escalation with Interleukin (IL)-1-Inhibitors. MATERIAL AND

methodsIn this study 59 pediatric FMF patients with at least one MEFV variant were included, classified according to INFEVERS and assigned to four cohorts based on the pathogenicity of the variants. Clinical features, colchicine dosage, and use of IL-1-Inhibitors were analyzed.

resultsCohort 1 with two pathogenic or probable pathogenic variants, showed the longest time delay until diagnosis despite a high genetic burden and low symptom frequency. Of the patients 31% received anakinra and 15% canakinumab. Cohort 2 included patients with one pathogenic or probable pathogenic variant combined with a variant of uncertain or benign significance and had the earliest disease onset; no patient received biologics. In cohort 3, with one confirmed pathogenic variant, two patients (7%) received anakinra followed by canakinumab. Cohort 4 with only variants of uncertain or benign significance, showed mild disease courses under colchicine treatment.

conclusionPathogenic MEFV variants, particularly in homozygous or compound-heterozygous form, were associated with earlier onset of symptoms, longer delay in diagnosis and greater therapeutic need. Early genetic testing could support targeted treatment escalation.