gms | German Medical Science

Introduction: Familial Mediterranean Fever (FMF) is the most common monogenic autoinflammatory disease. Uncontrolled systemic inflammation increases the risk for amyloidosis and organ failure. Early diagnosis and effective treatment decrease morbidity. The aim of this study was to determine risk factors associated with delay to diagnosis (DtD) and treatment start (DtT) in FMF.

Methods: A single-centre, observational study of consecutive FMF patients was performed between 01/2010 and 08/2021. Patients were included if (i) they fulfilled FMF classification criteria [1], (ii) were found to have a likely pathogenic or pathogenic MEFV gene variant, (iii) had a complete data capture for clinical phenotype, genotype, family history, symptom onset, diagnosis date and treatment start. DtD was defined as time from symptom onset to diagnosis; DtT as symptom onset to treatment start. DtD and DtT were analysed and compared between subgroups. Analyses were performed using SPSS (IBM SPSS Statistics 26). Significances were tested with Mann Whitney U test.

Results: A total of 49 FMF patients were included; 41% were female. A positive family history of FMF was documented in 53%. Median age at symptom onset was 2.9 years (0–13.4). Afebrile FMF attacks were reported in 4/49 patients (8%), fever duration ≥96 hours in 7/49 patients (14%). The most common variants detected were Met694Val (24x heterozygous, 7x homozygous) and Met680Ile (5x heterozygous). Median DtD was 1.1 years (0–10.8) overall. Patients with afebrile FMF attacks had a median DtD of 0.8 years (0.1–6.7), those with prolonged fever of 1 year (0.4–4.4). Comparison of subgroups with and without positive FMF family history revealed a significant difference: median DtD was 0.9 years (0–10.8) in those with a positive family history compared to 2.1 years (0.4–7.6) in those without (p=0.005). Median DtT was 1.4 years (0.1–10.9) overall. In those with positive family history 1.0 year (0.1–9.4) versus 2.1 years (0.4–10.9) in those without (p=0.01).

Conclusion: FMF is a common autoinflammatory disease. However, diagnosis and effective treatment are considerably delayed. Exploring the family history is key to an earlier diagnosis and treatment start. Close collaboration of affected families, primary care providers and specialists will optimize on-time diagnosis and therapeutic management.

Disclosures: None of the authors have to declare any conflicts of interest for this abstract.

Tatjana Welzel and Jasmin Kuemmerle-Deschner contributed equally and should be considered as shared senior author.