Does enthesopathy relate to M694V gene mutation in patients with Familial Mediterranean fever?

Familial Mediterranean fever (FMF) is a systemic hereditary autoinflammatory disorder. The present study aimed to investigate the relationship of enthesitis to FMF and to search the potential association between enthesitis and MEFV gene missense variations in patients with FMF. The study consisted of 72 FMF patients (mean age 29.12 ± 11.47 years, 32 females), 29 patients with ankylosing spondylitis (AS) (mean age 34.14 ± 11.73 years, 16 females), and 34 healthy volunteers (mean age 23.06 ± 6.41 years, 8 females). FMF patients were classified according to the kind of MEFV gene mutation. Doppler ultrasound was used to determine enthesitis based on the Outcome Measures in Rheumatoid Arthritis Clinical Trials (OMERACT) scoring system. OMERACT score was significantly different between FMF patients and control group (p < 0.001 in all patients, p = 0.009 in men, and p = 0.002 in women). However, it was not significantly different between FMF and AS patients in both sexes. OMERACT score did not differ between FMF patients with and without M694V gene mutation. The best cutoff point of OMERACT score to predict enthesitis was found as ≥0.5 with sensitivity of 29 %, specificity of 100 %, positive predictive value of 100 %, and negative predictive value of 40 %.