Serum Asprosin Level as a New Biomarker in Differentiating Familial Mediterranean Fever Attacks.

Introduction Familial Mediterranean fever (FMF) is a recessively inherited disease characterized by recurrent attacks of fever and sterile polyserositis. Recently, some proteins originating from adipose tissue have been demonstrated to play a critical role in the inflammatory process. Asprosin is a new adipokine secreted by adipose tissue, and proinflammatory cytokines have been determined to increase with the decrease of circulating asprosin. This study was designed to evaluate the level of asprosin in the acute attack and attack-free period in FMF patients. Materials and methods A total of 65 FMF patients were evaluated for this cross-sectional case-control study. Those who were obese and had concomitant diabetes mellitus, hypertension, heart failure, and rheumatological disease were excluded from the study. The patients were divided into two groups: attack-free period and attack period. Fifteen healthy individuals who were not obese and had no additional disease were included as the control group. Demographic data, gene analyses, laboratory findings, and symptoms were recorded at the time of diagnosis. Serum asprosin level was studied by enzyme-linked immunosorbent assay test in the outpatient clinic controls of the patients. Asprosin levels and other laboratory findings were compared between the attack, attack-free, and control groups. Results Of the patients included in the study, 50% were in the attack period, and 50% were in the free-attack period. The mean age of the FMF patients was 34±10 years. Asprosin level in the control [median (interquartile range (IQR))=30.4 (21.5-57.7) ng/mL] group was significantly higher than the attack [median (IQR)=21.5 (17.5-28) ng/mL] and attack-free [median (IQR)=19(18.7-23) ng/mL] groups (p=0.001). C-reactive protein and sedimentation levels were significantly higher in the attack group compared to the other two groups (p<0.001). There was a moderate correlation between C-reactive protein and asprosin levels (Ro=-0.314, p=0.01). The cut-off value of serum asprosin level was determined as 21.6 ng/mL; sensitivity was 78%, and specificity was 77% (p<0.001). Conclusion The study demonstrated that the serum asprosin levels of FMF patients with acute attack were lower than those in the attack-free periods and healthy controls. Asprosin is likely to have a role in the anti-inflammatory cascade.