Interleukin-33 and Familial Mediterranean Fever: A Novel Inflammatory Cytokine and a Common Autoinflammatory Disease

Objective: Familial Mediterranean Fever (FMF) is an autosomal recessive autoinflammatory disease, including reiterative feverish bouts of joint pain, and abdominal and chest pain as a consequence of serosal inflammation.In the course of acute attacks, multifarious proinflammatory cytokines have been depicted to increase.In previous studies, it has been underlined that IL-33, a recent member of the IL-1 cytokine superfamily, has an essential role in the inflammation.Here, we aimed to evaluate serum IL-33 levels in FMF patients to investigate its presumable importance in the FMF formation mechanism. Materials and Methods:A total of 58 FMF patients (21 females, 37 males; mean age 27.8 5.2 years, mean disease duration 8.2 3.7 years) and 22 healthy controls (10 females, 12 males, mean age 26.5 5.9 years) were incorporated into this research.ELISA was utilized to measure serum IL-33 concentrations. Results:The mean concentrations of serum IL-33 were 3.88 2.25 pg/ml and 2.89 0.48 pg/ml in the patient and control groups respectively.The mean serum IL-33 concentrations were 5.48 2.13 pg/ml and 2.27 0.36 pg/ml in the active phase and in the inactive phase respectively.According to these results, serum IL-33 concentrations were prominently higher in FMF patients compared with the control group (p<0.01).Moreover, serum IL-33 concentrations were measured significantly higher in the active phase compared with serum IL-33 levels in the inactive phase and controls respectively (p<0.0001 and p<0.0001).The mean serum IL-33 levels in patients with active FMF was associated with arthritis (p<0.05). Conclusion:To sum up, the high concentrations of serum IL-33 in the active FMF cases propose that IL-33 may operate a remarkable function in the pathogenesis of FMF.