Evaluation of serum CXC chemokine ligand 16 (CXCL16) as a novel inflammatory bio- marker or familial Mediterranean fever disease.

BACKGROUND/AIM: Familial Mediterranean fever (FMF) is a disease that is mainly diagnosed with clinical features. Several well- known inflammatory markers increase in FMF. However, there is still a need for diagnostic tests for specifying FMF and monitoring inflammatory activity. CXCL16 is a chemokine produced by inflammatory cells that demonstrate efficacy in the acute phase response. In this study, we aimed to investigate the relationship between CXCL16 levels and FMF disease and to evaluate CXCL16 levels as a novel biomarker for FMF. MATERIALS AND METHODS: Fifty-three male patients diagnosed with FMF and sixty healthy individuals were included in this cross- sectional study. Blood samples were taken in the first 24 h of the attack periods. Serum soluble CXCL16 was evaluated by enzyme-linked immunosorbent assay (ELISA) method. RESULTS: CXCL16 (P < 0.001), erythrocyte sedimentation rate (P < 0.001), C-reactive protein (P < 0.001), and fibrinogen (P = 0.005) were significantly higher in FMF group than in control group. Receiver operating characteristic (ROC) curve analysis revealed a cut off value of CXCL16 as 2.68 ng/ml with 83% sensitivity and 68% specificity (P < 0.001). Logistic regression analysis indicated that high CXCL16 and erythrocyte sedimentation rate levels were predictive parameters for FMF disease (OR 8.31; 95% CI 2.59-26.62; p <0.001) (OR 1.27; 95% CI 1.12-1.44; P < 0.001). There was no correlation between CXCL16 levels and attack frequency and disease duration (P = 0.395, P = 0.956). CONCLUSION: To the best of our knowledge, this is the first study evaluating serum soluble CXCL16 levels as a biomarker for FMF. CXCL16 levels were significantly higher and were predictive for monitoring inflammatory activity in patients with FMF. CXCL16 may be a promising biomarker for FMF diagnosis.