Assessment of serum TWEAK levels in patients with familial Mediterranean fever

Abstract

Background/Aim: Mediterranean fever is an autoinflammatory disease characterized by recurrent attacks. Tumor necrosis factor (TNF) - like weak inducer of apoptosis (TWEAK) is a member of the TNF ligand family, and it has been reported to contribute significantly to the initiation of many inflammatory and immunological processes. In previous studies, an increasing amount of evidence has implicated the participation of TWEAK / Fn14 pathway in the pathogenesis of rheumatic inflammatory diseases that include rheumatoid arthritis, systemic lupus erythematosus and Behçet's disease. The aim of this study was to investigate the serum TWEAK levels of patients with Familial Mediterranean fever (FMF) and its possible relationship with inflammatory markers and disease activity. Methods: Our study included 20 patients with FMF and 19 healthy volunteers. Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) were measured, and PRAS disease severity score was determined in patients with FMF. Also, the FMF attack period was questioned. Serum TWEAK levels were measured with available commercial Enzyme Linked Immunosorbent Assay kits. Results: There was no significant difference in terms of age and gender between the FMF group and the healthy control group (P>0.05, for all). ESR, CRP and serum TWEAK levels were significantly higher in patients with FMF (P<0.001 for all). PRAS score in FMF patients was 3.4. Serum TWEAK level was not correlated with ESR (r=-0.042, P=0.0801), CRP (r=-0.017 P=0.921), or PRAS score (r=0.247, P=0.149). The ESR and CRP levels of patients in FMF attack period were significantly higher compared to attack free period (P<0.001 for both) whereas there was no significant difference in serum TWEAK levels (P=0.686). Conclusions: Serum TWEAK levels are increased in FMF disease with attacks. However, this increase is not associated with increased ESR and CRP during FMF attacks. These results indicate that the TWEAK / Fn14 pathway plays a role in earlier stages where the inflammatory pathways have not differentiated yet. Serum TWEAK levels appear to be more successful in reflecting a lower degree of inflammation compared to ESR and CRP.