Comparative analysis of conventional and novel inflammatory biomarkers in Familial Mediterranean fever during attack-free periods.

Abstract

Background: Familial Mediterranean fever (FMF) is a monogenic autoinflammatory condition accompanied with periodic attacks of fever. The clinical utility of some novel inflammatory parameters has not been well explored in FMF. Hence, the aim of this study was to explore the accuracy of a variety of inflammatory indexes in patients with an FMF-attack-free period and without a complication of amyloidosis.

Methods: This cross-sectional study included a total of 114 patients with FMF (of them, 43.8% were men) and 97 controls (of them, 43.3% were men). Complete blood count, albumin, fibrinogen, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and serum amyloid A (SAA) were measured. Other parameters were calculated [i.e., platelet-albumin ratio (PAR), HALP score, systemic immune-inflammation index (SII), and pan-immune-inflammation value (PIV)]. Receiver operating characteristic (ROC) curve analysis was used to test the discriminative ability of each marker between patients with FMF and those without FMF.

Results: The area under the ROC curve for fibrinogen [AUC = 0.710, 95% CI (0.644-0.770)], CRP [AUC = 0.780 (0.718-0.834)], fibrinogen/albumin [AUC = 0.722 (0.657-0.782)], and CRP/albumin [AUC = 0.782 (0.720-0.836)] indicated satisfactory clinical accuracy. The AUCs for SAA [AUC = 0.844 (0.788-0.890)], SAA/albumin [AUC = 0.856 (0.801-0.900)], and PLT/SAA [AUC = 0.810 (0.750-0.861)] indicated good clinical accuracy. There was no difference between AUCs for SAA and SAA/albumin (P = 0.073), whereas the AUCs for these 2 parameters were significantly higher than the AUC for PLT/SAA (P = 0.033 and P = 0.005, respectively).

Conclusion: SAA and SAA/albumin ratio are the most reliable biomarkers in discriminating patients with FMF from healthy individuals.