Neutrophil-lymphocyte ratio in patients with familial Mediterranean fever.

Background: Blood neutrophil-to-lymphocyte (N/L) ratio is an indicator of the overall inflammatory status of the body, and an alteration in N/L ratio may be found in patients with familial Mediterranean fever (FMF). The aim of this study was to investigate the interrelationship between N/L ratio and FMF.

Methods: One hundred and fifteen patients and controls were enrolled in the study. The cases in the study were categorized as FMF with attack, FMF with attack-free period, and controls. The neutrophil and lymphocyte counts were recorded, and the N/L ratio was calculated from these parameters. All patients were diagnosed according to Tel Hashomer criteria.

Results: A total of 79 FMF patients were included in the study and all subjects were receiving colchicine treatment at the time. The serum N/L ratios of active patients were significantly higher than those of attack-free FMF patients and controls (P < 0.001). The optimum N/L ratio cut-off point for active FMF was 2.63 with sensitivity, specificity, positive predictive value, and negative predictive value of 0.62 (0.41-0.80), 0.85 (0.72-0.93), 0.67 (0.44-0.85), and 0.82 (0.69-0.91), respectively. The overall accuracy of the N/L ratio in determination of FMF patients during attack was 71%.

Conclusion: Our results demonstrate that N/L ratio is higher in patients with active FMF compared with FMF patients in remission and controls, and a cut-off value of 2.63 can be used to identify patients with active FMF.