The role of neutrophil lymphocyte ratio to leverage the differential diagnosis of familial Mediterranean fever attack and acute appendicitis

Background/Aims: Familial Mediterranean fever (FMF) is an autosomal recessive disorder characterized by attacks of fever and diffuse abdominal pain. The primary concern with this presentation is to distinguish it from acute appendicitis promptly. Thus, we aimed to evaluate the role of neutrophil lymphocyte ratio (NLR) to leverage the differential diagnosis of acute FMF attack with histologically proven appendicitis. Methods: Twenty-three patients with histologically confirmed acute appendicitis and 88 patients with acute attack of FMF were included in the study. NLR, C-reactive protein and other hematologic parameters were compared between the groups. Results: Neutrophil to lymphocyte ratio was significantly higher in patients with acute appendicitis compared to the FMF attack group ($8.24{\pm}6.31$ vs. $4.16{\pm}2.44$, p = 0.007). The performance of NLR in diagnosing acute appendicitis with receiver operating characteristic analysis with a cut-off value of 4.03 were; 78% sensitivity, 62% specificity, and area under the curve 0.760 (95% confidence interval, 0.655 to 0.8655; p < 0.001). Conclusions: This study showed that NLR, the simple and readily available inflammatory marker may have a useful role in distinguishing acute FMF attack from acute appendicitis.