Neutrophil-to-lymphocyte ratio as a predictor of acute appendicitis.

BACKGROUND Accurately diagnosing appendicitis can be difficult. This retrospective study aimed to evaluate the ability of the neutrophil-to-lymphocyte ratio (NLR) to predict acute appendicitis pre-operatively and to differentiate between simple and complicated appendicitis. METHODS A database of 1067 patients who underwent surgery was evaluated. Based on postoperative histopathological examination, the patients were divided into two groups: acute appendicitis (G1) and normal appendix (G2). Patients in the acute appendicitis group were further divided into two subgroups: simple appendicitis (G1a) and complicated (gangrenous and perforated) appendicitis (G1b). RESULTS G1 included 897 patients and G2 included 170 patients. Among the 897 G1 patients, there were 753 G1a patients and 144 G1b patients. A NLR of 4.68 was associated with acute appendicitis (G1 vs G2, p<0.001). The sensitivity and specificity were 65.3% and 54.7%, respectively. A NLR of 5.74 was associated with complicated appendicitis (G1a vs G1b, p<0.001). The sensitivity and specificity of the two clinical features were 70.8% and 48.5%, respectively. CONCLUSION We suggest that preoperative NLR is a useful parameter to aid in the diagnosis of acute appendicitis and differentiate between simple and complicated appendicitis, and can be used as an adjunct to the clinical examination.