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.