NEUTROPHIL–LYMPHOCYTE RATIO DERIVED FROM ROUTINE BLOOD COUNTS AS A PREDICTOR OF SEVERITY IN ACUTE APPENDICITIS: A HOSPITAL-BASED ANALYTICAL STUDY

Abstract

Background: Acute appendicitis is one of the most common surgical emergencies worldwide, with disease severity being a major determinant of morbidity and outcomes. Conventional laboratory markers such as total leukocyte count and C-reactive protein have limited ability to reliably predict severity. The neutrophil–lymphocyte ratio (NLR), derived from routine complete blood count parameters, has emerged as a simple inflammatory marker that may aid in prognostic stratification. However, evidence correlating NLR with histopathologically confirmed severity of appendicitis, particularly in the Indian setting, remains limited. Objectives: To manually calculate the neutrophil–lymphocyte ratio from complete blood count in patients with acute appendicitis and to evaluate its utility in assessing disease severity and predicting complicated appendicitis. Methods: A hospital-based analytical study was conducted over 12 months in a tertiary care teaching hospital. Adult patients with clinical suspicion of acute appendicitis who underwent emergency appendectomy were consecutively enrolled. Absolute neutrophil and lymphocyte counts obtained at admission were used to manually calculate NLR. Intraoperative findings were documented, and resected appendiceal specimens were subjected to histopathological examination, which served as the reference standard. Appendicitis was classified as moderate or severe, and complicated appendicitis was defined by perforation or gangrene. Receiver operating characteristic curve analysis was performed to assess the prognostic performance of NLR. Results: A total of 71 patients were included, with a mean age predominantly between 19 and 40 years and male predominance (63.4%). Histologically confirmed appendicitis was present in 64 patients (90.1%). Among confirmed cases, 38 (53.5%) had moderate appendicitis and 26 (36.6%) had severe appendicitis. Complicated appendicitis was observed in 17 patients (23.9%). An NLR cut-off of ≥5.7 differentiated moderate from severe appendicitis with an area under the curve (AUC) of 0.998, sensitivity of 96.15%, and specificity of 100%. An NLR cut-off >11.6 predicted complicated appendicitis with an AUC of 0.991, sensitivity of 100%, and specificity of 98.18%. NLR showed poor diagnostic performance for early appendicitis (AUC 0.563). Conclusion: The neutrophil–lymphocyte ratio is a highly effective prognostic marker for assessing severity and predicting complications in acute appendicitis. While it has limited diagnostic utility, its excellent performance in severity stratification supports its use as a simple, cost-effective adjunct to clinical evaluation, particularly in resource-limited settings.