The predictive value of neutrophil-to-lymphocyte ratio to diagnose acute appendicitis and grade its severity

Background: Acute appendicitis (AA) is one of the most common acute abdominal emergencies in the pediatric population, occurring commonly between the ages of 7-15 years. The diagnosis mostly depends upon typical presentation and clinical findings. Laboratory investigations and imaging techniques aid the diagnosis. Neutrophil to lymphocyte ratio (NLR) is a valuable indicator of diagnosis in questionable cases. Methods: This is a retrospective study consisting of 260 pediatric patients who underwent appendicectomy. The study was conducted at the Department of Pediatric Surgery, Maternity and Children’s Hospital Dammam, Saudi Arabia. The duration of the study was May 2018 to March 2021. The clinical features and initial preoperative total leukocyte count (TLC), with neutrophil and lymphocyte values, were collected. The neutrophil to lymphocyte ratio (NLR) was preoperatively calculated by dividing the values obtained. The patients were categorized in group 1 as non-appendicitis and group 2 as appendicitis. On the basis of histopathological findings, group 2 was further divided into catarrhal, phlegmonous, and gangrenous/perforated as groups A, B, and C respectively. The value of NLR was compared between the groups. Results: The children with acute appendicitis had a higher NLR than healthy children. Acute appendicitis was ruled out at 2 cut-off-value of NLR with 94% sensitivity and 100% specificity. An NLR of 3.5 was an accurate marker for acute appendicitis. Significant differences in NLR values were also observed in the severity of appendicitis. Phlegmonous appendicitis had 78% sensitivity and 82% specificity at a cut-off value of 6.0 while NLR of > 8.0 was the cut-off point for gangreneous/perforated appendicitis with 80 % sensitivity and 87% specificity. Conclusion: The NLR is a reliable biomarker to exclude, diagnose, and grade the severity of acute appendicitis. It is a valuable indicator of atypically presented cases or cases lacking adequate clinical findings. The yield of the test is increased in conjunction with other laboratory parameters.