Usefulness of cell ratios and the derived neutrophil-to-lymphocyte ratio in the diagnosis of pediatric acute appendicitis.

Objective: To analyze the accuracy of cell ratios in the diagnosis of pediatric acute appendicitis while introducing a new one -the derived neutrophil-to-lymphocyte ratio (dNLR).

Materials and methods: An observational, retrospective study of patients aged 0-15 years old diagnosed with acute appendicitis (AA) and with non-surgical abdominal pain (AP) treated in our institution from 2021 to 2022 was carried out. The neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR), and dNLR were compared between groups.

Results: 98 AA patients (30% of whom were female; age: 10 ± 3.3 years) and 97 AP patients (53% of whom were male; age: 9.3 ± 3.7 years) were included. NLR, MLR, PLR, and dNLR values were higher in AA patients than in AP patients: 9.6 IQR (interquartile range) 9.5 vs. 3.3 IQR 5.3: p< 0.0001; 0.7 IQR 0.6 vs. 0.46 IQR 0.7: p< 0.023; 199.8 IQR 163.9 vs. 134.0 IQR 129.2: p< 0.0001; and 5.29 IQR 3.9 vs. 2.39 IQR 2.7; p< 0.0001, respectively. Sensitivity, specificity, positive-negative predictive value, area under the ROC curve, and dNLR cut-off point for AA diagnosis were 70%, 78%, 77-72%, 0.811, and 3.98, respectively.

Conclusions: Cell ratios are useful and cost-effective inflammatory parameters in the diagnosis of pediatric acute appendicitis. The results of this study suggest dNLR has the greatest clinical accuracy.