Comparison of the Diagnostic Values of Leukocytes, Neutrophils, Neutrophil-to-Lymphocyte Ratio and Platelet-to-Lymphocyte Ratio in Distinguishing between Acute Appendicitis and Right Ureterolithiasis.

BACKGROUND: To compare the diagnostic values of leukocytes, neutrophils, neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) in distinguishing between acute appendicitis (AA) and right ureterolithiasis (RU).

METHODS: In this retrospective study, 106 patients diagnosed with AA (Appendicitis group) and 33 cases with RU (Ureterolithiasis group) were enrolled due to acute right lower abdominal pain. The levels of peripheral blood leukocyte counts (leukocytes), neutrophil counts (neutrophils), lymphocyte counts (lymphocytes), platelet counts (platelets), NLR and PLR were recorded and compared between the two groups. Student's t-test for independent samples was adopted for comparing the mean between the two groups. Model discrimination was evaluated using the area under the receiver operating characteristic curve (AUC). Comparison of AUC was performed using the Z-test.

RESULTS: The levels of leukocytes, neutrophils, NLR, and PLR were significantly increased in AA compared with RU (all p < 0.01), while there were no significant statistical differences of lymphocytes and platelets (all p > 0.05); moreover, AUC in distinguishing AA from RU was 0.797 (95% confidence interval (CI), 0.721 to 0.861) for leukocytes, 0.814 (95% CI, 0.740 to 0.875) for neutrophils, 0.770 (95% CI, 0.691 to 0.837) for NLR, and 0.608 (95% CI, 0.522 to 0.690) for PLR, and significant differences were observed between PLR and any of the three other parameters (all p < 0.01), while there were no significant statistical differences after pairwise comparison between leukocytes, neutrophils and NLR (all p > 0.05). Finally, the cutoff values were 13.1 × 109/L in distinguishing between AA and RU (specificity 87.88%, sensitivity 63.21%, and Youden index 0.511) for leukocytes, 7.4 x 109/L (specificity 69.70%, sensitivity 83.02%, and Youden index 0.527) for neutrophils, 5.57 (specificity 81.82%, sensitivity 68.87%, and Youden index 0.507) for NLR, and 182.5 (specificity 84.85%, sensitivity 37.74%, and Youden index 0.226) for PLR.

CONCLUSIONS: Leukocytes, neutrophils, and NLR can demonstrate more accurate and reliable diagnostic values than PLR, suggesting that they are useful and potential biomarkers in distinguishing between AA and RU.