Abstract
<title>Abstract</title> <p> Acute appendicitis remains the most common cause of acute abdomen. Delayed diagnosis is associated with morbidity rates of up to 35% and may result in perforated appendicitis. The natural course of appendicitis is variable, and progression to perforation is often unpredictable. Although imaging provides valuable clinical information, objective evidence of perforation may further guide treatment decisions. Accordingly, this study aimed to distinguish perforated appendicitis from simple appendicitis using laboratory biomarkers, in order to support preoperative treatment planning and predict the risk of complications. Between July 20, 2022, and December 31, 2023, a total of 180 patients who underwent surgery for acute appendicitis at the Department of General Surgery at Dokuz Eylül University Hospital, were analyzed. Laboratory data including white blood cell count (WBC), mean neutrophil volume (MNV), mean neutrophil conductivity (MNC), mean neutrophil scatter (MNS), mean monocyte volume (MMV), monocyte distribution width (MDW), early granulocyte cell volume (EGC-V), C-reactive protein (CRP), were prospectively collected and recorded in the hospital information management system. Platelet, monocyte, neutrophil, and lymphocyte counts were recorded, and the platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), and neutrophil-to-lymphocyte ratio (NLR) were calculated. Biomarkers were evaluated using univariate and multivariate analyses, and receiver operating characteristic (ROC) curve analysis was performed for statistically significant parameters. In univariate analysis, WBC, CRP, MNV, MMV, MDW, EGC-V, PLR, MLR, and NLR were all statistically significant ( <italic>p</italic> < 0.05). However, in multivariate analysis, only MLR and CRP remained significant independent predictors of perforated appendicitis. Each unit increase in CRP was associated with a 1.012-fold increase ( <italic>p</italic> < 0.001), and elevated MLR with a 6.256-fold increase ( <italic>p</italic> = 0.002), in the likelihood of perforation. MLR, a readily obtainable parameter from routine preoperative blood tests in patients with acute appendicitis, may be a useful marker for predicting perforation. In addition, biomarkers derived from VCS technology may provide supplementary diagnostic value in identifying perforated appendicitis. </p>