Systemic inflammatory markers for distinguishing uncomplicated and complicated acute appendicitis in adult patients

OBJECTIVE: This study aimed to investigate the predictive power of serum systemic inflammatory markers including neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), monocyte-eosinophil ratio (MER), and C-reactive protein (CRP) levels for distinguishing uncomplicated and complicated acute appendicitis in adult patients admitted to the emergency department (ED). METHODS: This retrospective, cross-sectional, observational, and single-center study enrolled 212 consecutive adult patients with acute appendicitis who were admitted to the ED of our tertiary care university hospital between January 1, 2019 and December 31 2021. Patients were divided into two groups (Group I, uncomplicated acute appendicitis; Group II, complicated appendicitis) according to their surgical findings and histopathological examination. Systemic inflammatory markers measured on admission were compared among patients to identify factors associated with complicated acute appendicitis. RESULTS: A total of 132 patients, 83 male (62.9%) and 49 female (37.1%), were included in the study. The mean age was 34.7±13.40 years. Based on the histopathological examination, the number of patients in Group I was 103 (78.03%) and 29 (21.96%) in Group II. Laboratory findings on admission revealed no significant differences between Groups I and II patients in terms of mean serum NLR, MER, and CRP values (p=0.096, p=0.248, and p=0.297, respectively). However, the mean serum PLR in Group II patients was statistically significantly higher than those in Group I (p=0.032). The mean serum monocyte and monocyte fraction (%) values were significantly lower, and the mean serum neutrophil fraction (%) value was higher in Group II patients compared to those with Group I. Receiving operator characteristic (ROC) analysis identified a serum PLR cutoff value of ≥133.73 for distinguishing uncomplicated and complicated acute appendicitis in adult patients, with 60% sensitivity and 58.4% specificity. In addition, ROC analysis revealed a cutoff monocyte fraction (%) level of ≤6, with 72% sensitivity and 64% specificity, for distinguishing uncomplicated and complicated acute appendicitis in adult patients. CONCLUSION: Our findings indicate that the mean serum NLR, MER, and CRP values measured on admission to ED in adult patients with acute appendicitis could not predict complicated acute appendicitis. However, mean serum PLR and neutrophil and monocyte counts can be useful in distinguishing complicated cases.