Prognostic Value of Preoperative Neutrophil-to-lymphocyte Ratio for Prediction of Severe Cholecystitis

BACKGROUND: The predictive value of preoperative neutrophil-to-lymphocyte ratio (NLR) in patients with cholecystitis has not been established. The aim of this study was to investigate preoperative NLR in patients with cholecystitis and to identify a relevant NLR value that discriminates between simple and severe cholecystitis. METHODS: This study included 136 patients who under went laparoscopic cholecystectomy due to cholecystitis. The Receiver Operating Characteristic (ROC) analysis was performed to identify the most useful NLR cut-off value in relation to the severity of cholecystitis. The patients were di vided into two groups according to the cut-off NLR value: high NLR group (≥4.18, n=23) and low NLR group (<4.18, n=113). Severe cholecystitis was defined as a state which includes inflammation, empyema, gangrene, perforation of gallbladder, adhesions or difficulty in dissecting Calot’s triangle. RESULTS: In the high NLR group, severe cholecystitis (p<0.0001) and higher C-reactive protein level (CRP) and white blood cells count (WBC) (p<0.0001) were significantly more frequent. There was no difference in homeostatic model assessment-insulin resistance index (HOMA-IR) between both groups before the operation (p<0.634). The incidence of severe cholecystitis was 16.9%. The NLR of 4.18 could predict severe cholecystitis with 78.3% sensitivity and 74.3% specificity. Spearman’s correlation revealed significant association between the preoperative NLR and HOMA-IR on day 1, (r=0.254, p=0.030) and between preoperative NLR and CRP on day 1 (ρ=0.355; p<0.0001). CONCLUSIONS: NLR ≥4.18 was significantly associated with severe cholecystitis. The preoperative NLR in patients under going cholecystectomy due to cholecystitis could be a useful surrogate marker of severe cholecystitis.