Evaluation of neutrophil-to-lymphocyte ratio as a potential biomarker for acute cholecystitis

Background: The diagnosis of acute cholecystitis (AC) is frequently associated with an increase in white cell count (WCC) and C-reactive protein (CRP). However, one or both of these inflammatory biomarkers can be normal in AC. The aim of this study was to evaluate and compare the discriminative powers of the neutrophil-to-lymphocyte ratio (NLR) with WCC and CRP in diagnosing AC. Methods: This was a retrospective cohort study. For more than a period of 5 y, 1959 patients were identified from the cholecystectomy Registry. Laparoscopic cholecystectomy patients with histologic evidence of AC were included if they also had preoperative WCC and CRP measurements. Eligibility criteria were met by 177 patients. These patients were compared with 45 control subjects who had normal gallbladder histology. Results: One unit of increase in the NLR was associated with a 2.5 times increase in the odds of AC (odds ratio = 2.48; 95% confidence interval [CI], 1.5-4.1; P < 0.0005). NLR cutoff values of 4.1 (95% CI, 3.42-4.79), 3.25 (95% CI, 1.95-4.54), and 4.17 (95% CI, 3.76-4.58) were diagnostic for the overall AC, mild, and moderate-severe AC, respectively. The NLR areas under the receiver operating characteristic curve in AC, mild, and moderate-severe AC were 94% (95% CI, 91%-97%), 87% (95% CI, 81%-93%), and 98% (95% CI, 96%-100%), respectively. The discriminative power of an NLR was superior to that of the WCC and similar to CRP for diagnosing AC and different grades of severity. Conclusions: NLR can be considered as a potential inflammatory biomarker for AC. (C) 2016 Elsevier Inc. All rights reserved.