Comparative performance among inflammatory biomarkers for pre-operative prediction of gangrenous cholecystitis

This study aimed to compare the diagnostic performance of inflammatory biomarkers derived from routine blood parameters in patients with acute cholecystitis, based on the hypothesis that these biomarkers can predict gangrenous cholecystitis independently of imaging before surgery.

Data from 187 consecutive adult patients who underwent laparoscopic cholecystectomy for acute cholecystitis during the same hospitalization were retrospectively analyzed in an observational cohort. After the exclusion of 7 cases, 180 patients constituted the analytic cohort. Gangrenous cholecystitis was defined as intraoperative or pathological verification. C-reactive protein (CRP) and six prespecified haemogram-derived indices - the neutrophil-, platelet- and monocyte-to-lymphocyte ratios (neutrophil-to-lymphocyte ratio [NLR], platelet-to-lymphocyte ratio [PLR], monocyte-to-lymphocyte ratio [MLR]) and three composite indices (systemic immune-inflammation index, systemic inflammation response index [SIRI], aggregate index of systemic inflammation) - were evaluated; diagnostic accuracy was assessed using receiver operating characteristic-area under the curve (ROC-AUC), cutoff points were determined using the Youden index, and an age- and sex-adjusted logistic regression model was established.

Gangrenous cholecystitis was confirmed in 33 of the 180 analyzed patients (18.3%). CRP was 163.00 mg/L (interquartile range [IQR] 39.00-224.00) in the gangrenous group and 15.00 mg/L (IQR 4.02-55.89) in the non-gangrenous group. Among hemogram-derived indices, SIRI (7.10 [4.09-10.03] vs. 2.48 [1.03-4.89]) and MLR (0.62 [0.40-0.79] vs. 0.31 [0.19-0.50]) were significantly higher in gangrenous cases (both p<0.001); NLR was 8.00 (5.32-12.90) vs. 4.00 (2.35-6.66) (p<0.001). In the ROC analysis, CRP showed the highest discriminatory power (AUC 0.81; 95% confidence interval 0.71-0.89); at a cutoff point of 61.0 mg/L, the sensitivity and specificity were 0.73 and 0.78, respectively. Among the derived indices, the highest AUCs were observed for SIRI and AISI. In the model including CRP and SIRI adjusted for age and sex, only CRP remained an independent predictor; each 10 mg/L increase in CRP was associated with a 14% increase in the odds of gangrenous cholecystitis.

CRP provides the highest discrimination for pre-operative prediction of gangrenous cholecystitis and was the only independent predictor in multivariable analysis. The hemogram-derived indices showed moderate univariable discrimination, but their additional value beyond CRP remains uncertain and requires further evaluation in larger, prospective cohorts.