Diagnostic value of serum calprotectin level in the diagnosis of acute cholecystitis and its role in the prediction of complicated cholecystitis

Aim: Acute cholecystitis is an inflammatory disease of the gallbladder caused by blockage of the cystic duct by gallstones or sludge. Delay in diagnosis of acute cholecystitis may lead to complications, additional morbidity and even mortality, so it is important to make its diagnosis early and with high accuracy. There is no study in the literature that directly addresses the correlation between acute cholecystitis and serum calprotectin levels. Our aim in this study is to explore the potential relationship between calprotectin and acute cholecystitis and to determine the clinical utility of calprotectin as a biomarker for complicated cholecystitis. Materials and Methods: Between November 1, 2023 and January 31, 2024, 54 inguinal hernia patients (control) who were scheduled for elective surgery, 54 patients with cholelithiasis (cholelithiasis) who were scheduled for elective surgery, 52 patients with acute cholecystitis (acute cholecystitis) who were hospitalized due to acute cholecystitis and were not operated on, and patients with conditions such as gangrene or perforation. Patients who required urgent cholecystectomy or cholecystostomy for various reasons (complicated cholecystitis) were included in the study and four groups were created. Age, gender, additional systemic diseases, height, weight and body-mass index (BMI) of the patients participating in the study, history and examination findings during hospitalization, and results of routine laboratory tests were evaluated. Routine ultrasonography imaging results, length of stay, operation time, conversion to open cholecystectomy, intraoperative findings, pathology result, presence of complications in the post-operative period, and surgical site infection, pain and other post-operative complications and complaints seen in the routine outpatient clinic examination in the second week after discharge were followed and included in the study. Serum calprotectin levels were measured by the ELISA method and its value in the diagnosis of acute cholecystitis and prediction of complications was investigated using statistical methods. Results: Serum calprotectin levels have been found to be more successful in the diagnosis of acute cholecystitis and in the prediction of complicated cholecystitis compared to ratios such as white blood cell count (WBC), C-reactive peptide (CRP), neutrophil to lymphocyte ratio (NLR) and C-reactive peptide to albumin ratio (CAR), which are frequently used for this purpose. A serum calprotectin level exceeding 8.72 ng/mL increased the likelihood of acute cholecystitis approximately 22-fold, and a serum calprotectin level of 15.20 ng/mL and above increased the likelihood of complicated cholecystitis approximately 20.1-fold during the patient's cholecystitis attack. In order to increase the test accuracy and predictive power in terms of complication prediction, the combination of serum calprotectin level cut-off value and the presence of deficiency increased the probability of the patient being in the complicated cholecystitis group approximately 200 times with a sensitivity of 66.70%, specificity of 98.10%, positive predictive value of 98.10%, negative predictive value of 91.20% and test accuracy of 92.53%. Conclusion: Serum calprotectin levels were found to be successful in predicting the diagnosis of acute cholecystitis and were observed to be more successful than traditional markers such as NLR, CRP and CAR. We think that incorporating calprotectin level into clinical practice may be an important step towards improving medical care and will positively affect patients' overall health outcomes. Keywords: Acute cholecystitis, Calprotectin, Prediction, Complicated cholecystitis