Procalcitonin and C-reactive protein as biomarkers for diagnosing and assessing the severity of acute cholecystitis.

Background: Acute cholecystitis (AC) is a common condition in emergency departments (EDs), where timely diagnosis and severity assessment are critical for treatment decisions and outcome prediction. Methods: This study included 194 patients with AC to evaluate the diagnostic and severity-grading performance of procalcitonin (PCT) and C-reactive protein (CRP). Receiver operating characteristic (ROC) curve analysis was used to determine optimal cut-off values for discriminating between severity grades according to the Tokyo Guidelines. Results: Elevated levels of PCT and CRP were observed in 73.2 and 67% of cases, respectively. PCT demonstrated a sensitivity of 75.6% and specificity of 64.8% at a cut-off value of ≤ 0.595 ng/mL for distinguishing grade I from grades II to III. For differentiating grade III from grades I to II, PCT showed a sensitivity of 62.5% and specificity of 92.1% at a cut-off value of ≥5.095 ng/mL. Similarly, CRP had a sensitivity of 82.9% and specificity of 64.8% at a cut-off value of ≤78 mg/L for grade I versus grades II to III, and a sensitivity of 62.5% and specificity of 69.7% at a cut-off value of ≥82.5 mg/L for grade III versus grades I to II. Conclusion: Both PCT and CRP are valuable biomarkers for diagnosing AC and assessing its severity.