Comparison of Interleukin-6, C-Reactive Protein, Procalcitonin, and the Computed Tomography Severity Index for Early Prediction of Severity of Acute Pancreatitis

BACKGROUND/AIMS: Acute pancreatitis (AP) is a common gastrointestinal disease associated with hospitalization. With the increase in its incidence, AP has become a greater burden on healthcare resources. Early identification of patients with mild AP can facilitate the appropriate use of resources. We aimed to investigate the ability of inflammatory markers, including interleukin-6 (IL-6), procalcitonin, and C-reactive protein (CRP), as well as various scoring systems to differentiate mild AP from more severe diseases. METHODS: We retrospectively investigated patients hospitalized with AP, for whom severity assessment and clinical course confirmation were possible. Inflammatory markers were measured at admission, and CRP levels were measured 24 hours after admission (CRP2). Predictive values were calculated using the area under the receiver operating characteristic curve (AUROC) and logistic regression model analysis. RESULTS: Of 103 patients with AP, 42 (40.8%) were diagnosed with mild AP according to the revised Atlanta classification. Based on the AUROC, IL-6 (0.755, p<0.001), CRP2 (0.787, p<0.001), and computed tomography severity index (CTSI) (0.851, p<0.001) were useful predictors of mild AP. With standard cutoff values, the diagnostic sensitivity, specificity, and accuracy were 83.3%, 62.3%, and 70.9% for IL-6 (<50 pg/mL), and 78.6%, 63.9%, and 69.9% for CRP2 (<50 mg/L), respectively. The AUROC of IL-6 and CRP2 were significantly higher than those of other inflammatory markers and were not significantly different from that of CTSI. CONCLUSIONS: IL-6, CRP2, and CTSI are helpful for early differentiation of AP severity. Among inflammatory markers, IL-6 has the advantage of early prediction of mild pancreatitis at the time of admission.