A comparative study of the activation peptide of carboxypeptidase B and trypsinogen as early predictors of the severity of acute pancreatitis

Serum and urine concentrations of the activation peptide of carboxypeptidase B (CAPAP) and urinary trypsinogen activation peptide (TAP) as prognostic markers in acute pancreatitis were compared. Fifty-two patients with acute pancreatitis hospitalized within 24 hours after symptom onset were prospectively studied. Blood and urine samples were obtained during the first 3 days of the hospital stay. Pancreatitis was severe in 17 patients and mild in 35 (Atlanta criteria). Median serum CAPAP levels on days 1 and 2 and of urine CAPAP and TAP on days 1, 2, and 3 were significantly higher in severe pancreatitis than in mild disease. On the first day of admission, TAP was the most accurate predictor of severity (sensitivity, 92.3%; specificity, 80%; positive and negative predictive values, 63.2% and 96.6%, respectively), with a 4.61 positive likelihood ratio for a cutoff value of 18.10 nmol/L, whereas within 24 hours after symptom onset, urinary CAPAP was superior (sensitivity, 88.9%; specificity, 81.3%; positive and negative predictive values 72.7% and 92.9%, respectively), with a 4.72 positive likelihood ratio for a cutoff value of 15.45 nmol/L. Serum and urine CAPAP levels and urinary TAP are accurate in the early assessment of severity in acute pancreatitis. Urine CAPAP levels was the most accurate marker 24 hours after onset of symptoms.