Protease activation, pancreatic leakage, and inflammation in acute pancreatitis: differences between mild and severe cases and changes over the first three days.

The pathophysiology of acute pancreatitis (AP) may be studied using markers of protease activation (active carboxypeptidase B (aCAP), the activation peptide of carboxypeptidase B (CAPAP)), leakage of pancreatic enzymes (trypsinogen-2, procarboxypeptidase B (proCAP), amylase), and inflammation (monocyte chemoattractant protein-1 (MCP-1), CRP). This prospective study included 140 cases of AP. Mild (n = 124) and severe (n = 16) cases were compared with respect to serum levels of trypsinogen-2, proCAP, amylase, aCAP, CAPAP (serum/urine), MCP-1 (serum/urine) and CRP on days 1, 2 and 3 from onset of symptoms. All patients with information on all 3 days were included in a time-course analysis (n = 44-55, except amylase: n = 27). High levels in severe versus mild cases were seen for trypsinogen-2, CAPAP in serum and urine, and MCP-1 in serum on days 1-3. No differences were seen for proCAP, amylase and aCAP. MCP-1 in urine was significantly elevated on day 1-2, and CRP on day 2-3. CAPAP and MCP-1 levels peaked early and stayed elevated for 48 h in serum. Protease activation and inflammation are early events in AP, with high levels of these markers within 24 h. Protease activation declines after 48 h, whereas inflammation is present for a longer time.