Bactericidal/Permeability-Increasing Protein and Group I and II Phospholipase A2 During the Induction Phase of Human Acute Pancreatitis

Activated endogenous mediators of inflammation have important roles in the pathogenesis and complications of acute pancreatitis (AP). These mediators include bactericidal/ permeability-increasing protein (BPI) and phospholipase A2 (PLA2). The time course of their activation during human AP is not known. The aim of this study was to evaluate the kinetics of BPI, group I (pancreatic) and group II (synovial type) PLA2 during human AP with temporally defined onset, as being induced by endoscopic retrograde cholangiopancreatography (ERCP). Serum samples of 273 consecutive patients undergoing ERCP were collected before and at 3, 6, and 24 h after ERCP. Twenty-four (8.7%) patients developed ERCP-induced pancreatitis. Seven of them were graded to have a severe disease. Forty randomly selected patients undergoing ERCP without evidence of pancreatitis served as controls. The serum concentrations of BPI and groups I and II PLA2 were measured by specific immunoassays. The mean concentration of BPI increased from 14 to 26 microg/L at 24 h after ERCP in patients with AP. In the control group, BPI values remained unchanged, and the difference was statistically significant (p<0.001). The increase of BPI was seen in 22 of 28 patients with AP at 3 h after the onset of the disease. BPI values were higher in severe post-ERCP pancreatitis than in mild disease (p = 0.07; NS). The serum concentrations of group II PLA2 before ERCP were consistently higher in the control patients than in the patients with pancreatitis, 65.8 and 14.2 microg/L, respectively. High baseline values in the control group were associated with preexisting infectious diseases. Thereafter, the mean concentration decreased in the control group to 44 microg/L and increased in the pancreatitis group up to 27.5 microg/L. The difference was statistically significant (p = 0.007). Increased group II PLA2 values were seen in 10 of 17 patients with mild AP and in five of seven patients with severe disease. There were no significant differences in group I or II PLA2 values in patients with mild or severe AP. The serum concentration of group I PLA2 increased in the patients with post-ERCP pancreatitis from 5.4 to 37.5 microg/L at 24 h. The difference was statistically significant, (p< 0.001) as compared with controls. In conclusion, in acute pancreatitis, the increase of BPI in serum starts at 3 h after the onset of the disease, and the concentration seems to correlate with the severity of the disease. Increased group II PLA2 concentrations also were seen in patients with mild AP. The kinetics of group I PLA2 resembles that of other pancreatic enzymes.