Evidence of complement catabolism in acute pancreatitis

Active proteolytic enzymes are released into the gland parenchyma and surrounding tissues during episodes of acute pancreatitis. Since complement components are potential substrates for active proteases and may be the source of biologically active peptides capable of mediating tissue injury, we have examined sera obtained from 12 patients during 13 episodes of acute pancreatitis for evidence of complement catabolism. In 8 of 13 acute phase sera, there were decreased levels of CH50, C3, C4, or some combination thereof as well as degradation products of C3 (revealed by crossed immunoelectrophoresis). In convalescent sera, levels of complement components were normal or elevated. Measurements of alpha1-antitrypsin, alpha2-macroglobulin, and trypsin inhibitory capacity failed to reveal evidence of protease-antiprotease imbalance. These findings provide evidence of complement catabolism in acute pancreatitis and suggest the possibility that activated complement components may play a role in the pathogenesis of some systemic pathologic changes which occur in this disease.