Predictive value of complement activation fragments C3a and sC5b-9 for development of severe disease in patients with acute pancreatitis.

Background: Complement activation has been shown to occur in patients with acute pancreatitis. However, the diagnostic potential of complement activation products in plasma for predicting severe disease remains unclear to date.
Methods: The daily levels of the complement anaphylatoxin C3a and the soluble terminal complement complex sC5b-9 were determined by ELISA in plasma of patients with mild (n = 16) or severe (n = 14) acute pancreatitis during the first week after onset of symptoms, and in healthy control subjects (n = 14).
Results: Both C3a and sC5b-9 were significantly elevated during the first 7 days in plasma of patients with severe acute pancreatitis (C3a: 459.3 +/- 407.5 ng/mL (mean +/- s); sC5b-9: 617.9 +/- 297.7 ng/mL), as compared to patients with mild disease (C3a: 172 +/- 149.5 ng/mL; sC5b-9: 306.7 +/- 167.3 ng/mL) or controls (C3a: 102.3 +/- 19.7 ng/mL; sC5b-9: 40.64 +/- 19.7 ng/mL; P < 0.001, repeated measures ANOVA). The analysis of both parameters in combination during the first week after onset of symptoms revealed a high sensitivity (0.93) and specificity (0.88) as well as high negative and positive predictive values (0.93 and 0.87, respectively) with an odds ratio of 91.0 for the development of pancreatic necrosis (P < 0.0001, Fisher exact test).
Conclusion: In patients with acute pancreatitis, the plasma levels of complement C3a and sC5b-9 measured daily during the first week after onset of symptoms represent highly specific and sensitive parameters for the prediction of severe acute pancreatitis.