title: Complement and contact activation during cardiovascular operations in infants.
abstract: BACKGROUND
  By comparing the results of cardiac operations with or without cardiopulmonary bypass (CPB) in infants in a prospective study, we sought to determine which part of the postoperative systemic inflammatory response was caused by CPB.
  
  
  METHODS
  Thirty-five patients were divided into two groups: 11 infants operated on without CPB and 24 infants operated on with CPB. Blood samples were drawn before, during, and after the operation. We assessed complement function and the concentrations or activities of C1q, C3, C4, C1 inhibitor, factor B, the activated split product C3a, and prekallikrein and factor XIIa of the contact system.
  
  
  RESULTS
  All of the patients exhibited a decrease of complement proteins. This was greater in infants who underwent CPB. A increase in C3a and factor XIIa and changes in prekallikrein activity occurred only in infants during CPB.
  
  
  CONCLUSIONS
  Complement activation occurs in all infants, but is significantly higher in the group with CPB. Contact activation only occurs in patients who undergo CPB. Thus, the inflammatory response is caused by the use of a CPB circuit and to a lesser degree by surgical procedures and anesthesia.
authors.affiliation: Department of Neonatology, Virchow-Charité-Hospital, Humboldt University, Berlin, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Sonntag
authors.forename: I
authors.initials: I
authors.lastname: Dähnert
authors.forename: B
authors.initials: B
authors.lastname: Stiller
authors.forename: R
authors.initials: R
authors.lastname: Hetzer
authors.forename: P E
authors.initials: PE
authors.lastname: Lange
mesh_terms: D006348:Cardiac Surgical Procedures; D002315:Cardiopulmonary Bypass / Q000009:adverse effects; D003167:Complement Activation; D011415:Complement Factor B / Q000032:analysis; D003165:Complement System Proteins / Q000032:analysis; D015956:Factor XIIa / Q000032:analysis; D005260:Female; D006330:Heart Defects, Congenital / Q000601:surgery; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011288:Prekallikrein / Q000378:metabolism; D011446:Prospective Studies; D018746:Systemic Inflammatory Response Syndrome / Q000209:etiology / Q000378:metabolism
chemical_list: D003165:Complement System Proteins; D011288:Prekallikrein; D015956:Factor XIIa; D011415:Complement Factor B