Complement activation and lung permeability during cardiopulmonary bypass

Ann Thorac Surg. 1990 Oct;50(4):597-601. doi: 10.1016/0003-4975(90)90196-d.


Pulmonary dysfunction after cardiopulmonary bypass has been attributed to the damaging effects of complement activation on the lung. To further explore this phenomenon, we measured plasma levels of activated complement components (radioimmunoassay), assessed neutrophil n-formyl-methionyl-leucyl-phenylalanine (FMLP) receptor status (radioligand saturation binding assay), and quantified pulmonary epithelial permeability as radioaerosol lung clearance of technetium 99m-labeled diethylenetriamine pentaacetic acid in a series of 8 patients undergoing cardiopulmonary bypass. Significant elevations of plasma C3adesArg, C4adesArg, and C5adesArg levels were seen just after CPB, indicating activation of both the classic and alternate complement pathways. Neutrophil activation was evident as increased expression of neutrophil FMLP surface receptors after bypass. Despite the presence of complement and neutrophil activation, increased pulmonary epithelial permeability was not seen. These data support the hypothesis that complement and neutrophil activation during cardiopulmonary bypass is not associated with acute lung injury, at least not pulmonary epithelial injury. One can therefore infer that increased pulmonary epithelial permeability in patients at high risk for and experiencing sepsis-induced and trauma-induced adult respiratory distress syndrome may be due to factors other than complement and neutrophil activation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Capillary Permeability / physiology*
  • Cardiopulmonary Bypass*
  • Complement Activation / immunology*
  • Complement C3a / analysis
  • Complement C4a / analysis
  • Female
  • Humans
  • Lung / physiology*
  • Lymphocyte Activation / immunology
  • Male
  • Middle Aged
  • N-Formylmethionine Leucyl-Phenylalanine / immunology
  • Neutrophils / immunology
  • Radioimmunoassay
  • Receptors, Formyl Peptide
  • Receptors, Immunologic / analysis
  • Technetium Tc 99m Pentetate


  • Receptors, Formyl Peptide
  • Receptors, Immunologic
  • complement C3a, des-Arg-(77)-
  • complement C4a, des-Arg
  • N-Formylmethionine Leucyl-Phenylalanine
  • Complement C3a
  • Complement C4a
  • Technetium Tc 99m Pentetate